st/mesa: simplify and improve CopyTexSubImage

It has become a bit messy.

Changes:

- finally correct checking for transfer ops depending on the base format

- making sure the base internal format and the texture format match
  (we were ignoring it, but it's important for correctness)

- the way-too-strict rule that both src and dst base formats must be the same
  was dropped; ensuring the simpler and more permissive rule mentioned above
  is enough

- stop using util_blit_pixels; pipe->blit is flexible enough, and now that we
  have RGBX and red-alpha formats, pipe->blit can be used for more cases

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

1 files changed, 4 insertions, 0 deletions

diff --git a/src/mesa/main/texstore.h b/src/mesa/main/texstore.h
index 107f2130015..75f24bd45ac 100644
--- a/src/mesa/main/texstore.h
+++ b/src/mesa/main/texstore.h
@@ -69,6 +69,10 @@
 extern GLboolean
 _mesa_texstore(TEXSTORE_PARAMS);
 
+extern GLboolean
+_mesa_texstore_needs_transfer_ops(struct gl_context *ctx,
+                                  GLenum baseInternalFormat,
+                                  gl_format dstFormat);
 
 extern GLboolean
 _mesa_texstore_can_use_memcpy(struct gl_context *ctx,