From 82443ea46b32111744aa62a42a24312027e512f8 Mon Sep 17 00:00:00 2001 From: Simon Ser Date: Wed, 25 Nov 2020 15:58:37 +0100 Subject: render/drm_format_set: introduce wlr_drm_format_intersect Intersects modifiers from two wlr_drm_format structs. If either format doesn't support modifiers, the resulting format won't support modifiers. --- render/drm_format_set.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'render') diff --git a/render/drm_format_set.c b/render/drm_format_set.c index 54fc8ae1..d6be706d 100644 --- a/render/drm_format_set.c +++ b/render/drm_format_set.c @@ -137,3 +137,39 @@ struct wlr_drm_format *wlr_drm_format_dup(const struct wlr_drm_format *format) { memcpy(duped_format, format, format_size); return duped_format; } + +struct wlr_drm_format *wlr_drm_format_intersect( + const struct wlr_drm_format *a, const struct wlr_drm_format *b) { + assert(a->format == b->format); + + size_t format_cap = a->len < b->len ? a->len : b->len; + size_t format_size = sizeof(struct wlr_drm_format) + + format_cap * sizeof(a->modifiers[0]); + struct wlr_drm_format *format = calloc(1, format_size); + if (format == NULL) { + wlr_log_errno(WLR_ERROR, "Allocation failed"); + return NULL; + } + format->format = a->format; + format->cap = format_cap; + + for (size_t i = 0; i < a->len; i++) { + for (size_t j = 0; j < b->len; j++) { + if (a->modifiers[i] == b->modifiers[j]) { + assert(format->len < format->cap); + format->modifiers[format->len] = a->modifiers[i]; + format->len++; + break; + } + } + } + + // If both formats support modifiers, but the intersection is empty, then + // the formats aren't compatible with each other + if (format->len == 0 && a->len > 0 && b->len > 0) { + free(format); + return NULL; + } + + return format; +} -- cgit v1.2.3