gallium: introduce GLSL based interpolation rules. (v2)

This introduces an unspecified interpolation paramter that is only allowed for
color semantics, so a specified GLSL interpolation will override the ShadeModel
specified interpolation, but not vice-versa.

This fixes a lot of the interpolation tests in piglit.

v2: rename from unspecified to color

Signed-off-by: Dave Airlie <[email protected]>

6 files changed, 18 insertions, 5 deletions

diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
index 3e2b899d40e..52d4ff4e80b 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
@@ -2371,6 +2371,10 @@ exec_declaration(struct tgsi_exec_machine *mach,
                eval = eval_perspective_coef;
                break;
 
+            case TGSI_INTERPOLATE_COLOR:
+               eval = mach->flatshade_color ? eval_constant_coef : eval_perspective_coef;
+               break;
+
             default:
                assert(0);
                return;
diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.h b/src/gallium/auxiliary/tgsi/tgsi_exec.h
index 223da2cb1c6..0817e14101b 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.h
@@ -263,7 +263,7 @@ struct tgsi_exec_machine
    const struct tgsi_interp_coef *InterpCoefs;
    struct tgsi_exec_vector       QuadPos;
    float                         Face;    /**< +1 if front facing, -1 if back facing */
-
+   bool                          flatshade_color;
    /* Conditional execution masks */
    uint CondMask;  /**< For IF/ELSE/ENDIF */
    uint LoopMask;  /**< For BGNLOOP/ENDLOOP */
diff --git a/src/gallium/auxiliary/tgsi/tgsi_strings.c b/src/gallium/auxiliary/tgsi/tgsi_strings.c
index aa12493d9b0..de9152dae21 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_strings.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_strings.c
@@ -117,7 +117,8 @@ const char *tgsi_interpolate_names[TGSI_INTERPOLATE_COUNT] =
 {
    "CONSTANT",
    "LINEAR",
-   "PERSPECTIVE"
+   "PERSPECTIVE",
+   "COLOR"
 };
 
 const char *tgsi_primitive_names[PIPE_PRIM_MAX] =
diff --git a/src/gallium/drivers/softpipe/sp_quad_fs.c b/src/gallium/drivers/softpipe/sp_quad_fs.c
index 7b08cd0cf30..7800ba8442f 100644
--- a/src/gallium/drivers/softpipe/sp_quad_fs.c
+++ b/src/gallium/drivers/softpipe/sp_quad_fs.c
@@ -74,6 +74,7 @@ shade_quad(struct quad_stage *qs, struct quad_header *quad)
    struct tgsi_exec_machine *machine = softpipe->fs_machine;
 
    /* run shader */
+   machine->flatshade_color = softpipe->rasterizer->flatshade ? TRUE : FALSE;
    return softpipe->fs_variant->run( softpipe->fs_variant, machine, quad );
 }
 
diff --git a/src/gallium/drivers/softpipe/sp_state_derived.c b/src/gallium/drivers/softpipe/sp_state_derived.c
index 56859971d8e..7b2b04e84e9 100644
--- a/src/gallium/drivers/softpipe/sp_state_derived.c
+++ b/src/gallium/drivers/softpipe/sp_state_derived.c
@@ -100,6 +100,9 @@ softpipe_get_vertex_info(struct softpipe_context *softpipe)
          case TGSI_INTERPOLATE_PERSPECTIVE:
             interp = INTERP_PERSPECTIVE;
             break;
+         case TGSI_INTERPOLATE_COLOR:
+            assert(fsInfo->input_semantic_name[i] == TGSI_SEMANTIC_COLOR);
+            break;
          default:
             assert(0);
             interp = INTERP_LINEAR;
@@ -111,8 +114,11 @@ softpipe_get_vertex_info(struct softpipe_context *softpipe)
             break;
 
          case TGSI_SEMANTIC_COLOR:
-            if (softpipe->rasterizer->flatshade) {
-               interp = INTERP_CONSTANT;
+            if (fsInfo->input_interpolate[i] == TGSI_INTERPOLATE_COLOR) {
+               if (softpipe->rasterizer->flatshade)
+                  interp = INTERP_CONSTANT;
+               else
+                  interp = INTERP_PERSPECTIVE;
             }
             break;
          }
diff --git a/src/gallium/include/pipe/p_shader_tokens.h b/src/gallium/include/pipe/p_shader_tokens.h
index 2fbe1df8312..cb1e698996e 100644
--- a/src/gallium/include/pipe/p_shader_tokens.h
+++ b/src/gallium/include/pipe/p_shader_tokens.h
@@ -100,7 +100,8 @@ enum tgsi_file_type {
 #define TGSI_INTERPOLATE_CONSTANT      0
 #define TGSI_INTERPOLATE_LINEAR        1
 #define TGSI_INTERPOLATE_PERSPECTIVE   2
-#define TGSI_INTERPOLATE_COUNT         3
+#define TGSI_INTERPOLATE_COLOR         3 /* special color case for smooth/flat */
+#define TGSI_INTERPOLATE_COUNT         4
 
 #define TGSI_CYLINDRICAL_WRAP_X (1 << 0)
 #define TGSI_CYLINDRICAL_WRAP_Y (1 << 1)