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Type: Posts; User: Aliii

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  1. Thank you! I know instancing but AFAIK it is not...

    Thank you! I know instancing but AFAIK it is not efficient if my instances are single quads. If I want to render a field of sunflowers that are single textured quads I would rather pack them in a...
  2. Render vegetation as quads - What render method

    I want to render vegetation - trees, grass patches - using textured quads. I guess I would render no more than like 15K such quads per frame. What method do I use for drawing them if I want best...
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    Thank you! I'm using a PBO now and it works...

    Thank you! I'm using a PBO now and it works without slowness. If I understand it correctly, the PBO has its data in the normal RAM because of the GL_STREAM_READ hint, and if I only map it after the...
  4. Oi!, sorry for this very late answer. I don't...

    Oi!, sorry for this very late answer. I don't know which drivers specifically. My driver didn't give the right value. (Which was nvidia 340 or 304 on linux)
    I did some research and saw that I'm not...
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    Reading back data from texture. GPU -> CPU

    I'm rendering stuff into a texture with an FBO every frame and I need to read that data. I mean I need the data on the CPU side. I tried to use glGetTexImage but it's horribly slow. (I tried it with...
  6. I tried something like that once but I used...

    I tried something like that once but I used baseVertex calls and it turned out that many drivers don't work as the spec says and some add the base-vertex to gl_VertexID and some don't. So I couldn't...
  7. Thanks! I guess this is the least bad solution to...

    Thanks! I guess this is the least bad solution to index if there are already 20 or so bytes per vertex then 1 more is acceptable, except if I draw the same mesh twice.


    Yes, I have both fog and...
  8. Updating the model-matrices when drawing multiple objects

    Speaking of OpenGL 3.3, let's say I want to draw multiple objects. They have different geometry so I can't use instanced rendering. Before each draw call I need to update the model-matrix uniform of...
  9. Thanks! Sadly, it returns 0. Which is according...

    Thanks! Sadly, it returns 0. Which is according to this post is a driver bug:
    https://www.opengl.org/discussion_boards/showthread.php/171380-NVIDIA-drivers-not-returning-the-right-profile-mas

    I...
  10. How to get if current GL context is Core or Compatibility

    Is there a way to get wheter the current OpenGL version is CORE or COMPATIBILITY? ...the same way I can get the version numbers glGetIntegerv(GL_MAJOR_VERSION, ...). Thanks!
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    Thanks! Thats OK then, Im using shaders. It was...

    Thanks! Thats OK then, Im using shaders. It was just strange.

    Im putting it here if anybody else runs into this:
    "Non-antialiased point size may be clamped to an implementation-dependent ...
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    I dont really get it. I set it to 500 with...

    I dont really get it. I set it to 500 with glPointSize( 500) ...if I querry the current size, it says 500. Also it draws it 500 pixels wide. It just says that the range is from 1 to 63.
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    Strange value from GL_POINT_SIZE_RANGE

    Im trying to get the maximum allowed size for points.



    float sizes[2];
    glGetFloatv( GL_POINT_SIZE_RANGE, sizes);

    It says 1.0 and 63.375. Now thats not true, I can set it to 500 and it...
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    Using OpenGL with SDL

    I want to move my project from Win to Linux. It seems like on Linux its not easy to set up the basic window, message loop, input handling, ...so I was thinking about using SDL.
    Im hearing things...
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    Thanks for the clarification! I see that...

    Thanks for the clarification! I see that glTexStorage is superior, I just want to stick to OpenGL3.3 for now.
    I didnt know about glGenerateMipmap. Is there any reason not to use it and upload the...
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    Thanks for the answers! I still dont understand...

    Thanks for the answers! I still dont understand the difference here between glTexImage and glTexSubImage. Does glTexImage define only 1 mip-map level for the given texture? It says "glTexImage3D —...
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    Array Texture confusion

    I want to make an array-texture from 2D textures with mipmaps, but Im confused.

    This is one of the "tutorials" I looked at:
    https://www.opengl.org/wiki/Array_Texture

    Here they use...
  18. The profilers I use:...

    The profilers I use:
    https://code.google.com/p/shinyprofiler/
    http://www.codersnotes.com/sleepy

    To measure certain GL calls ....use a performance counter. Use glFinish to isolate the GL call.
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    Right way to check for errors

    How should I check for errors? In release mode I cant check them with while(...)glGetError after every single gl call. I can write macros that will only check in debug mode but some important calls...
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    Thanks! I will try the geom shader approach then.

    Thanks! I will try the geom shader approach then.
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    Thanks! Actually, I wanted to do text rendering...

    Thanks! Actually, I wanted to do text rendering and particles, where I want to provide the center of a quad while its 4 points are calculated in the vertex shader(as the width of the quads is fixed)....
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    Fetching vertex attributes at different rate

    Is there a way to fetch different vertex attributes at different rate. Like to use new vertex coordinates per every execution of the vertex shader but use the same color for 3 vertices. This would...
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    Thanks! It works now as expected. Now it also...

    Thanks! It works now as expected. Now it also gives an INVALID_ENUM error if I try to use the GL_POINT_SPRITE.
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    Thanks! "What is removed? Point sprites?...

    Thanks!
    "What is removed? Point sprites? Certainly not! Just glEnable(GL_POINT_SPRITE) is removed since it is always on in post GL 3.2 versions."

    I understand that in 3.2+ core it should be...
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    OK:) Thanks anyway!

    OK:) Thanks anyway!
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