render/drm-format-set: add wlr_drm_format_set_intersect

This intersects two DRM format sets. This is useful for implementing
DMA-BUF feedback in compositors, see e.g. the Sway PR [1].

[1]: https://github.com/swaywm/sway/pull/6313
This commit is contained in:
Simon Ser 2021-12-01 13:35:50 +01:00 committed by Simon Zeni
parent 92080b3a01
commit 7201aae3d6
2 changed files with 47 additions and 0 deletions

View file

@ -63,4 +63,13 @@ bool wlr_drm_format_set_has(const struct wlr_drm_format_set *set,
bool wlr_drm_format_set_add(struct wlr_drm_format_set *set, uint32_t format, bool wlr_drm_format_set_add(struct wlr_drm_format_set *set, uint32_t format,
uint64_t modifier); uint64_t modifier);
/**
* Intersect two DRM format sets `a` and `b`, storing in the destination set
* `dst` the format + modifier pairs which are in both source sets.
*
* Returns false on failure or when the intersection is empty.
*/
bool wlr_drm_format_set_intersect(struct wlr_drm_format_set *dst,
const struct wlr_drm_format_set *a, const struct wlr_drm_format_set *b);
#endif #endif

View file

@ -175,3 +175,41 @@ struct wlr_drm_format *wlr_drm_format_intersect(
return format; return format;
} }
bool wlr_drm_format_set_intersect(struct wlr_drm_format_set *dst,
const struct wlr_drm_format_set *a, const struct wlr_drm_format_set *b) {
assert(dst != a && dst != b);
struct wlr_drm_format_set out = {0};
out.capacity = a->len < b->len ? a->len : b->len;
out.formats = calloc(out.capacity, sizeof(struct wlr_drm_format *));
if (out.formats == NULL) {
wlr_log_errno(WLR_ERROR, "Allocation failed");
return false;
}
for (size_t i = 0; i < a->len; i++) {
for (size_t j = 0; j < b->len; j++) {
if (a->formats[i]->format == b->formats[j]->format) {
// When the two formats have no common modifier, keep
// intersecting the rest of the formats: they may be compatible
// with each other
struct wlr_drm_format *format =
wlr_drm_format_intersect(a->formats[i], b->formats[j]);
if (format != NULL) {
out.formats[out.len] = format;
out.len++;
}
break;
}
}
}
if (out.len == 0) {
wlr_drm_format_set_finish(&out);
return false;
}
*dst = out;
return true;
}