[Mesa-dev] [PATCH] gallivm: fix texel fetch for array textures

[sroland at vmware.com]

From: Roland Scheidegger <sroland at vmware.com>

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 (no overlap of texelFetch and array texture tests in piglit).
---
 src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c |   55 ++++++++++++++-------
 1 file 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 ba265b2..701e8c1 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 */
-- 
1.7.9.5