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Type: Posts; User: mbentrup

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    You seem to be using GLEW, note that current GLEW...

    You seem to be using GLEW, note that current GLEW doesn't work properly with OpenGL core contexts.
  2. Those are the character codes of '0', '1' and...

    Those are the character codes of '0', '1' and '2'. Try
    printf("%d\n", '0');
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    Yes, that is generally correct. However, there...

    Yes, that is generally correct. However, there are some points you have to consider:

    - the FPS increase only until another stage becomes the bottleneck. If your VS and FS stages for example are...
  4. Your switch statement is incorrect, you compare...

    Your switch statement is incorrect, you compare the int i to the character constants '0', '1' and '2'. That way you'd have to pass 48, 49 and 50 for light 0, light 1 or light 2.

    You should just do...
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    You don't access the VBO, you access the memory...

    You don't access the VBO, you access the memory that it is mapped to, and all threads in a process share their memory. You have to be careful regarding synchronization, but otherwise it is perfectly...
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    You could map/unmap the VBOs from the main thread...

    You could map/unmap the VBOs from the main thread and just fill in the data from the worker threads.
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    You pass 0-based pointers in...

    You pass 0-based pointers in glVertexAttribPointer, but at that time no VBO is bound to GL_ARRAY_BUFFER, so the address is not the start of your VBO, but the start of CPU memory, which is usually not...
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    try -I./include/GL (notice the "." before the...

    try -I./include/GL (notice the "." before the first "/")
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    The color gradient is not produced by the...

    The color gradient is not produced by the shaders, it is part of the rasterization process.

    The shader has some limited influence on the interpolation, it can choose between three interpolation...
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    gl3w exposes only the functions of the OpenGL...

    gl3w exposes only the functions of the OpenGL core profile, so you have to either upgrade your code to modern OpenGL or use a wrapper supports the compatibility profile, like GLEW.
  11. Floating point precision is 23 bits, that is a...

    Floating point precision is 23 bits, that is a resolution of 0,000244141 pixels on a 2k screen, so it is unlikely that you see any floating point precision issues.

    The more likely issue is that...
  12. I don't really understand what you mean by empty,...

    I don't really understand what you mean by empty, a region of constant color ?

    However, all TC formats have a fixed compression ratio, the compressed size of an "empty" texture is exactly the same...
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    By the way, you seem to use a float uniform where...

    By the way, you seem to use a float uniform where a bool uniform would be more appropriate. If the driver knows that there are only 2 possible input values it can compile two shader variants to avoid...
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    Well, actually the trend in graphics APIs (Metal,...

    Well, actually the trend in graphics APIs (Metal, DX12, glNext) is to go away from abstraction, closer to the hardware.
  15. If you don't have ARB_shader_stencil_export, you...

    If you don't have ARB_shader_stencil_export, you can still write a specific value to the stencil buffer in ceil(log2(N)) passes, if you write one bit of the stencil per pass. However, I'd just use a...
  16. I think every driver keeps a flag per texture...

    I think every driver keeps a flag per texture that is set on validation and reset on modification, so that further validations are not done until the texture is changed.
  17. On old GPUs the FP implementation is not always...

    On old GPUs the FP implementation is not always IEEE compliant, but as far as i know that non-compliance is mostly in areas like NaNs and denormal number handling. You can assume that the floats have...
  18. Sticky: EGL ? It already has the means to load various...

    EGL ? It already has the means to load various APIs and I guess vendors shipping EGL for their products will have to work on a common EGL ABI for Windows anyway.
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    ASTC can encode one- and two-channel images, but...

    ASTC can encode one- and two-channel images, but you have to encode them as luminance resp. luminance+alpha and the HDR range is basically FP16, I think that is the same range as BPTC.
  20. The first thing I'd do would be to look into the...

    The first thing I'd do would be to look into the KHR_debug output, Nvidia may give some hints if the shader hits a slow path.
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    Small nitpick: vertex attributes are not...

    Small nitpick: vertex attributes are not flat-shaded, only varyings can be flat-shaded.

    Another way to implement clipping of primitives is to use (drumroll) vertex clipping. Just write the four...
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    In practice OpenGL 3.0 added very little new...

    In practice OpenGL 3.0 added very little new functionality over 2.1, because a lot of it was already available as common extensions to 2.1 (framebuffer object, floating point textures etc.), and...
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    The changes of OpenGL 3.3 and later versions have...

    The changes of OpenGL 3.3 and later versions have been released separately as ARB extensions too, so restricting the GL version wouldn't necessarily disable any features.
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    Hi Alfonse, the 4.5 core spec says in A.5 ...

    Hi Alfonse,

    the 4.5 core spec says in A.5 with corrolary

    This indicates that there is a distinction between the vertex as identified by vertex ID, etc. and vertex shader invocation. There may...
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    MESA does it, though their stub segfaults instead...

    MESA does it, though their stub segfaults instead of returning an OpenGL error: http://cgit.freedesktop.org/mesa/mesa/tree/src/mapi/glapi/glapi_getproc.c#n502

    This has been discussed extensively...
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