backend/drm: strip alpha channel on scan-out
@@ -859,6 +859,15 @@ static bool drm_connector_schedule_frame(struct wlr_output *output) {
return true;
}
+static uint32_t strip_alpha_channel(uint32_t format) {
+ switch (format) {
+ case DRM_FORMAT_ARGB8888:
+ return DRM_FORMAT_XRGB8888;
+ default:
+ return DRM_FORMAT_INVALID;
+ }
+}
+
static bool drm_connector_set_dmabuf(struct wlr_output *output,
struct wlr_dmabuf_attributes *attribs) {
struct wlr_drm_connector *conn = get_drm_connector_from_output(output);
@@ -875,10 +884,22 @@ static bool drm_connector_set_dmabuf(struct wlr_output *output,
if (attribs->width != output->width || attribs->height != output->height) {
return false;
}
+
+ struct wlr_dmabuf_attributes attribs_stripped_alpha;
if (!wlr_drm_format_set_has(&crtc->primary->formats,
attribs->format, attribs->modifier)) {
+ // The format isn't supported by the plane. Try stripping the alpha
+ // channel, if any.
+ uint32_t format = strip_alpha_channel(attribs->format);
+ if (format != DRM_FORMAT_INVALID && wlr_drm_format_set_has(
+ &crtc->primary->formats, format, attribs->modifier)) {
+ attribs_stripped_alpha = *attribs;
+ attribs_stripped_alpha.format = format;
+ attribs = &attribs_stripped_alpha;
+ } else {
return false;
}
+ }
struct gbm_bo *bo = import_gbm_bo(&drm->renderer, attribs);
if (bo == NULL) {
