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.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/gallium/drivers/r300/r300_screen.c b/src/gallium/drivers/r300/r300_screen.c
index cd3c88d170b..48a65696359 100644
--- a/src/gallium/drivers/r300/r300_screen.c
+++ b/src/gallium/drivers/r300/r300_screen.c
@@ -102,6 +102,7 @@ static int r300_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
         case PIPE_CAP_TEXTURE_BARRIER:
         case PIPE_CAP_TGSI_CAN_COMPACT_VARYINGS:
         case PIPE_CAP_TGSI_CAN_COMPACT_CONSTANTS:
+        case PIPE_CAP_VERTEX_COLOR_CLAMPED:
             return 1;
 
         /* r300 cannot do swizzling of compressed textures. Supported otherwise. */
@@ -109,7 +110,7 @@ static int r300_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
             return util_format_s3tc_enabled ? r300screen->caps.dxtc_swizzle : 1;
 
         /* Supported on r500 only. */
-        case PIPE_CAP_FRAGMENT_COLOR_CLAMP_CONTROL:
+        case PIPE_CAP_VERTEX_COLOR_UNCLAMPED:
         case PIPE_CAP_MIXED_COLORBUFFER_FORMATS:
         case PIPE_CAP_SM3:
             return is_r500 ? 1 : 0;
@@ -135,6 +136,7 @@ static int r300_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
         case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
         case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
         case PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME:
+        case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
             return 0;
 
         /* SWTCL-only features. */