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authorMichel Dänzer <michel.daenzer@amd.com>2018-10-19 11:02:41 +0200
committerMichel Dänzer <michel@daenzer.net>2018-10-25 09:15:56 +0200
commitad6dfb0124860cf67730bde85867f81d9258c84d (patch)
tree293abc88f7068107de80bf76d8178645accc6297 /src
parentc9d43c1deb9a9cfc41a8d6439caf46d12d220853 (diff)
Detect and fix up non-premultiplied cursor data
X server >= 1.18 already had code for this, but it only caught cases where some pixels have 0 for alpha and non-0 for a non-alpha component. Turns out some apps (e.g. the Civilization VI game) use non-premultiplied cursor data which doesn't have such pixels, but can still result in visual artifacts. This uses the method suggested by Kamil in https://bugs.freedesktop.org/92309#c19: check for pixels where any colour component value is larger than the alpha value, which isn't possible with premultiplied alpha. There can still be non-premultiplied data which won't be caught by this, but that should result in slightly incorrect colours and/or blending at the worst, not wildly incorrect colours such as shown in the bug report below. v2: * Disable the check with current xserver Git master, which already does the same check now. Bugzilla: https://bugs.freedesktop.org/108355 Suggested-by: Kamil Páral <kamil.paral@gmail.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'src')
-rw-r--r--src/drmmode_display.c91
1 files changed, 60 insertions, 31 deletions
diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index ec45d57..34b3d87 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -1500,49 +1500,65 @@ drmmode_cursor_src_offset(Rotation rotation, int width, int height,
#endif
-static uint32_t
-drmmode_cursor_gamma_passthrough(xf86CrtcPtr crtc, uint32_t argb)
-{
- uint32_t alpha = argb >> 24;
-
- if (!alpha)
- return 0;
-
- return argb;
-}
-
-static uint32_t
-drmmode_cursor_gamma(xf86CrtcPtr crtc, uint32_t argb)
+static Bool
+drmmode_cursor_pixel(xf86CrtcPtr crtc, uint32_t *argb, Bool premultiplied,
+ Bool apply_gamma)
{
- uint32_t alpha = argb >> 24;
+ uint32_t alpha = *argb >> 24;
uint32_t rgb[3];
int i;
- if (!alpha)
- return 0;
+ if (premultiplied) {
+#if XORG_VERSION_CURRENT < XORG_VERSION_NUMERIC(1, 20, 99, 0, 0)
+ if (*argb > (alpha | alpha << 8 | alpha << 16 | alpha << 24))
+ /* Doesn't look like premultiplied alpha */
+ return FALSE;
+#endif
+
+ if (!apply_gamma)
+ return TRUE;
+ }
- /* Un-premultiply alpha */
+ if (!alpha) {
+ *argb = 0;
+ return TRUE;
+ }
+
+ /* Extract RGB */
for (i = 0; i < 3; i++)
- rgb[i] = ((argb >> (i * 8)) & 0xff) * 0xff / alpha;
+ rgb[i] = (*argb >> (i * 8)) & 0xff;
- /* Apply gamma correction and pre-multiply alpha */
- rgb[0] = (crtc->gamma_blue[rgb[0]] >> 8) * alpha / 0xff;
- rgb[1] = (crtc->gamma_green[rgb[1]] >> 8) * alpha / 0xff;
- rgb[2] = (crtc->gamma_red[rgb[2]] >> 8) * alpha / 0xff;
+ if (premultiplied) {
+ /* Un-premultiply alpha */
+ for (i = 0; i < 3; i++)
+ rgb[i] = rgb[i] * 0xff / alpha;
+ }
- return alpha << 24 | rgb[2] << 16 | rgb[1] << 8 | rgb[0];
+ if (apply_gamma) {
+ rgb[0] = crtc->gamma_blue[rgb[0]] >> 8;
+ rgb[1] = crtc->gamma_green[rgb[1]] >> 8;
+ rgb[2] = crtc->gamma_red[rgb[2]] >> 8;
+ }
+
+ /* Premultiply alpha */
+ for (i = 0; i < 3; i++)
+ rgb[i] = rgb[i] * alpha / 0xff;
+
+ *argb = alpha << 24 | rgb[2] << 16 | rgb[1] << 8 | rgb[0];
+ return TRUE;
}
static void drmmode_do_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image, uint32_t *ptr)
{
ScrnInfoPtr pScrn = crtc->scrn;
AMDGPUInfoPtr info = AMDGPUPTR(pScrn);
- uint32_t (*cursor_gamma)(xf86CrtcPtr crtc, uint32_t argb) =
- drmmode_cursor_gamma;
+ Bool premultiplied = TRUE;
+ Bool apply_gamma = TRUE;
+ uint32_t argb;
if ((crtc->scrn->depth != 24 && crtc->scrn->depth != 32) ||
drmmode_cm_enabled(&info->drmmode))
- cursor_gamma = drmmode_cursor_gamma_passthrough;
+ apply_gamma = FALSE;
#if XF86_CRTC_VERSION < 7
if (crtc->driverIsPerformingTransform) {
@@ -1550,15 +1566,20 @@ static void drmmode_do_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image, uint32_
int dstx, dsty;
int srcoffset;
+retry_transform:
for (dsty = 0; dsty < cursor_h; dsty++) {
for (dstx = 0; dstx < cursor_w; dstx++) {
srcoffset = drmmode_cursor_src_offset(crtc->rotation,
cursor_w,
cursor_h,
dstx, dsty);
-
- ptr[dsty * info->cursor_w + dstx] =
- cpu_to_le32(cursor_gamma(crtc, image[srcoffset]));
+ argb = image[srcoffset];
+ if (!drmmode_cursor_pixel(crtc, &argb, premultiplied,
+ apply_gamma)) {
+ premultiplied = FALSE;
+ goto retry_transform;
+ }
+ ptr[dsty * info->cursor_w + dstx] = cpu_to_le32(argb);
}
}
} else
@@ -1567,8 +1588,16 @@ static void drmmode_do_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image, uint32_
uint32_t cursor_size = info->cursor_w * info->cursor_h;
int i;
- for (i = 0; i < cursor_size; i++)
- ptr[i] = cpu_to_le32(cursor_gamma(crtc, image[i]));
+retry:
+ for (i = 0; i < cursor_size; i++) {
+ argb = image[i];
+ if (!drmmode_cursor_pixel(crtc, &argb, premultiplied,
+ apply_gamma)) {
+ premultiplied = FALSE;
+ goto retry;
+ }
+ ptr[i] = cpu_to_le32(argb);
+ }
}
}