Apple
OpenGL conditional rendering bug on MacOS X
At least on Intel HD4000 GPUs there seems to be a bug regarding conditional rendering in OpenGL on 10.8 Mountain Lion: After the conditional rendering the condition state (ignore draw calls or execute them) is ‘stuck’ until the next draw call gets issued – this can ignore glClear calls which shouldn’t get ignored. Here’s an [...]
Noperspective varying interpolation bug on MacOS X
There seems to be a bug with noperspective varyings in OpenGL 3.2 contexts on MacOS X on Intel HD4000 hardware: The varying does not get interpolated and all fragments of the triangle get the same value (similar to flat interpolation). Note that in the left screen shot the image looks similar to perspective correct interpolated texture [...]
First hints of OpenGL 4 on MacOS X?
No Mac currently supports more than OpenGL 3.2 even tho all current Macs could support OpenGL 4.x. Apple doesn’t comment on this situation but it seems, that at least some features of newer GL versions made it into the drivers. The lastest GLSL version MacOS supports is 150, at least that’s what glGetString(GL_SHADING_LANGUAGE_VERSION) tells us. [...]
Is the GPU of the 13″ Retina MacBook Pro too weak?
When Apple can first out with ‘retina’ (high resolution) displays for there Macs the big 15″ notebooks were upgraded first, not the smaller 11″ – 13″ ones. At first you wonder why, as it is probably simpler to build smaller displays with high dpi. But on second thought you realise, that you need a good [...]
OpenGL Programmable Blending – APPLE_shader_framebuffer_fetch
Large parts of the rendering pipeline are user programmable through shaders nowadays. One of the remaining fixed-functions is fragment blending: The new fragments (shaded by the fragment shader) don’t neccessarily have to overwrite the corresponding framebuffer entry, we can set different blending operations. The set of possible operations however is fixed. There have been requests [...]
MacOS X OpenGL driver status
MacOS X 10.8 Mountain Lion was released earlier today and with it the hope for updated OpenGL. Currently the OpenGL Capability Table isn’t updated for 10.8 (or even 10.7.4) yet but there haven’t been much improvements anyway: Current OpenGL support is still 3.2. GL_ARB_instanced_arrays, GL_ARB_occlusion_query2 and GL_ARB_timer_query are still the only supported extensions from OpenGL [...]
MacOS X OpenGL driver bugs
Once in a while I run across a bug in Apples OpenGL implementation. Providing an up-to-date and performant OpenGL implementation is not an easy task, and you have to wonder why Apple tries to do this on there own and not letting Intel, NVidia and AMD provide the drivers as they do on Windows and [...]
Mac OpenGL capabilities
The latest MacBook Pro just got a GeForce 650M – a Kepler based GPU. This chip is not only capable of delivering OpenGL 4.2 but also shiny new features like bindless textures: one way of supporting Virtual Texturing in hardware and maybe something we will see in some form in OpenGL 5.0. This makes it [...]
Windowless OpenGL on MacOS X
As it turns out, windowless OpenGL applications are not only possible on Linux, but also on MacOS X – and it’s quite simple to set up. But first a little bit of background about OpenGL on Apple: At the lowest layer, OpenGL is handled by CGL (Core OpenGL), based on top of that are AGL [...]
[NSOpenGLContext flushBuffer] might not do what you think
OpenGL on MacOS X has some problems with bugs and missing support of newer features. Sadly, even the Cocoa part of the 3D API (which gets defined by Apple, not the ARB) has some quirks. [NSOpenGLContext flushBuffer] is used to swap the backbuffer to the front in double buffered applications, in single buffered apps it [...]