swr: Account for index_bias in offsets

When calculating buffer offsets for client buffers account for info.index_bias.

Fixes the follow piglit tests:
arb_draw_elements_base_vertex-drawelements-user_varrays
arb_draw_elements_base_vertex-negative-index-user_varrays

Reviewed-By: Bruce Cherniak <bruce.cherniak@intel.com>

diff --git a/src/gallium/drivers/swr/swr_state.cpp b/src/gallium/drivers/swr/swr_state.cpp
index 4530d377ee904b5bf22197a3f2ccdef5a9777639..d320c901168a2d3c5b9ae47c3c6c73461d789aba 100644 (file)
--- a/src/gallium/drivers/swr/swr_state.cpp
+++ b/src/gallium/drivers/swr/swr_state.cpp
@@ -1012,8 +1012,8 @@ swr_user_vbuf_range(const struct pipe_draw_info *info,
       *size = elems * vb->stride;
    } else if (vb->stride) {
       elems = info->max_index - info->min_index + 1;
-      *totelems = info->max_index + 1;
-      *base = info->min_index * vb->stride;
+      *totelems = (info->max_index + info->index_bias) + 1;
+      *base = (info->min_index + info->index_bias) * vb->stride;
       *size = elems * vb->stride;
    } else {
       *totelems = 1;
@@ -1304,7 +1304,7 @@ swr_update_derived(struct pipe_context *pipe,
             uint32_t base;
             swr_user_vbuf_range(&info, ctx->velems, vb, i, &elems, &base, &size);
             partial_inbounds = 0;
-            min_vertex_index = info.min_index;
+            min_vertex_index = info.min_index + info.index_bias;
 
             size = AlignUp(size, 4);
             /* If size of client memory copy is too large, don't copy. The