@iquilezles Maybe the article should further mention that the true evil of if statements in shaders only comes when the neighbouring shader invocations take different paths, as both instances must execute both paths and then throw one away
@MoArtis@Visuwyg It helps reduce the distortion caused by affine texture mapping. As other people said, it also provides more detailed vertex lighting.
@PierreTerdiman That's so strange. Is this something done intentionally by Windows (or maybe the driver before presenting to the screen) to make graphics smoother or is this some artefact from the pixels being passed through a 100 layers of Windows code...