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.

8 files changed, 23 insertions, 8 deletions

diff --git a/src/gallium/drivers/i915/i915_screen.c b/src/gallium/drivers/i915/i915_screen.c
index 6fc854f20f1..aef0ed6980d 100644
--- a/src/gallium/drivers/i915/i915_screen.c
+++ b/src/gallium/drivers/i915/i915_screen.c
@@ -181,6 +181,7 @@ i915_get_param(struct pipe_screen *screen, enum pipe_cap cap)
    case PIPE_CAP_VERTEX_ELEMENT_INSTANCE_DIVISOR:
    case PIPE_CAP_BLEND_EQUATION_SEPARATE:
    case PIPE_CAP_TGSI_INSTANCEID:
+   case PIPE_CAP_VERTEX_COLOR_CLAMPED:
       return 1;
 
    /* Unsupported features (boolean caps). */
@@ -196,12 +197,13 @@ i915_get_param(struct pipe_screen *screen, enum pipe_cap cap)
    case PIPE_CAP_SEAMLESS_CUBE_MAP:
    case PIPE_CAP_SEAMLESS_CUBE_MAP_PER_TEXTURE:
    case PIPE_CAP_SCALED_RESOLVE:
-   case PIPE_CAP_FRAGMENT_COLOR_CLAMP_CONTROL:
+   case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
    case PIPE_CAP_MIXED_COLORBUFFER_FORMATS:
    case PIPE_CAP_CONDITIONAL_RENDER:
    case PIPE_CAP_TEXTURE_BARRIER:
    case PIPE_CAP_TGSI_CAN_COMPACT_VARYINGS:
    case PIPE_CAP_TGSI_CAN_COMPACT_CONSTANTS:
+   case PIPE_CAP_VERTEX_COLOR_UNCLAMPED:
       return 0;
 
    /* Features we can lie about (boolean caps). */
diff --git a/src/gallium/drivers/nv50/nv50_screen.c b/src/gallium/drivers/nv50/nv50_screen.c
index 7ee90f18543..536e06471b6 100644
--- a/src/gallium/drivers/nv50/nv50_screen.c
+++ b/src/gallium/drivers/nv50/nv50_screen.c
@@ -112,7 +112,9 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
       return 1;
    case PIPE_CAP_MAX_RENDER_TARGETS:
       return 8;
-   case PIPE_CAP_FRAGMENT_COLOR_CLAMP_CONTROL:
+   case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
+   case PIPE_CAP_VERTEX_COLOR_UNCLAMPED:
+   case PIPE_CAP_VERTEX_COLOR_CLAMPED:
       return 1;
    case PIPE_CAP_TIMER_QUERY:
    case PIPE_CAP_OCCLUSION_QUERY:
diff --git a/src/gallium/drivers/nvc0/nvc0_screen.c b/src/gallium/drivers/nvc0/nvc0_screen.c
index f9ad39df706..5116646949c 100644
--- a/src/gallium/drivers/nvc0/nvc0_screen.c
+++ b/src/gallium/drivers/nvc0/nvc0_screen.c
@@ -99,7 +99,9 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
       return 1;
    case PIPE_CAP_MAX_RENDER_TARGETS:
       return 8;
-   case PIPE_CAP_FRAGMENT_COLOR_CLAMP_CONTROL:
+   case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
+   case PIPE_CAP_VERTEX_COLOR_UNCLAMPED:
+   case PIPE_CAP_VERTEX_COLOR_CLAMPED:
       return 1;
    case PIPE_CAP_TIMER_QUERY:
    case PIPE_CAP_OCCLUSION_QUERY:
diff --git a/src/gallium/drivers/nvfx/nvfx_screen.c b/src/gallium/drivers/nvfx/nvfx_screen.c
index ead777de784..2a3289f04fd 100644
--- a/src/gallium/drivers/nvfx/nvfx_screen.c
+++ b/src/gallium/drivers/nvfx/nvfx_screen.c
@@ -72,6 +72,7 @@ nvfx_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 	case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER:
 	case PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT:
 	case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER:
+	case PIPE_CAP_VERTEX_COLOR_CLAMPED:
 		return 1;
 	case PIPE_CAP_DEPTH_CLIP_DISABLE:
 		return 0; // TODO: implement depth clamp
@@ -80,7 +81,8 @@ nvfx_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 	case PIPE_CAP_MAX_TEXTURE_ARRAY_LAYERS:
 	case PIPE_CAP_TGSI_INSTANCEID:
 	case PIPE_CAP_VERTEX_ELEMENT_INSTANCE_DIVISOR:
-	case PIPE_CAP_FRAGMENT_COLOR_CLAMP_CONTROL:
+	case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
+	case PIPE_CAP_VERTEX_COLOR_UNCLAMPED:
 	case PIPE_CAP_SEAMLESS_CUBE_MAP:
 	case PIPE_CAP_SEAMLESS_CUBE_MAP_PER_TEXTURE:
 	case PIPE_CAP_SHADER_STENCIL_EXPORT:
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. */
diff --git a/src/gallium/drivers/r300/r300_state.c b/src/gallium/drivers/r300/r300_state.c
index 2bc703669ae..5d4a895e87c 100644
--- a/src/gallium/drivers/r300/r300_state.c
+++ b/src/gallium/drivers/r300/r300_state.c
@@ -1036,7 +1036,8 @@ static void* r300_create_rs_state(struct pipe_context* pipe,
     float point_texcoord_bottom = 0;/* R300_GA_POINT_T0: 0x4204 */
     float point_texcoord_right = 1; /* R300_GA_POINT_S1: 0x4208 */
     float point_texcoord_top = 0;   /* R300_GA_POINT_T1: 0x420c */
-    boolean vclamp = state->clamp_vertex_color;
+    boolean vclamp = state->clamp_vertex_color ||
+                     !r300_context(pipe)->screen->caps.is_r500;
     CB_LOCALS;
 
     /* Copy rasterizer state. */
diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
index 3d85160c14c..bd9267f0d9a 100644
--- a/src/gallium/drivers/r600/r600_pipe.c
+++ b/src/gallium/drivers/r600/r600_pipe.c
@@ -361,11 +361,11 @@ static int r600_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER:
 	case PIPE_CAP_SM3:
 	case PIPE_CAP_SEAMLESS_CUBE_MAP:
-	case PIPE_CAP_FRAGMENT_COLOR_CLAMP_CONTROL:
 	case PIPE_CAP_PRIMITIVE_RESTART:
 	case PIPE_CAP_CONDITIONAL_RENDER:
 	case PIPE_CAP_TEXTURE_BARRIER:
 	case PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME:
+	case PIPE_CAP_VERTEX_COLOR_UNCLAMPED:
 		return 1;
 
 	/* Supported except the original R600. */
@@ -385,6 +385,8 @@ static int r600_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_SCALED_RESOLVE:
 	case PIPE_CAP_TGSI_CAN_COMPACT_VARYINGS:
 	case PIPE_CAP_TGSI_CAN_COMPACT_CONSTANTS:
+	case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
+	case PIPE_CAP_VERTEX_COLOR_CLAMPED:
 		return 0;
 
 	/* Stream output. */
diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
index 34592a9b21f..37bbc43f325 100644
--- a/src/gallium/drivers/softpipe/sp_screen.c
+++ b/src/gallium/drivers/softpipe/sp_screen.c
@@ -128,7 +128,9 @@ softpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
       return 7;
    case PIPE_CAP_CONDITIONAL_RENDER:
       return 1;
-   case PIPE_CAP_FRAGMENT_COLOR_CLAMP_CONTROL:
+   case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
+   case PIPE_CAP_VERTEX_COLOR_UNCLAMPED: /* draw module */
+   case PIPE_CAP_VERTEX_COLOR_CLAMPED: /* draw module */
       return 1;
    default:
       return 0;