From 28d1a506c8d09fa66170978c85566c34cbf1cc0a Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Sun, 9 Aug 2015 23:45:44 -0700 Subject: [PATCH] mesa/formats: Fix swizzle flipping for big-endian targets 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. Reviewed-by: Iago Toral Reviewed-by: Oded Gabbay Cc: "10.6 10.5" --- 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 @@ _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; } -- 2.7.4