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Thread: glDrawElements access violation on AMD card, weird behavior

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  1. #1
    Member Regular Contributor Nowhere-01's Avatar
    Join Date
    Feb 2011

    Exclamation glDrawElements access violation on AMD card, weird behavior

    hey, yesterday i've finally got my AMD card for test(HD6670) and what a piece of crap it is... i'm talking mostly about drivers. i can't debug. almost everything doesn't work, but no OpenGL errors. best hint i can get - gDebugger catches access violation errors occasionally.

    configuration: win 7 x64, catalyst 13.1, Gigabyte HD 6670, WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB.
    my application works flawlessly on my main nVidia card, gDebugger doesn't catch any errors. all deprecated stuff replaced.

    example of code, that doesn't work on AMD:

    //init quad
    Code :
       GLfloat quadVertices[] = {
       -1.0f, -1.0f, 0.0f, 0.0f, 0.0f,         //bottom left corner
       -1.0f,  1.0f, 0.0f, 0.0f, 1.0f,         //top left corner
        1.0f,  1.0f, 0.0f, 1.0f, 1.0f,         //top right corner
        1.0f, -1.0f, 0.0f, 1.0f, 0.0f};      //bottom right corner
       GLubyte quadIndices[] = {2,1,0, // first triangle (bottom left - top left - top right)
        3,2,0};                                  // second triangle (bottom left - top right - bottom right)
       glGenVertexArrays(1, &quadVertexArrayObjectId);
        glGenBuffers(1, &quadVertexBufferId);
        glBindBuffer(GL_ARRAY_BUFFER, quadVertexBufferId); //Bind the vertex buffer
        glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 20, &quadVertices[0], GL_STATIC_DRAW);
        glGenBuffers(1, &quadIndexBufferId);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, quadIndexBufferId); //Bind the vertex buffer
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLubyte) * 6, &quadIndices[0], GL_STATIC_DRAW);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 5, BUFFER_OFFSET(0)); //vertex
        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 5, BUFFER_OFFSET(12)); //tex coord
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

    //render sprite for occlusion query:
    Code :
            glBeginQueryARB(GL_SAMPLES_PASSED_ARB, occQueryObject);
            modelViewMatrix = currentViewMatrix * modelMatrix;
            modelViewMatrix = glm::scale(modelViewMatrix, glm::vec3(occluderScale * 3.0f, occluderScale* 3.0f, 1.0f));
            glUniformMatrix4fv(SShader[shaderId].shaderSet[programId].uniform_modelViewMatrix, 1, 0, glm::value_ptr(modelViewMatrix));
            glUniformMatrix4fv(SShader[shaderId].shaderSet[programId].uniform_projectionMatrix, 1, 0, glm::value_ptr(currentProjectionMatrix));
            glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, 0); //access violation with gDebugger

    there are several cases like that in my code. i've checked contents of Framebuffer, this code draws correctly without gDebugger. but conditional rendering doesn't work. neither for these sprites, neither for normal objects, which are not getting any errors on that stage and also draw correctly into occlusion query buffer and gbuffer.

    also, amd doesn't seem to like that:
    Code :
    glBindFramebuffer(GL_FRAMEBUFFER, lightBufferId);
        glBindFramebuffer(GL_READ_FRAMEBUFFER, gBufferId);
        glBlitFramebuffer(0, 0, gBufferWidth, gBufferHeight, 0, 0, screenw, screenh, GL_DEPTH_BUFFER_BIT, GL_NEAREST);

    althrough they don't explain why. just another access violation with gDebugger and nothing working in normal mode;
    maybe i'm doing something embarassing?
    Last edited by Nowhere-01; 02-13-2013 at 04:59 AM.

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