gallivm: overhaul of texture sampling code

The new lp_build_sample_general() function will handle all sampling
modes for all texture types.  Still incomplete, but a few additional
sampling modes are now supported.

1D textures should work and most of the code for 3D textures is in place.
No support for cube maps yet.  No support for different min/mag filters.

1 files changed, 17 insertions, 7 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
index 311c9f1b9e..543fd5fea3 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
@@ -155,14 +155,16 @@ lp_build_gather(LLVMBuilderRef builder,
 /**
  * Compute the offset of a pixel.
  *
- * x, y, y_stride are vectors
+ * x, y, z, y_stride, z_stride are vectors
  */
 LLVMValueRef
 lp_build_sample_offset(struct lp_build_context *bld,
                        const struct util_format_description *format_desc,
                        LLVMValueRef x,
                        LLVMValueRef y,
-                       LLVMValueRef y_stride)
+                       LLVMValueRef z,
+                       LLVMValueRef y_stride,
+                       LLVMValueRef z_stride)
 {
    LLVMValueRef x_stride;
    LLVMValueRef offset;
@@ -178,6 +180,10 @@ lp_build_sample_offset(struct lp_build_context *bld,
       LLVMValueRef y_offset_lo, y_offset_hi;
       LLVMValueRef offset_lo, offset_hi;
 
+      /* XXX 1D & 3D addressing not done yet */
+      assert(!z);
+      assert(!z_stride);
+
       x_lo = LLVMBuildAnd(bld->builder, x, bld->one, "");
       y_lo = LLVMBuildAnd(bld->builder, y, bld->one, "");
 
@@ -201,13 +207,17 @@ lp_build_sample_offset(struct lp_build_context *bld,
       offset = lp_build_add(bld, offset_hi, offset_lo);
    }
    else {
-      LLVMValueRef x_offset;
-      LLVMValueRef y_offset;
+      offset = lp_build_mul(bld, x, x_stride);
 
-      x_offset = lp_build_mul(bld, x, x_stride);
-      y_offset = lp_build_mul(bld, y, y_stride);
+      if (y && y_stride) {
+         LLVMValueRef y_offset = lp_build_mul(bld, y, y_stride);
+         offset = lp_build_add(bld, offset, y_offset);
+      }
 
-      offset = lp_build_add(bld, x_offset, y_offset);
+      if (z && z_stride) {
+         LLVMValueRef z_offset = lp_build_mul(bld, z, z_stride);
+         offset = lp_build_add(bld, offset, z_offset);
+      }
    }
 
    return offset;