− | | Appears to be related to Microsoft's [https://msdn.microsoft.com/en-us/library/windows/desktop/bb174703.aspx lit] instruction; DST = clamp(SRC1, min={0, -127.9961, 0, 0}, max={inf, 127.9961, 0, inf}); n.b.: 127.9961 = 0x7FFF / 0x100 | + | | Partial lighting computation, may be used in conjunction with EX2, LG2, etc to compute the vertex lighting coefficients. See the [https://msdn.microsoft.com/en-us/library/windows/desktop/bb174703.aspx Microsoft] and [https://registry.khronos.org/OpenGL/extensions/ARB/ARB_vertex_program.txt ARB] docs for more information on how to implement the full lit function; DST = {max(src.x, 0), max(min(src.y, 127.9961), -127.9961), 0, max(src.w, 0)} and it sets the cmp.x and cmp.y flags based on if the respective src.x and src.w components are >= 0. |