implement surface sizing

examples/compositor/main.c

@@ -45,8 +45,8 @@ void handle_output_frame(struct output_state *output, struct timespec *ts) {
 		struct wlr_surface *surface = wl_resource_get_user_data(_res);
 		wlr_surface_flush_damage(surface);
 		if (surface->texture->valid) {
-			wlr_texture_get_matrix(surface->texture, &matrix,
-					&wlr_output->transform_matrix, 200, 200);
+			wlr_surface_get_matrix(surface, &matrix,
+				&wlr_output->transform_matrix, 200, 200);
 			wlr_render_with_matrix(sample->renderer, surface->texture, &matrix);
 
 			struct wlr_frame_callback *cb, *cnext;

include/wlr/types/wlr_surface.h

@@ -53,5 +53,7 @@ struct wlr_renderer;
 struct wlr_surface *wlr_surface_create(struct wl_resource *res,
 		struct wlr_renderer *renderer);
 void wlr_surface_flush_damage(struct wlr_surface *surface);
+void wlr_surface_get_matrix(struct wlr_surface *surface, float (*matrix)[16],
+		const float (*projection)[16], int x, int y);
 
 #endif

types/wlr_surface.c

@@ -5,6 +5,7 @@
 #include <wlr/egl.h>
 #include <wlr/render/interface.h>
 #include <wlr/types/wlr_surface.h>
+#include <wlr/render/matrix.h>
 
 static void surface_destroy(struct wl_client *client, struct wl_resource *resource) {
 	wl_resource_destroy(resource);
@@ -268,3 +269,16 @@ struct wlr_surface *wlr_surface_create(struct wl_resource *res,
 			surface, destroy_surface);
 	return surface;
 }
+
+void wlr_surface_get_matrix(struct wlr_surface *surface,
+		float (*matrix)[16], const float (*projection)[16], int x, int y) {
+	int width = surface->texture->width / surface->current.scale;
+	int height = surface->texture->height / surface->current.scale;
+	float world[16];
+	wlr_matrix_identity(matrix);
+	wlr_matrix_translate(&world, x, y, 0);
+	wlr_matrix_mul(matrix, &world, matrix);
+	wlr_matrix_scale(&world, width, height, 1);
+	wlr_matrix_mul(matrix, &world, matrix);
+	wlr_matrix_mul(projection, matrix, matrix);
+}