st/egl: add premultiplied alpha support to wayland

Return true for NATIVE_PARAM_PREMULTIPLIED_ALPHA when all formats with
alpha support premultiplied alpha.  Currently, it means when argb32 and
argb32_pre are both supported.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/gallium/state_trackers/egl/wayland/native_wayland.c b/src/gallium/state_trackers/egl/wayland/native_wayland.c
index 14cc908cf7a..b2dab8fae53 100644
--- a/src/gallium/state_trackers/egl/wayland/native_wayland.c
+++ b/src/gallium/state_trackers/egl/wayland/native_wayland.c
@@ -60,9 +60,13 @@ static int
 wayland_display_get_param(struct native_display *ndpy,
                           enum native_param_type param)
 {
+   struct wayland_display *display = wayland_display(ndpy);
    int val;
 
    switch (param) {
+   case NATIVE_PARAM_PREMULTIPLIED_ALPHA:
+      val = display->param_premultiplied_alpha;
+      break;
    case NATIVE_PARAM_USE_NATIVE_BUFFER:
    case NATIVE_PARAM_PRESERVE_BUFFER:
    case NATIVE_PARAM_MAX_SWAP_INTERVAL:
@@ -283,6 +287,20 @@ wayland_surface_present(struct native_surface *nsurf,
    if (ctrl->preserve || ctrl->swap_interval)
       return FALSE;
 
+   /* force buffers to be re-created if they will be presented differently */
+   if (surface->premultiplied_alpha != ctrl->premultiplied_alpha) {
+      enum wayland_buffer_type buffer;
+
+      for (buffer = 0; buffer < WL_BUFFER_COUNT; ++buffer) {
+         if (surface->buffer[buffer]) {
+            wl_buffer_destroy(surface->buffer[buffer]);
+            surface->buffer[buffer] = NULL;
+         }
+      }
+
+      surface->premultiplied_alpha = ctrl->premultiplied_alpha;
+   }
+
    switch (ctrl->natt) {
    case NATIVE_ATTACHMENT_FRONT_LEFT:
       ret = TRUE;