kc3-lang/angle/samples/texture_wrap/TextureWrap.cpp

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• Hash : 35cd7332
  Author :
  Date : 2018-12-02T12:03:33
  

  Refactor test shader style.
  
  This change enforces a lot more consistency. We pass const char * to
  the Compile functions instead of std::string. Also fixes the
  indentation of C++11 block comments to be more consistent.
  
  Bug: angleproject:2995
  Change-Id: Id6e5ea94055d8cbd420df4ea2e81b2d96cb5ce78
  Reviewed-on: https://chromium-review.googlesource.com/c/1357103
  Reviewed-by: Jamie Madill <jmadill@chromium.org>
  Commit-Queue: Jamie Madill <jmadill@chromium.org>
  

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• samples/texture_wrap/TextureWrap.cpp

• //
  // Copyright (c) 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 TextureWrap.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 TextureWrapSample : public SampleApplication
  {
    public:
      TextureWrapSample(int argc, char **argv) : SampleApplication("TextureWrap", 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
          mTexture = CreateMipMappedTexture2D();
  
          glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
  
          return true;
      }
  
      void destroy() override { glDeleteProgram(mProgram); }
  
      void draw() override
      {
          GLfloat vertices[] = {
              -0.3f, 0.3f,  0.0f, 1.0f,  // Position 0
              -1.0f, -1.0f,              // TexCoord 0
              -0.3f, -0.3f, 0.0f, 1.0f,  // Position 1
              -1.0f, 2.0f,               // TexCoord 1
              0.3f,  -0.3f, 0.0f, 1.0f,  // Position 2
              2.0f,  2.0f,               // TexCoord 2
              0.3f,  0.3f,  0.0f, 1.0f,  // Position 3
              2.0f,  -1.0f               // TexCoord 3
          };
          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);
          glEnableVertexAttribArray(mPositionLoc);
  
          // Load the texture coordinate
          glVertexAttribPointer(mTexCoordLoc, 2, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
                                vertices + 4);
          glEnableVertexAttribArray(mTexCoordLoc);
  
          // Set the sampler texture unit to 0
          glUniform1i(mSamplerLoc, 0);
  
          // Draw quad with repeat wrap mode
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
          glUniform1f(mOffsetLoc, -0.7f);
          glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
  
          // Draw quad with clamp to edge wrap mode
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
          glUniform1f(mOffsetLoc, 0.0f);
          glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
  
          // Draw quad with mirrored repeat
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);
          glUniform1f(mOffsetLoc, 0.7f);
          glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
      }
  
    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 mTexture;
  };
  
  int main(int argc, char **argv)
  {
      TextureWrapSample app(argc, argv);
      return app.run();
  }
  

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