text: /******************************************************************************
   * The MIT License (MIT)
   *
   * Copyright (c) 2015-2019 Baldur Karlsson
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   ******************************************************************************/
  
  #include "gl_test.h"
  
  RD_TEST(GL_Shader_Editing, OpenGLGraphicsTest)
  {
    static constexpr const char *Description =
        "Ensures that shader editing works with different combinations of shader re-use and handles "
        "locations that change between the pre-edit and post-edit shaders.";
  
    const char *vertex = R"EOSHADER(
  #version 430 core
  
  layout(location = 0) in vec3 Position;
  layout(location = 1) in vec4 Color;
  layout(location = 2) in vec2 UV;
  
  #define v2f v2f_block \
  {                     \
  	vec4 pos;           \
  	vec4 col;           \
  	vec4 uv;            \
  }
  
  out v2f vertOut;
  
  out gl_PerVertex { vec4 gl_Position; };
  
  void main()
  {
  	vertOut.pos = vec4(Position.xyz, 1);
  	gl_Position = vertOut.pos;
  	vertOut.col = Color;
  	vertOut.uv = vec4(UV.xy, 0, 1);
  }
  
  )EOSHADER";
  
    const char *pixel = R"EOSHADER(
  #version 430 core
  
  layout(location = 0, index = 0) out vec4 Color;
  
  layout(location = 9) uniform vec4 col;
  
  void main()
  {
  	Color = col.rgba;
  }
  
  )EOSHADER";
  
    const char *pixel2 = R"EOSHADER(
  #version 430 core
  
  layout(location = 0, index = 0) out vec4 Color;
  
  // we hope that having these uniforms be first both alphabetically, by use, and by declaration, that
  // they'll be assigned earlier locations.
  // Then when we remove the declration and use it should force zcol to get a lower location value
  // after the edit.
  #if 1
  uniform vec4 acol;
  uniform vec4 bcol;
  uniform vec4 ccol;
  #endif
  uniform vec4 zcol;
  
  void main()
  {
  #if 1
    Color = acol + bcol + ccol;
  #endif
  	Color += zcol.rgba;
  }
  
  )EOSHADER";
  
    int main()
    {
      // initialise, create window, create context, etc
      if(!Init())
        return 3;
  
      GLuint vao = MakeVAO();
      glBindVertexArray(vao);
  
      GLuint vb = MakeBuffer();
      glBindBuffer(GL_ARRAY_BUFFER, vb);
      glBufferStorage(GL_ARRAY_BUFFER, sizeof(DefaultTri), DefaultTri, 0);
  
      glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(DefaultA2V), (void *)(0));
      glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, sizeof(DefaultA2V), (void *)(sizeof(Vec3f)));
      glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(DefaultA2V),
                            (void *)(sizeof(Vec3f) + sizeof(Vec4f)));
  
      glEnableVertexAttribArray(0);
      glEnableVertexAttribArray(1);
      glEnableVertexAttribArray(2);
  
      GLuint fixedprog = MakeProgram();
      GLuint dynamicprog = MakeProgram();
  
      GLuint vs = glCreateShader(GL_VERTEX_SHADER);
      glShaderSource(vs, 1, &vertex, NULL);
      glCompileShader(vs);
  
      GLuint fs1 = glCreateShader(GL_FRAGMENT_SHADER);
      glShaderSource(fs1, 1, &pixel, NULL);
      glCompileShader(fs1);
  
      GLuint fs2 = glCreateShader(GL_FRAGMENT_SHADER);
      glShaderSource(fs2, 1, &pixel2, NULL);
      glCompileShader(fs2);
  
      glAttachShader(fixedprog, vs);
      glAttachShader(fixedprog, fs1);
      glLinkProgram(fixedprog);
      glDetachShader(fixedprog, vs);
      glDetachShader(fixedprog, fs1);
  
      glAttachShader(dynamicprog, vs);
      glAttachShader(dynamicprog, fs2);
      glLinkProgram(dynamicprog);
      glDetachShader(dynamicprog, vs);
      glDetachShader(dynamicprog, fs2);
  
      glDeleteShader(vs);
      glDeleteShader(fs1);
      glDeleteShader(fs2);
  
      GLuint pipe = MakePipeline();
  
      GLuint vssepprog = glCreateShaderProgramv(GL_VERTEX_SHADER, 1, &vertex);
      GLuint fssepprog = glCreateShaderProgramv(GL_FRAGMENT_SHADER, 1, &pixel);
  
      glUseProgramStages(pipe, GL_VERTEX_SHADER_BIT, vssepprog);
      glUseProgramStages(pipe, GL_FRAGMENT_SHADER_BIT, fssepprog);
  
      glProgramUniform4f(fssepprog, 9, 0.0f, 1.0f, 0.0f, 1.0f);
  
      // render offscreen to make picked values accurate
      GLuint fbo = MakeFBO();
      glBindFramebuffer(GL_FRAMEBUFFER, fbo);
  
      // Color render texture
      GLuint colattach = MakeTexture();
  
      glBindTexture(GL_TEXTURE_2D, colattach);
      glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA32F, screenWidth, screenHeight);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colattach, 0);
  
      GLuint zcol = glGetUniformLocation(dynamicprog, "zcol");
  
      while(Running())
      {
        float col[] = {0.4f, 0.5f, 0.6f, 1.0f};
        glClearBufferfv(GL_COLOR, 0, col);
  
        glBindVertexArray(vao);
  
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
        glUseProgram(fixedprog);
  
        GLsizei hw = GLsizei(screenWidth) / 2;
        GLsizei hh = GLsizei(screenHeight) / 2;
  
        glViewport(0, hh, hw, hh);
  
        glUniform4f(9, 0.0f, 1.0f, 0.0f, 1.0f);
        glUniform4f(10, 1.0f, 0.0f, 0.0f, 1.0f);
  
        glDrawArrays(GL_TRIANGLES, 0, 3);
  
        glViewport(hw, hh, hw, hh);
  
        glUniform4f(9, 0.0f, 0.5f, 0.0f, 1.0f);
        glUniform4f(10, 0.5f, 0.0f, 0.0f, 1.0f);
  
        setMarker("fixedprog");
        glDrawArrays(GL_TRIANGLES, 0, 3);
  
        glViewport(0, 0, hw, hh);
  
        glUseProgram(dynamicprog);
        glUniform4f(zcol, 0.0f, 1.0f, 0.0f, 1.0f);
        setMarker("dynamicprog");
        glDrawArrays(GL_TRIANGLES, 0, 3);
  
        glViewport(hw, 0, hw, hh);
  
        // finally draw with the separable pipeline to ensure we can edit that
        glBindProgramPipeline(pipe);
        glUseProgram(0);
        setMarker("sepprog");
        glDrawArrays(GL_TRIANGLES, 0, 3);
        glBindProgramPipeline(0);
  
        // give us a point to select where all uniforms are trashed
        glUseProgram(fixedprog);
        glUniform4f(9, 0.0f, 0.0f, 0.0f, 1.0f);
        glUniform4f(10, 0.0f, 0.0f, 0.0f, 1.0f);
        glUseProgram(dynamicprog);
        glUniform4f(zcol, 0.0f, 0.0f, 0.0f, 1.0f);
  
        glBlitNamedFramebuffer(fbo, 0, 0, 0, screenWidth, screenHeight, 0, 0, screenWidth,
                               screenHeight, GL_COLOR_BUFFER_BIT, GL_NEAREST);
  
        Present();
      }
  
      return 0;
    }
  };
  
  REGISTER_TEST();
  