The swizzle defines where in the format you should look for any given
channel. When we flip the format around for BE targets, we need to
change
the destinations of the swizzles, not the sources. For example, say
the
format is an RGBX format with a swizzle of xyz1 on LE. Then it should
be
wzy1 on BE; however, the code as it was before, would have made it
1zyx on
BE which is clearly wrong.
Cc: Iago Toral <[email protected]>
Cc: Oded Gabbay <[email protected]>
---
src/mesa/main/formats.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/src/mesa/main/formats.c b/src/mesa/main/formats.c
index d927073..27590ed 100644
--- a/src/mesa/main/formats.c
+++ b/src/mesa/main/formats.c
@@ -354,14 +354,22 @@
mi_mesa_array_format_flip_channels(mesa_array_format format)
return format;
if (num_channels == 2) {
- _mesa_array_format_set_swizzle(&format, swizzle[1], swizzle[0],
- swizzle[2], swizzle[3]);
+ /* Assert that the swizzle makes sense for 2 channels */
+ for (unsigned i = 0; i < 4; i++)
+ assert(swizzle[i] != 2 && swizzle[i] != 3);
+
+ static const uint8_t flip_xy[6] = { 1, 0, 2, 3, 4, 5 };
+ _mesa_array_format_set_swizzle(&format,
+ flip_xy[swizzle[0]],
flip_xy[swizzle[1]],
+ flip_xy[swizzle[2]],
flip_xy[swizzle[3]]);
return format;
}
if (num_channels == 4) {
- _mesa_array_format_set_swizzle(&format, swizzle[3], swizzle[2],
- swizzle[1], swizzle[0]);
+ static const uint8_t flip[6] = { 3, 2, 1, 0, 4, 5 };
+ _mesa_array_format_set_swizzle(&format,
+ flip[swizzle[0]],
flip[swizzle[1]],
+ flip[swizzle[2]],
flip[swizzle[3]]);
return format;
}
--:-)
2.4.3
