Full-screen quad mapping bug?
Hi,
Usually bloom is a post-process rendered to a full-screen quad but you'd need to see the game's source code to be sure (is this it? http://dev.xonotic.org/projects/xono...ository_Access). It looks like the mapping could be wrong in the open driver or it could be a bug in the game's source. Usually the approach is you render off-screen to a texture that's bounded to a framebuffer object, then you assign it to a full-screen quad and blend it on top of the rendered screen before calling swap via GLX/EGL/whatever. Now the gallium driver might be getting confused with UV co-ordinates and isn't placing the texture in the right spot (it looks offset, perhaps it is expecting a signed value and the UVs 0.0f,0.0f could correspond to the middle (with a UV range of -0.5f,0.5f) while the catalyst driver has 0.5f,0.5f as the middle (with a UV range of 0.0f,1.0f), something like that as a guess, or it's a shader bug.
I can't view the source to be sure, is there a web portal to view it without downloading the whole thing?
-MistaED
Hi,
Usually bloom is a post-process rendered to a full-screen quad but you'd need to see the game's source code to be sure (is this it? http://dev.xonotic.org/projects/xono...ository_Access). It looks like the mapping could be wrong in the open driver or it could be a bug in the game's source. Usually the approach is you render off-screen to a texture that's bounded to a framebuffer object, then you assign it to a full-screen quad and blend it on top of the rendered screen before calling swap via GLX/EGL/whatever. Now the gallium driver might be getting confused with UV co-ordinates and isn't placing the texture in the right spot (it looks offset, perhaps it is expecting a signed value and the UVs 0.0f,0.0f could correspond to the middle (with a UV range of -0.5f,0.5f) while the catalyst driver has 0.5f,0.5f as the middle (with a UV range of 0.0f,1.0f), something like that as a guess, or it's a shader bug.
I can't view the source to be sure, is there a web portal to view it without downloading the whole thing?
-MistaED
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