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kc3-lang/angle/src/libANGLE/validationES2.cpp

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  • Author : Geoff Lang
    Date : 2016-10-20 11:38:11
    Hash : 496c02df
    Message : Implement robust the GetBufferPointerv entry point. BUG=angleproject:1354 Change-Id: Id7dd8438224adb1e2729bcdc18a306e5dfc83a3b Reviewed-on: https://chromium-review.googlesource.com/401399 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org>

  • src/libANGLE/validationES2.cpp
  • //
    // Copyright (c) 2013-2014 The ANGLE Project Authors. All rights reserved.
    // Use of this source code is governed by a BSD-style license that can be
    // found in the LICENSE file.
    //
    
    // validationES2.cpp: Validation functions for OpenGL ES 2.0 entry point parameters
    
    #include "libANGLE/validationES2.h"
    
    #include <cstdint>
    
    #include "common/mathutil.h"
    #include "common/string_utils.h"
    #include "common/utilities.h"
    #include "libANGLE/Context.h"
    #include "libANGLE/Texture.h"
    #include "libANGLE/Framebuffer.h"
    #include "libANGLE/FramebufferAttachment.h"
    #include "libANGLE/Renderbuffer.h"
    #include "libANGLE/Shader.h"
    #include "libANGLE/Uniform.h"
    #include "libANGLE/formatutils.h"
    #include "libANGLE/validationES.h"
    #include "libANGLE/validationES3.h"
    
    namespace gl
    {
    
    namespace
    {
    
    bool IsPartialBlit(gl::Context *context,
                       const FramebufferAttachment *readBuffer,
                       const FramebufferAttachment *writeBuffer,
                       GLint srcX0,
                       GLint srcY0,
                       GLint srcX1,
                       GLint srcY1,
                       GLint dstX0,
                       GLint dstY0,
                       GLint dstX1,
                       GLint dstY1)
    {
        const Extents &writeSize = writeBuffer->getSize();
        const Extents &readSize  = readBuffer->getSize();
    
        if (srcX0 != 0 || srcY0 != 0 || dstX0 != 0 || dstY0 != 0 || dstX1 != writeSize.width ||
            dstY1 != writeSize.height || srcX1 != readSize.width || srcY1 != readSize.height)
        {
            return true;
        }
    
        if (context->getGLState().isScissorTestEnabled())
        {
            const Rectangle &scissor = context->getGLState().getScissor();
            return scissor.x > 0 || scissor.y > 0 || scissor.width < writeSize.width ||
                   scissor.height < writeSize.height;
        }
    
        return false;
    }
    
    template <typename T>
    bool ValidatePathInstances(gl::Context *context,
                               GLsizei numPaths,
                               const void *paths,
                               GLuint pathBase)
    {
        const auto *array = static_cast<const T *>(paths);
    
        for (GLsizei i = 0; i < numPaths; ++i)
        {
            const GLuint pathName = array[i] + pathBase;
            if (context->hasPath(pathName) && !context->hasPathData(pathName))
            {
                context->handleError(gl::Error(GL_INVALID_OPERATION, "No such path object."));
                return false;
            }
        }
        return true;
    }
    
    bool ValidateInstancedPathParameters(gl::Context *context,
                                         GLsizei numPaths,
                                         GLenum pathNameType,
                                         const void *paths,
                                         GLuint pathBase,
                                         GLenum transformType,
                                         const GLfloat *transformValues)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                gl::Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
    
        if (paths == nullptr)
        {
            context->handleError(gl::Error(GL_INVALID_VALUE, "No path name array."));
            return false;
        }
    
        if (numPaths < 0)
        {
            context->handleError(gl::Error(GL_INVALID_VALUE, "Invalid (negative) numPaths."));
            return false;
        }
    
        if (!angle::IsValueInRangeForNumericType<std::uint32_t>(numPaths))
        {
            context->handleError(gl::Error(GL_INVALID_OPERATION, "Overflow in numPaths."));
            return false;
        }
    
        std::uint32_t pathNameTypeSize = 0;
        std::uint32_t componentCount   = 0;
    
        switch (pathNameType)
        {
            case GL_UNSIGNED_BYTE:
                pathNameTypeSize = sizeof(GLubyte);
                if (!ValidatePathInstances<GLubyte>(context, numPaths, paths, pathBase))
                    return false;
                break;
    
            case GL_BYTE:
                pathNameTypeSize = sizeof(GLbyte);
                if (!ValidatePathInstances<GLbyte>(context, numPaths, paths, pathBase))
                    return false;
                break;
    
            case GL_UNSIGNED_SHORT:
                pathNameTypeSize = sizeof(GLushort);
                if (!ValidatePathInstances<GLushort>(context, numPaths, paths, pathBase))
                    return false;
                break;
    
            case GL_SHORT:
                pathNameTypeSize = sizeof(GLshort);
                if (!ValidatePathInstances<GLshort>(context, numPaths, paths, pathBase))
                    return false;
                break;
    
            case GL_UNSIGNED_INT:
                pathNameTypeSize = sizeof(GLuint);
                if (!ValidatePathInstances<GLuint>(context, numPaths, paths, pathBase))
                    return false;
                break;
    
            case GL_INT:
                pathNameTypeSize = sizeof(GLint);
                if (!ValidatePathInstances<GLint>(context, numPaths, paths, pathBase))
                    return false;
                break;
    
            default:
                context->handleError(gl::Error(GL_INVALID_ENUM, "Invalid path name type."));
                return false;
        }
    
        switch (transformType)
        {
            case GL_NONE:
                componentCount = 0;
                break;
            case GL_TRANSLATE_X_CHROMIUM:
            case GL_TRANSLATE_Y_CHROMIUM:
                componentCount = 1;
                break;
            case GL_TRANSLATE_2D_CHROMIUM:
                componentCount = 2;
                break;
            case GL_TRANSLATE_3D_CHROMIUM:
                componentCount = 3;
                break;
            case GL_AFFINE_2D_CHROMIUM:
            case GL_TRANSPOSE_AFFINE_2D_CHROMIUM:
                componentCount = 6;
                break;
            case GL_AFFINE_3D_CHROMIUM:
            case GL_TRANSPOSE_AFFINE_3D_CHROMIUM:
                componentCount = 12;
                break;
            default:
                context->handleError(gl::Error(GL_INVALID_ENUM, "Invalid transformation."));
                return false;
        }
        if (componentCount != 0 && transformValues == nullptr)
        {
            context->handleError(gl::Error(GL_INVALID_VALUE, "No transform array given."));
            return false;
        }
    
        angle::CheckedNumeric<std::uint32_t> checkedSize(0);
        checkedSize += (numPaths * pathNameTypeSize);
        checkedSize += (numPaths * sizeof(GLfloat) * componentCount);
        if (!checkedSize.IsValid())
        {
            context->handleError(gl::Error(GL_INVALID_OPERATION, "Overflow in num paths."));
            return false;
        }
    
        return true;
    }
    
    bool IsValidCopyTextureFormat(Context *context, GLenum internalFormat)
    {
        const InternalFormat &internalFormatInfo = GetInternalFormatInfo(internalFormat);
        switch (internalFormatInfo.format)
        {
            case GL_ALPHA:
            case GL_LUMINANCE:
            case GL_LUMINANCE_ALPHA:
            case GL_RGB:
            case GL_RGBA:
                return true;
    
            case GL_RED:
                return context->getClientMajorVersion() >= 3 || context->getExtensions().textureRG;
    
            case GL_BGRA_EXT:
                return context->getExtensions().textureFormatBGRA8888;
    
            default:
                return false;
        }
    }
    
    bool IsValidCopyTextureDestinationFormatType(Context *context, GLint internalFormat, GLenum type)
    {
        switch (internalFormat)
        {
            case GL_RGB:
            case GL_RGBA:
                break;
    
            case GL_BGRA_EXT:
                return context->getExtensions().textureFormatBGRA8888;
    
            default:
                return false;
        }
    
        switch (type)
        {
            case GL_UNSIGNED_BYTE:
                break;
    
            default:
                return false;
        }
    
        return true;
    }
    
    bool IsValidCopyTextureDestinationTarget(Context *context, GLenum target)
    {
        switch (target)
        {
            case GL_TEXTURE_2D:
                return true;
    
            // TODO(geofflang): accept GL_TEXTURE_RECTANGLE_ARB if the texture_rectangle extension is
            // supported
    
            default:
                return false;
        }
    }
    
    bool IsValidCopyTextureSourceTarget(Context *context, GLenum target)
    {
        if (IsValidCopyTextureDestinationTarget(context, target))
        {
            return true;
        }
    
        // TODO(geofflang): accept GL_TEXTURE_EXTERNAL_OES if the texture_external extension is
        // supported
    
        return false;
    }
    
    }  // anonymous namespace
    
    bool ValidateES2TexImageParameters(Context *context,
                                       GLenum target,
                                       GLint level,
                                       GLenum internalformat,
                                       bool isCompressed,
                                       bool isSubImage,
                                       GLint xoffset,
                                       GLint yoffset,
                                       GLsizei width,
                                       GLsizei height,
                                       GLint border,
                                       GLenum format,
                                       GLenum type,
                                       GLsizei imageSize,
                                       const GLvoid *pixels)
    {
        if (!ValidTexture2DDestinationTarget(context, target))
        {
            context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        if (!ValidImageSizeParameters(context, target, level, width, height, 1, isSubImage))
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        if (level < 0 || xoffset < 0 ||
            std::numeric_limits<GLsizei>::max() - xoffset < width ||
            std::numeric_limits<GLsizei>::max() - yoffset < height)
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        if (!isSubImage && !isCompressed && internalformat != format)
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        const gl::Caps &caps = context->getCaps();
    
        if (target == GL_TEXTURE_2D)
        {
            if (static_cast<GLuint>(width) > (caps.max2DTextureSize >> level) ||
                static_cast<GLuint>(height) > (caps.max2DTextureSize >> level))
            {
                context->handleError(Error(GL_INVALID_VALUE));
                return false;
            }
        }
        else if (IsCubeMapTextureTarget(target))
        {
            if (!isSubImage && width != height)
            {
                context->handleError(Error(GL_INVALID_VALUE));
                return false;
            }
    
            if (static_cast<GLuint>(width) > (caps.maxCubeMapTextureSize >> level) ||
                static_cast<GLuint>(height) > (caps.maxCubeMapTextureSize >> level))
            {
                context->handleError(Error(GL_INVALID_VALUE));
                return false;
            }
        }
        else
        {
            context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        gl::Texture *texture = context->getTargetTexture(IsCubeMapTextureTarget(target) ? GL_TEXTURE_CUBE_MAP : target);
        if (!texture)
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        if (isSubImage)
        {
            if (format != GL_NONE)
            {
                if (gl::GetSizedInternalFormat(format, type) !=
                    texture->getFormat(target, level).asSized())
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
            }
    
            if (static_cast<size_t>(xoffset + width) > texture->getWidth(target, level) ||
                static_cast<size_t>(yoffset + height) > texture->getHeight(target, level))
            {
                context->handleError(Error(GL_INVALID_VALUE));
                return false;
            }
        }
        else
        {
            if (texture->getImmutableFormat())
            {
                context->handleError(Error(GL_INVALID_OPERATION));
                return false;
            }
        }
    
        // Verify zero border
        if (border != 0)
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        if (isCompressed)
        {
            GLenum actualInternalFormat =
                isSubImage ? texture->getFormat(target, level).asSized() : internalformat;
            switch (actualInternalFormat)
            {
              case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
              case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
                if (!context->getExtensions().textureCompressionDXT1)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
                if (!context->getExtensions().textureCompressionDXT1)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
                if (!context->getExtensions().textureCompressionDXT5)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_ETC1_RGB8_OES:
                if (!context->getExtensions().compressedETC1RGB8Texture)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_ETC1_RGB8_LOSSY_DECODE_ANGLE:
                  if (!context->getExtensions().lossyETCDecode)
                  {
                      context->handleError(
                          Error(GL_INVALID_ENUM, "ANGLE_lossy_etc_decode extension is not supported"));
                      return false;
                  }
                  break;
              default:
                  context->handleError(Error(
                      GL_INVALID_ENUM, "internalformat is not a supported compressed internal format"));
                  return false;
            }
            if (!ValidCompressedImageSize(context, actualInternalFormat, width, height))
            {
                context->handleError(Error(GL_INVALID_OPERATION));
                return false;
            }
        }
        else
        {
            // validate <type> by itself (used as secondary key below)
            switch (type)
            {
              case GL_UNSIGNED_BYTE:
              case GL_UNSIGNED_SHORT_5_6_5:
              case GL_UNSIGNED_SHORT_4_4_4_4:
              case GL_UNSIGNED_SHORT_5_5_5_1:
              case GL_UNSIGNED_SHORT:
              case GL_UNSIGNED_INT:
              case GL_UNSIGNED_INT_24_8_OES:
              case GL_HALF_FLOAT_OES:
              case GL_FLOAT:
                break;
              default:
                  context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
    
            // validate <format> + <type> combinations
            // - invalid <format> -> sets INVALID_ENUM
            // - invalid <format>+<type> combination -> sets INVALID_OPERATION
            switch (format)
            {
              case GL_ALPHA:
              case GL_LUMINANCE:
              case GL_LUMINANCE_ALPHA:
                switch (type)
                {
                  case GL_UNSIGNED_BYTE:
                  case GL_FLOAT:
                  case GL_HALF_FLOAT_OES:
                    break;
                  default:
                      context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                }
                break;
              case GL_RED:
              case GL_RG:
                  if (!context->getExtensions().textureRG)
                  {
                      context->handleError(Error(GL_INVALID_ENUM));
                      return false;
                  }
                  switch (type)
                  {
                    case GL_UNSIGNED_BYTE:
                    case GL_FLOAT:
                    case GL_HALF_FLOAT_OES:
                      break;
                    default:
                        context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                  }
                  break;
              case GL_RGB:
                switch (type)
                {
                  case GL_UNSIGNED_BYTE:
                  case GL_UNSIGNED_SHORT_5_6_5:
                  case GL_FLOAT:
                  case GL_HALF_FLOAT_OES:
                    break;
                  default:
                      context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_RGBA:
                switch (type)
                {
                  case GL_UNSIGNED_BYTE:
                  case GL_UNSIGNED_SHORT_4_4_4_4:
                  case GL_UNSIGNED_SHORT_5_5_5_1:
                  case GL_FLOAT:
                  case GL_HALF_FLOAT_OES:
                    break;
                  default:
                      context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_BGRA_EXT:
                switch (type)
                {
                  case GL_UNSIGNED_BYTE:
                    break;
                  default:
                      context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_SRGB_EXT:
              case GL_SRGB_ALPHA_EXT:
                if (!context->getExtensions().sRGB)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                switch (type)
                {
                  case GL_UNSIGNED_BYTE:
                    break;
                  default:
                      context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:  // error cases for compressed textures are handled below
              case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
              case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
              case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
                break;
              case GL_DEPTH_COMPONENT:
                switch (type)
                {
                  case GL_UNSIGNED_SHORT:
                  case GL_UNSIGNED_INT:
                    break;
                  default:
                      context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_DEPTH_STENCIL_OES:
                switch (type)
                {
                  case GL_UNSIGNED_INT_24_8_OES:
                    break;
                  default:
                      context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              default:
                  context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
    
            switch (format)
            {
              case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
              case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
                if (context->getExtensions().textureCompressionDXT1)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
                if (context->getExtensions().textureCompressionDXT3)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
                if (context->getExtensions().textureCompressionDXT5)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_ETC1_RGB8_OES:
                if (context->getExtensions().compressedETC1RGB8Texture)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_ETC1_RGB8_LOSSY_DECODE_ANGLE:
                  if (context->getExtensions().lossyETCDecode)
                  {
                      context->handleError(
                          Error(GL_INVALID_OPERATION,
                                "ETC1_RGB8_LOSSY_DECODE_ANGLE can't work with this type."));
                      return false;
                  }
                  else
                  {
                      context->handleError(
                          Error(GL_INVALID_ENUM, "ANGLE_lossy_etc_decode extension is not supported."));
                      return false;
                  }
                  break;
              case GL_DEPTH_COMPONENT:
              case GL_DEPTH_STENCIL_OES:
                if (!context->getExtensions().depthTextures)
                {
                    context->handleError(Error(GL_INVALID_VALUE));
                    return false;
                }
                if (target != GL_TEXTURE_2D)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                // OES_depth_texture supports loading depth data and multiple levels,
                // but ANGLE_depth_texture does not
                if (pixels != NULL || level != 0)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              default:
                break;
            }
    
            if (type == GL_FLOAT)
            {
                if (!context->getExtensions().textureFloat)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
            }
            else if (type == GL_HALF_FLOAT_OES)
            {
                if (!context->getExtensions().textureHalfFloat)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
            }
        }
    
        if (!ValidImageDataSize(context, target, width, height, 1, internalformat, type, pixels,
                                imageSize))
        {
            return false;
        }
    
        return true;
    }
    
    bool ValidateES2CopyTexImageParameters(ValidationContext *context,
                                           GLenum target,
                                           GLint level,
                                           GLenum internalformat,
                                           bool isSubImage,
                                           GLint xoffset,
                                           GLint yoffset,
                                           GLint x,
                                           GLint y,
                                           GLsizei width,
                                           GLsizei height,
                                           GLint border)
    {
        if (!ValidTexture2DDestinationTarget(context, target))
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid texture target"));
            return false;
        }
    
        Format textureFormat = Format::Invalid();
        if (!ValidateCopyTexImageParametersBase(context, target, level, internalformat, isSubImage,
                                                xoffset, yoffset, 0, x, y, width, height, border,
                                                &textureFormat))
        {
            return false;
        }
    
        const gl::Framebuffer *framebuffer = context->getGLState().getReadFramebuffer();
        GLenum colorbufferFormat           = framebuffer->getReadColorbuffer()->getFormat().asSized();
        const auto &formatInfo             = *textureFormat.info;
    
        // [OpenGL ES 2.0.24] table 3.9
        if (isSubImage)
        {
            switch (formatInfo.format)
            {
              case GL_ALPHA:
                if (colorbufferFormat != GL_ALPHA8_EXT &&
                    colorbufferFormat != GL_RGBA4 &&
                    colorbufferFormat != GL_RGB5_A1 &&
                    colorbufferFormat != GL_RGBA8_OES)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_LUMINANCE:
                  if (colorbufferFormat != GL_R8_EXT &&
                      colorbufferFormat != GL_RG8_EXT &&
                      colorbufferFormat != GL_RGB565 &&
                      colorbufferFormat != GL_RGB8_OES &&
                      colorbufferFormat != GL_RGBA4 &&
                      colorbufferFormat != GL_RGB5_A1 &&
                      colorbufferFormat != GL_RGBA8_OES)
                  {
                      context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                  }
                  break;
              case GL_RED_EXT:
                  if (colorbufferFormat != GL_R8_EXT &&
                      colorbufferFormat != GL_RG8_EXT &&
                      colorbufferFormat != GL_RGB565 &&
                      colorbufferFormat != GL_RGB8_OES &&
                      colorbufferFormat != GL_RGBA4 &&
                      colorbufferFormat != GL_RGB5_A1 &&
                      colorbufferFormat != GL_RGBA8_OES &&
                      colorbufferFormat != GL_R32F &&
                      colorbufferFormat != GL_RG32F &&
                      colorbufferFormat != GL_RGB32F &&
                      colorbufferFormat != GL_RGBA32F)
                  {
                      context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                  }
                  break;
              case GL_RG_EXT:
                  if (colorbufferFormat != GL_RG8_EXT &&
                      colorbufferFormat != GL_RGB565 &&
                      colorbufferFormat != GL_RGB8_OES &&
                      colorbufferFormat != GL_RGBA4 &&
                      colorbufferFormat != GL_RGB5_A1 &&
                      colorbufferFormat != GL_RGBA8_OES &&
                      colorbufferFormat != GL_RG32F &&
                      colorbufferFormat != GL_RGB32F &&
                      colorbufferFormat != GL_RGBA32F)
                  {
                      context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                  }
                  break;
              case GL_RGB:
                if (colorbufferFormat != GL_RGB565 &&
                    colorbufferFormat != GL_RGB8_OES &&
                    colorbufferFormat != GL_RGBA4 &&
                    colorbufferFormat != GL_RGB5_A1 &&
                    colorbufferFormat != GL_RGBA8_OES &&
                    colorbufferFormat != GL_RGB32F &&
                    colorbufferFormat != GL_RGBA32F)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_LUMINANCE_ALPHA:
              case GL_RGBA:
                if (colorbufferFormat != GL_RGBA4 &&
                    colorbufferFormat != GL_RGB5_A1 &&
                    colorbufferFormat != GL_RGBA8_OES &&
                    colorbufferFormat != GL_RGBA32F)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
              case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
              case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
              case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
              case GL_ETC1_RGB8_OES:
              case GL_ETC1_RGB8_LOSSY_DECODE_ANGLE:
                  context->handleError(Error(GL_INVALID_OPERATION));
                return false;
              case GL_DEPTH_COMPONENT:
              case GL_DEPTH_STENCIL_OES:
                  context->handleError(Error(GL_INVALID_OPERATION));
                return false;
              default:
                  context->handleError(Error(GL_INVALID_OPERATION));
                return false;
            }
    
            if (formatInfo.type == GL_FLOAT && !context->getExtensions().textureFloat)
            {
                context->handleError(Error(GL_INVALID_OPERATION));
                return false;
            }
        }
        else
        {
            switch (internalformat)
            {
              case GL_ALPHA:
                if (colorbufferFormat != GL_ALPHA8_EXT &&
                    colorbufferFormat != GL_RGBA4 &&
                    colorbufferFormat != GL_RGB5_A1 &&
                    colorbufferFormat != GL_BGRA8_EXT &&
                    colorbufferFormat != GL_RGBA8_OES &&
                    colorbufferFormat != GL_BGR5_A1_ANGLEX)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_LUMINANCE:
                  if (colorbufferFormat != GL_R8_EXT &&
                      colorbufferFormat != GL_RG8_EXT &&
                      colorbufferFormat != GL_RGB565 &&
                      colorbufferFormat != GL_RGB8_OES &&
                      colorbufferFormat != GL_RGBA4 &&
                      colorbufferFormat != GL_RGB5_A1 &&
                      colorbufferFormat != GL_BGRA8_EXT &&
                      colorbufferFormat != GL_RGBA8_OES &&
                      colorbufferFormat != GL_BGR5_A1_ANGLEX)
                  {
                      context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                  }
                  break;
              case GL_RED_EXT:
                  if (colorbufferFormat != GL_R8_EXT &&
                      colorbufferFormat != GL_RG8_EXT &&
                      colorbufferFormat != GL_RGB565 &&
                      colorbufferFormat != GL_RGB8_OES &&
                      colorbufferFormat != GL_RGBA4 &&
                      colorbufferFormat != GL_RGB5_A1 &&
                      colorbufferFormat != GL_BGRA8_EXT &&
                      colorbufferFormat != GL_RGBA8_OES &&
                      colorbufferFormat != GL_BGR5_A1_ANGLEX)
                  {
                      context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                  }
                  break;
              case GL_RG_EXT:
                  if (colorbufferFormat != GL_RG8_EXT &&
                      colorbufferFormat != GL_RGB565 &&
                      colorbufferFormat != GL_RGB8_OES &&
                      colorbufferFormat != GL_RGBA4 &&
                      colorbufferFormat != GL_RGB5_A1 &&
                      colorbufferFormat != GL_BGRA8_EXT &&
                      colorbufferFormat != GL_RGBA8_OES &&
                      colorbufferFormat != GL_BGR5_A1_ANGLEX)
                  {
                      context->handleError(Error(GL_INVALID_OPERATION));
                      return false;
                  }
                  break;
              case GL_RGB:
                if (colorbufferFormat != GL_RGB565 &&
                    colorbufferFormat != GL_RGB8_OES &&
                    colorbufferFormat != GL_RGBA4 &&
                    colorbufferFormat != GL_RGB5_A1 &&
                    colorbufferFormat != GL_BGRA8_EXT &&
                    colorbufferFormat != GL_RGBA8_OES &&
                    colorbufferFormat != GL_BGR5_A1_ANGLEX)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_LUMINANCE_ALPHA:
              case GL_RGBA:
                if (colorbufferFormat != GL_RGBA4 &&
                    colorbufferFormat != GL_RGB5_A1 &&
                    colorbufferFormat != GL_BGRA8_EXT &&
                    colorbufferFormat != GL_RGBA8_OES &&
                    colorbufferFormat != GL_BGR5_A1_ANGLEX)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
              case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
                if (context->getExtensions().textureCompressionDXT1)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
                if (context->getExtensions().textureCompressionDXT3)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
                if (context->getExtensions().textureCompressionDXT5)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_ETC1_RGB8_OES:
                if (context->getExtensions().compressedETC1RGB8Texture)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
              case GL_ETC1_RGB8_LOSSY_DECODE_ANGLE:
                  if (context->getExtensions().lossyETCDecode)
                  {
                      context->handleError(Error(GL_INVALID_OPERATION,
                                                 "ETC1_RGB8_LOSSY_DECODE_ANGLE can't be copied to."));
                      return false;
                  }
                  else
                  {
                      context->handleError(
                          Error(GL_INVALID_ENUM, "ANGLE_lossy_etc_decode extension is not supported."));
                      return false;
                  }
                  break;
              case GL_DEPTH_COMPONENT:
              case GL_DEPTH_COMPONENT16:
              case GL_DEPTH_COMPONENT32_OES:
              case GL_DEPTH_STENCIL_OES:
              case GL_DEPTH24_STENCIL8_OES:
                if (context->getExtensions().depthTextures)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                else
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
              default:
                  context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
        }
    
        // If width or height is zero, it is a no-op.  Return false without setting an error.
        return (width > 0 && height > 0);
    }
    
    bool ValidateES2TexStorageParameters(Context *context, GLenum target, GLsizei levels, GLenum internalformat,
                                         GLsizei width, GLsizei height)
    {
        if (target != GL_TEXTURE_2D && target != GL_TEXTURE_CUBE_MAP)
        {
            context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        if (width < 1 || height < 1 || levels < 1)
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        if (target == GL_TEXTURE_CUBE_MAP && width != height)
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        if (levels != 1 && levels != gl::log2(std::max(width, height)) + 1)
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        const gl::InternalFormat &formatInfo = gl::GetInternalFormatInfo(internalformat);
        if (formatInfo.format == GL_NONE || formatInfo.type == GL_NONE)
        {
            context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        const gl::Caps &caps = context->getCaps();
    
        switch (target)
        {
          case GL_TEXTURE_2D:
            if (static_cast<GLuint>(width) > caps.max2DTextureSize ||
                static_cast<GLuint>(height) > caps.max2DTextureSize)
            {
                context->handleError(Error(GL_INVALID_VALUE));
                return false;
            }
            break;
          case GL_TEXTURE_CUBE_MAP:
            if (static_cast<GLuint>(width) > caps.maxCubeMapTextureSize ||
                static_cast<GLuint>(height) > caps.maxCubeMapTextureSize)
            {
                context->handleError(Error(GL_INVALID_VALUE));
                return false;
            }
            break;
          default:
              context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        if (levels != 1 && !context->getExtensions().textureNPOT)
        {
            if (!gl::isPow2(width) || !gl::isPow2(height))
            {
                context->handleError(Error(GL_INVALID_OPERATION));
                return false;
            }
        }
    
        switch (internalformat)
        {
          case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
          case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
            if (!context->getExtensions().textureCompressionDXT1)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            break;
          case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
            if (!context->getExtensions().textureCompressionDXT3)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            break;
          case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
            if (!context->getExtensions().textureCompressionDXT5)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            break;
          case GL_ETC1_RGB8_OES:
            if (!context->getExtensions().compressedETC1RGB8Texture)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            break;
          case GL_ETC1_RGB8_LOSSY_DECODE_ANGLE:
              if (!context->getExtensions().lossyETCDecode)
              {
                  context->handleError(
                      Error(GL_INVALID_ENUM, "ANGLE_lossy_etc_decode extension is not supported."));
                  return false;
              }
              break;
          case GL_RGBA32F_EXT:
          case GL_RGB32F_EXT:
          case GL_ALPHA32F_EXT:
          case GL_LUMINANCE32F_EXT:
          case GL_LUMINANCE_ALPHA32F_EXT:
            if (!context->getExtensions().textureFloat)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            break;
          case GL_RGBA16F_EXT:
          case GL_RGB16F_EXT:
          case GL_ALPHA16F_EXT:
          case GL_LUMINANCE16F_EXT:
          case GL_LUMINANCE_ALPHA16F_EXT:
            if (!context->getExtensions().textureHalfFloat)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            break;
          case GL_R8_EXT:
          case GL_RG8_EXT:
          case GL_R16F_EXT:
          case GL_RG16F_EXT:
          case GL_R32F_EXT:
          case GL_RG32F_EXT:
            if (!context->getExtensions().textureRG)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            break;
          case GL_DEPTH_COMPONENT16:
          case GL_DEPTH_COMPONENT32_OES:
          case GL_DEPTH24_STENCIL8_OES:
            if (!context->getExtensions().depthTextures)
            {
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
            }
            if (target != GL_TEXTURE_2D)
            {
                context->handleError(Error(GL_INVALID_OPERATION));
                return false;
            }
            // ANGLE_depth_texture only supports 1-level textures
            if (levels != 1)
            {
                context->handleError(Error(GL_INVALID_OPERATION));
                return false;
            }
            break;
          default:
            break;
        }
    
        gl::Texture *texture = context->getTargetTexture(target);
        if (!texture || texture->id() == 0)
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        if (texture->getImmutableFormat())
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        return true;
    }
    
    bool ValidateDiscardFramebufferEXT(Context *context, GLenum target, GLsizei numAttachments,
                                       const GLenum *attachments)
    {
        if (!context->getExtensions().discardFramebuffer)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        bool defaultFramebuffer = false;
    
        switch (target)
        {
          case GL_FRAMEBUFFER:
              defaultFramebuffer =
                  (context->getGLState().getTargetFramebuffer(GL_FRAMEBUFFER)->id() == 0);
              break;
          default:
              context->handleError(Error(GL_INVALID_ENUM, "Invalid framebuffer target"));
            return false;
        }
    
        return ValidateDiscardFramebufferBase(context, target, numAttachments, attachments, defaultFramebuffer);
    }
    
    bool ValidateBindVertexArrayOES(Context *context, GLuint array)
    {
        if (!context->getExtensions().vertexArrayObject)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        return ValidateBindVertexArrayBase(context, array);
    }
    
    bool ValidateDeleteVertexArraysOES(Context *context, GLsizei n)
    {
        if (!context->getExtensions().vertexArrayObject)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        return ValidateGenOrDelete(context, n);
    }
    
    bool ValidateGenVertexArraysOES(Context *context, GLsizei n)
    {
        if (!context->getExtensions().vertexArrayObject)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        return ValidateGenOrDelete(context, n);
    }
    
    bool ValidateIsVertexArrayOES(Context *context)
    {
        if (!context->getExtensions().vertexArrayObject)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        return true;
    }
    
    bool ValidateProgramBinaryOES(Context *context,
                                  GLuint program,
                                  GLenum binaryFormat,
                                  const void *binary,
                                  GLint length)
    {
        if (!context->getExtensions().getProgramBinary)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        return ValidateProgramBinaryBase(context, program, binaryFormat, binary, length);
    }
    
    bool ValidateGetProgramBinaryOES(Context *context,
                                     GLuint program,
                                     GLsizei bufSize,
                                     GLsizei *length,
                                     GLenum *binaryFormat,
                                     void *binary)
    {
        if (!context->getExtensions().getProgramBinary)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        return ValidateGetProgramBinaryBase(context, program, bufSize, length, binaryFormat, binary);
    }
    
    static bool ValidDebugSource(GLenum source, bool mustBeThirdPartyOrApplication)
    {
        switch (source)
        {
            case GL_DEBUG_SOURCE_API:
            case GL_DEBUG_SOURCE_SHADER_COMPILER:
            case GL_DEBUG_SOURCE_WINDOW_SYSTEM:
            case GL_DEBUG_SOURCE_OTHER:
                // Only THIRD_PARTY and APPLICATION sources are allowed to be manually inserted
                return !mustBeThirdPartyOrApplication;
    
            case GL_DEBUG_SOURCE_THIRD_PARTY:
            case GL_DEBUG_SOURCE_APPLICATION:
                return true;
    
            default:
                return false;
        }
    }
    
    static bool ValidDebugType(GLenum type)
    {
        switch (type)
        {
            case GL_DEBUG_TYPE_ERROR:
            case GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR:
            case GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR:
            case GL_DEBUG_TYPE_PERFORMANCE:
            case GL_DEBUG_TYPE_PORTABILITY:
            case GL_DEBUG_TYPE_OTHER:
            case GL_DEBUG_TYPE_MARKER:
            case GL_DEBUG_TYPE_PUSH_GROUP:
            case GL_DEBUG_TYPE_POP_GROUP:
                return true;
    
            default:
                return false;
        }
    }
    
    static bool ValidDebugSeverity(GLenum severity)
    {
        switch (severity)
        {
            case GL_DEBUG_SEVERITY_HIGH:
            case GL_DEBUG_SEVERITY_MEDIUM:
            case GL_DEBUG_SEVERITY_LOW:
            case GL_DEBUG_SEVERITY_NOTIFICATION:
                return true;
    
            default:
                return false;
        }
    }
    
    bool ValidateDebugMessageControlKHR(Context *context,
                                        GLenum source,
                                        GLenum type,
                                        GLenum severity,
                                        GLsizei count,
                                        const GLuint *ids,
                                        GLboolean enabled)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (!ValidDebugSource(source, false) && source != GL_DONT_CARE)
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid debug source."));
            return false;
        }
    
        if (!ValidDebugType(type) && type != GL_DONT_CARE)
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid debug type."));
            return false;
        }
    
        if (!ValidDebugSeverity(severity) && severity != GL_DONT_CARE)
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid debug severity."));
            return false;
        }
    
        if (count > 0)
        {
            if (source == GL_DONT_CARE || type == GL_DONT_CARE)
            {
                context->handleError(Error(
                    GL_INVALID_OPERATION,
                    "If count is greater than zero, source and severity cannot be GL_DONT_CARE."));
                return false;
            }
    
            if (severity != GL_DONT_CARE)
            {
                context->handleError(
                    Error(GL_INVALID_OPERATION,
                          "If count is greater than zero, severity must be GL_DONT_CARE."));
                return false;
            }
        }
    
        return true;
    }
    
    bool ValidateDebugMessageInsertKHR(Context *context,
                                       GLenum source,
                                       GLenum type,
                                       GLuint id,
                                       GLenum severity,
                                       GLsizei length,
                                       const GLchar *buf)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (!context->getGLState().getDebug().isOutputEnabled())
        {
            // If the DEBUG_OUTPUT state is disabled calls to DebugMessageInsert are discarded and do
            // not generate an error.
            return false;
        }
    
        if (!ValidDebugSeverity(severity))
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid debug severity."));
            return false;
        }
    
        if (!ValidDebugType(type))
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid debug type."));
            return false;
        }
    
        if (!ValidDebugSource(source, true))
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid debug source."));
            return false;
        }
    
        size_t messageLength = (length < 0) ? strlen(buf) : length;
        if (messageLength > context->getExtensions().maxDebugMessageLength)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Message length is larger than GL_MAX_DEBUG_MESSAGE_LENGTH."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateDebugMessageCallbackKHR(Context *context,
                                         GLDEBUGPROCKHR callback,
                                         const void *userParam)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        return true;
    }
    
    bool ValidateGetDebugMessageLogKHR(Context *context,
                                       GLuint count,
                                       GLsizei bufSize,
                                       GLenum *sources,
                                       GLenum *types,
                                       GLuint *ids,
                                       GLenum *severities,
                                       GLsizei *lengths,
                                       GLchar *messageLog)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (bufSize < 0 && messageLog != nullptr)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "bufSize must be positive if messageLog is not null."));
            return false;
        }
    
        return true;
    }
    
    bool ValidatePushDebugGroupKHR(Context *context,
                                   GLenum source,
                                   GLuint id,
                                   GLsizei length,
                                   const GLchar *message)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (!ValidDebugSource(source, true))
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid debug source."));
            return false;
        }
    
        size_t messageLength = (length < 0) ? strlen(message) : length;
        if (messageLength > context->getExtensions().maxDebugMessageLength)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Message length is larger than GL_MAX_DEBUG_MESSAGE_LENGTH."));
            return false;
        }
    
        size_t currentStackSize = context->getGLState().getDebug().getGroupStackDepth();
        if (currentStackSize >= context->getExtensions().maxDebugGroupStackDepth)
        {
            context->handleError(
                Error(GL_STACK_OVERFLOW,
                      "Cannot push more than GL_MAX_DEBUG_GROUP_STACK_DEPTH debug groups."));
            return false;
        }
    
        return true;
    }
    
    bool ValidatePopDebugGroupKHR(Context *context)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        size_t currentStackSize = context->getGLState().getDebug().getGroupStackDepth();
        if (currentStackSize <= 1)
        {
            context->handleError(Error(GL_STACK_UNDERFLOW, "Cannot pop the default debug group."));
            return false;
        }
    
        return true;
    }
    
    static bool ValidateObjectIdentifierAndName(Context *context, GLenum identifier, GLuint name)
    {
        switch (identifier)
        {
            case GL_BUFFER:
                if (context->getBuffer(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid buffer."));
                    return false;
                }
                return true;
    
            case GL_SHADER:
                if (context->getShader(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid shader."));
                    return false;
                }
                return true;
    
            case GL_PROGRAM:
                if (context->getProgram(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid program."));
                    return false;
                }
                return true;
    
            case GL_VERTEX_ARRAY:
                if (context->getVertexArray(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid vertex array."));
                    return false;
                }
                return true;
    
            case GL_QUERY:
                if (context->getQuery(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid query."));
                    return false;
                }
                return true;
    
            case GL_TRANSFORM_FEEDBACK:
                if (context->getTransformFeedback(name) == nullptr)
                {
                    context->handleError(
                        Error(GL_INVALID_VALUE, "name is not a valid transform feedback."));
                    return false;
                }
                return true;
    
            case GL_SAMPLER:
                if (context->getSampler(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid sampler."));
                    return false;
                }
                return true;
    
            case GL_TEXTURE:
                if (context->getTexture(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid texture."));
                    return false;
                }
                return true;
    
            case GL_RENDERBUFFER:
                if (context->getRenderbuffer(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid renderbuffer."));
                    return false;
                }
                return true;
    
            case GL_FRAMEBUFFER:
                if (context->getFramebuffer(name) == nullptr)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "name is not a valid framebuffer."));
                    return false;
                }
                return true;
    
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid identifier."));
                return false;
        }
    }
    
    static bool ValidateLabelLength(Context *context, GLsizei length, const GLchar *label)
    {
        size_t labelLength = 0;
    
        if (length < 0)
        {
            if (label != nullptr)
            {
                labelLength = strlen(label);
            }
        }
        else
        {
            labelLength = static_cast<size_t>(length);
        }
    
        if (labelLength > context->getExtensions().maxLabelLength)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Label length is larger than GL_MAX_LABEL_LENGTH."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateObjectLabelKHR(Context *context,
                                GLenum identifier,
                                GLuint name,
                                GLsizei length,
                                const GLchar *label)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (!ValidateObjectIdentifierAndName(context, identifier, name))
        {
            return false;
        }
    
        if (!ValidateLabelLength(context, length, label))
        {
            return false;
        }
    
        return true;
    }
    
    bool ValidateGetObjectLabelKHR(Context *context,
                                   GLenum identifier,
                                   GLuint name,
                                   GLsizei bufSize,
                                   GLsizei *length,
                                   GLchar *label)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (bufSize < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "bufSize cannot be negative."));
            return false;
        }
    
        if (!ValidateObjectIdentifierAndName(context, identifier, name))
        {
            return false;
        }
    
        return true;
    }
    
    static bool ValidateObjectPtrName(Context *context, const void *ptr)
    {
        if (context->getFenceSync(reinterpret_cast<GLsync>(const_cast<void *>(ptr))) == nullptr)
        {
            context->handleError(Error(GL_INVALID_VALUE, "name is not a valid sync."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateObjectPtrLabelKHR(Context *context,
                                   const void *ptr,
                                   GLsizei length,
                                   const GLchar *label)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (!ValidateObjectPtrName(context, ptr))
        {
            return false;
        }
    
        if (!ValidateLabelLength(context, length, label))
        {
            return false;
        }
    
        return true;
    }
    
    bool ValidateGetObjectPtrLabelKHR(Context *context,
                                      const void *ptr,
                                      GLsizei bufSize,
                                      GLsizei *length,
                                      GLchar *label)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        if (bufSize < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "bufSize cannot be negative."));
            return false;
        }
    
        if (!ValidateObjectPtrName(context, ptr))
        {
            return false;
        }
    
        return true;
    }
    
    bool ValidateGetPointervKHR(Context *context, GLenum pname, void **params)
    {
        if (!context->getExtensions().debug)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not enabled"));
            return false;
        }
    
        // TODO: represent this in Context::getQueryParameterInfo.
        switch (pname)
        {
            case GL_DEBUG_CALLBACK_FUNCTION:
            case GL_DEBUG_CALLBACK_USER_PARAM:
                break;
    
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid pname."));
                return false;
        }
    
        return true;
    }
    
    bool ValidateBlitFramebufferANGLE(Context *context,
                                      GLint srcX0,
                                      GLint srcY0,
                                      GLint srcX1,
                                      GLint srcY1,
                                      GLint dstX0,
                                      GLint dstY0,
                                      GLint dstX1,
                                      GLint dstY1,
                                      GLbitfield mask,
                                      GLenum filter)
    {
        if (!context->getExtensions().framebufferBlit)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Blit extension not available."));
            return false;
        }
    
        if (srcX1 - srcX0 != dstX1 - dstX0 || srcY1 - srcY0 != dstY1 - dstY0)
        {
            // TODO(jmadill): Determine if this should be available on other implementations.
            context->handleError(Error(
                GL_INVALID_OPERATION,
                "Scaling and flipping in BlitFramebufferANGLE not supported by this implementation."));
            return false;
        }
    
        if (filter == GL_LINEAR)
        {
            context->handleError(Error(GL_INVALID_ENUM, "Linear blit not supported in this extension"));
            return false;
        }
    
        Framebuffer *readFramebuffer = context->getGLState().getReadFramebuffer();
        Framebuffer *drawFramebuffer = context->getGLState().getDrawFramebuffer();
    
        if (mask & GL_COLOR_BUFFER_BIT)
        {
            const FramebufferAttachment *readColorAttachment = readFramebuffer->getReadColorbuffer();
            const FramebufferAttachment *drawColorAttachment = drawFramebuffer->getFirstColorbuffer();
    
            if (readColorAttachment && drawColorAttachment)
            {
                if (!(readColorAttachment->type() == GL_TEXTURE &&
                      readColorAttachment->getTextureImageIndex().type == GL_TEXTURE_2D) &&
                    readColorAttachment->type() != GL_RENDERBUFFER &&
                    readColorAttachment->type() != GL_FRAMEBUFFER_DEFAULT)
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
    
                for (size_t drawbufferIdx = 0;
                     drawbufferIdx < drawFramebuffer->getDrawbufferStateCount(); ++drawbufferIdx)
                {
                    const FramebufferAttachment *attachment =
                        drawFramebuffer->getDrawBuffer(drawbufferIdx);
                    if (attachment)
                    {
                        if (!(attachment->type() == GL_TEXTURE &&
                              attachment->getTextureImageIndex().type == GL_TEXTURE_2D) &&
                            attachment->type() != GL_RENDERBUFFER &&
                            attachment->type() != GL_FRAMEBUFFER_DEFAULT)
                        {
                            context->handleError(Error(GL_INVALID_OPERATION));
                            return false;
                        }
    
                        // Return an error if the destination formats do not match
                        if (!Format::SameSized(attachment->getFormat(),
                                               readColorAttachment->getFormat()))
                        {
                            context->handleError(Error(GL_INVALID_OPERATION));
                            return false;
                        }
                    }
                }
    
                if (readFramebuffer->getSamples(context->getContextState()) != 0 &&
                    IsPartialBlit(context, readColorAttachment, drawColorAttachment, srcX0, srcY0,
                                  srcX1, srcY1, dstX0, dstY0, dstX1, dstY1))
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
            }
        }
    
        GLenum masks[]       = {GL_DEPTH_BUFFER_BIT, GL_STENCIL_BUFFER_BIT};
        GLenum attachments[] = {GL_DEPTH_ATTACHMENT, GL_STENCIL_ATTACHMENT};
        for (size_t i = 0; i < 2; i++)
        {
            if (mask & masks[i])
            {
                const FramebufferAttachment *readBuffer =
                    readFramebuffer->getAttachment(attachments[i]);
                const FramebufferAttachment *drawBuffer =
                    drawFramebuffer->getAttachment(attachments[i]);
    
                if (readBuffer && drawBuffer)
                {
                    if (IsPartialBlit(context, readBuffer, drawBuffer, srcX0, srcY0, srcX1, srcY1,
                                      dstX0, dstY0, dstX1, dstY1))
                    {
                        // only whole-buffer copies are permitted
                        ERR(
                            "Only whole-buffer depth and stencil blits are supported by this "
                            "implementation.");
                        context->handleError(Error(GL_INVALID_OPERATION));
                        return false;
                    }
    
                    if (readBuffer->getSamples() != 0 || drawBuffer->getSamples() != 0)
                    {
                        context->handleError(Error(GL_INVALID_OPERATION));
                        return false;
                    }
                }
            }
        }
    
        return ValidateBlitFramebufferParameters(context, srcX0, srcY0, srcX1, srcY1, dstX0, dstY0,
                                                 dstX1, dstY1, mask, filter);
    }
    
    bool ValidateClear(ValidationContext *context, GLbitfield mask)
    {
        auto fbo = context->getGLState().getDrawFramebuffer();
        if (fbo->checkStatus(context->getContextState()) != GL_FRAMEBUFFER_COMPLETE)
        {
            context->handleError(Error(GL_INVALID_FRAMEBUFFER_OPERATION));
            return false;
        }
    
        if ((mask & ~(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT)) != 0)
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        return true;
    }
    
    bool ValidateDrawBuffersEXT(ValidationContext *context, GLsizei n, const GLenum *bufs)
    {
        if (!context->getExtensions().drawBuffers)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension not supported."));
            return false;
        }
    
        return ValidateDrawBuffersBase(context, n, bufs);
    }
    
    bool ValidateTexImage2D(Context *context,
                            GLenum target,
                            GLint level,
                            GLint internalformat,
                            GLsizei width,
                            GLsizei height,
                            GLint border,
                            GLenum format,
                            GLenum type,
                            const GLvoid *pixels)
    {
        if (context->getClientMajorVersion() < 3)
        {
            return ValidateES2TexImageParameters(context, target, level, internalformat, false, false,
                                                 0, 0, width, height, border, format, type, -1, pixels);
        }
    
        ASSERT(context->getClientMajorVersion() >= 3);
        return ValidateES3TexImage2DParameters(context, target, level, internalformat, false, false, 0,
                                               0, 0, width, height, 1, border, format, type, -1,
                                               pixels);
    }
    
    bool ValidateTexImage2DRobust(Context *context,
                                  GLenum target,
                                  GLint level,
                                  GLint internalformat,
                                  GLsizei width,
                                  GLsizei height,
                                  GLint border,
                                  GLenum format,
                                  GLenum type,
                                  GLsizei bufSize,
                                  const GLvoid *pixels)
    {
        if (!ValidateRobustEntryPoint(context, bufSize))
        {
            return false;
        }
    
        if (context->getClientMajorVersion() < 3)
        {
            return ValidateES2TexImageParameters(context, target, level, internalformat, false, false,
                                                 0, 0, width, height, border, format, type, bufSize,
                                                 pixels);
        }
    
        ASSERT(context->getClientMajorVersion() >= 3);
        return ValidateES3TexImage2DParameters(context, target, level, internalformat, false, false, 0,
                                               0, 0, width, height, 1, border, format, type, bufSize,
                                               pixels);
    }
    
    bool ValidateTexSubImage2D(Context *context,
                               GLenum target,
                               GLint level,
                               GLint xoffset,
                               GLint yoffset,
                               GLsizei width,
                               GLsizei height,
                               GLenum format,
                               GLenum type,
                               const GLvoid *pixels)
    {
    
        if (context->getClientMajorVersion() < 3)
        {
            return ValidateES2TexImageParameters(context, target, level, GL_NONE, false, true, xoffset,
                                                 yoffset, width, height, 0, format, type, -1, pixels);
        }
    
        ASSERT(context->getClientMajorVersion() >= 3);
        return ValidateES3TexImage2DParameters(context, target, level, GL_NONE, false, true, xoffset,
                                               yoffset, 0, width, height, 1, 0, format, type, -1,
                                               pixels);
    }
    
    bool ValidateTexSubImage2DRobustANGLE(Context *context,
                                          GLenum target,
                                          GLint level,
                                          GLint xoffset,
                                          GLint yoffset,
                                          GLsizei width,
                                          GLsizei height,
                                          GLenum format,
                                          GLenum type,
                                          GLsizei bufSize,
                                          const GLvoid *pixels)
    {
        if (!ValidateRobustEntryPoint(context, bufSize))
        {
            return false;
        }
    
        if (context->getClientMajorVersion() < 3)
        {
            return ValidateES2TexImageParameters(context, target, level, GL_NONE, false, true, xoffset,
                                                 yoffset, width, height, 0, format, type, bufSize,
                                                 pixels);
        }
    
        ASSERT(context->getClientMajorVersion() >= 3);
        return ValidateES3TexImage2DParameters(context, target, level, GL_NONE, false, true, xoffset,
                                               yoffset, 0, width, height, 1, 0, format, type, bufSize,
                                               pixels);
    }
    
    bool ValidateCompressedTexImage2D(Context *context,
                                      GLenum target,
                                      GLint level,
                                      GLenum internalformat,
                                      GLsizei width,
                                      GLsizei height,
                                      GLint border,
                                      GLsizei imageSize,
                                      const GLvoid *data)
    {
        if (context->getClientMajorVersion() < 3)
        {
            if (!ValidateES2TexImageParameters(context, target, level, internalformat, true, false, 0,
                                               0, width, height, border, GL_NONE, GL_NONE, -1, data))
            {
                return false;
            }
        }
        else
        {
            ASSERT(context->getClientMajorVersion() >= 3);
            if (!ValidateES3TexImage2DParameters(context, target, level, internalformat, true, false, 0,
                                                 0, 0, width, height, 1, border, GL_NONE, GL_NONE, -1,
                                                 data))
            {
                return false;
            }
        }
    
        const InternalFormat &formatInfo = GetInternalFormatInfo(internalformat);
        auto blockSizeOrErr =
            formatInfo.computeCompressedImageSize(GL_UNSIGNED_BYTE, gl::Extents(width, height, 1));
        if (blockSizeOrErr.isError())
        {
            context->handleError(blockSizeOrErr.getError());
            return false;
        }
    
        if (imageSize < 0 || static_cast<GLuint>(imageSize) != blockSizeOrErr.getResult())
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        return true;
    }
    
    bool ValidateCompressedTexSubImage2D(Context *context,
                                         GLenum target,
                                         GLint level,
                                         GLint xoffset,
                                         GLint yoffset,
                                         GLsizei width,
                                         GLsizei height,
                                         GLenum format,
                                         GLsizei imageSize,
                                         const GLvoid *data)
    {
        if (context->getClientMajorVersion() < 3)
        {
            if (!ValidateES2TexImageParameters(context, target, level, GL_NONE, true, true, xoffset,
                                               yoffset, width, height, 0, GL_NONE, GL_NONE, -1, data))
            {
                return false;
            }
        }
        else
        {
            ASSERT(context->getClientMajorVersion() >= 3);
            if (!ValidateES3TexImage2DParameters(context, target, level, GL_NONE, true, true, xoffset,
                                                 yoffset, 0, width, height, 1, 0, GL_NONE, GL_NONE, -1,
                                                 data))
            {
                return false;
            }
        }
    
        const InternalFormat &formatInfo = GetInternalFormatInfo(format);
        auto blockSizeOrErr =
            formatInfo.computeCompressedImageSize(GL_UNSIGNED_BYTE, gl::Extents(width, height, 1));
        if (blockSizeOrErr.isError())
        {
            context->handleError(blockSizeOrErr.getError());
            return false;
        }
    
        if (imageSize < 0 || static_cast<GLuint>(imageSize) != blockSizeOrErr.getResult())
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        return true;
    }
    
    bool ValidateGetBufferPointervOES(Context *context, GLenum target, GLenum pname, void **params)
    {
        return ValidateGetBufferPointervBase(context, target, pname, nullptr, params);
    }
    
    bool ValidateMapBufferOES(Context *context, GLenum target, GLenum access)
    {
        if (!context->getExtensions().mapBuffer)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Map buffer extension not available."));
            return false;
        }
    
        if (!ValidBufferTarget(context, target))
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid buffer target."));
            return false;
        }
    
        Buffer *buffer = context->getGLState().getTargetBuffer(target);
    
        if (buffer == nullptr)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Attempted to map buffer object zero."));
            return false;
        }
    
        if (access != GL_WRITE_ONLY_OES)
        {
            context->handleError(Error(GL_INVALID_ENUM, "Non-write buffer mapping not supported."));
            return false;
        }
    
        if (buffer->isMapped())
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Buffer is already mapped."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateUnmapBufferOES(Context *context, GLenum target)
    {
        if (!context->getExtensions().mapBuffer)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Map buffer extension not available."));
            return false;
        }
    
        return ValidateUnmapBufferBase(context, target);
    }
    
    bool ValidateMapBufferRangeEXT(Context *context,
                                   GLenum target,
                                   GLintptr offset,
                                   GLsizeiptr length,
                                   GLbitfield access)
    {
        if (!context->getExtensions().mapBufferRange)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "Map buffer range extension not available."));
            return false;
        }
    
        return ValidateMapBufferRangeBase(context, target, offset, length, access);
    }
    
    bool ValidateFlushMappedBufferRangeEXT(Context *context,
                                           GLenum target,
                                           GLintptr offset,
                                           GLsizeiptr length)
    {
        if (!context->getExtensions().mapBufferRange)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "Map buffer range extension not available."));
            return false;
        }
    
        return ValidateFlushMappedBufferRangeBase(context, target, offset, length);
    }
    
    bool ValidateBindTexture(Context *context, GLenum target, GLuint texture)
    {
        Texture *textureObject = context->getTexture(texture);
        if (textureObject && textureObject->getTarget() != target && texture != 0)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Invalid texture"));
            return false;
        }
    
        if (!context->getGLState().isBindGeneratesResourceEnabled() &&
            !context->isTextureGenerated(texture))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Texture was not generated"));
            return false;
        }
    
        switch (target)
        {
            case GL_TEXTURE_2D:
            case GL_TEXTURE_CUBE_MAP:
                break;
    
            case GL_TEXTURE_3D:
            case GL_TEXTURE_2D_ARRAY:
                if (context->getClientMajorVersion() < 3)
                {
                    context->handleError(Error(GL_INVALID_ENUM, "GLES 3.0 disabled"));
                    return false;
                }
                break;
            case GL_TEXTURE_EXTERNAL_OES:
                if (!context->getExtensions().eglImageExternal &&
                    !context->getExtensions().eglStreamConsumerExternal)
                {
                    context->handleError(
                        Error(GL_INVALID_ENUM, "External texture extension not enabled"));
                    return false;
                }
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid target"));
                return false;
        }
    
        return true;
    }
    
    bool ValidateBindUniformLocationCHROMIUM(Context *context,
                                             GLuint program,
                                             GLint location,
                                             const GLchar *name)
    {
        if (!context->getExtensions().bindUniformLocation)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_bind_uniform_location is not available."));
            return false;
        }
    
        Program *programObject = GetValidProgram(context, program);
        if (!programObject)
        {
            return false;
        }
    
        if (location < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Location cannot be less than 0."));
            return false;
        }
    
        const Caps &caps = context->getCaps();
        if (static_cast<size_t>(location) >=
            (caps.maxVertexUniformVectors + caps.maxFragmentUniformVectors) * 4)
        {
            context->handleError(Error(GL_INVALID_VALUE,
                                       "Location must be less than (MAX_VERTEX_UNIFORM_VECTORS + "
                                       "MAX_FRAGMENT_UNIFORM_VECTORS) * 4"));
            return false;
        }
    
        if (strncmp(name, "gl_", 3) == 0)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "Name cannot start with the reserved \"gl_\" prefix."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateCoverageModulationCHROMIUM(Context *context, GLenum components)
    {
        if (!context->getExtensions().framebufferMixedSamples)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_framebuffer_mixed_samples is not available."));
            return false;
        }
        switch (components)
        {
            case GL_RGB:
            case GL_RGBA:
            case GL_ALPHA:
            case GL_NONE:
                break;
            default:
                context->handleError(
                    Error(GL_INVALID_ENUM,
                          "GLenum components is not one of GL_RGB, GL_RGBA, GL_ALPHA or GL_NONE."));
                return false;
        }
    
        return true;
    }
    
    // CHROMIUM_path_rendering
    
    bool ValidateMatrix(Context *context, GLenum matrixMode, const GLfloat *matrix)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        if (matrixMode != GL_PATH_MODELVIEW_CHROMIUM && matrixMode != GL_PATH_PROJECTION_CHROMIUM)
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid matrix mode."));
            return false;
        }
        if (matrix == nullptr)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Invalid matrix."));
            return false;
        }
        return true;
    }
    
    bool ValidateMatrixMode(Context *context, GLenum matrixMode)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        if (matrixMode != GL_PATH_MODELVIEW_CHROMIUM && matrixMode != GL_PATH_PROJECTION_CHROMIUM)
        {
            context->handleError(Error(GL_INVALID_ENUM, "Invalid matrix mode."));
            return false;
        }
        return true;
    }
    
    bool ValidateGenPaths(Context *context, GLsizei range)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
    
        // range = 0 is undefined in NV_path_rendering.
        // we add stricter semantic check here and require a non zero positive range.
        if (range <= 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid range."));
            return false;
        }
    
        if (!angle::IsValueInRangeForNumericType<std::uint32_t>(range))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Range overflow."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateDeletePaths(Context *context, GLuint path, GLsizei range)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
    
        // range = 0 is undefined in NV_path_rendering.
        // we add stricter semantic check here and require a non zero positive range.
        if (range <= 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid range."));
            return false;
        }
    
        angle::CheckedNumeric<std::uint32_t> checkedRange(path);
        checkedRange += range;
    
        if (!angle::IsValueInRangeForNumericType<std::uint32_t>(range) || !checkedRange.IsValid())
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Range overflow."));
            return false;
        }
        return true;
    }
    
    bool ValidatePathCommands(Context *context,
                              GLuint path,
                              GLsizei numCommands,
                              const GLubyte *commands,
                              GLsizei numCoords,
                              GLenum coordType,
                              const void *coords)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        if (!context->hasPath(path))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such path object."));
            return false;
        }
    
        if (numCommands < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid number of commands."));
            return false;
        }
        else if (numCommands > 0)
        {
            if (!commands)
            {
                context->handleError(Error(GL_INVALID_VALUE, "No commands array given."));
                return false;
            }
        }
    
        if (numCoords < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid number of coordinates."));
            return false;
        }
        else if (numCoords > 0)
        {
            if (!coords)
            {
                context->handleError(Error(GL_INVALID_VALUE, "No coordinate array given."));
                return false;
            }
        }
    
        std::uint32_t coordTypeSize = 0;
        switch (coordType)
        {
            case GL_BYTE:
                coordTypeSize = sizeof(GLbyte);
                break;
    
            case GL_UNSIGNED_BYTE:
                coordTypeSize = sizeof(GLubyte);
                break;
    
            case GL_SHORT:
                coordTypeSize = sizeof(GLshort);
                break;
    
            case GL_UNSIGNED_SHORT:
                coordTypeSize = sizeof(GLushort);
                break;
    
            case GL_FLOAT:
                coordTypeSize = sizeof(GLfloat);
                break;
    
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid coordinate type."));
                return false;
        }
    
        angle::CheckedNumeric<std::uint32_t> checkedSize(numCommands);
        checkedSize += (coordTypeSize * numCoords);
        if (!checkedSize.IsValid())
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Coord size overflow."));
            return false;
        }
    
        // early return skips command data validation when it doesn't exist.
        if (!commands)
            return true;
    
        GLsizei expectedNumCoords = 0;
        for (GLsizei i = 0; i < numCommands; ++i)
        {
            switch (commands[i])
            {
                case GL_CLOSE_PATH_CHROMIUM:  // no coordinates.
                    break;
                case GL_MOVE_TO_CHROMIUM:
                case GL_LINE_TO_CHROMIUM:
                    expectedNumCoords += 2;
                    break;
                case GL_QUADRATIC_CURVE_TO_CHROMIUM:
                    expectedNumCoords += 4;
                    break;
                case GL_CUBIC_CURVE_TO_CHROMIUM:
                    expectedNumCoords += 6;
                    break;
                case GL_CONIC_CURVE_TO_CHROMIUM:
                    expectedNumCoords += 5;
                    break;
                default:
                    context->handleError(Error(GL_INVALID_ENUM, "Invalid command."));
                    return false;
            }
        }
        if (expectedNumCoords != numCoords)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid number of coordinates."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateSetPathParameter(Context *context, GLuint path, GLenum pname, GLfloat value)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        if (!context->hasPath(path))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such path object."));
            return false;
        }
    
        switch (pname)
        {
            case GL_PATH_STROKE_WIDTH_CHROMIUM:
                if (value < 0.0f)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "Invalid stroke width."));
                    return false;
                }
                break;
            case GL_PATH_END_CAPS_CHROMIUM:
                switch (static_cast<GLenum>(value))
                {
                    case GL_FLAT_CHROMIUM:
                    case GL_SQUARE_CHROMIUM:
                    case GL_ROUND_CHROMIUM:
                        break;
                    default:
                        context->handleError(Error(GL_INVALID_ENUM, "Invalid end caps."));
                        return false;
                }
                break;
            case GL_PATH_JOIN_STYLE_CHROMIUM:
                switch (static_cast<GLenum>(value))
                {
                    case GL_MITER_REVERT_CHROMIUM:
                    case GL_BEVEL_CHROMIUM:
                    case GL_ROUND_CHROMIUM:
                        break;
                    default:
                        context->handleError(Error(GL_INVALID_ENUM, "Invalid join style."));
                        return false;
                }
            case GL_PATH_MITER_LIMIT_CHROMIUM:
                if (value < 0.0f)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "Invalid miter limit."));
                    return false;
                }
                break;
    
            case GL_PATH_STROKE_BOUND_CHROMIUM:
                // no errors, only clamping.
                break;
    
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid path parameter."));
                return false;
        }
        return true;
    }
    
    bool ValidateGetPathParameter(Context *context, GLuint path, GLenum pname, GLfloat *value)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
    
        if (!context->hasPath(path))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such path object."));
            return false;
        }
        if (!value)
        {
            context->handleError(Error(GL_INVALID_VALUE, "No value array."));
            return false;
        }
    
        switch (pname)
        {
            case GL_PATH_STROKE_WIDTH_CHROMIUM:
            case GL_PATH_END_CAPS_CHROMIUM:
            case GL_PATH_JOIN_STYLE_CHROMIUM:
            case GL_PATH_MITER_LIMIT_CHROMIUM:
            case GL_PATH_STROKE_BOUND_CHROMIUM:
                break;
    
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid path parameter."));
                return false;
        }
    
        return true;
    }
    
    bool ValidatePathStencilFunc(Context *context, GLenum func, GLint ref, GLuint mask)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
    
        switch (func)
        {
            case GL_NEVER:
            case GL_ALWAYS:
            case GL_LESS:
            case GL_LEQUAL:
            case GL_EQUAL:
            case GL_GEQUAL:
            case GL_GREATER:
            case GL_NOTEQUAL:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid stencil function."));
                return false;
        }
    
        return true;
    }
    
    // Note that the spec specifies that for the path drawing commands
    // if the path object is not an existing path object the command
    // does nothing and no error is generated.
    // However if the path object exists but has not been specified any
    // commands then an error is generated.
    
    bool ValidateStencilFillPath(Context *context, GLuint path, GLenum fillMode, GLuint mask)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        if (context->hasPath(path) && !context->hasPathData(path))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such path object."));
            return false;
        }
    
        switch (fillMode)
        {
            case GL_COUNT_UP_CHROMIUM:
            case GL_COUNT_DOWN_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid fill mode."));
                return false;
        }
    
        if (!isPow2(mask + 1))
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid stencil bit mask."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateStencilStrokePath(Context *context, GLuint path, GLint reference, GLuint mask)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        if (context->hasPath(path) && !context->hasPathData(path))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such path or path has no data."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateCoverPath(Context *context, GLuint path, GLenum coverMode)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        if (context->hasPath(path) && !context->hasPathData(path))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such path object."));
            return false;
        }
    
        switch (coverMode)
        {
            case GL_CONVEX_HULL_CHROMIUM:
            case GL_BOUNDING_BOX_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid cover mode."));
                return false;
        }
        return true;
    }
    
    bool ValidateStencilThenCoverFillPath(Context *context,
                                          GLuint path,
                                          GLenum fillMode,
                                          GLuint mask,
                                          GLenum coverMode)
    {
        return ValidateStencilFillPath(context, path, fillMode, mask) &&
               ValidateCoverPath(context, path, coverMode);
    }
    
    bool ValidateStencilThenCoverStrokePath(Context *context,
                                            GLuint path,
                                            GLint reference,
                                            GLuint mask,
                                            GLenum coverMode)
    {
        return ValidateStencilStrokePath(context, path, reference, mask) &&
               ValidateCoverPath(context, path, coverMode);
    }
    
    bool ValidateIsPath(Context *context)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
        return true;
    }
    
    bool ValidateCoverFillPathInstanced(Context *context,
                                        GLsizei numPaths,
                                        GLenum pathNameType,
                                        const void *paths,
                                        GLuint pathBase,
                                        GLenum coverMode,
                                        GLenum transformType,
                                        const GLfloat *transformValues)
    {
        if (!ValidateInstancedPathParameters(context, numPaths, pathNameType, paths, pathBase,
                                             transformType, transformValues))
            return false;
    
        switch (coverMode)
        {
            case GL_CONVEX_HULL_CHROMIUM:
            case GL_BOUNDING_BOX_CHROMIUM:
            case GL_BOUNDING_BOX_OF_BOUNDING_BOXES_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid cover mode."));
                return false;
        }
    
        return true;
    }
    
    bool ValidateCoverStrokePathInstanced(Context *context,
                                          GLsizei numPaths,
                                          GLenum pathNameType,
                                          const void *paths,
                                          GLuint pathBase,
                                          GLenum coverMode,
                                          GLenum transformType,
                                          const GLfloat *transformValues)
    {
        if (!ValidateInstancedPathParameters(context, numPaths, pathNameType, paths, pathBase,
                                             transformType, transformValues))
            return false;
    
        switch (coverMode)
        {
            case GL_CONVEX_HULL_CHROMIUM:
            case GL_BOUNDING_BOX_CHROMIUM:
            case GL_BOUNDING_BOX_OF_BOUNDING_BOXES_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid cover mode."));
                return false;
        }
    
        return true;
    }
    
    bool ValidateStencilFillPathInstanced(Context *context,
                                          GLsizei numPaths,
                                          GLenum pathNameType,
                                          const void *paths,
                                          GLuint pathBase,
                                          GLenum fillMode,
                                          GLuint mask,
                                          GLenum transformType,
                                          const GLfloat *transformValues)
    {
    
        if (!ValidateInstancedPathParameters(context, numPaths, pathNameType, paths, pathBase,
                                             transformType, transformValues))
            return false;
    
        switch (fillMode)
        {
            case GL_COUNT_UP_CHROMIUM:
            case GL_COUNT_DOWN_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid fill mode."));
                return false;
        }
        if (!isPow2(mask + 1))
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid stencil bit mask."));
            return false;
        }
        return true;
    }
    
    bool ValidateStencilStrokePathInstanced(Context *context,
                                            GLsizei numPaths,
                                            GLenum pathNameType,
                                            const void *paths,
                                            GLuint pathBase,
                                            GLint reference,
                                            GLuint mask,
                                            GLenum transformType,
                                            const GLfloat *transformValues)
    {
        if (!ValidateInstancedPathParameters(context, numPaths, pathNameType, paths, pathBase,
                                             transformType, transformValues))
            return false;
    
        // no more validation here.
    
        return true;
    }
    
    bool ValidateStencilThenCoverFillPathInstanced(Context *context,
                                                   GLsizei numPaths,
                                                   GLenum pathNameType,
                                                   const void *paths,
                                                   GLuint pathBase,
                                                   GLenum fillMode,
                                                   GLuint mask,
                                                   GLenum coverMode,
                                                   GLenum transformType,
                                                   const GLfloat *transformValues)
    {
        if (!ValidateInstancedPathParameters(context, numPaths, pathNameType, paths, pathBase,
                                             transformType, transformValues))
            return false;
    
        switch (coverMode)
        {
            case GL_CONVEX_HULL_CHROMIUM:
            case GL_BOUNDING_BOX_CHROMIUM:
            case GL_BOUNDING_BOX_OF_BOUNDING_BOXES_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid cover mode."));
                return false;
        }
    
        switch (fillMode)
        {
            case GL_COUNT_UP_CHROMIUM:
            case GL_COUNT_DOWN_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid fill mode."));
                return false;
        }
        if (!isPow2(mask + 1))
        {
            context->handleError(Error(GL_INVALID_VALUE, "Invalid stencil bit mask."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateStencilThenCoverStrokePathInstanced(Context *context,
                                                     GLsizei numPaths,
                                                     GLenum pathNameType,
                                                     const void *paths,
                                                     GLuint pathBase,
                                                     GLint reference,
                                                     GLuint mask,
                                                     GLenum coverMode,
                                                     GLenum transformType,
                                                     const GLfloat *transformValues)
    {
        if (!ValidateInstancedPathParameters(context, numPaths, pathNameType, paths, pathBase,
                                             transformType, transformValues))
            return false;
    
        switch (coverMode)
        {
            case GL_CONVEX_HULL_CHROMIUM:
            case GL_BOUNDING_BOX_CHROMIUM:
            case GL_BOUNDING_BOX_OF_BOUNDING_BOXES_CHROMIUM:
                break;
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid cover mode."));
                return false;
        }
    
        return true;
    }
    
    bool ValidateBindFragmentInputLocation(Context *context,
                                           GLuint program,
                                           GLint location,
                                           const GLchar *name)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
    
        const GLint MaxLocation = context->getCaps().maxVaryingVectors * 4;
        if (location >= MaxLocation)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Location exceeds max varying."));
            return false;
        }
    
        const auto *programObject = context->getProgram(program);
        if (!programObject)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such program."));
            return false;
        }
    
        if (!name)
        {
            context->handleError(Error(GL_INVALID_VALUE, "No name given."));
            return false;
        }
    
        if (angle::BeginsWith(name, "gl_"))
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Cannot bind a built-in variable."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateProgramPathFragmentInputGen(Context *context,
                                             GLuint program,
                                             GLint location,
                                             GLenum genMode,
                                             GLint components,
                                             const GLfloat *coeffs)
    {
        if (!context->getExtensions().pathRendering)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_path_rendering is not available."));
            return false;
        }
    
        const auto *programObject = context->getProgram(program);
        if (!programObject || programObject->isFlaggedForDeletion())
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such program."));
            return false;
        }
    
        if (!programObject->isLinked())
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Program is not linked."));
            return false;
        }
    
        switch (genMode)
        {
            case GL_NONE:
                if (components != 0)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "Invalid components."));
                    return false;
                }
                break;
    
            case GL_OBJECT_LINEAR_CHROMIUM:
            case GL_EYE_LINEAR_CHROMIUM:
            case GL_CONSTANT_CHROMIUM:
                if (components < 1 || components > 4)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "Invalid components."));
                    return false;
                }
                if (!coeffs)
                {
                    context->handleError(Error(GL_INVALID_VALUE, "No coefficients array given."));
                    return false;
                }
                break;
    
            default:
                context->handleError(Error(GL_INVALID_ENUM, "Invalid gen mode."));
                return false;
        }
    
        // If the location is -1 then the command is silently ignored
        // and no further validation is needed.
        if (location == -1)
            return true;
    
        const auto &binding = programObject->getFragmentInputBindingInfo(location);
    
        if (!binding.valid)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "No such binding."));
            return false;
        }
    
        if (binding.type != GL_NONE)
        {
            GLint expectedComponents = 0;
            switch (binding.type)
            {
                case GL_FLOAT:
                    expectedComponents = 1;
                    break;
                case GL_FLOAT_VEC2:
                    expectedComponents = 2;
                    break;
                case GL_FLOAT_VEC3:
                    expectedComponents = 3;
                    break;
                case GL_FLOAT_VEC4:
                    expectedComponents = 4;
                    break;
                default:
                    context->handleError(Error(GL_INVALID_OPERATION,
                        "Fragment input type is not a floating point scalar or vector."));
                    return false;
            }
            if (expectedComponents != components && genMode != GL_NONE)
            {
                context->handleError(Error(GL_INVALID_OPERATION, "Unexpected number of components"));
                return false;
            }
        }
        return true;
    }
    
    bool ValidateCopyTextureCHROMIUM(Context *context,
                                     GLuint sourceId,
                                     GLuint destId,
                                     GLint internalFormat,
                                     GLenum destType,
                                     GLboolean unpackFlipY,
                                     GLboolean unpackPremultiplyAlpha,
                                     GLboolean unpackUnmultiplyAlpha)
    {
        if (!context->getExtensions().copyTexture)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_copy_texture extension not available."));
            return false;
        }
    
        const gl::Texture *source = context->getTexture(sourceId);
        if (source == nullptr)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Source texture is not a valid texture object."));
            return false;
        }
    
        if (!IsValidCopyTextureSourceTarget(context, source->getTarget()))
        {
            context->handleError(Error(GL_INVALID_VALUE, "Source texture a valid texture type."));
            return false;
        }
    
        GLenum sourceTarget = source->getTarget();
        ASSERT(sourceTarget != GL_TEXTURE_CUBE_MAP);
        if (source->getWidth(sourceTarget, 0) == 0 || source->getHeight(sourceTarget, 0) == 0)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Level 0 of the source texture must be defined."));
            return false;
        }
    
        const gl::Format &sourceFormat = source->getFormat(sourceTarget, 0);
        if (!IsValidCopyTextureFormat(context, sourceFormat.format))
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "Source texture internal format is invalid."));
            return false;
        }
    
        const gl::Texture *dest = context->getTexture(destId);
        if (dest == nullptr)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Destination texture is not a valid texture object."));
            return false;
        }
    
        if (!IsValidCopyTextureDestinationTarget(context, dest->getTarget()))
        {
            context->handleError(Error(GL_INVALID_VALUE, "Destination texture a valid texture type."));
            return false;
        }
    
        if (!IsValidCopyTextureDestinationFormatType(context, internalFormat, destType))
        {
            context->handleError(
                Error(GL_INVALID_OPERATION,
                      "Destination internal format and type combination is not valid."));
            return false;
        }
    
        if (dest->getImmutableFormat())
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Destination texture is immutable."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateCopySubTextureCHROMIUM(Context *context,
                                        GLuint sourceId,
                                        GLuint destId,
                                        GLint xoffset,
                                        GLint yoffset,
                                        GLint x,
                                        GLint y,
                                        GLsizei width,
                                        GLsizei height,
                                        GLboolean unpackFlipY,
                                        GLboolean unpackPremultiplyAlpha,
                                        GLboolean unpackUnmultiplyAlpha)
    {
        if (!context->getExtensions().copyTexture)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_CHROMIUM_copy_texture extension not available."));
            return false;
        }
    
        const gl::Texture *source = context->getTexture(sourceId);
        if (source == nullptr)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Source texture is not a valid texture object."));
            return false;
        }
    
        if (!IsValidCopyTextureSourceTarget(context, source->getTarget()))
        {
            context->handleError(Error(GL_INVALID_VALUE, "Source texture a valid texture type."));
            return false;
        }
    
        GLenum sourceTarget = source->getTarget();
        ASSERT(sourceTarget != GL_TEXTURE_CUBE_MAP);
        if (source->getWidth(sourceTarget, 0) == 0 || source->getHeight(sourceTarget, 0) == 0)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Level 0 of the source texture must be defined."));
            return false;
        }
    
        if (x < 0 || y < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "x and y cannot be negative."));
            return false;
        }
    
        if (width < 0 || height < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "width and height cannot be negative."));
            return false;
        }
    
        if (static_cast<size_t>(x + width) > source->getWidth(sourceTarget, 0) ||
            static_cast<size_t>(y + height) > source->getHeight(sourceTarget, 0))
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Source texture not large enough to copy from."));
            return false;
        }
    
        const gl::Format &sourceFormat = source->getFormat(sourceTarget, 0);
        if (!IsValidCopyTextureFormat(context, sourceFormat.format))
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "Source texture internal format is invalid."));
            return false;
        }
    
        const gl::Texture *dest = context->getTexture(destId);
        if (dest == nullptr)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Destination texture is not a valid texture object."));
            return false;
        }
    
        if (!IsValidCopyTextureDestinationTarget(context, dest->getTarget()))
        {
            context->handleError(Error(GL_INVALID_VALUE, "Destination texture a valid texture type."));
            return false;
        }
    
        GLenum destTarget = dest->getTarget();
        ASSERT(destTarget != GL_TEXTURE_CUBE_MAP);
        if (dest->getWidth(sourceTarget, 0) == 0 || dest->getHeight(sourceTarget, 0) == 0)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Level 0 of the destination texture must be defined."));
            return false;
        }
    
        const gl::Format &destFormat = dest->getFormat(destTarget, 0);
        if (!IsValidCopyTextureDestinationFormatType(context, destFormat.format, destFormat.type))
        {
            context->handleError(
                Error(GL_INVALID_OPERATION,
                      "Destination internal format and type combination is not valid."));
            return false;
        }
    
        if (xoffset < 0 || yoffset < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "xoffset and yoffset cannot be negative."));
            return false;
        }
    
        if (static_cast<size_t>(xoffset + width) > dest->getWidth(destTarget, 0) ||
            static_cast<size_t>(yoffset + height) > dest->getHeight(destTarget, 0))
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Destination texture not large enough to copy to."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateCompressedCopyTextureCHROMIUM(Context *context, GLuint sourceId, GLuint destId)
    {
        if (!context->getExtensions().copyCompressedTexture)
        {
            context->handleError(Error(GL_INVALID_OPERATION,
                                       "GL_CHROMIUM_copy_compressed_texture extension not available."));
            return false;
        }
    
        const gl::Texture *source = context->getTexture(sourceId);
        if (source == nullptr)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Source texture is not a valid texture object."));
            return false;
        }
    
        if (source->getTarget() != GL_TEXTURE_2D)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Source texture must be of type GL_TEXTURE_2D."));
            return false;
        }
    
        if (source->getWidth(GL_TEXTURE_2D, 0) == 0 || source->getHeight(GL_TEXTURE_2D, 0) == 0)
        {
            context->handleError(Error(GL_INVALID_VALUE, "Source texture must level 0 defined."));
            return false;
        }
    
        const gl::Format &sourceFormat = source->getFormat(GL_TEXTURE_2D, 0);
        if (!sourceFormat.info->compressed)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "Source texture must have a compressed internal format."));
            return false;
        }
    
        const gl::Texture *dest = context->getTexture(destId);
        if (dest == nullptr)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Destination texture is not a valid texture object."));
            return false;
        }
    
        if (dest->getTarget() != GL_TEXTURE_2D)
        {
            context->handleError(
                Error(GL_INVALID_VALUE, "Destination texture must be of type GL_TEXTURE_2D."));
            return false;
        }
    
        if (dest->getImmutableFormat())
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Destination cannot be immutable."));
            return false;
        }
    
        return true;
    }
    
    bool ValidateCreateShader(Context *context, GLenum type)
    {
        switch (type)
        {
            case GL_VERTEX_SHADER:
            case GL_FRAGMENT_SHADER:
                break;
            case GL_COMPUTE_SHADER:
                if (context->getGLVersion().isES31())
                {
                    break;
                }
            default:
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
        }
    
        return true;
    }
    
    bool ValidateBufferData(ValidationContext *context,
                            GLenum target,
                            GLsizeiptr size,
                            const GLvoid *data,
                            GLenum usage)
    {
        if (size < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        switch (usage)
        {
            case GL_STREAM_DRAW:
            case GL_STATIC_DRAW:
            case GL_DYNAMIC_DRAW:
                break;
    
            case GL_STREAM_READ:
            case GL_STREAM_COPY:
            case GL_STATIC_READ:
            case GL_STATIC_COPY:
            case GL_DYNAMIC_READ:
            case GL_DYNAMIC_COPY:
                if (context->getClientMajorVersion() < 3)
                {
                    context->handleError(Error(GL_INVALID_ENUM));
                    return false;
                }
                break;
    
            default:
                context->handleError(Error(GL_INVALID_ENUM));
                return false;
        }
    
        if (!ValidBufferTarget(context, target))
        {
            context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        Buffer *buffer = context->getGLState().getTargetBuffer(target);
    
        if (!buffer)
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        return true;
    }
    
    bool ValidateBufferSubData(ValidationContext *context,
                               GLenum target,
                               GLintptr offset,
                               GLsizeiptr size,
                               const GLvoid *data)
    {
        if (size < 0 || offset < 0)
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        if (!ValidBufferTarget(context, target))
        {
            context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        Buffer *buffer = context->getGLState().getTargetBuffer(target);
    
        if (!buffer)
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        if (buffer->isMapped())
        {
            context->handleError(Error(GL_INVALID_OPERATION));
            return false;
        }
    
        // Check for possible overflow of size + offset
        angle::CheckedNumeric<size_t> checkedSize(size);
        checkedSize += offset;
        if (!checkedSize.IsValid())
        {
            context->handleError(Error(GL_OUT_OF_MEMORY));
            return false;
        }
    
        if (size + offset > buffer->getSize())
        {
            context->handleError(Error(GL_INVALID_VALUE));
            return false;
        }
    
        return true;
    }
    
    bool ValidateEnableExtensionANGLE(ValidationContext *context, const GLchar *name)
    {
        if (!context->getExtensions().webglCompatibility)
        {
            context->handleError(
                Error(GL_INVALID_OPERATION, "GL_ANGLE_webgl_compatibility is not available."));
            return false;
        }
    
        const ExtensionInfoMap &extensionInfos = GetExtensionInfoMap();
        auto extension                         = extensionInfos.find(name);
        if (extension == extensionInfos.end() || !extension->second.Enableable)
        {
            context->handleError(Error(GL_INVALID_OPERATION, "Extension %s is not enableable.", name));
            return false;
        }
    
        return true;
    }
    
    bool ValidateActiveTexture(ValidationContext *context, GLenum texture)
    {
        if (texture < GL_TEXTURE0 ||
            texture > GL_TEXTURE0 + context->getCaps().maxCombinedTextureImageUnits - 1)
        {
            context->handleError(Error(GL_INVALID_ENUM));
            return false;
        }
    
        return true;
    }
    
    bool ValidateAttachShader(ValidationContext *context, GLuint program, GLuint shader)
    {
        Program *programObject = GetValidProgram(context, program);
        if (!programObject)
        {
            return false;
        }
    
        Shader *shaderObject = GetValidShader(context, shader);
        if (!shaderObject)
        {
            return false;
        }
    
        switch (shaderObject->getType())
        {
            case GL_VERTEX_SHADER:
            {
                if (programObject->getAttachedVertexShader())
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
            }
            case GL_FRAGMENT_SHADER:
            {
                if (programObject->getAttachedFragmentShader())
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
            }
            case GL_COMPUTE_SHADER:
            {
                if (programObject->getAttachedComputeShader())
                {
                    context->handleError(Error(GL_INVALID_OPERATION));
                    return false;
                }
                break;
            }
            default:
                UNREACHABLE();
                break;
        }
    
        return true;
    }
    
    }  // namespace gl