[PATCH v14 34/41] compositor-drm: Ignore occluded views

[Pekka Paalanen]

On Wed, 20 Dec 2017 12:26:51 +0000
Daniel Stone <daniels at collabora.com> wrote:

> When trying to assign planes, keep track of the areas which are
> already occluded, and ignore views which are completely occluded. This
> allows us to build a state using planes only, when there are occluded
> views which cannot go into a plane behind views which can.
> 
> Signed-off-by: Daniel Stone <daniels at collabora.com>
> ---
>  libweston/compositor-drm.c | 37 ++++++++++++++++++++++++++++++++-----
>  1 file changed, 32 insertions(+), 5 deletions(-)
> 
> diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
> index 845f43e5b..71027a5ae 100644
> --- a/libweston/compositor-drm.c
> +++ b/libweston/compositor-drm.c
> @@ -3054,7 +3054,7 @@ drm_output_propose_state(struct weston_output *output_base,
>  	struct drm_output *output = to_drm_output(output_base);
>  	struct drm_output_state *state;
>  	struct weston_view *ev;
> -	pixman_region32_t surface_overlap, renderer_region;
> +	pixman_region32_t surface_overlap, renderer_region, occluded_region;
>  	struct weston_plane *primary = &output_base->compositor->primary_plane;
>  
>  	assert(!output->state_last);
> @@ -3076,9 +3076,12 @@ drm_output_propose_state(struct weston_output *output_base,
>  	 * as we do for flipping full screen surfaces.
>  	 */
>  	pixman_region32_init(&renderer_region);
> +	pixman_region32_init(&occluded_region);
>  
>  	wl_list_for_each(ev, &output_base->compositor->view_list, link) {
>  		struct weston_plane *next_plane = NULL;
> +		pixman_region32_t clipped_view;
> +		bool occluded = false;
>  
>  		/* If this view doesn't touch our output at all, there's no
>  		 * reason to do anything with it. */
> @@ -3090,13 +3093,27 @@ drm_output_propose_state(struct weston_output *output_base,
>  		if (ev->output_mask != (1u << output->base.id))
>  			next_plane = primary;
>  
> +		/* Ignore views we know to be totally occluded. */
> +		pixman_region32_init(&clipped_view);
> +		pixman_region32_intersect(&clipped_view,
> +					  &ev->transform.boundingbox,
> +					  &output->base.region);
> +
> +		pixman_region32_init(&surface_overlap);
> +		pixman_region32_subtract(&surface_overlap, &clipped_view,
> +					 &occluded_region);
> +		occluded = !pixman_region32_not_empty(&surface_overlap);
> +		if (occluded) {
> +			pixman_region32_fini(&surface_overlap);
> +			pixman_region32_fini(&clipped_view);
> +			continue;
> +		}
> +
>  		/* Since we process views from top to bottom, we know that if
>  		 * the view intersects the calculated renderer region, it must
>  		 * be part of, or occluded by, it, and cannot go on a plane. */
> -		pixman_region32_init(&surface_overlap);
>  		pixman_region32_intersect(&surface_overlap, &renderer_region,
> -					  &ev->transform.boundingbox);
> -
> +					  &clipped_view);
>  		if (pixman_region32_not_empty(&surface_overlap))
>  			next_plane = primary;
>  		pixman_region32_fini(&surface_overlap);
> @@ -3104,6 +3121,9 @@ drm_output_propose_state(struct weston_output *output_base,
>  		if (next_plane == NULL)
>  			next_plane = drm_output_prepare_cursor_view(state, ev);
>  
> +		if (next_plane == NULL && !drm_view_is_opaque(ev))
> +			next_plane = primary;
> +
>  		if (next_plane == NULL)
>  			next_plane = drm_output_prepare_scanout_view(state, ev);
>  
> @@ -3116,9 +3136,16 @@ drm_output_propose_state(struct weston_output *output_base,
>  		if (next_plane == primary)
>  			pixman_region32_union(&renderer_region,
>  					      &renderer_region,
> -					      &ev->transform.boundingbox);
> +					      &clipped_view);
> +		else if (output->cursor_plane &&
> +			 next_plane != &output->cursor_plane->base)

Should this not be:

	if (!output->cursor_plane || next_plane != &output->cursor_plane->base)

so that lack of a cursor plane goes straight to occluded?

> +			pixman_region32_union(&occluded_region,
> +					      &occluded_region,
> +					      &clipped_view);
> +		pixman_region32_fini(&clipped_view);
>  	}
>  	pixman_region32_fini(&renderer_region);
> +	pixman_region32_fini(&occluded_region);
>  
>  	return state;
>  }

I cannot find any other fault here, and I stared at this for a long
time.


Thanks,
pq
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