gallium/u_pstipple: add ability to specify a fixed texture unit

E.g. r600g can use slot 17, which is outside of the API range.

Reviewed-by: Glenn Kennard <glenn.kennard@gmail.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

3 files changed, 21 insertions, 9 deletions

diff --git a/src/gallium/auxiliary/util/u_pstipple.c b/src/gallium/auxiliary/util/u_pstipple.c
index 1e1ec4a..0a20bdb 100644
--- a/src/gallium/auxiliary/util/u_pstipple.c
+++ b/src/gallium/auxiliary/util/u_pstipple.c
@@ -182,6 +182,8 @@ struct pstip_transform_context {
    int freeSampler;  /** an available sampler for the pstipple */
    int numImmed;
    uint coordOrigin;
+   unsigned fixedUnit;
+   bool hasFixedUnit;
 };
 
 
@@ -279,7 +281,8 @@ pstip_transform_prolog(struct tgsi_transform_context *ctx)
    }
 
    /* declare new sampler */
-   tgsi_transform_sampler_decl(ctx, pctx->freeSampler);
+   tgsi_transform_sampler_decl(ctx,
+         pctx->hasFixedUnit ? pctx->fixedUnit : pctx->freeSampler);
 
    /* Declare temp[0] reg if not already declared.
     * We can always use temp[0] since this code is before
@@ -318,7 +321,8 @@ pstip_transform_prolog(struct tgsi_transform_context *ctx)
    tgsi_transform_tex_2d_inst(ctx,
                               TGSI_FILE_TEMPORARY, texTemp,
                               TGSI_FILE_TEMPORARY, texTemp,
-                              pctx->freeSampler);
+                              pctx->hasFixedUnit ? pctx->fixedUnit
+                                                 : pctx->freeSampler);
 
    /* KILL_IF -texTemp;   # if -texTemp < 0, kill fragment */
    tgsi_transform_kill_inst(ctx,
@@ -330,12 +334,16 @@ pstip_transform_prolog(struct tgsi_transform_context *ctx)
 /**
  * Given a fragment shader, return a new fragment shader which
  * samples a stipple texture and executes KILL.
+ *
  * \param samplerUnitOut  returns the index of the sampler unit which
- *                        will be used to sample the stipple texture
+ *                        will be used to sample the stipple texture;
+ *                        if NULL, the fixed unit is used
+ * \param fixedUnit       fixed texture unit used for the stipple texture
  */
 struct tgsi_token *
 util_pstipple_create_fragment_shader(const struct tgsi_token *tokens,
-                                     unsigned *samplerUnitOut)
+                                     unsigned *samplerUnitOut,
+                                     unsigned fixedUnit)
 {
    struct pstip_transform_context transform;
    const uint newLen = tgsi_num_tokens(tokens) + NUM_NEW_TOKENS;
@@ -352,6 +360,8 @@ util_pstipple_create_fragment_shader(const struct tgsi_token *tokens,
    transform.wincoordInput = -1;
    transform.maxInput = -1;
    transform.coordOrigin = TGSI_FS_COORD_ORIGIN_UPPER_LEFT;
+   transform.hasFixedUnit = !samplerUnitOut;
+   transform.fixedUnit = fixedUnit;
    transform.base.prolog = pstip_transform_prolog;
    transform.base.transform_declaration = pstip_transform_decl;
    transform.base.transform_immediate = pstip_transform_immed;
@@ -368,9 +378,10 @@ util_pstipple_create_fragment_shader(const struct tgsi_token *tokens,
    tgsi_dump(new_fs->tokens, 0);
 #endif
 
-   assert(transform.freeSampler < PIPE_MAX_SAMPLERS);
-   *samplerUnitOut = transform.freeSampler;
+   if (samplerUnitOut) {
+      assert(transform.freeSampler < PIPE_MAX_SAMPLERS);
+      *samplerUnitOut = transform.freeSampler;
+   }
 
    return new_tokens;
 }
-
diff --git a/src/gallium/auxiliary/util/u_pstipple.h b/src/gallium/auxiliary/util/u_pstipple.h
index 13155e7..249c58b 100644
--- a/src/gallium/auxiliary/util/u_pstipple.h
+++ b/src/gallium/auxiliary/util/u_pstipple.h
@@ -49,7 +49,8 @@ util_pstipple_create_sampler(struct pipe_context *pipe);
 
 struct tgsi_token *
 util_pstipple_create_fragment_shader(const struct tgsi_token *tokens,
-                                     unsigned *samplerUnitOut);
+                                     unsigned *samplerUnitOut,
+                                     unsigned fixed_unit);
 
 
 #endif
diff --git a/src/gallium/drivers/softpipe/sp_state_shader.c b/src/gallium/drivers/softpipe/sp_state_shader.c
index 58a2498..8ab2903 100644
--- a/src/gallium/drivers/softpipe/sp_state_shader.c
+++ b/src/gallium/drivers/softpipe/sp_state_shader.c
@@ -64,7 +64,7 @@ create_fs_variant(struct softpipe_context *softpipe,
          /* get new shader that implements polygon stippling */
          var->tokens = 
             util_pstipple_create_fragment_shader(curfs->tokens,
-                                                 &var->stipple_sampler_unit);
+                                                 &var->stipple_sampler_unit, 0);
       }
       else
 #endif