kc3-lang/angle/src/libGLESv2/utilities.cpp

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• Author : shannon.woods@transgaming.com
  Date : 2013-02-28 23:16:20
  Hash : bdf2d80f
  Message : Add precompiled header support for the libGLESv2 project. TRAC #22518 Signed-off-by: Geoff Lang Signed-off-by: Shannon Woods Author: Jamie Madill git-svn-id: https://angleproject.googlecode.com/svn/branches/dx11proto@1938 736b8ea6-26fd-11df-bfd4-992fa37f6226

• src/libGLESv2/utilities.cpp

• #include "precompiled.h"
  //
  // Copyright (c) 2002-2013 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.
  //
  
  // utilities.cpp: Conversion functions and other utility routines.
  
  #include "libGLESv2/utilities.h"
  #include "libGLESv2/mathutil.h"
  
  namespace gl
  {
  
  int UniformComponentCount(GLenum type)
  {
      switch (type)
      {
        case GL_BOOL:
        case GL_FLOAT:
        case GL_INT:
        case GL_SAMPLER_2D:
        case GL_SAMPLER_CUBE:
            return 1;
        case GL_BOOL_VEC2:
        case GL_FLOAT_VEC2:
        case GL_INT_VEC2:
            return 2;
        case GL_INT_VEC3:
        case GL_FLOAT_VEC3:
        case GL_BOOL_VEC3:
            return 3;
        case GL_BOOL_VEC4:
        case GL_FLOAT_VEC4:
        case GL_INT_VEC4:
        case GL_FLOAT_MAT2:
            return 4;
        case GL_FLOAT_MAT3:
            return 9;
        case GL_FLOAT_MAT4:
            return 16;
        default:
            UNREACHABLE();
      }
  
      return 0;
  }
  
  GLenum UniformComponentType(GLenum type)
  {
      switch(type)
      {
        case GL_BOOL:
        case GL_BOOL_VEC2:
        case GL_BOOL_VEC3:
        case GL_BOOL_VEC4:
            return GL_BOOL;
        case GL_FLOAT:
        case GL_FLOAT_VEC2:
        case GL_FLOAT_VEC3:
        case GL_FLOAT_VEC4:
        case GL_FLOAT_MAT2:
        case GL_FLOAT_MAT3:
        case GL_FLOAT_MAT4:
            return GL_FLOAT;
        case GL_INT:
        case GL_SAMPLER_2D:
        case GL_SAMPLER_CUBE:
        case GL_INT_VEC2:
        case GL_INT_VEC3:
        case GL_INT_VEC4:
            return GL_INT;
        default:
            UNREACHABLE();
      }
  
      return GL_NONE;
  }
  
  size_t UniformComponentSize(GLenum type)
  {
      switch(type)
      {
        case GL_BOOL:  return sizeof(GLint);
        case GL_FLOAT: return sizeof(GLfloat);
        case GL_INT:   return sizeof(GLint);
        default:       UNREACHABLE();
      }
  
      return 0;
  }
  
  size_t UniformInternalSize(GLenum type)
  {
      // Expanded to 4-element vectors
      return UniformComponentSize(UniformComponentType(type)) * VariableRowCount(type) * 4;
  }
  
  size_t UniformExternalSize(GLenum type)
  {
      return UniformComponentSize(UniformComponentType(type)) * UniformComponentCount(type);
  }
  
  int VariableRowCount(GLenum type)
  {
      switch (type)
      {
        case GL_NONE:
          return 0;
        case GL_BOOL:
        case GL_FLOAT:
        case GL_INT:
        case GL_BOOL_VEC2:
        case GL_FLOAT_VEC2:
        case GL_INT_VEC2:
        case GL_INT_VEC3:
        case GL_FLOAT_VEC3:
        case GL_BOOL_VEC3:
        case GL_BOOL_VEC4:
        case GL_FLOAT_VEC4:
        case GL_INT_VEC4:
        case GL_SAMPLER_2D:
        case GL_SAMPLER_CUBE:
          return 1;
        case GL_FLOAT_MAT2:
          return 2;
        case GL_FLOAT_MAT3:
          return 3;
        case GL_FLOAT_MAT4:
          return 4;
        default:
          UNREACHABLE();
      }
  
      return 0;
  }
  
  int VariableColumnCount(GLenum type)
  {
      switch (type)
      {
        case GL_NONE:
          return 0;
        case GL_BOOL:
        case GL_FLOAT:
        case GL_INT:
        case GL_SAMPLER_2D:
        case GL_SAMPLER_CUBE:
          return 1;
        case GL_BOOL_VEC2:
        case GL_FLOAT_VEC2:
        case GL_INT_VEC2:
        case GL_FLOAT_MAT2:
          return 2;
        case GL_INT_VEC3:
        case GL_FLOAT_VEC3:
        case GL_BOOL_VEC3:
        case GL_FLOAT_MAT3:
          return 3;
        case GL_BOOL_VEC4:
        case GL_FLOAT_VEC4:
        case GL_INT_VEC4:
        case GL_FLOAT_MAT4:
          return 4;
        default:
          UNREACHABLE();
      }
  
      return 0;
  }
  
  int AllocateFirstFreeBits(unsigned int *bits, unsigned int allocationSize, unsigned int bitsSize)
  {
      ASSERT(allocationSize <= bitsSize);
  
      unsigned int mask = std::numeric_limits<unsigned int>::max() >> (std::numeric_limits<unsigned int>::digits - allocationSize);
  
      for (unsigned int i = 0; i < bitsSize - allocationSize + 1; i++)
      {
          if ((*bits & mask) == 0)
          {
              *bits |= mask;
              return i;
          }
  
          mask <<= 1;
      }
  
      return -1;
  }
  
  GLsizei ComputePitch(GLsizei width, GLint internalformat, GLint alignment)
  {
      ASSERT(alignment > 0 && isPow2(alignment));
  
      GLsizei rawPitch = ComputePixelSize(internalformat) * width;
      return (rawPitch + alignment - 1) & ~(alignment - 1);
  }
  
  GLsizei ComputeCompressedPitch(GLsizei width, GLenum internalformat)
  {
      return ComputeCompressedSize(width, 1, internalformat);
  }
  
  GLsizei ComputeCompressedSize(GLsizei width, GLsizei height, GLenum internalformat)
  {
      switch (internalformat)
      {
        case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
        case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
          return 8 * ((width + 3) / 4) * ((height + 3) / 4);
        case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
        case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
          return 16 * ((width + 3) / 4) * ((height + 3) / 4);
        default:
          return 0;
      }
  }
  
  bool IsCompressed(GLenum format)
  {
      if(format == GL_COMPRESSED_RGB_S3TC_DXT1_EXT ||
         format == GL_COMPRESSED_RGBA_S3TC_DXT1_EXT ||
         format == GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE ||
         format == GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE)
      {
          return true;
      }
      else
      {
          return false;
      }
  }
  
  bool IsDepthTexture(GLenum format)
  {
      if (format == GL_DEPTH_COMPONENT ||
          format == GL_DEPTH_STENCIL_OES ||
          format == GL_DEPTH_COMPONENT16 ||
          format == GL_DEPTH_COMPONENT32_OES ||
          format == GL_DEPTH24_STENCIL8_OES)
      {
          return true;
      }
  
      return false;
  }
  
  bool IsStencilTexture(GLenum format)
  {
      if (format == GL_DEPTH_STENCIL_OES ||
          format == GL_DEPTH24_STENCIL8_OES)
      {
          return true;
      }
  
      return false;
  }
  
  void MakeValidSize(bool isImage, bool isCompressed, GLsizei *requestWidth, GLsizei *requestHeight, int *levelOffset)
  {
      int upsampleCount = 0;
  
      if (isCompressed)
      {
          // Don't expand the size of full textures that are at least 4x4
          // already.
          if (isImage || *requestWidth < 4 || *requestHeight < 4)
          {
              while (*requestWidth % 4 != 0 || *requestHeight % 4 != 0)
              {
                  *requestWidth <<= 1;
                  *requestHeight <<= 1;
                  upsampleCount++;
              }
          }
      }
      *levelOffset = upsampleCount;
  }
  
  // Returns the size, in bytes, of a single texel in an Image
  int ComputePixelSize(GLint internalformat)
  {
      switch (internalformat)
      {
        case GL_ALPHA8_EXT:                       return sizeof(unsigned char);
        case GL_LUMINANCE8_EXT:                   return sizeof(unsigned char);
        case GL_ALPHA32F_EXT:                     return sizeof(float);
        case GL_LUMINANCE32F_EXT:                 return sizeof(float);
        case GL_ALPHA16F_EXT:                     return sizeof(unsigned short);
        case GL_LUMINANCE16F_EXT:                 return sizeof(unsigned short);
        case GL_LUMINANCE8_ALPHA8_EXT:            return sizeof(unsigned char) * 2;
        case GL_LUMINANCE_ALPHA32F_EXT:           return sizeof(float) * 2;
        case GL_LUMINANCE_ALPHA16F_EXT:           return sizeof(unsigned short) * 2;
        case GL_RGB8_OES:                         return sizeof(unsigned char) * 3;
        case GL_RGB565:                           return sizeof(unsigned short);
        case GL_RGB32F_EXT:                       return sizeof(float) * 3;
        case GL_RGB16F_EXT:                       return sizeof(unsigned short) * 3;
        case GL_RGBA8_OES:                        return sizeof(unsigned char) * 4;
        case GL_RGBA4:                            return sizeof(unsigned short);
        case GL_RGB5_A1:                          return sizeof(unsigned short);
        case GL_RGBA32F_EXT:                      return sizeof(float) * 4;
        case GL_RGBA16F_EXT:                      return sizeof(unsigned short) * 4;
        case GL_BGRA8_EXT:                        return sizeof(unsigned char) * 4;
        case GL_BGRA4_ANGLEX:                     return sizeof(unsigned short);
        case GL_BGR5_A1_ANGLEX:                   return sizeof(unsigned short);
        default: UNREACHABLE();
      }
  
      return 0;
  }
  
  bool IsCubemapTextureTarget(GLenum target)
  {
      return (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X && target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z);
  }
  
  bool IsInternalTextureTarget(GLenum target)
  {
      return target == GL_TEXTURE_2D || IsCubemapTextureTarget(target);
  }
  
  GLint ConvertSizedInternalFormat(GLenum format, GLenum type)
  {
      switch (format)
      {
        case GL_ALPHA:
          switch (type)
          {
            case GL_UNSIGNED_BYTE:    return GL_ALPHA8_EXT;
            case GL_FLOAT:            return GL_ALPHA32F_EXT;
            case GL_HALF_FLOAT_OES:   return GL_ALPHA16F_EXT;
            default:                  UNIMPLEMENTED();
          }
          break;
        case GL_LUMINANCE:
          switch (type)
          {
            case GL_UNSIGNED_BYTE:    return GL_LUMINANCE8_EXT;
            case GL_FLOAT:            return GL_LUMINANCE32F_EXT;
            case GL_HALF_FLOAT_OES:   return GL_LUMINANCE16F_EXT;
            default:                  UNIMPLEMENTED();
          }
          break;
        case GL_LUMINANCE_ALPHA:
          switch (type)
          {
            case GL_UNSIGNED_BYTE:    return GL_LUMINANCE8_ALPHA8_EXT;
            case GL_FLOAT:            return GL_LUMINANCE_ALPHA32F_EXT;
            case GL_HALF_FLOAT_OES:   return GL_LUMINANCE_ALPHA16F_EXT;
            default:                  UNIMPLEMENTED();
          }
          break;
        case GL_RGB:
          switch (type)
          {
            case GL_UNSIGNED_BYTE:            return GL_RGB8_OES;
            case GL_UNSIGNED_SHORT_5_6_5:     return GL_RGB565;
            case GL_FLOAT:                    return GL_RGB32F_EXT;
            case GL_HALF_FLOAT_OES:           return GL_RGB16F_EXT;
            default:                          UNIMPLEMENTED();
          }
          break;
        case GL_RGBA:
          switch (type)
          {
            case GL_UNSIGNED_BYTE:            return GL_RGBA8_OES;
            case GL_UNSIGNED_SHORT_4_4_4_4:   return GL_RGBA4;
            case GL_UNSIGNED_SHORT_5_5_5_1:   return GL_RGB5_A1;
            case GL_FLOAT:                    return GL_RGBA32F_EXT;
            case GL_HALF_FLOAT_OES:           return GL_RGBA16F_EXT;
              break;
            default:                          UNIMPLEMENTED();
          }
          break;
        case GL_BGRA_EXT:
          switch (type)
          {
            case GL_UNSIGNED_BYTE:                    return GL_BGRA8_EXT;
            case GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT:   return GL_BGRA4_ANGLEX;
            case GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT:   return GL_BGR5_A1_ANGLEX;
            default:                                  UNIMPLEMENTED();
          }
          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:
          return format;
        case GL_DEPTH_COMPONENT:
          switch (type)
          {
            case GL_UNSIGNED_SHORT:           return GL_DEPTH_COMPONENT16;
            case GL_UNSIGNED_INT:             return GL_DEPTH_COMPONENT32_OES;
            default:                          UNIMPLEMENTED();
          }
          break;
        case GL_DEPTH_STENCIL_OES:
          switch (type)
          {
            case GL_UNSIGNED_INT_24_8_OES:    return GL_DEPTH24_STENCIL8_OES;
            default:                          UNIMPLEMENTED();
          }
          break;
        default:
          UNIMPLEMENTED();
      }
  
      return GL_NONE;
  }
  
  GLenum ExtractFormat(GLenum internalformat)
  {
      switch (internalformat)
      {
        case GL_RGB565:                          return GL_RGB;
        case GL_RGBA4:                           return GL_RGBA;
        case GL_RGB5_A1:                         return GL_RGBA;
        case GL_RGB8_OES:                        return GL_RGB;
        case GL_RGBA8_OES:                       return GL_RGBA;
        case GL_LUMINANCE8_ALPHA8_EXT:           return GL_LUMINANCE_ALPHA;
        case GL_LUMINANCE8_EXT:                  return GL_LUMINANCE;
        case GL_ALPHA8_EXT:                      return GL_ALPHA;
        case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:    return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
        case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:   return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
        case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE: return GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE;
        case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE: return GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE;
        case GL_RGBA32F_EXT:                     return GL_RGBA;
        case GL_RGB32F_EXT:                      return GL_RGB;
        case GL_ALPHA32F_EXT:                    return GL_ALPHA;
        case GL_LUMINANCE32F_EXT:                return GL_LUMINANCE;
        case GL_LUMINANCE_ALPHA32F_EXT:          return GL_LUMINANCE_ALPHA;
        case GL_RGBA16F_EXT:                     return GL_RGBA;
        case GL_RGB16F_EXT:                      return GL_RGB;
        case GL_ALPHA16F_EXT:                    return GL_ALPHA;
        case GL_LUMINANCE16F_EXT:                return GL_LUMINANCE;
        case GL_LUMINANCE_ALPHA16F_EXT:          return GL_LUMINANCE_ALPHA;
        case GL_BGRA8_EXT:                       return GL_BGRA_EXT;
        case GL_DEPTH_COMPONENT16:               return GL_DEPTH_COMPONENT;
        case GL_DEPTH_COMPONENT32_OES:           return GL_DEPTH_COMPONENT;
        case GL_DEPTH24_STENCIL8_OES:            return GL_DEPTH_STENCIL_OES;
        default:                                 return GL_NONE;   // Unsupported
      }
  }
  
  GLenum ExtractType(GLenum internalformat)
  {
      switch (internalformat)
      {
        case GL_RGB565:                          return GL_UNSIGNED_SHORT_5_6_5;
        case GL_RGBA4:                           return GL_UNSIGNED_SHORT_4_4_4_4;
        case GL_RGB5_A1:                         return GL_UNSIGNED_SHORT_5_5_5_1;
        case GL_RGB8_OES:                        return GL_UNSIGNED_BYTE;
        case GL_RGBA8_OES:                       return GL_UNSIGNED_BYTE;
        case GL_LUMINANCE8_ALPHA8_EXT:           return GL_UNSIGNED_BYTE;
        case GL_LUMINANCE8_EXT:                  return GL_UNSIGNED_BYTE;
        case GL_ALPHA8_EXT:                      return GL_UNSIGNED_BYTE;
        case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:    return GL_UNSIGNED_BYTE;
        case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:   return GL_UNSIGNED_BYTE;
        case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE: return GL_UNSIGNED_BYTE;
        case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE: return GL_UNSIGNED_BYTE;
        case GL_RGBA32F_EXT:                     return GL_FLOAT;
        case GL_RGB32F_EXT:                      return GL_FLOAT;
        case GL_ALPHA32F_EXT:                    return GL_FLOAT;
        case GL_LUMINANCE32F_EXT:                return GL_FLOAT;
        case GL_LUMINANCE_ALPHA32F_EXT:          return GL_FLOAT;
        case GL_RGBA16F_EXT:                     return GL_HALF_FLOAT_OES;
        case GL_RGB16F_EXT:                      return GL_HALF_FLOAT_OES;
        case GL_ALPHA16F_EXT:                    return GL_HALF_FLOAT_OES;
        case GL_LUMINANCE16F_EXT:                return GL_HALF_FLOAT_OES;
        case GL_LUMINANCE_ALPHA16F_EXT:          return GL_HALF_FLOAT_OES;
        case GL_BGRA8_EXT:                       return GL_UNSIGNED_BYTE;
        case GL_DEPTH_COMPONENT16:               return GL_UNSIGNED_SHORT;
        case GL_DEPTH_COMPONENT32_OES:           return GL_UNSIGNED_INT;
        case GL_DEPTH24_STENCIL8_OES:            return GL_UNSIGNED_INT_24_8_OES;
        default:                                 return GL_NONE;   // Unsupported
      }
  }
  
  bool IsColorRenderable(GLenum internalformat)
  {
      switch (internalformat)
      {
        case GL_RGBA4:
        case GL_RGB5_A1:
        case GL_RGB565:
        case GL_RGB8_OES:
        case GL_RGBA8_OES:
          return true;
        case GL_DEPTH_COMPONENT16:
        case GL_STENCIL_INDEX8:
        case GL_DEPTH24_STENCIL8_OES:
          return false;
        case GL_BGRA8_EXT:
            return true;
        default:
          UNIMPLEMENTED();
      }
  
      return false;
  }
  
  bool IsDepthRenderable(GLenum internalformat)
  {
      switch (internalformat)
      {
        case GL_DEPTH_COMPONENT16:
        case GL_DEPTH24_STENCIL8_OES:
          return true;
        case GL_STENCIL_INDEX8:
        case GL_RGBA4:
        case GL_RGB5_A1:
        case GL_RGB565:
        case GL_RGB8_OES:
        case GL_RGBA8_OES:
          return false;
        default:
          UNIMPLEMENTED();
      }
  
      return false;
  }
  
  bool IsStencilRenderable(GLenum internalformat)
  {
      switch (internalformat)
      {
        case GL_STENCIL_INDEX8:
        case GL_DEPTH24_STENCIL8_OES:
          return true;
        case GL_RGBA4:
        case GL_RGB5_A1:
        case GL_RGB565:
        case GL_RGB8_OES:
        case GL_RGBA8_OES:
        case GL_DEPTH_COMPONENT16:
          return false;
        default:
          UNIMPLEMENTED();
      }
  
      return false;
  }
  
  bool IsFloat32Format(GLint internalformat)
  {
      switch (internalformat)
      {
        case GL_RGBA32F_EXT:
        case GL_RGB32F_EXT:
        case GL_ALPHA32F_EXT:
        case GL_LUMINANCE32F_EXT:
        case GL_LUMINANCE_ALPHA32F_EXT:
          return true;
        default:
          return false;
      }
  }
  
  bool IsFloat16Format(GLint internalformat)
  {
      switch (internalformat)
      {
        case GL_RGBA16F_EXT:
        case GL_RGB16F_EXT:
        case GL_ALPHA16F_EXT:
        case GL_LUMINANCE16F_EXT:
        case GL_LUMINANCE_ALPHA16F_EXT:
          return true;
        default:
          return false;
      }
  }
  
  unsigned int GetAlphaSize(GLenum colorFormat)
  {
      switch (colorFormat)
      {
        case GL_RGBA16F_EXT:
          return 16;
        case GL_RGBA32F_EXT:
          return 32;
        case GL_RGBA4:
          return 4;
        case GL_RGBA8_OES:
        case GL_BGRA8_EXT:
          return 8;
        case GL_RGB5_A1:
          return 1;
        case GL_RGB8_OES:
        case GL_RGB565:
        case GL_RGB32F_EXT:
        case GL_RGB16F_EXT:
          return 0;
        default:
          return 0;
      }
  }
  
  unsigned int GetRedSize(GLenum colorFormat)
  {
      switch (colorFormat)
      {
        case GL_RGBA16F_EXT:
        case GL_RGB16F_EXT:
          return 16;
        case GL_RGBA32F_EXT:
        case GL_RGB32F_EXT:
          return 32;
        case GL_RGBA4:
          return 4;
        case GL_RGBA8_OES:
        case GL_BGRA8_EXT:
        case GL_RGB8_OES:
          return 8;
        case GL_RGB5_A1:
        case GL_RGB565:
          return 5;
        default:
          return 0;
      }
  }
  
  unsigned int GetGreenSize(GLenum colorFormat)
  {
      switch (colorFormat)
      {
        case GL_RGBA16F_EXT:
        case GL_RGB16F_EXT:
          return 16;
        case GL_RGBA32F_EXT:
        case GL_RGB32F_EXT:
          return 32;
        case GL_RGBA4:
          return 4;
        case GL_RGBA8_OES:
        case GL_BGRA8_EXT:
        case GL_RGB8_OES:
          return 8;
        case GL_RGB5_A1:
          return 5;
        case GL_RGB565:
          return 6;
        default:
          return 0;
      }
  }
  
  unsigned int GetBlueSize(GLenum colorFormat)
  {
      switch (colorFormat)
      {
        case GL_RGBA16F_EXT:
        case GL_RGB16F_EXT:
          return 16;
        case GL_RGBA32F_EXT:
        case GL_RGB32F_EXT:
          return 32;
        case GL_RGBA4:
          return 4;
        case GL_RGBA8_OES:
        case GL_BGRA8_EXT:
        case GL_RGB8_OES:
          return 8;
        case GL_RGB5_A1:
        case GL_RGB565:
          return 5;
        default:
          return 0;
      }
  }
  
  unsigned int GetDepthSize(GLenum depthFormat)
  {
      switch (depthFormat)
      {
        case GL_DEPTH_COMPONENT16:        return 16;
        case GL_DEPTH_COMPONENT32_OES:    return 32;
        case GL_DEPTH24_STENCIL8_OES:     return 24;
        default:                          return 0;
      }
  }
  
  unsigned int GetStencilSize(GLenum stencilFormat)
  {
      switch (stencilFormat)
      {
        case GL_DEPTH24_STENCIL8_OES:     return 8;
        default:                          return 0;
      }
  }
  
  bool IsTriangleMode(GLenum drawMode)
  {
      switch (drawMode)
      {
        case GL_TRIANGLES:
        case GL_TRIANGLE_FAN:
        case GL_TRIANGLE_STRIP:
          return true;
        case GL_POINTS:
        case GL_LINES:
        case GL_LINE_LOOP:
        case GL_LINE_STRIP:
          return false;
        default: UNREACHABLE();
      }
  
      return false;
  }
  
  }
  
  std::string getTempPath()
  {
      char path[MAX_PATH];
      DWORD pathLen = GetTempPathA(sizeof(path) / sizeof(path[0]), path);
      if (pathLen == 0)
      {
          UNREACHABLE();
          return std::string();
      }
  
      UINT unique = GetTempFileNameA(path, "sh", 0, path);
      if (unique == 0)
      {
          UNREACHABLE();
          return std::string();
      }
      
      return path;
  }
  
  void writeFile(const char* path, const void* content, size_t size)
  {
      FILE* file = fopen(path, "w");
      if (!file)
      {
          UNREACHABLE();
          return;
      }
  
      fwrite(content, sizeof(char), size, file);
      fclose(file);
  }