diff options
| -rw-r--r-- | include/render/drm_format_set.h | 9 | ||||
| -rw-r--r-- | render/drm_format_set.c | 36 |
2 files changed, 45 insertions, 0 deletions
diff --git a/include/render/drm_format_set.h b/include/render/drm_format_set.h index ae1fcc47..78b70e9b 100644 --- a/include/render/drm_format_set.h +++ b/include/render/drm_format_set.h @@ -4,5 +4,14 @@ #include <wlr/render/drm_format_set.h> struct wlr_drm_format *wlr_drm_format_dup(const struct wlr_drm_format *format); +/** + * Intersect modifiers for two DRM formats. + * + * Both arguments must have the same format field. If the formats aren't + * compatible, NULL is returned. If either format doesn't support any modifier, + * a format that doesn't support any modifier is returned. + */ +struct wlr_drm_format *wlr_drm_format_intersect( + const struct wlr_drm_format *a, const struct wlr_drm_format *b); #endif 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; +} |