POLYTYPE_GCOL (3) - Linux Man Pages
POLYTYPE_GCOL: Polygon rendering mode type Allegro game programming library.
POLYTYPE_GCOL - Polygon rendering mode type Allegro game programming library.
A single-color gouraud shaded polygon. The colors for each vertex are taken
from the `c' value, and interpolated across the polygon. This is very fast,
but will only work in 256-color modes if your palette contains a smooth
gradient between the colors. In truecolor modes it interprets the color as
a packed, display-format value as produced by the makecol() function.