kc3-lang/angle/samples/sample_util/texture_utils.cpp

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• Hash : ee9a7df0
  Author :
  Date : 2023-01-30T18:25:27
  

  IWYU: usage of size_t requires include in texture_utils
  
  Bug: chromium:957519
  Change-Id: I69a1455c0c1570cffa5964b8a5e856643961e603
  Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4352889
  Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
  Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
  

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• samples/sample_util/texture_utils.cpp

• //
  // Copyright 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.
  //
  
  #include "texture_utils.h"
  #include <array>
  #include <cstddef>
  
  GLuint CreateSimpleTexture2D()
  {
      // Use tightly packed data
      glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  
      // Generate a texture object
      GLuint texture;
      glGenTextures(1, &texture);
  
      // Bind the texture object
      glBindTexture(GL_TEXTURE_2D, texture);
  
      // Load the texture: 2x2 Image, 3 bytes per pixel (R, G, B)
      const size_t width                 = 2;
      const size_t height                = 2;
      GLubyte pixels[width * height * 3] = {
          255, 0,   0,    // Red
          0,   255, 0,    // Green
          0,   0,   255,  // Blue
          255, 255, 0,    // Yellow
      };
      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, pixels);
  
      // Set the filtering mode
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  
      return texture;
  }
  
  GLuint CreateSimpleTextureCubemap()
  {
      // Generate a texture object
      GLuint texture;
      glGenTextures(1, &texture);
  
      // Bind the texture object
      glBindTexture(GL_TEXTURE_CUBE_MAP, texture);
  
      // Load the texture faces
      GLubyte pixels[6][3] = {// Face 0 - Red
                              {255, 0, 0},
                              // Face 1 - Green,
                              {0, 255, 0},
                              // Face 3 - Blue
                              {0, 0, 255},
                              // Face 4 - Yellow
                              {255, 255, 0},
                              // Face 5 - Purple
                              {255, 0, 255},
                              // Face 6 - White
                              {255, 255, 255}};
  
      for (size_t i = 0; i < 6; i++)
      {
          glTexImage2D(static_cast<GLenum>(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i), 0, GL_RGB, 1, 1, 0,
                       GL_RGB, GL_UNSIGNED_BYTE, &pixels[i]);
      }
  
      // Set the filtering mode
      glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
      glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  
      return texture;
  }
  
  GLuint CreateMipMappedTexture2D()
  {
      // Texture object handle
      const size_t width  = 256;
      const size_t height = 256;
      std::array<GLubyte, width * height * 3> pixels;
  
      const size_t checkerSize = 8;
      for (size_t y = 0; y < height; y++)
      {
          for (size_t x = 0; x < width; x++)
          {
              GLubyte rColor = 0;
              GLubyte bColor = 0;
  
              if ((x / checkerSize) % 2 == 0)
              {
                  rColor = 255 * ((y / checkerSize) % 2);
                  bColor = 255 * (1 - ((y / checkerSize) % 2));
              }
              else
              {
                  bColor = 255 * ((y / checkerSize) % 2);
                  rColor = 255 * (1 - ((y / checkerSize) % 2));
              }
  
              pixels[(y * height + x) * 3]     = rColor;
              pixels[(y * height + x) * 3 + 1] = 0;
              pixels[(y * height + x) * 3 + 2] = bColor;
          }
      }
  
      // Generate a texture object
      GLuint texture;
      glGenTextures(1, &texture);
  
      // Bind the texture object
      glBindTexture(GL_TEXTURE_2D, texture);
  
      // Load mipmap level 0
      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE,
                   pixels.data());
  
      // Generate mipmaps
      glGenerateMipmap(GL_TEXTURE_2D);
  
      // Set the filtering mode
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  
      return texture;
  }
  

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