Mesa (master): gallivm: fix texel fetch for array textures

[Roland Scheidegger]

Module: Mesa
Branch: master
Commit: a460aea3f14222af46f88d1bc686f82180b8a872
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=a460aea3f14222af46f88d1bc686f82180b8a872

Author: Roland Scheidegger <sroland at vmware.com>
Date:   Thu Dec 13 19:12:58 2012 +0100

gallivm: fix texel fetch for array textures

Since we don't call lp_build_sample_common() in the texel fetch path we missed
the layer fixup code. If someone would have tried to do texelFetch with array
textures it would have crashed for sure.
Not really tested (can't run the piglit test being able to use texelFetch with
array samplers for now with llvmpipe).

Reviewed-by: José Fonseca <jfonseca at vmware.com>

---

 src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c |   55 ++++++++++++++------
 1 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index 8c59119..6839478 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -973,6 +973,28 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
    }
 }
 
+
+/**
+ * Clamp layer coord to valid values.
+ */
+static LLVMValueRef
+lp_build_layer_coord(struct lp_build_sample_context *bld,
+                     unsigned unit,
+                     LLVMValueRef layer)
+{
+   LLVMValueRef maxlayer;
+
+   layer = lp_build_iround(&bld->coord_bld, layer);
+   maxlayer = bld->dynamic_state->depth(bld->dynamic_state,
+                                        bld->gallivm, unit);
+   maxlayer = lp_build_sub(&bld->int_bld, maxlayer, bld->int_bld.one);
+   maxlayer = lp_build_broadcast_scalar(&bld->int_coord_bld, maxlayer);
+   return lp_build_clamp(&bld->int_coord_bld, layer,
+                         bld->int_coord_bld.zero, maxlayer);
+
+}
+
+
 /**
  * Calculate cube face, lod, mip levels.
  */
@@ -1018,23 +1040,11 @@ lp_build_sample_common(struct lp_build_sample_context *bld,
       face_derivs.ddx_ddy[1] = NULL;
       derivs = &face_derivs;
    }
-   else if (target == PIPE_TEXTURE_1D_ARRAY ||
-            target == PIPE_TEXTURE_2D_ARRAY) {
-      LLVMValueRef layer, maxlayer;
-
-      if (target == PIPE_TEXTURE_1D_ARRAY) {
-         layer = *t;
-      }
-      else {
-         layer = *r;
-      }
-      layer = lp_build_iround(&bld->coord_bld, layer);
-      maxlayer = bld->dynamic_state->depth(bld->dynamic_state,
-                                           bld->gallivm, unit);
-      maxlayer = lp_build_sub(&bld->int_bld, maxlayer, bld->int_bld.one);
-      maxlayer = lp_build_broadcast_scalar(&bld->int_coord_bld, maxlayer);
-      *r = lp_build_clamp(&bld->int_coord_bld, layer,
-                          bld->int_coord_bld.zero, maxlayer);
+   else if (target == PIPE_TEXTURE_1D_ARRAY) {
+      *r = lp_build_layer_coord(bld, unit, *t);
+   }
+   else if (target == PIPE_TEXTURE_2D_ARRAY) {
+      *r = lp_build_layer_coord(bld, unit, *r);
    }
 
    /*
@@ -1205,6 +1215,7 @@ lp_build_fetch_texel(struct lp_build_sample_context *bld,
    struct lp_build_context *perquadi_bld = &bld->perquadi_bld;
    struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
    unsigned dims = bld->dims, chan;
+   unsigned target = bld->static_state->target;
    LLVMValueRef size, ilevel;
    LLVMValueRef row_stride_vec = NULL, img_stride_vec = NULL;
    LLVMValueRef x = coords[0], y = coords[1], z = coords[2];
@@ -1227,6 +1238,16 @@ lp_build_fetch_texel(struct lp_build_sample_context *bld,
    lp_build_extract_image_sizes(bld, &bld->int_size_bld, int_coord_bld->type,
                                 size, &width, &height, &depth);
 
+   if (target == PIPE_TEXTURE_1D_ARRAY ||
+       target == PIPE_TEXTURE_2D_ARRAY) {
+      if (target == PIPE_TEXTURE_1D_ARRAY) {
+         z = lp_build_layer_coord(bld, unit, y);
+      }
+      else {
+         z = lp_build_layer_coord(bld, unit, z);
+      }
+   }
+
    /* This is a lot like border sampling */
    if (offsets[0]) {
       /* XXX coords are really unsigned, offsets are signed */