The PlayStation 1 was unable to properly account for the camera perspective during the texturing process, resulting in strange graphical artefacts when viewing walls and floors from certain angles. Straight lines in textures might start to look bent, so the PS1 had a reputation for having slightly wonky textures. This problem was due to the PS1 using affine texture mapping, and in this shader, the perspective effect (which is usually automatically applied) is removed in order to recreate the affine mapping effect.