Attachment 143228 Details for Bug 109451 – test program source code

test program source code

gl_bug.c (text/x-csrc), 7.14 KB, created by Dorian Wouters on 2019-01-24 19:34:19 UTC

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Creator: Dorian Wouters

Created: 2019-01-24 19:34:19 UTC

Size: 7.14 KB

patch

obsolete

>// i965/Ivy Bridge/OpenGL state tracking bug with GL_TRIANGLE_FAN followed by GL_LINE_STRIP
>// with primitive restart
>//
>// Found by Dorian Wouters / "ElementW" / perso@elementw.net
>//
>// Originally encountered as a Blender bug: https://developer.blender.org/T60762
>// Command stream & data extracted using apitrace
>//
>// Requires SDL2 and GL 3.3+
>// Compile, either with GLEW or libepoxy:
>// * gcc -o gl_bug -DUSE_GLEW -lGLEW -lGL -lSDL2 gl_bug.c
>// * gcc -o gl_bug -DUSE_EPOXY -lepoxy -lSDL2 gl_bug.c
>//
>// Add -DNUDGE_BUFFER to see how writing to the buffer fixes it
>// (reading it back to CPU-side memory also fixes it)
>
>#ifdef USE_GLEW
>#include <GL/glew.h>
>#endif
>#ifdef USE_EPOXY
>#include <epoxy/gl.h>
>#endif
>
>#include <SDL2/SDL.h>
>#include <stdbool.h>
>
>void GLAPIENTRY
>MessageCallback( GLenum source,
>                 GLenum type,
>                 GLuint id,
>                 GLenum severity,
>                 GLsizei length,
>                 const GLchar* message,
>                 const void* userParam )
>{
>  (void) source;
>  (void) id;
>  (void) length;
>  (void) userParam;
>  fprintf( stderr, "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
>           ( type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : "" ),
>            type, severity, message );
>}
>
>int main(int argc, char **argv) {
>  (void) argc;
>  (void) argv;
>  SDL_Init(SDL_INIT_VIDEO);
>  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
>  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
>  SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
>  SDL_Window *win = SDL_CreateWindow("primitive restart bug", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 800, 600, SDL_WINDOW_OPENGL);
>  SDL_GLContext *glc = SDL_GL_CreateContext(win);
>#ifdef USE_GLEW
>  glewInit();
>#endif
>
>  glEnable(GL_DEBUG_OUTPUT);
>  glDebugMessageCallback(MessageCallback, 0);
>
>  GLuint vboId, iboId, vaoId;
>  {
>    
>    const GLfloat vertices[] = {
>      0.375,             0,
>      0.625,             0,
>      0.625,          0.25,
>      0.375,          0.25,
>      0.375,          0.25,
>      0.625,          0.25,
>      0.625,           0.5,
>      0.375,           0.5,
>      0.375,           0.5,
>      0.625,           0.5,
>      0.625,          0.75,
>      0.375,          0.75,
>      0.375,          0.75,
>      0.625,          0.75,
>      0.625,             1,
>      0.375,             1,
>      0.125,           0.5,
>      0.375,           0.5,
>      0.375,          0.75,
>      0.125,          0.75,
>      0.625,           0.5,
>      0.875,           0.5,
>      0.875,          0.75,
>      0.625,          0.75
>    };
>    glGenBuffers(1, &vboId);
>    glBindBuffer(GL_ARRAY_BUFFER, vboId);
>    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_DYNAMIC_DRAW);
>
>    const GLbyte indices[] = {
>      0x00, 0x01, 0x02, 0x03, 0x00, 0xff,
>      0x04, 0x05, 0x06, 0x07, 0x04, 0xff,
>      0x08, 0x09, 0x0a, 0x0b, 0x08, 0xff,
>      0x0c, 0x0d, 0x0e, 0x0f, 0x0c, 0xff,
>      0x10, 0x11, 0x12, 0x13, 0x10, 0xff,
>      0x14, 0x15, 0x16, 0x17, 0x14, 0xff
>    };
>    glGenBuffers(1, &iboId);
>    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, iboId);
>    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
>
>    glGenVertexArrays(1, &vaoId);
>  }
>  GLuint vertexShader, fragmentShader, shader;
>  GLuint fillVertexShader, fillShader;
>  GLint colorLoc;
>  {
>    vertexShader = glCreateShader(GL_VERTEX_SHADER);
>    const char *const vertexSource =
>        "#version 330\n"
>        "layout(location = 0) in vec2 vtx;\n"
>        "noperspective out vec4 finalColor;\n"
>        "uniform vec4 color; // = vec4(0.752941);\n"
>        //"const vec4 selectColor = vec4(1.0, 0.521569, 0.0, 1.0);\n"
>        "void main() {\n"
>        "gl_Position = vec4(vtx.x-.5, vtx.y-.5, 0.0, 1.0);\n"
>        "finalColor = color;\n"
>        "}";
>    glShaderSource(vertexShader, 1, &vertexSource, (GLint*)0);
>    glCompileShader(vertexShader);
>    fillVertexShader = glCreateShader(GL_VERTEX_SHADER);
>    const char *const fillVertexSource =
>        "#version 330\n"
>        "layout(location = 0) in vec2 vtx;\n"
>        "noperspective out vec4 finalColor;\n"
>        "void main() {\n"
>        "gl_Position = vec4(vtx.x-.5, vtx.y-.5, 0.0, 1.0);\n"
>        "finalColor = vec4(1.0, 1.0, 1.0, 0.1);\n"
>        "}";
>    glShaderSource(fillVertexShader, 1, &fillVertexSource, (GLint*)0);
>    glCompileShader(fillVertexShader);
>    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
>    const char *const fragmentSource =
>        "#version 330 core\n"
>        "#extension GL_ARB_texture_gather: enable\n"
>        "#define GPU_ARB_texture_gather\n"
>        "#extension GL_ARB_texture_query_lod: enable\n"
>        "noperspective in vec4 finalColor;\n"
>        "out vec4 fragColor;\n"
>        "void main (void) { fragColor = finalColor; }";
>    glShaderSource(fragmentShader, 1, &fragmentSource, (GLint*)0);
>    glCompileShader(fragmentShader);
>    
>    shader = glCreateProgram();
>    glAttachShader(shader, vertexShader);
>    glAttachShader(shader, fragmentShader);
>    glLinkProgram(shader);
>    colorLoc = glGetUniformLocation(shader, "color");
>    
>    fillShader = glCreateProgram();
>    glAttachShader(fillShader, fillVertexShader);
>    glAttachShader(fillShader, fragmentShader);
>    glLinkProgram(fillShader);
>  }
>  glFrontFace(GL_CW);
>  glCullFace(GL_BACK);
>  glBlendEquationSeparate(GL_FUNC_ADD, GL_FUNC_ADD);
>  glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ZERO);
>
>  SDL_Event e;
>  bool quit = false;
>  while (!quit) {
>    while (SDL_PollEvent(&e)) {
>      if (e.type == SDL_QUIT) {
>        quit = true;
>      }
>      if (e.type == SDL_KEYDOWN) {
>        quit = true;
>      }
>      if (e.type == SDL_MOUSEBUTTONDOWN) {
>        quit = true;
>      }
>    }
>    glClearColor(0.266667f, 0.266667f, 0.266667f, 1.f);
>    glClear(GL_COLOR_BUFFER_BIT);
>    glEnable(GL_BLEND);
>    glEnable(GL_PRIMITIVE_RESTART);
>    glPrimitiveRestartIndex(0xFF);
>    
>    // POLYGON BACKGROUND
>    
>    glBindVertexArray(vaoId);
>
>    glBindBuffer(GL_ARRAY_BUFFER, vboId);
>    glEnableVertexAttribArray(0);
>    glVertexAttribPointer(0, 2, GL_FLOAT, false, 8, (GLvoid*)0);
>    
>    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, iboId);
>
>    glUseProgram(fillShader);
>    
>    glDrawRangeElements(GL_TRIANGLE_FAN, 0, 23, 36, GL_UNSIGNED_BYTE, (const GLvoid*)0);
>    // At this point drawing LINE_STRIPs using the same ELEMENT_ARRAY_BUFFER
>    // fails to use restart markers unless the buffer is messed with inbetween
>    
>    // LINES
>
>#ifdef NUDGE_BUFFER
>    uint8_t zero = 0;
>    glBufferSubData(GL_ARRAY_BUFFER, 0, 1, &zero);
>#endif
>
>    glUseProgram(shader);
>
>    glLineWidth(3);
>    glUniform4f(colorLoc, 0.f, 0.f, 0.f, 1.f);
>    glDrawRangeElements(GL_LINE_STRIP, 0, 23, 36, GL_UNSIGNED_BYTE, (const GLvoid*)0);
>    
>    glLineWidth(1);
>    glUniform4f(colorLoc, 0.752941f, 0.752941f, 0.752941f, 1.f);
>    glDrawRangeElements(GL_LINE_STRIP, 0, 23, 36, GL_UNSIGNED_BYTE, (const GLvoid*)0);
>
>    glDisable(GL_PRIMITIVE_RESTART);
>
>    glDisableVertexAttribArray(0);
>    glBindVertexArray(0);
>
>    SDL_GL_SwapWindow(win);
>  }
>  glDeleteProgram(shader);
>  glDeleteShader(vertexShader);
>  glDeleteShader(fragmentShader);
>  glDeleteBuffers(1, &iboId);
>  glDeleteBuffers(1, &vboId);
>
>  SDL_GL_DeleteContext(glc);
>  SDL_DestroyWindow(win);
>  SDL_Quit();
>  return 0;
>}

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Attachments on bug 109451: 143227 | 143228 | 143256

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