output: add wlr_output_init_render

Co-authored-by: Simon Zeni <simon@bl4ckb0ne.ca>

include/wlr/types/wlr_output.h

@@ -182,6 +182,8 @@ struct wlr_output {
 	struct wlr_buffer *cursor_front_buffer;
 	int software_cursor_locks; // number of locks forcing software cursors
 
+	struct wlr_allocator *allocator;
+	struct wlr_renderer *renderer;
 	struct wlr_swapchain *swapchain;
 	struct wlr_buffer *back_buffer, *front_buffer;
 
@@ -256,6 +258,18 @@ struct wlr_surface;
 void wlr_output_enable(struct wlr_output *output, bool enable);
 void wlr_output_create_global(struct wlr_output *output);
 void wlr_output_destroy_global(struct wlr_output *output);
+/**
+ * Initialize the output's rendering subsystem with the provided allocator and
+ * renderer. Can only be called once.
+ *
+ * Call this function prior to any call to wlr_output_attach_render,
+ * wlr_output_commit or wlr_output_cursor_create.
+ *
+ * The buffer capabilities of the provided must match the capabilities of the
+ * output's backend. Returns false otherwise.
+ */
+bool wlr_output_init_render(struct wlr_output *output,
+	struct wlr_allocator *allocator, struct wlr_renderer *renderer);
 /**
  * Returns the preferred mode for this output. If the output doesn't support
  * modes, returns NULL.

types/output/cursor.c

@@ -6,7 +6,6 @@
 #include <wlr/types/wlr_matrix.h>
 #include <wlr/types/wlr_surface.h>
 #include <wlr/util/log.h>
-#include "backend/backend.h"
 #include "render/allocator/allocator.h"
 #include "render/swapchain.h"
 #include "types/wlr_output.h"
@@ -38,7 +37,7 @@ void wlr_output_lock_software_cursors(struct wlr_output *output, bool lock) {
 }
 
 static void output_scissor(struct wlr_output *output, pixman_box32_t *rect) {
-	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->backend);
+	struct wlr_renderer *renderer = output->renderer;
 	assert(renderer);
 
 	struct wlr_box box = {
@@ -71,8 +70,7 @@ static void output_cursor_get_box(struct wlr_output_cursor *cursor,
 
 static void output_cursor_render(struct wlr_output_cursor *cursor,
 		pixman_region32_t *damage) {
-	struct wlr_renderer *renderer =
-		wlr_backend_get_renderer(cursor->output->backend);
+	struct wlr_renderer *renderer = cursor->output->renderer;
 	assert(renderer);
 
 	struct wlr_texture *texture = cursor->texture;
@@ -195,7 +193,7 @@ static void output_cursor_update_visible(struct wlr_output_cursor *cursor) {
 }
 
 static struct wlr_drm_format *output_pick_cursor_format(struct wlr_output *output) {
-	struct wlr_allocator *allocator = backend_get_allocator(output->backend);
+	struct wlr_allocator *allocator = output->allocator;
 	assert(allocator != NULL);
 
 	const struct wlr_drm_format_set *display_formats = NULL;
@@ -226,17 +224,9 @@ static struct wlr_buffer *render_cursor_buffer(struct wlr_output_cursor *cursor)
 		return NULL;
 	}
 
-	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->backend);
-	if (renderer == NULL) {
-		wlr_log(WLR_ERROR, "Failed to get backend renderer");
-		return NULL;
-	}
-
-	struct wlr_allocator *allocator = backend_get_allocator(output->backend);
-	if (allocator == NULL) {
-		wlr_log(WLR_ERROR, "Failed to get backend allocator");
-		return NULL;
-	}
+	struct wlr_allocator *allocator = output->allocator;
+	struct wlr_renderer *renderer = output->renderer;
+	assert(allocator != NULL && renderer != NULL);
 
 	int width = texture->width;
 	int height = texture->height;
@@ -370,8 +360,7 @@ static bool output_cursor_attempt_hardware(struct wlr_output_cursor *cursor) {
 bool wlr_output_cursor_set_image(struct wlr_output_cursor *cursor,
 		const uint8_t *pixels, int32_t stride, uint32_t width, uint32_t height,
 		int32_t hotspot_x, int32_t hotspot_y) {
-	struct wlr_renderer *renderer =
-		wlr_backend_get_renderer(cursor->output->backend);
+	struct wlr_renderer *renderer = cursor->output->renderer;
 	if (!renderer) {
 		// if the backend has no renderer, we can't draw a cursor, but this is
 		// actually okay, for ex. with the noop backend

types/output/render.c

@@ -11,6 +11,30 @@
 #include "render/wlr_renderer.h"
 #include "types/wlr_output.h"
 
+bool wlr_output_init_render(struct wlr_output *output,
+		struct wlr_allocator *allocator, struct wlr_renderer *renderer) {
+	assert(output->allocator == NULL && allocator != NULL);
+	assert(output->renderer == NULL && renderer != NULL);
+
+	uint32_t backend_caps = backend_get_buffer_caps(output->backend);
+	uint32_t renderer_caps = renderer_get_render_buffer_caps(renderer);
+
+	if (!(backend_caps & allocator->buffer_caps)) {
+		wlr_log(WLR_ERROR, "output backend and allocator buffer capabilities "
+			"don't match");
+		return false;
+	} else if (!(backend_caps & renderer_caps)) {
+		wlr_log(WLR_ERROR, "output backend and renderer buffer capabilities "
+			"don't match");
+		return false;
+	}
+
+	output->allocator = allocator;
+	output->renderer = renderer;
+
+	return true;
+}
+
 /**
  * Ensure the output has a suitable swapchain. The swapchain is re-created if
  * necessary.
@@ -29,11 +53,8 @@ static bool output_create_swapchain(struct wlr_output *output,
 		return true;
 	}
 
-	struct wlr_allocator *allocator = backend_get_allocator(output->backend);
-	if (allocator == NULL) {
-		wlr_log(WLR_ERROR, "Failed to get backend allocator");
-		return false;
-	}
+	struct wlr_allocator *allocator = output->allocator;
+	assert(allocator != NULL);
 
 	const struct wlr_drm_format_set *display_formats = NULL;
 	if (output->impl->get_primary_formats) {
@@ -80,7 +101,7 @@ static bool output_attach_back_buffer(struct wlr_output *output,
 		return false;
 	}
 
-	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->backend);
+	struct wlr_renderer *renderer = output->renderer;
 	assert(renderer != NULL);
 
 	struct wlr_buffer *buffer =
@@ -103,7 +124,7 @@ void output_clear_back_buffer(struct wlr_output *output) {
 		return;
 	}
 
-	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->backend);
+	struct wlr_renderer *renderer = output->renderer;
 	assert(renderer != NULL);
 
 	renderer_bind_buffer(renderer, NULL);
@@ -130,7 +151,7 @@ static bool output_attach_empty_buffer(struct wlr_output *output) {
 	int width, height;
 	output_pending_resolution(output, &width, &height);
 
-	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->backend);
+	struct wlr_renderer *renderer = output->renderer;
 	wlr_renderer_begin(renderer, width, height);
 	wlr_renderer_clear(renderer, (float[]){0, 0, 0, 0});
 	wlr_renderer_end(renderer);
@@ -211,8 +232,8 @@ void wlr_output_lock_attach_render(struct wlr_output *output, bool lock) {
 
 struct wlr_drm_format *output_pick_format(struct wlr_output *output,
 		const struct wlr_drm_format_set *display_formats) {
-	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->backend);
-	struct wlr_allocator *allocator = backend_get_allocator(output->backend);
+	struct wlr_renderer *renderer = output->renderer;
+	struct wlr_allocator *allocator = output->allocator;
 	assert(renderer != NULL && allocator != NULL);
 
 	const struct wlr_drm_format_set *render_formats =
@@ -264,7 +285,9 @@ struct wlr_drm_format *output_pick_format(struct wlr_output *output,
 }
 
 uint32_t wlr_output_preferred_read_format(struct wlr_output *output) {
-	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->backend);
+	struct wlr_renderer *renderer = output->renderer;
+	assert(renderer != NULL);
+
 	if (!renderer->impl->preferred_read_format || !renderer->impl->read_pixels) {
 		return DRM_FORMAT_INVALID;
 	}