[PATCH v2 2/4] windowscodecs/tests: Add a DXT3 test image for DDS decoder.

[Ziqing Hui]

We only tested DXT1 images with 1 blocks before. That's not enough.

Also, for CopyBlocks(), when boundsInBlocks parameter is NULL, the stride should be the stride of the frame itself.

Signed-off-by: Ziqing Hui 
---
 dlls/windowscodecs/tests/ddsformat.c | 67 ++++++++++++++++++++++++----
 1 file changed, 59 insertions(+), 8 deletions(-)