render: introduce wlr_allocator

include/render/allocator.h

@@ -0,0 +1,42 @@
+#ifndef RENDER_ALLOCATOR
+#define RENDER_ALLOCATOR
+
+#include <stdbool.h>
+#include <wayland-server-core.h>
+#include <wlr/render/dmabuf.h>
+#include <wlr/render/drm_format_set.h>
+
+struct wlr_allocator;
+
+struct wlr_allocator_interface {
+	struct wlr_buffer *(*create_buffer)(struct wlr_allocator *alloc,
+		int width, int height, const struct wlr_drm_format *format);
+	void (*destroy)(struct wlr_allocator *alloc);
+};
+
+struct wlr_allocator {
+	const struct wlr_allocator_interface *impl;
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+};
+
+/**
+ * Destroy the allocator.
+ */
+void wlr_allocator_destroy(struct wlr_allocator *alloc);
+/**
+ * Allocate a new buffer.
+ *
+ * When the caller is done with it, they must unreference it by calling
+ * wlr_buffer_drop.
+ */
+struct wlr_buffer *wlr_allocator_create_buffer(struct wlr_allocator *alloc,
+	int width, int height, const struct wlr_drm_format *format);
+
+// For wlr_allocator implementors
+void wlr_allocator_init(struct wlr_allocator *alloc,
+	const struct wlr_allocator_interface *impl);
+
+#endif

render/allocator.c

@@ -0,0 +1,20 @@
+#include <assert.h>
+#include <stdlib.h>
+#include "render/allocator.h"
+
+void wlr_allocator_init(struct wlr_allocator *alloc,
+		const struct wlr_allocator_interface *impl) {
+	assert(impl && impl->destroy && impl->create_buffer);
+	alloc->impl = impl;
+	wl_signal_init(&alloc->events.destroy);
+}
+
+void wlr_allocator_destroy(struct wlr_allocator *alloc) {
+	wl_signal_emit(&alloc->events.destroy, NULL);
+	alloc->impl->destroy(alloc);
+}
+
+struct wlr_buffer *wlr_allocator_create_buffer(struct wlr_allocator *alloc,
+		int width, int height, const struct wlr_drm_format *format) {
+	return alloc->impl->create_buffer(alloc, width, height, format);
+}

render/meson.build

@@ -1,4 +1,5 @@
 wlr_files += files(
+	'allocator.c',
 	'dmabuf.c',
 	'egl.c',
 	'drm_format_set.c',