abs1nth Wrote:aegidian Wrote:I know that's why they are disabled in the current build and I thought I should investigate a little...
they were only disabled because of the crash on non-opengl2.0 cards/drivers, which has been fixed, so my plan was to enable them on the next release again. they are on by default in the RC1.
aegidian Wrote:The second (IMO) more serious problem is that the glsl code is causing OpenGL to fall back to software rendering of the shader effects.
are you sure it falls back to software rendering? i'd think this would lead to framerates below 1fps, not 16.
i seem to remember something about a call that determines if the rendering currently is software or hardware - could be used to make sure...
i also seem to remember reading something on the apple opengl lists about a way to prevent software fallbacks, but since we are using SDL and not CGL directly this may not work.
leopards OpenGL drivers include a ton of previously unavailable features (even some that aren't even in the windows opengl drivers), but they are really alpha-state at best (not that tiger was much better anyway). i uncovered many simple ways to reproducibly freeze my machine while working on a simple demo for university. i also had issues with the for loop in glsl fucking everything up.
Yeah, "software rendering of the
shader effect". Basically the glsl effect is being done on the CPU rather than the GPU causing a massive slowdown in the rendering pipeline - and yes there's new stuff in leopard that lets you pre-flight shaders to determine if they're being done in the GPU or the CPU ('software fallback').
Also - if I can workout where SDL initialises the OpenGL context there's a NoRecovery flag that can be set that will disable any shaders that cause the fall back - stopping the situation from causing a drop in frame rates. This combined with the pre-flight of shaders would be the ideal all-round situation, but I think a simpler solution is more likely.
I suspect some of the problems I'm seeing may also stem from the texture units being handled differently. glBindTexture(some-texture-unit, 0) doesn't stop the brake-light texture from being rendered for example. Instead to fix this the self_illuminated uniform variable has to be reinstated in the graphics.cpp code and the shader code. even then it still shows up in the landscape as well as the car.
I still don't completely understand VDrift's graphic pipeline yet - I'm piecing stuff together as I work my way through the code. With luck - I may yet find some solutions to this.
