compositor: Add flags parameter to wlsc_output_init

Currently available flags:
 - WL_OUTPUT_FLIPPED

compositor/compositor-drm.c

@@ -208,7 +208,7 @@ create_output_for_connector(struct drm_compositor *ec,
 
 	memset(output, 0, sizeof *output);
 	wlsc_output_init(&output->base, &ec->base, 0, 0,
-			 mode->hdisplay, mode->vdisplay);
+			 mode->hdisplay, mode->vdisplay, 0);
 
 	output->crtc_id = resources->crtcs[i];
 	output->connector_id = connector->connector_id;

compositor/compositor-wayland.c

@@ -233,7 +233,7 @@ wayland_compositor_create_output(struct wayland_compositor *c,
 		return -1;
 	memset(output, 0, sizeof *output);
 
-	wlsc_output_init(&output->base, &c->base, 0, 0, width, height);
+	wlsc_output_init(&output->base, &c->base, 0, 0, width, height, 0);
 	output->parent.surface =
 		wl_compositor_create_surface(c->parent.compositor);
 	wl_surface_set_user_data(output->parent.surface, output);

compositor/compositor-x11.c

@@ -363,7 +363,7 @@ x11_compositor_create_output(struct x11_compositor *c, int width, int height)
 		return -1;
 
 	memset(output, 0, sizeof *output);
-	wlsc_output_init(&output->base, &c->base, 0, 0, width, height);
+	wlsc_output_init(&output->base, &c->base, 0, 0, width, height, 0);
 
 	values[1] = c->null_cursor;
 	output->window = xcb_generate_id(c->conn);

compositor/compositor.c

@@ -1288,8 +1288,10 @@ init_shaders(struct wlsc_compositor *ec)
 
 void
 wlsc_output_init(struct wlsc_output *output, struct wlsc_compositor *c,
-		 int x, int y, int width, int height)
+		 int x, int y, int width, int height, uint32_t flags)
 {
+	int flip;
+
 	output->compositor = c;
 	output->x = x;
 	output->y = y;
@@ -1305,8 +1307,11 @@ wlsc_output_init(struct wlsc_output *output, struct wlsc_compositor *c,
 	wlsc_matrix_translate(&output->matrix,
 			      -output->x - output->width / 2.0,
 			      -output->y - output->height / 2.0, 0);
+
+	flip = (flags & WL_OUTPUT_FLIPPED) ? -1 : 1;
 	wlsc_matrix_scale(&output->matrix,
-			  2.0 / output->width, 2.0 / output->height, 1);
+			  2.0 / output->width,
+			  flip * 2.0 / output->height, 1);
 
 	output->object.interface = &wl_output_interface;
 	wl_display_add_object(c->wl_display, &output->object);

compositor/compositor.h

@@ -130,6 +130,10 @@ struct wlsc_compositor {
 #define MODIFIER_ALT	(1 << 9)
 #define MODIFIER_SUPER	(1 << 10)
 
+enum wlsc_output_flags {
+	WL_OUTPUT_FLIPPED = 0x01
+};
+
 struct wlsc_vector {
 	GLfloat f[4];
 };
@@ -215,7 +219,7 @@ int
 wlsc_compositor_init(struct wlsc_compositor *ec, struct wl_display *display);
 void
 wlsc_output_init(struct wlsc_output *output, struct wlsc_compositor *c,
-		 int x, int y, int width, int height);
+		 int x, int y, int width, int height, uint32_t flags);
 void
 wlsc_input_device_init(struct wlsc_input_device *device,
 		       struct wlsc_compositor *ec);