render/swapchain: make public

We've had this struct for a while. It'd be useful for compositors
if they want to manage the swap chains themselves instead of being
forced to use wlr_output's. Some compositors might also want to use
a swapchain without an output.

1 files changed, 50 insertions, 0 deletions

diff --git a/include/wlr/render/swapchain.h b/include/wlr/render/swapchain.h
new file mode 100644
index 00000000..38b1fb8b
--- /dev/null
+++ b/include/wlr/render/swapchain.h
@@ -0,0 +1,50 @@
+#ifndef WLR_RENDER_SWAPCHAIN_H
+#define WLR_RENDER_SWAPCHAIN_H
+
+#include <stdbool.h>
+#include <wayland-server-core.h>
+#include <wlr/render/drm_format_set.h>
+
+#define WLR_SWAPCHAIN_CAP 4
+
+struct wlr_swapchain_slot {
+	struct wlr_buffer *buffer;
+	bool acquired; // waiting for release
+	int age;
+
+	struct wl_listener release;
+};
+
+struct wlr_swapchain {
+	struct wlr_allocator *allocator; // NULL if destroyed
+
+	int width, height;
+	struct wlr_drm_format *format;
+
+	struct wlr_swapchain_slot slots[WLR_SWAPCHAIN_CAP];
+
+	struct wl_listener allocator_destroy;
+};
+
+struct wlr_swapchain *wlr_swapchain_create(
+	struct wlr_allocator *alloc, int width, int height,
+	const struct wlr_drm_format *format);
+void wlr_swapchain_destroy(struct wlr_swapchain *swapchain);
+/**
+ * Acquire a buffer from the swap chain.
+ *
+ * The returned buffer is locked. When the caller is done with it, they must
+ * unlock it by calling wlr_buffer_unlock.
+ */
+struct wlr_buffer *wlr_swapchain_acquire(struct wlr_swapchain *swapchain,
+	int *age);
+/**
+ * Mark the buffer as submitted for presentation. This needs to be called by
+ * swap chain users on frame boundaries.
+ *
+ * If the buffer hasn't been created via the swap chain, the call is ignored.
+ */
+void wlr_swapchain_set_buffer_submitted(struct wlr_swapchain *swapchain,
+	struct wlr_buffer *buffer);
+
+#endif