from geometry to pixels


GLSL Syntax Highlighting for QTCreator (and Kate)

The syntax highlighter in QTCreator for GLSL shaders is currently far from ideal: It’s basically stuck at OpenGL 2.1. If you write shaders for OpenGL 3 (and later) or OpenGL ES 3, you will see a lot of red marks indicating errors in your code simply because QTCreator doesn’t know the latest keywords. On the […]


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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 […]


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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. […]


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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 […]


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Which GPUs support OpenGL ES 3.0?

With OpenGL ES 3 (codename Halti) was just released, the question arrises who will be the first to provide hardware support in there mobile GPUs. In fact, there are already some chips in the pipeline that support all the features necessary so we could see full ES3 support soon: PowerVR Series5 SGX545 from ImgTec, announced […]


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OpenGL 4.3 released

In addition to OpenGL ES 3.0 Khronos also released OpenGL 4.3 today. The latest incarnation of the desktop variant of this rendering API comes with some surprises. OpenGL 4.1 added ES 2 compatibility, so from 2010 onwards GL was a superset of the embedded version. While ES 3 is based on GL 3.3 (without geometry […]


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Book Review: OpenGL Insights

OpenGL Insights edited by Patrick Cozzi and Christophe Riccio is collection of 44 articles about modern OpenGL programming, techniques and related topics. The articles itself account for 653 full colored pages, so each ‘insight’ is a compact portion of knowledge.¬†This book does not only cover (desktop) OpenGL: 35 chapters are dealing with this API while […]


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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 […]


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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 […]


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Texture Compression

We all know image compression from common formats like JPEG or PNG. For rendering the textures can be compressed as well, but here different formats are used than the ones we are familiar with. The reason here is that there are special requirements when it comes to texture compression: Small texture size Fast decompression Fast […]


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