Intensity/Alpha Maps

/* DECAL ENV */
glBindTextureEXT ( { SPOTLIGHT, PROJSHADOW, CUTOUT } );

glDepthFunc ( GL_LEQUAL );
glDisable ( GL_LIGHTING );
glBlendFunc ( GL_ONE, GL_ZERO );

CulledDisplayList* = DrawScene();

glBindTextureEXT ( COMMON_TEXTURE );

glDepthFunc ( GL_EQUAL* );
glEnable ( GL_LIGHTING );

/* INTENSITY MAP */
glBlendFunc ( { GL_DST_COLOR, GL_DST_ALPHA }*, GL_ZERO );

glCallList ( CulledDisplayList );