st/mesa: do vertex and fragment color clamping in shaders
For ARB_color_buffer_float. Most hardware can't do it and st/mesa is
the perfect place for a fallback.
The exceptions are:
- r500 (vertex clamp only)
- nv50 (both)
- nvc0 (both)
- softpipe (both)
We also have to take into account that r300 can do CLAMPED vertex colors only,
while r600 can do UNCLAMPED vertex colors only. The difference can be expressed
with the two new CAPs.
diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index dc1d33f..a3fd4db 100644
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -76,6 +76,17 @@
{
struct st_context *st = st_context(ctx);
+ /* Replace _NEW_FRAG_CLAMP with ST_NEW_FRAGMENT_PROGRAM for the fallback. */
+ if (st->clamp_frag_color_in_shader && (new_state & _NEW_FRAG_CLAMP)) {
+ new_state &= ~_NEW_FRAG_CLAMP;
+ st->dirty.st |= ST_NEW_FRAGMENT_PROGRAM;
+ }
+
+ /* Update the vertex shader if ctx->Light._ClampVertexColor was changed. */
+ if (st->clamp_vert_color_in_shader && (new_state & _NEW_LIGHT)) {
+ st->dirty.st |= ST_NEW_VERTEX_PROGRAM;
+ }
+
st->dirty.mesa |= new_state;
st->dirty.st |= ST_NEW_MESA;