[Mesa-dev] [PATCH 5/5] st/egl: add premultiplied alpha support to wayland

[Benjamin Franzke]

2011/9/8 Chia-I Wu <olvaffe at gmail.com>:
> From: Chia-I Wu <olv at lunarg.com>
>
> 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.
> ---
>  .../state_trackers/egl/wayland/native_drm.c        |    8 ++++++--
>  .../state_trackers/egl/wayland/native_shm.c        |    6 +++++-
>  .../state_trackers/egl/wayland/native_wayland.c    |   18 ++++++++++++++++++
>  .../state_trackers/egl/wayland/native_wayland.h    |    3 +++
>  4 files changed, 32 insertions(+), 3 deletions(-)
>
> diff --git a/src/gallium/state_trackers/egl/wayland/native_drm.c b/src/gallium/state_trackers/egl/wayland/native_drm.c
> index facab32..e177e7c 100644
> --- a/src/gallium/state_trackers/egl/wayland/native_drm.c
> +++ b/src/gallium/state_trackers/egl/wayland/native_drm.c
> @@ -114,8 +114,8 @@ wayland_create_drm_buffer(struct wayland_display *display,
>
>    switch (surface->color_format) {
>    case PIPE_FORMAT_B8G8R8A8_UNORM:
> -      /* assume premultiplied */
> -      format = WL_DRM_FORMAT_PREMULTIPLIED_ARGB32;
> +      format = (surface->premultiplied_alpha) ?
> +         WL_DRM_FORMAT_PREMULTIPLIED_ARGB32 : WL_DRM_FORMAT_ARGB32;
>       break;
>    case PIPE_FORMAT_B8G8R8X8_UNORM:
>       format = WL_DRM_FORMAT_XRGB32;
> @@ -255,6 +255,10 @@ wayland_drm_display_init_screen(struct native_display *ndpy)
>    if (!wayland_drm_display_add_configs(drmdpy))
>       return FALSE;
>
> +   /* check that premultiplied alpha is supported for all formats with alpha */
> +   if (!drmdpy->argb32 || drmdpy->argb32_pre)
> +      drmdpy->base.param_premultiplied_alpha = TRUE;

Why enable premultiplied alpha if argb32 is not exposed?
What isnt covered with just: "if (drmdpy->argb32_pre)"?.

> +
>    drmdpy->base.base.screen =
>       drmdpy->event_handler->new_drm_screen(&drmdpy->base.base,
>                                             NULL, drmdpy->fd);
> diff --git a/src/gallium/state_trackers/egl/wayland/native_shm.c b/src/gallium/state_trackers/egl/wayland/native_shm.c
> index 5882e74..e2d2437 100644
> --- a/src/gallium/state_trackers/egl/wayland/native_shm.c
> +++ b/src/gallium/state_trackers/egl/wayland/native_shm.c
> @@ -95,7 +95,8 @@ wayland_create_shm_buffer(struct wayland_display *display,
>
>    switch (surface->color_format) {
>    case PIPE_FORMAT_B8G8R8A8_UNORM:
> -      format = WL_SHM_FORMAT_PREMULTIPLIED_ARGB32;
> +      format = (surface->premultiplied_alpha) ?
> +         WL_SHM_FORMAT_PREMULTIPLIED_ARGB32 : WL_SHM_FORMAT_ARGB32;
>       break;
>    case PIPE_FORMAT_B8G8R8X8_UNORM:
>       format = WL_SHM_FORMAT_XRGB32;
> @@ -165,6 +166,9 @@ wayland_shm_display_init_screen(struct native_display *ndpy)
>    if (!wayland_shm_display_add_configs(shmdpy))
>       return FALSE;
>
> +   /* assume all formats are supported */
> +   shmdpy->base.param_premultiplied_alpha = TRUE;
> +
>    winsys = wayland_create_sw_winsys(shmdpy->base.dpy);
>    if (!winsys)
>       return FALSE;
> diff --git a/src/gallium/state_trackers/egl/wayland/native_wayland.c b/src/gallium/state_trackers/egl/wayland/native_wayland.c
> index 14cc908..b2dab8f 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;
> diff --git a/src/gallium/state_trackers/egl/wayland/native_wayland.h b/src/gallium/state_trackers/egl/wayland/native_wayland.h
> index 93e670b..6cf98a8 100644
> --- a/src/gallium/state_trackers/egl/wayland/native_wayland.h
> +++ b/src/gallium/state_trackers/egl/wayland/native_wayland.h
> @@ -44,6 +44,8 @@ struct wayland_display {
>
>    struct wayland_config *configs;
>    int num_configs;
> +   /* true if all formats with alpha support premultiplied alpha */
> +   boolean param_premultiplied_alpha;
>
>    struct wl_buffer *(*create_buffer)(struct wayland_display *display,
>                                       struct wayland_surface *surface,
> @@ -79,6 +81,7 @@ struct wayland_surface {
>    unsigned int attachment_mask;
>
>    boolean block_swap_buffers;
> +   boolean premultiplied_alpha;
>  };
>
>  struct wayland_config {
> --
> 1.7.5.4
>
>