[Mesa-dev] [PATCH] st/nine: Forbid POSITION0 and fix depth input for PS3.0

[Axel Davy]

POSITION0 input is forbidden for PS3.0 apparently.

Besides for depth input we weren't using the system value
version if needed

Signed-off-by: Axel Davy <axel.davy at ens.fr>

---
Could be better having it separated into two patches perhaps.
It should get into Mesa 11.2, to prevent regression caused
by the introduction of position as system value.

 src/gallium/state_trackers/nine/nine_shader.c | 44 +++++++++++++++++----------
 1 file changed, 28 insertions(+), 16 deletions(-)

diff --git a/src/gallium/state_trackers/nine/nine_shader.c b/src/gallium/state_trackers/nine/nine_shader.c
index a7a7da2..40f06a8 100644
--- a/src/gallium/state_trackers/nine/nine_shader.c
+++ b/src/gallium/state_trackers/nine/nine_shader.c
@@ -830,6 +830,18 @@ nine_ureg_dst_register(unsigned file, int index)
     return ureg_dst(ureg_src_register(file, index));
 }
 
+static inline struct ureg_src
+nine_get_position_input(struct shader_translator *tx)
+{
+    struct ureg_program *ureg = tx->ureg;
+
+    if (tx->wpos_is_sysval)
+        return ureg_DECL_system_value(ureg, TGSI_SEMANTIC_POSITION, 0);
+    else
+        return ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION,
+                                  0, TGSI_INTERPOLATE_LINEAR);
+}
+
 static struct ureg_src
 tx_src_param(struct shader_translator *tx, const struct sm1_src_param *param)
 {
@@ -955,16 +967,8 @@ tx_src_param(struct shader_translator *tx, const struct sm1_src_param *param)
     case D3DSPR_MISCTYPE:
         switch (param->idx) {
         case D3DSMO_POSITION:
-           if (ureg_src_is_undef(tx->regs.vPos)) {
-              if (tx->wpos_is_sysval) {
-                  tx->regs.vPos =
-                      ureg_DECL_system_value(ureg, TGSI_SEMANTIC_POSITION, 0);
-              } else {
-                  tx->regs.vPos =
-                      ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION, 0,
-                                         TGSI_INTERPOLATE_LINEAR);
-              }
-           }
+           if (ureg_src_is_undef(tx->regs.vPos))
+              tx->regs.vPos = nine_get_position_input(tx);
            if (tx->shift_wpos) {
                /* TODO: do this only once */
                struct ureg_dst wpos = tx_scratch(tx);
@@ -2048,9 +2052,22 @@ DECL_SPECIAL(DCL)
             unsigned interp_location = 0;
             /* SM3 only, SM2 input semantic determined by file */
             assert(sem.reg.idx < Elements(tx->regs.v));
+
+            if (tgsi.Name == TGSI_SEMANTIC_POSITION) {
+                /* Position0/PositionT0 are forbidden (likely because vPos already does that)
+                 *  is forbidden. */
+                if (sem.usage == D3DDECLUSAGE_POSITION && sem.usage_idx == 0 ||
+                    sem.usage == D3DDECLUSAGE_POSITIONT)
+                    return D3DERR_INVALIDCALL;
+                /* Following code is for depth (PositionT is not possible) */
+                tx->regs.v[sem.reg.idx] = nine_get_position_input(tx);
+                return D3D_OK;
+            }
+
             if (sem.reg.mod & NINED3DSPDM_CENTROID ||
                 (tgsi.Name == TGSI_SEMANTIC_COLOR && tx->info->force_color_in_centroid))
                 interp_location = TGSI_INTERPOLATE_LOC_CENTROID;
+
             tx->regs.v[sem.reg.idx] = ureg_DECL_fs_input_cyl_centroid(
                 ureg, tgsi.Name, tgsi.Index,
                 nine_tgsi_to_interp_mode(&tgsi),
@@ -3269,12 +3286,7 @@ shader_add_ps_fog_stage(struct shader_translator *tx, struct ureg_src src_col)
     }
 
     if (tx->info->fog_mode != D3DFOG_NONE) {
-        if (tx->wpos_is_sysval) {
-            depth = ureg_DECL_system_value(ureg, TGSI_SEMANTIC_POSITION, 0);
-        } else {
-            depth = ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION, 0,
-                                       TGSI_INTERPOLATE_LINEAR);
-        }
+        depth = nine_get_position_input(tx);
         depth = ureg_scalar(depth, TGSI_SWIZZLE_Z);
     }
 
-- 
2.7.0