output: add wlr_output_state_set_layers()

examples/output-layers.c

@@ -82,11 +82,9 @@ static void output_handle_frame(struct wl_listener *listener, void *data) {
 		};
 	}
 
-	struct wlr_output_state output_state = {
-		.committed = WLR_OUTPUT_STATE_LAYERS,
-		.layers = layers_arr.data,
-		.layers_len = layers_arr.size / sizeof(struct wlr_output_layer_state),
-	};
+	struct wlr_output_state output_state = {0};
+	wlr_output_state_set_layers(&output_state, layers_arr.data,
+		layers_arr.size / sizeof(struct wlr_output_layer_state));
 
 	if (!wlr_output_test_state(output->wlr_output, &output_state)) {
 		wlr_log(WLR_ERROR, "wlr_output_test() failed");

include/wlr/types/wlr_output.h

@@ -580,6 +580,13 @@ bool wlr_output_state_set_gamma_lut(struct wlr_output_state *state,
  */
 void wlr_output_state_set_damage(struct wlr_output_state *state,
 	const pixman_region32_t *damage);
+/**
+ * Set the state's layers.
+ *
+ * The array must be kept valid by the caller until wlr_output_state_finish().
+ */
+void wlr_output_state_set_layers(struct wlr_output_state *state,
+	struct wlr_output_layer_state *layers, size_t layers_len);
 
 
 /**

types/output/output.c

@@ -478,9 +478,7 @@ void wlr_output_set_damage(struct wlr_output *output,
 
 void wlr_output_set_layers(struct wlr_output *output,
 		struct wlr_output_layer_state *layers, size_t layers_len) {
-	output->pending.committed |= WLR_OUTPUT_STATE_LAYERS;
-	output->pending.layers = layers;
-	output->pending.layers_len = layers_len;
+	wlr_output_state_set_layers(&output->pending, layers, layers_len);
 }
 
 static void output_state_clear_gamma_lut(struct wlr_output_state *state) {

types/output/state.c

@@ -120,3 +120,10 @@ bool wlr_output_state_set_gamma_lut(struct wlr_output_state *state,
 	state->gamma_lut = gamma_lut;
 	return true;
 }
+
+void wlr_output_state_set_layers(struct wlr_output_state *state,
+		struct wlr_output_layer_state *layers, size_t layers_len) {
+	state->committed |= WLR_OUTPUT_STATE_LAYERS;
+	state->layers = layers;
+	state->layers_len = layers_len;
+}