kc3-lang/angle/samples/mip_map_2d/MipMap2D.cpp

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• Hash : 9d737966
  Author :
  Date : 2019-08-14T12:25:12
  

  Standardize copyright notices to project style
  
  For all "ANGLE Project" copyrights, standardize to the format specified
  by the style guide. Changes:
  - "Copyright (c)" and "Copyright(c)" changed to just "Copyright".
  - Removed the second half of date ranges ("Y1Y1-Y2Y2"->"Y1Y1").
  - Fixed a small number of files that had no copyright date using the
    initial commit year from the version control history.
  - Fixed one instance of copyright being "The ANGLE Project" rather than
    "The ANGLE Project Authors"
  
  These changes are applied both to the copyright of source file, and
  where applicable to copyright statements that are generated by
  templates.
  
  BUG=angleproject:3811
  
  Change-Id: I973dd65e4ef9deeba232d5be74c768256a0eb2e5
  Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1754397
  Commit-Queue: Jamie Madill <jmadill@chromium.org>
  Reviewed-by: Jamie Madill <jmadill@chromium.org>
  

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• samples/mip_map_2d/MipMap2D.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.
  //
  
  //            Based on MipMap2D.c from
  // Book:      OpenGL(R) ES 2.0 Programming Guide
  // Authors:   Aaftab Munshi, Dan Ginsburg, Dave Shreiner
  // ISBN-10:   0321502795
  // ISBN-13:   9780321502797
  // Publisher: Addison-Wesley Professional
  // URLs:      http://safari.informit.com/9780321563835
  //            http://www.opengles-book.com
  
  #include "SampleApplication.h"
  
  #include "texture_utils.h"
  #include "util/shader_utils.h"
  
  class MipMap2DSample : public SampleApplication
  {
    public:
      MipMap2DSample(int argc, char **argv) : SampleApplication("MipMap2D", argc, argv) {}
  
      bool initialize() override
      {
          constexpr char kVS[] = R"(uniform float u_offset;
  attribute vec4 a_position;
  attribute vec2 a_texCoord;
  varying vec2 v_texCoord;
  void main()
  {
      gl_Position = a_position;
      gl_Position.x += u_offset;
      v_texCoord = a_texCoord;
  })";
  
          constexpr char kFS[] = R"(precision mediump float;
  varying vec2 v_texCoord;
  uniform sampler2D s_texture;
  void main()
  {
      gl_FragColor = texture2D(s_texture, v_texCoord);
  })";
  
          mProgram = CompileProgram(kVS, kFS);
          if (!mProgram)
          {
              return false;
          }
  
          // Get the attribute locations
          mPositionLoc = glGetAttribLocation(mProgram, "a_position");
          mTexCoordLoc = glGetAttribLocation(mProgram, "a_texCoord");
  
          // Get the sampler location
          mSamplerLoc = glGetUniformLocation(mProgram, "s_texture");
  
          // Get the offset location
          mOffsetLoc = glGetUniformLocation(mProgram, "u_offset");
  
          // Load the texture
          mTextureID = CreateMipMappedTexture2D();
  
          // Check Anisotropy limits
          glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &mMaxAnisotropy);
  
          glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
  
          return true;
      }
  
      void destroy() override
      {
          glDeleteProgram(mProgram);
          glDeleteTextures(1, &mTextureID);
      }
  
      void draw() override
      {
          const GLfloat vertices[] = {
              -0.25f, 0.5f,  0.0f, 5.0f,  // Position 0
              0.0f,   0.0f,               // TexCoord 0
              -0.25f, -0.5f, 0.0f, 1.0f,  // Position 1
              0.0f,   1.0f,               // TexCoord 1
              0.25f,  -0.5f, 0.0f, 1.0f,  // Position 2
              1.0f,   1.0f,               // TexCoord 2
              0.25f,  0.5f,  0.0f, 5.0f,  // Position 3
              1.0f,   0.0f                // TexCoord 3
          };
          const GLushort indices[] = {0, 1, 2, 0, 2, 3};
  
          // Set the viewport
          glViewport(0, 0, getWindow()->getWidth(), getWindow()->getHeight());
  
          // Clear the color buffer
          glClear(GL_COLOR_BUFFER_BIT);
  
          // Use the program object
          glUseProgram(mProgram);
  
          // Load the vertex position
          glVertexAttribPointer(mPositionLoc, 4, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), vertices);
          // Load the texture coordinate
          glVertexAttribPointer(mTexCoordLoc, 2, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
                                vertices + 4);
  
          glEnableVertexAttribArray(mPositionLoc);
          glEnableVertexAttribArray(mTexCoordLoc);
  
          // Bind the texture
          glActiveTexture(GL_TEXTURE0);
          glBindTexture(GL_TEXTURE_2D, mTextureID);
  
          // Set the sampler texture unit to 0
          glUniform1i(mSamplerLoc, 0);
  
          // Draw quad with nearest sampling
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
          glUniform1f(mOffsetLoc, -0.6f);
          glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
  
          // Draw quad with trilinear filtering
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
          glUniform1f(mOffsetLoc, 0.0f);
          glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
  
          // Draw quad with anisotropic filtering
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
          glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, mMaxAnisotropy);
          glUniform1f(mOffsetLoc, 0.6f);
          glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
          glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.0f);
      }
  
    private:
      // Handle to a program object
      GLuint mProgram;
  
      // Attribute locations
      GLint mPositionLoc;
      GLint mTexCoordLoc;
  
      // Sampler location
      GLint mSamplerLoc;
  
      // Offset location
      GLint mOffsetLoc;
  
      // Texture handle
      GLuint mTextureID;
  
      float mMaxAnisotropy;
  };
  
  int main(int argc, char **argv)
  {
      MipMap2DSample app(argc, argv);
      return app.run();
  }
  

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