Carmack's Reverse In Doom 3 Has Work-Around

Posted by Michael Larabel on November 18, 2011

It looks like the patent issue with the open-source Doom 3 game won't severely delay the push of this code to the public. John Carmack has already worked around the legal issue within the id Tech 4 engine.

It was only three days ago that this patent issue came to light and was delaying the push of this open-source code, but yesterday Carmack announced he had a workaround in place for the legal issue surrounding Carmack's Reverse / the stencil buffer implementation of shadow volumes patented by Creative Labs.

The kicker? The workaround for this patent amounts to four lines of new code and two lines of changed code.

Yesterday Carmack had tweeted, "this demonstrates the idiocy of the patent -- the workaround added four lines of code and changed two."

Hopefully this workaround won't severely hamper the performance or reduce the image quality even more than what it's at now in the Mesa/Gallium3D drivers. See yesterday's benchmarks of Doom 3 on Mesa/Gallium3D to see how the game is performing and looking when using the open-source Intel, AMD/ATI, and NVIDIA Linux graphics drivers.

Should there not be any further issues with the Doom 3 / id Tech 4 code, hopefully it will be pushed soon.

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