diff options
| -rw-r--r-- | types/wlr_output.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/types/wlr_output.c b/types/wlr_output.c index 2207c2e5..611309db 100644 --- a/types/wlr_output.c +++ b/types/wlr_output.c @@ -1118,7 +1118,15 @@ enum wl_output_transform wlr_output_transform_invert( enum wl_output_transform wlr_output_transform_compose( enum wl_output_transform tr_a, enum wl_output_transform tr_b) { uint32_t flipped = (tr_a ^ tr_b) & WL_OUTPUT_TRANSFORM_FLIPPED; - uint32_t rotated = - (tr_a + tr_b) & (WL_OUTPUT_TRANSFORM_90 | WL_OUTPUT_TRANSFORM_180); + uint32_t rotation_mask = WL_OUTPUT_TRANSFORM_90 | WL_OUTPUT_TRANSFORM_180; + uint32_t rotated; + if (tr_b & WL_OUTPUT_TRANSFORM_FLIPPED) { + // When a rotation of k degrees is followed by a flip, the + // equivalent transform is a flip followed by a rotation of + // -k degrees. + rotated = (tr_b - tr_a) & rotation_mask; + } else { + rotated = (tr_a + tr_b) & rotation_mask; + } return flipped | rotated; } |