gallium/util, mesa: Refactor etc1 unpack function

Move the body of util_etc1_rgb8_unpack_rgba_unorm8 into a new function
that can be shared between gallium and dri drivers,
texcompress_etc_tmp.h:etc1_unpack_rgba8888.

CC: Chia-I <olv@lunarg.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/src/mesa/main/texcompress_etc_tmp.h b/src/mesa/main/texcompress_etc_tmp.h
index 5c8c6de..8bbb2cd 100644
--- a/src/mesa/main/texcompress_etc_tmp.h
+++ b/src/mesa/main/texcompress_etc_tmp.h
@@ -134,3 +134,37 @@ TAG(etc1_fetch_texel)(const struct TAG(etc1_block) *block,
    dst[1] = TAG(etc1_clamp)(base_color[1], modifier);
    dst[2] = TAG(etc1_clamp)(base_color[2], modifier);
 }
+
+static void
+etc1_unpack_rgba8888(uint8_t *dst_row,
+                     unsigned dst_stride,
+                     const uint8_t *src_row,
+                     unsigned src_stride,
+                     unsigned width,
+                     unsigned height)
+{
+   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
+   struct etc1_block block;
+   unsigned x, y, i, j;
+
+   for (y = 0; y < height; y += bh) {
+      const uint8_t *src = src_row;
+
+      for (x = 0; x < width; x+= bw) {
+         etc1_parse_block(&block, src);
+
+         for (j = 0; j < bh; j++) {
+            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
+            for (i = 0; i < bw; i++) {
+               etc1_fetch_texel(&block, i, j, dst);
+               dst[3] = 255;
+               dst += comps;
+            }
+         }
+
+         src += bs;
+      }
+
+      src_row += src_stride;
+   }
+}