| Message ID | 20240624101040.82726-1-phil@philjordan.eu |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] Cursor: 8 -> 1 bit alpha downsampling improvement | expand |
On 2024/06/24 19:10, Phil Dennis-Jordan wrote: > Mouse cursors with 8 bit alpha were downsampled to 1-bit opacity maps by > turning alpha values of 255 into 1 and everything else into 0. This > means that mostly-opaque pixels ended up completely invisible. > > This patch changes the behaviour so that only pixels with less than 50% > alpha (0-127) are treated as transparent when converted to 1-bit alpha. > > This greatly improves the subjective appearance of anti-aliased mouse > cursors, such as those used by macOS, when using a front-end UI without > support for alpha-blended cursors, such as some VNC clients. > > Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu> Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
diff --git a/ui/cursor.c b/ui/cursor.c index 29717b3ecb..dd3853320d 100644 --- a/ui/cursor.c +++ b/ui/cursor.c @@ -232,7 +232,7 @@ void cursor_get_mono_mask(QEMUCursor *c, int transparent, uint8_t *mask) for (y = 0; y < c->height; y++) { bit = 0x80; for (x = 0; x < c->width; x++, data++) { - if ((*data & 0xff000000) != 0xff000000) { + if ((*data & 0x80000000) == 0x0) { /* Alpha < 0x80 (128) */ if (transparent != 0) { mask[x/8] |= bit; }
Mouse cursors with 8 bit alpha were downsampled to 1-bit opacity maps by turning alpha values of 255 into 1 and everything else into 0. This means that mostly-opaque pixels ended up completely invisible. This patch changes the behaviour so that only pixels with less than 50% alpha (0-127) are treated as transparent when converted to 1-bit alpha. This greatly improves the subjective appearance of anti-aliased mouse cursors, such as those used by macOS, when using a front-end UI without support for alpha-blended cursors, such as some VNC clients. Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu> --- ui/cursor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)