Texture layers and blending modes

(Position 12)

TechTest Room showing 3 different Blending-Modes

Here we test multiple texture layers and different blending modes. The three walls of this room have two textures each. First texture is always same as the base texture in all rooms, while the second is blended with a different mode each.
TechTest Room showing Shade-Blending

Left wall has the so called 'shade' mode. That is src*dst*2 (implemented as src*dst+dst*src). This mode is the most used mode for multilayered texturing, and is also used for lightmaps on most world polygons.
TechTest Room showing Alpha-Blended

Front wall has its second texture alpha blended.
TechTest Room showing Add-Blended

The right wall has its second texture added to the first texture.