gallium: add TGSI_SEMANTIC_TEXCOORD,PCOORD v3

This makes it possible to identify gl_TexCoord and gl_PointCoord
for drivers where sprite coordinate replacement is restricted.

The new PIPE_CAP_TGSI_TEXCOORD decides whether these varyings
should be hidden behind the GENERIC semantic or not.

With this patch only nvc0 and nv30 will request that they be used.

v2: introduce a CAP so other drivers don't have to bother with
the new semantic

v3: adapt to introduction gl_varying_slot enum

3 files changed, 30 insertions, 20 deletions

diff --git a/src/gallium/drivers/nv30/nv30_screen.c b/src/gallium/drivers/nv30/nv30_screen.c
index 90c367280d4..e17ee76fbd1 100644
--- a/src/gallium/drivers/nv30/nv30_screen.c
+++ b/src/gallium/drivers/nv30/nv30_screen.c
@@ -79,6 +79,7 @@ nv30_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_TGSI_FS_COORD_ORIGIN_LOWER_LEFT:
    case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER:
    case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER:
+   case PIPE_CAP_TGSI_TEXCOORD:
    case PIPE_CAP_USER_CONSTANT_BUFFERS:
    case PIPE_CAP_USER_INDEX_BUFFERS:
       return 1;
diff --git a/src/gallium/drivers/nv30/nvfx_fragprog.c b/src/gallium/drivers/nv30/nvfx_fragprog.c
index 935804e8e14..4be7dec2c03 100644
--- a/src/gallium/drivers/nv30/nvfx_fragprog.c
+++ b/src/gallium/drivers/nv30/nvfx_fragprog.c
@@ -927,15 +927,17 @@ nvfx_fragprog_parse_decl_input(struct nv30_context *nvfx, struct nvfx_fpc *fpc,
    case TGSI_SEMANTIC_FACE:
       hw = NV40_FP_OP_INPUT_SRC_FACING;
       break;
-   case TGSI_SEMANTIC_GENERIC:
-      if (fdec->Semantic.Index >= 8)
-         return TRUE;
-
+   case TGSI_SEMANTIC_TEXCOORD:
+      assert(fdec->Semantic.Index < 8);
       fpc->fp->texcoord[fdec->Semantic.Index] = fdec->Semantic.Index;
       fpc->fp->texcoords |= (1 << fdec->Semantic.Index);
       fpc->fp->vp_or |= (0x00004000 << fdec->Semantic.Index);
       hw = NVFX_FP_OP_INPUT_SRC_TC(fdec->Semantic.Index);
       break;
+   case TGSI_SEMANTIC_GENERIC:
+   case TGSI_SEMANTIC_PCOORD:
+      /* will be assigned to remaining TC slots later */
+      return TRUE;
    default:
       assert(0);
       return FALSE;
@@ -955,22 +957,24 @@ nvfx_fragprog_assign_generic(struct nv30_context *nvfx, struct nvfx_fpc *fpc,
 
    switch (fdec->Semantic.Name) {
    case TGSI_SEMANTIC_GENERIC:
-      if (fdec->Semantic.Index >= 8) {
-         for (hw = 0; hw < num_texcoords; hw++) {
-            if (fpc->fp->texcoord[hw] == 0xffff) {
-               fpc->fp->texcoord[hw] = fdec->Semantic.Index;
-               if (hw <= 7) {
-                  fpc->fp->texcoords |= (0x1 << hw);
-                  fpc->fp->vp_or |= (0x00004000 << hw);
-               } else {
-                  fpc->fp->vp_or |= (0x00001000 << (hw - 8));
-               }
-               if (fdec->Semantic.Index == 9)
-                  fpc->fp->point_sprite_control |= (0x00000100 << hw);
-               hw = NVFX_FP_OP_INPUT_SRC_TC(hw);
-               fpc->r_input[idx] = nvfx_reg(NVFXSR_INPUT, hw);
-               return TRUE;
+   case TGSI_SEMANTIC_PCOORD:
+      for (hw = 0; hw < num_texcoords; hw++) {
+         if (fpc->fp->texcoord[hw] == 0xffff) {
+            if (hw <= 7) {
+               fpc->fp->texcoords |= (0x1 << hw);
+               fpc->fp->vp_or |= (0x00004000 << hw);
+            } else {
+               fpc->fp->vp_or |= (0x00001000 << (hw - 8));
+            }
+            if (fdec->Semantic.Name == TGSI_SEMANTIC_PCOORD) {
+               fpc->fp->texcoord[hw] = 0xfffe;
+               fpc->fp->point_sprite_control |= (0x00000100 << hw);
+            } else {
+               fpc->fp->texcoord[hw] = fdec->Semantic.Index + 8;
             }
+            hw = NVFX_FP_OP_INPUT_SRC_TC(hw);
+            fpc->r_input[idx] = nvfx_reg(NVFXSR_INPUT, hw);
+            return TRUE;
          }
          return FALSE;
       }
diff --git a/src/gallium/drivers/nv30/nvfx_vertprog.c b/src/gallium/drivers/nv30/nvfx_vertprog.c
index 74dba38001c..b73d4184045 100644
--- a/src/gallium/drivers/nv30/nvfx_vertprog.c
+++ b/src/gallium/drivers/nv30/nvfx_vertprog.c
@@ -819,6 +819,7 @@ nvfx_vertprog_parse_decl_output(struct nv30_context *nv30, struct nvfx_vpc *vpc,
 {
    unsigned num_texcoords = nv30->is_nv4x ? 10 : 8;
    unsigned idx = fdec->Range.First;
+   unsigned semantic_index = fdec->Semantic.Index;
    int hw = 0, i;
 
    switch (fdec->Semantic.Name) {
@@ -860,8 +861,12 @@ nvfx_vertprog_parse_decl_output(struct nv30_context *nv30, struct nvfx_vpc *vpc,
       hw = NVFX_VP(INST_DEST_PSZ);
       break;
    case TGSI_SEMANTIC_GENERIC:
+      /* this is really an identifier for VP/FP linkage */
+      semantic_index += 8;
+      /* fall through */
+   case TGSI_SEMANTIC_TEXCOORD:
       for (i = 0; i < num_texcoords; i++) {
-         if (vpc->vp->texcoord[i] == fdec->Semantic.Index) {
+         if (vpc->vp->texcoord[i] == semantic_index) {
             hw = NVFX_VP(INST_DEST_TC(i));
             break;
          }