Textures seem to be byteswapped on big endian architectures

Submitted by Adam Stylinski

Assigned to Nouveau Project

Description

When using an NV43 based GPU on a PPC64 kernel with a 64 bit userspace, it seems applications will have byte swapped textures when specified with GL_RGBA and GL_UNSIGNED_BYTE. Matplotlib will do this when blit=True for the plot routines, and several games will have this issue. In particular, for Legacy Doom, I've found that if I swap the textures so that they are A,B,G,R just before the textures are mapped, everything is correct.

I also found that doing glPixelStorei(GL_UNPACK_BYTES, GL_TRUE) and choosing GL_UNSIGNED_INT_8_8_8_8 as the representation seemed to also remedy this. I found that the _REV variant didn't byte swap the textures back to the incorrect ordering (this is probably a different bug).

Easiest way to demonstrate the bug: svn co https://svn.code.sf.net/p/doomlegacy/svn/legacy_one/trunk doomlegacy cd doomlegacy make OS=LINUX make cd bin Grab this archive: https://sourceforge.net/projects/doomlegacy/files/1.47.2/doomlegacy_1.47.2_common.zip/download, unzip it, extract legacy.wad into the bin directory Grab this archive: https://github.com/freedoom/freedoom/releases/download/v0.11.3/freedoom-0.11.3.zip, extract, move freedoom1.wad into the bin directory. Then do: ./doomlegacy -iwad freedoom1.wad -opengl

Version: 18.3

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