POLYTYPE_ATEX_TRANS (3) - Linux Man Pages
POLYTYPE_ATEX_TRANS: Polygon rendering mode type Allegro game programming library.
POLYTYPE_ATEX_TRANS, POLYTYPE_PTEX_TRANS - Polygon rendering mode type Allegro game programming library.
Render translucent textures. All the general rules for drawing
translucent things apply. However, these modes have a major
limitation: they only work with memory bitmaps or linear frame
buffers (not with banked frame buffers). Don't even try, they do not
check and your program will die horribly (or at least draw wrong