compositor-drm: Reshuffle and comment plane conditions

Try to harmonise the various plane-import paths a little bit, starting
with reshuffling and commenting the conditions to do so.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Armin Krezović <krezovic.armin@gmail.com>
Differential Revision: https://phabricator.freedesktop.org/D1413

diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
index fad031724fac326d9c462e70527709ca2c722a19..70514eac0fab072647d7553d3d9b9471c18c2f39 100644 (file)
--- a/libweston/compositor-drm.c
+++ b/libweston/compositor-drm.c
@@ -502,18 +502,28 @@ drm_output_prepare_scanout_view(struct drm_output *output,
        struct gbm_bo *bo;
        uint32_t format;
 
-       if (ev->geometry.x != output->base.x ||
-           ev->geometry.y != output->base.y ||
-           buffer == NULL || b->gbm == NULL ||
-           buffer->width != output->base.current_mode->width ||
-           buffer->height != output->base.current_mode->height ||
-           output->base.transform != viewport->buffer.transform ||
-           ev->transform.enabled)
+       /* We use GBM to import buffers. */
+       if (b->gbm == NULL)
+               return NULL;
+
+       if (buffer == NULL)
                return NULL;
 
+       /* Make sure our view is exactly compatible with the output. */
+       if (ev->geometry.x != output->base.x ||
+           ev->geometry.y != output->base.y)
+               return NULL;
+       if (ev->transform.enabled)
+               return NULL;
        if (ev->geometry.scissor_enabled)
                return NULL;
 
+       if (buffer->width != output->base.current_mode->width ||
+           buffer->height != output->base.current_mode->height)
+               return NULL;
+       if (viewport->buffer.transform != output->base.transform)
+               return NULL;
+
        bo = gbm_bo_import(b->gbm, GBM_BO_IMPORT_WL_BUFFER,
                           buffer->resource, GBM_BO_USE_SCANOUT);
 
@@ -950,34 +960,33 @@ drm_output_prepare_overlay_view(struct drm_output *output,
        uint32_t format;
        wl_fixed_t sx1, sy1, sx2, sy2;
 
-       if (b->gbm == NULL)
-               return NULL;
-
-       if (viewport->buffer.transform != output->base.transform)
-               return NULL;
-
-       if (viewport->buffer.scale != output->base.current_scale)
-               return NULL;
-
        if (b->sprites_are_broken)
                return NULL;
 
+       /* Don't import buffers which span multiple outputs. */
        if (ev->output_mask != (1u << output->base.id))
                return NULL;
 
-       if (ev->surface->buffer_ref.buffer == NULL)
+       /* We can only import GBM buffers. */
+       if (b->gbm == NULL)
                return NULL;
-       buffer_resource = ev->surface->buffer_ref.buffer->resource;
 
-       if (ev->alpha != 1.0f)
+       if (ev->surface->buffer_ref.buffer == NULL)
                return NULL;
-
+       buffer_resource = ev->surface->buffer_ref.buffer->resource;
        if (wl_shm_buffer_get(buffer_resource))
                return NULL;
 
+       if (viewport->buffer.transform != output->base.transform)
+               return NULL;
+       if (viewport->buffer.scale != output->base.current_scale)
+               return NULL;
        if (!drm_view_transform_supported(ev))
                return NULL;
 
+       if (ev->alpha != 1.0f)
+               return NULL;
+
        wl_list_for_each(s, &b->sprite_list, link) {
                if (!drm_sprite_crtc_supported(output, s))
                        continue;
@@ -1114,23 +1123,20 @@ drm_output_prepare_cursor_view(struct drm_output *output,
        struct weston_buffer_viewport *viewport = &ev->surface->buffer_viewport;
        struct wl_shm_buffer *shmbuf;
 
-       if (ev->transform.enabled &&
-           (ev->transform.matrix.type > WESTON_MATRIX_TRANSFORM_TRANSLATE))
-               return NULL;
-       if (b->gbm == NULL)
-               return NULL;
-       if (output->base.transform != WL_OUTPUT_TRANSFORM_NORMAL)
-               return NULL;
-       if (viewport->buffer.scale != output->base.current_scale)
+       if (b->cursors_are_broken)
                return NULL;
+
        if (output->cursor_view)
                return NULL;
+
+       /* Don't import buffers which span multiple outputs. */
        if (ev->output_mask != (1u << output->base.id))
                return NULL;
-       if (b->cursors_are_broken)
-               return NULL;
-       if (ev->geometry.scissor_enabled)
+
+       /* We use GBM to import SHM buffers. */
+       if (b->gbm == NULL)
                return NULL;
+
        if (ev->surface->buffer_ref.buffer == NULL)
                return NULL;
        shmbuf = wl_shm_buffer_get(ev->surface->buffer_ref.buffer->resource);
@@ -1138,6 +1144,17 @@ drm_output_prepare_cursor_view(struct drm_output *output,
                return NULL;
        if (wl_shm_buffer_get_format(shmbuf) != WL_SHM_FORMAT_ARGB8888)
                return NULL;
+
+       if (output->base.transform != WL_OUTPUT_TRANSFORM_NORMAL)
+               return NULL;
+       if (ev->transform.enabled &&
+           (ev->transform.matrix.type > WESTON_MATRIX_TRANSFORM_TRANSLATE))
+               return NULL;
+       if (viewport->buffer.scale != output->base.current_scale)
+               return NULL;
+       if (ev->geometry.scissor_enabled)
+               return NULL;
+
        if (ev->surface->width > b->cursor_width ||
            ev->surface->height > b->cursor_height)
                return NULL;