swaybg: implement scaling mode "stretch"

swaybg/main.c

@@ -12,6 +12,10 @@ list_t *surfaces;
 
 struct registry *registry;
 
+enum scaling_mode_t {
+	SCALING_MODE_STRETCH,
+};
+
 void sway_terminate(void) {
 	int i;
 	for (i = 0; i < surfaces->length; ++i) {
@@ -49,16 +53,33 @@ int main(int argc, const char **argv) {
 	desktop_shell_set_background(registry->desktop_shell, output->output, window->surface);
 	list_add(surfaces, window);
 
-	const char *scaling_mode = argv[3];
 	cairo_surface_t *image = cairo_image_surface_create_from_png(argv[2]);
 	double width = cairo_image_surface_get_width(image);
 	double height = cairo_image_surface_get_height(image);
 
+	const char *scaling_mode_str = argv[3];
+	enum scaling_mode_t scaling_mode;
+	if (strcmp(scaling_mode_str, "stretch") == 0) {
+		scaling_mode = SCALING_MODE_STRETCH;
+	} 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) {
-			cairo_scale(window->cairo, window->width / width, window->height / height);
-			cairo_set_source_surface(window->cairo, image, 0, 0);
+
+			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;
+				default:
+					sway_abort("Scaling mode '%s' not implemented yet!", scaling_mode_str);
+			}
+
 			cairo_paint(window->cairo);
 
 			window_render(window);