swrast: Make a teximage's stored RowStride be in terms of bytes per row.

For hardware drivers with pitch alignment requirements, a
non-power-of-two-sized texture format won't end up being an integer number
of pixels per row.  Also, avoids having to change our units between
MapTextureImage's rowStride and swrast's RowStride.

This doesn't fully convert the compressed texel fetch path, but does make
sure we don't drop any bits (not that we'd expect to).

Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/mesa/swrast/s_texfetch.c b/src/mesa/swrast/s_texfetch.c
index a9bc3fad0a2..f6c269d8baf 100644
--- a/src/mesa/swrast/s_texfetch.c
+++ b/src/mesa/swrast/s_texfetch.c
@@ -98,8 +98,16 @@ static void
 fetch_compressed(const struct swrast_texture_image *swImage,
                  GLint i, GLint j, GLint k, GLfloat *texel)
 {
+   /* The FetchCompressedTexel function takes an integer pixel rowstride,
+    * while the image's rowstride is bytes per row of blocks.
+    */
+   GLuint bw, bh;
+   GLuint texelBytes = _mesa_get_format_bytes(swImage->Base.TexFormat);
+   _mesa_get_format_block_size(swImage->Base.TexFormat, &bw, &bh);
+   assert(swImage->RowStride * bw % texelBytes == 0);
+
    swImage->FetchCompressedTexel(swImage->ImageSlices[k],
-                                 swImage->RowStride,
+                                 swImage->RowStride * bw / texelBytes,
                                  i, j, texel);
 }