Copy+paste swaybg code to swaylock for testing

swaybg/main.c

@@ -56,8 +56,8 @@ int main(int argc, const char **argv) {
 	desktop_shell_set_background(registry->desktop_shell, output->output, window->surface);
 	list_add(surfaces, window);
 
-	GError *err=NULL;
-	GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(argv[2],&err);
+	GError *err = NULL;
+	GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(argv[2], &err);
 	if (!pixbuf) {
 		sway_abort("Failed to load background image.");
 	}

swaylock/main.c

@@ -1,8 +1,10 @@
 #include "wayland-swaylock-client-protocol.h"
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "client/window.h"
 #include "client/registry.h"
+#include "client/cairo.h"
 #include "log.h"
 
 list_t *surfaces;
@@ -17,6 +19,13 @@ enum scaling_mode {
 };
 
 void sway_terminate(void) {
+	int i;
+	for (i = 0; i < surfaces->length; ++i) {
+		struct window *window = surfaces->items[i];
+		window_teardown(window);
+	}
+	list_free(surfaces);
+	registry_teardown(registry);
 	exit(EXIT_FAILURE);
 }
 
@@ -32,12 +41,125 @@ int main(int argc, char **argv) {
 	int i;
 	for (i = 0; i < registry->outputs->length; ++i) {
 		struct output_state *output = registry->outputs->items[i];
-		struct window *window = window_setup(registry, output->width, output->height, false);
+		struct window *window = window_setup(registry, output->width, output->height, true);
 		if (!window) {
 			sway_abort("Failed to create surfaces.");
 		}
 		lock_set_lock_surface(registry->swaylock, output->output, window->surface);
 		list_add(surfaces, window);
 	}
+
+	GError *err = NULL;
+	GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(argv[1], &err); // TODO: Parse i3lock arguments
+	if (!pixbuf) {
+		sway_abort("Failed to load background image.");
+	}
+	cairo_surface_t *image = gdk_cairo_image_surface_create_from_pixbuf(pixbuf);
+	g_object_unref(pixbuf);
+	if (!image) {
+		sway_abort("Failed to read background image.");
+	}
+	double width = cairo_image_surface_get_width(image);
+	double height = cairo_image_surface_get_height(image);
+
+	const char *scaling_mode_str = argv[2];
+	enum scaling_mode scaling_mode = SCALING_MODE_STRETCH;
+	if (strcmp(scaling_mode_str, "stretch") == 0) {
+		scaling_mode = SCALING_MODE_STRETCH;
+	} else if (strcmp(scaling_mode_str, "fill") == 0) {
+		scaling_mode = SCALING_MODE_FILL;
+	} else if (strcmp(scaling_mode_str, "fit") == 0) {
+		scaling_mode = SCALING_MODE_FIT;
+	} else if (strcmp(scaling_mode_str, "center") == 0) {
+		scaling_mode = SCALING_MODE_CENTER;
+	} else if (strcmp(scaling_mode_str, "tile") == 0) {
+		scaling_mode = SCALING_MODE_TILE;
+	} else {
+		sway_abort("Unsupported scaling mode: %s", scaling_mode_str);
+	}
+
+	for (i = 0; i < surfaces->length; ++i) {
+		struct window *window = surfaces->items[i];
+		if (window_prerender(window) && window->cairo) {
+			switch (scaling_mode) {
+			case SCALING_MODE_STRETCH:
+				cairo_scale(window->cairo,
+						(double) window->width / width,
+						(double) window->height / height);
+				cairo_set_source_surface(window->cairo, image, 0, 0);
+				break;
+			case SCALING_MODE_FILL:
+			{
+				double window_ratio = (double) window->width / window->height;
+				double bg_ratio = width / height;
+
+				if (window_ratio > bg_ratio) {
+					double scale = (double) window->width / width;
+					cairo_scale(window->cairo, scale, scale);
+					cairo_set_source_surface(window->cairo, image,
+							0,
+							(double) window->height/2 / scale - height/2);
+				} else {
+					double scale = (double) window->height / height;
+					cairo_scale(window->cairo, scale, scale);
+					cairo_set_source_surface(window->cairo, image,
+							(double) window->width/2 / scale - width/2,
+							0);
+				}
+				break;
+			}
+			case SCALING_MODE_FIT:
+			{
+				double window_ratio = (double) window->width / window->height;
+				double bg_ratio = width / height;
+
+				if (window_ratio > bg_ratio) {
+					double scale = (double) window->height / height;
+					cairo_scale(window->cairo, scale, scale);
+					cairo_set_source_surface(window->cairo, image,
+							(double) window->width/2 / scale - width/2,
+							0);
+				} else {
+					double scale = (double) window->width / width;
+					cairo_scale(window->cairo, scale, scale);
+					cairo_set_source_surface(window->cairo, image,
+							0,
+							(double) window->height/2 / scale - height/2);
+				}
+				break;
+			}
+			case SCALING_MODE_CENTER:
+				cairo_set_source_surface(window->cairo, image,
+						(double) window->width/2 - width/2,
+						(double) window->height/2 - height/2);
+				break;
+			case SCALING_MODE_TILE:
+			{
+				cairo_pattern_t *pattern = cairo_pattern_create_for_surface(image);
+				cairo_pattern_set_extend(pattern, CAIRO_EXTEND_REPEAT);
+				cairo_set_source(window->cairo, pattern);
+				break;
+			}
+			default:
+				sway_abort("Scaling mode '%s' not implemented yet!", scaling_mode_str);
+			}
+
+			cairo_paint(window->cairo);
+
+			window_render(window);
+		}
+	}
+
+	cairo_surface_destroy(image);
+
+	while (wl_display_dispatch(registry->display) != -1);
+
+	for (i = 0; i < surfaces->length; ++i) {
+		struct window *window = surfaces->items[i];
+		window_teardown(window);
+	}
+	list_free(surfaces);
+	registry_teardown(registry);
+
 	return 0;
 }