output: Drop wlr_output_attach_render

include/wlr/types/wlr_output.h

@@ -120,9 +120,8 @@ struct wlr_render_pass;
  * The `frame` event will be emitted when it is a good time for the compositor
  * to submit a new frame.
  *
- * To render a new frame, compositors should call wlr_output_attach_render(),
- * render and call wlr_output_commit(). No rendering should happen outside a
- * `frame` event handler or before wlr_output_attach_render().
+ * To render a new frame, compositors should call wlr_output_begin_render_pass(),
+ * perform rendering on that render pass and finally call wlr_output_commit().
  */
 struct wlr_output {
 	const struct wlr_output_impl *impl;

include/wlr/types/wlr_output_layer.h

@@ -18,8 +18,8 @@
  * An output layer.
  *
  * Output layers are displayed between the output primary buffer (see
- * wlr_output_attach_buffer() and wlr_output_attach_render()) and the cursor
- * buffer. They can offload some rendering work to the backend.
+ * wlr_output_attach_buffer()) and the cursor buffer. They can offload some
+ * rendering work to the backend.
  *
  * To configure output layers, callers should call wlr_output_layer_create() to
  * create layers, attach struct wlr_output_layer_state onto

types/output/render.c

@@ -57,32 +57,6 @@ void output_clear_back_buffer(struct wlr_output *output) {
 	output->back_buffer = NULL;
 }
 
-bool wlr_output_attach_render(struct wlr_output *output, int *buffer_age) {
-	assert(output->back_buffer == NULL);
-
-	if (!wlr_output_configure_primary_swapchain(output, &output->pending,
-			&output->swapchain)) {
-		return false;
-	}
-
-	struct wlr_renderer *renderer = output->renderer;
-	assert(renderer != NULL);
-
-	struct wlr_buffer *buffer =
-		wlr_swapchain_acquire(output->swapchain, buffer_age);
-	if (buffer == NULL) {
-		return false;
-	}
-
-	if (!renderer_bind_buffer(renderer, buffer)) {
-		wlr_buffer_unlock(buffer);
-		return false;
-	}
-
-	output->back_buffer = buffer;
-	return true;
-}
-
 static struct wlr_buffer *output_acquire_empty_buffer(struct wlr_output *output,
 		const struct wlr_output_state *state) {
 	assert(!(state->committed & WLR_OUTPUT_STATE_BUFFER));
@@ -247,13 +221,24 @@ uint32_t wlr_output_preferred_read_format(struct wlr_output *output) {
 		return DRM_FORMAT_INVALID;
 	}
 
-	if (!wlr_output_attach_render(output, NULL)) {
+	if (!wlr_output_configure_primary_swapchain(output, &output->pending, &output->swapchain)) {
+		return false;
+	}
+
+	struct wlr_buffer *buffer = wlr_swapchain_acquire(output->swapchain, NULL);
+	if (buffer == NULL) {
+		return false;
+	}
+
+	if (!wlr_renderer_begin_with_buffer(renderer, buffer)) {
+		wlr_buffer_unlock(buffer);
 		return false;
 	}
 
 	uint32_t fmt = renderer->impl->preferred_read_format(renderer);
 
-	output_clear_back_buffer(output);
+	wlr_renderer_end(renderer);
+	wlr_buffer_unlock(buffer);
 
 	return fmt;
 }