kc3-lang/angle/samples/simple_vertex_shader/SimpleVertexShader.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/simple_vertex_shader/SimpleVertexShader.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 Simple_VertexShader.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/Matrix.h"
  #include "util/geometry_utils.h"
  #include "util/shader_utils.h"
  
  #include <cmath>
  
  class SimpleVertexShaderSample : public SampleApplication
  {
    public:
      SimpleVertexShaderSample(int argc, char **argv)
          : SampleApplication("SimpleVertexShader", argc, argv)
      {}
  
      bool initialize() override
      {
          constexpr char kVS[] = R"(uniform mat4 u_mvpMatrix;
  attribute vec4 a_position;
  attribute vec2 a_texcoord;
  varying vec2 v_texcoord;
  void main()
  {
      gl_Position = u_mvpMatrix * a_position;
      v_texcoord = a_texcoord;
  })";
  
          constexpr char kFS[] = R"(precision mediump float;
  varying vec2 v_texcoord;
  void main()
  {
      gl_FragColor = vec4(v_texcoord.x, v_texcoord.y, 1.0, 1.0);
  })";
  
          mProgram = CompileProgram(kVS, kFS);
          if (!mProgram)
          {
              return false;
          }
  
          // Get the attribute locations
          mPositionLoc = glGetAttribLocation(mProgram, "a_position");
          mTexcoordLoc = glGetAttribLocation(mProgram, "a_texcoord");
  
          // Get the uniform locations
          mMVPMatrixLoc = glGetUniformLocation(mProgram, "u_mvpMatrix");
  
          // Generate the geometry data
          GenerateCubeGeometry(0.5f, &mCube);
  
          // Set an initial rotation
          mRotation = 45.0f;
  
          glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
          glCullFace(GL_BACK);
          glEnable(GL_CULL_FACE);
  
          return true;
      }
  
      void destroy() override { glDeleteProgram(mProgram); }
  
      void step(float dt, double totalTime) override
      {
          mRotation = fmod(mRotation + (dt * 40.0f), 360.0f);
  
          Matrix4 perspectiveMatrix = Matrix4::perspective(
              60.0f, float(getWindow()->getWidth()) / getWindow()->getHeight(), 1.0f, 20.0f);
  
          Matrix4 modelMatrix = Matrix4::translate(angle::Vector3(0.0f, 0.0f, -2.0f)) *
                                Matrix4::rotate(mRotation, angle::Vector3(1.0f, 0.0f, 1.0f));
  
          Matrix4 viewMatrix = Matrix4::identity();
  
          Matrix4 mvpMatrix = perspectiveMatrix * viewMatrix * modelMatrix;
  
          // Load the matrices
          glUniformMatrix4fv(mMVPMatrixLoc, 1, GL_FALSE, mvpMatrix.data);
      }
  
      void draw() override
      {
          // 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, 3, GL_FLOAT, GL_FALSE, 0, mCube.positions.data());
          glEnableVertexAttribArray(mPositionLoc);
  
          // Load the texcoord data
          glVertexAttribPointer(mTexcoordLoc, 2, GL_FLOAT, GL_FALSE, 0, mCube.texcoords.data());
          glEnableVertexAttribArray(mTexcoordLoc);
  
          // Draw the cube
          glDrawElements(GL_TRIANGLES, static_cast<GLsizei>(mCube.indices.size()), GL_UNSIGNED_SHORT,
                         mCube.indices.data());
      }
  
    private:
      // Handle to a program object
      GLuint mProgram;
  
      // Attribute locations
      GLint mPositionLoc;
      GLint mTexcoordLoc;
  
      // Uniform locations
      GLuint mMVPMatrixLoc;
  
      // Current rotation
      float mRotation;
  
      // Geometry data
      CubeGeometry mCube;
  };
  
  int main(int argc, char **argv)
  {
      SimpleVertexShaderSample app(argc, argv);
      return app.run();
  }
  

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