backend: make set_image_property take const args

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/backend/backend.h

@@ -335,7 +335,7 @@ struct backend_operations {
 	 * @return             whether the operation is successful
 	 */
 	bool (*set_image_property)(backend_t *backend_data, enum image_properties prop,
-	                           image_handle image, void *args) attr_nonnull(1, 3);
+	                           image_handle image, const void *args) attr_nonnull(1, 3);
 
 	/**
 	 * Manipulate an image. Image properties are untouched.

src/backend/backend_common.c

@@ -467,11 +467,11 @@ image_handle default_clone_image(backend_t *base attr_unused, image_handle image
 }
 
 bool default_set_image_property(backend_t *base attr_unused, enum image_properties op,
-                                image_handle image, void *arg) {
+                                image_handle image, const void *arg) {
 	auto tex = (struct backend_image *)image;
-	int *iargs = arg;
-	bool *bargs = arg;
-	double *dargs = arg;
+	const int *iargs = arg;
+	const bool *bargs = arg;
+	const double *dargs = arg;
 	switch (op) {
 	case IMAGE_PROPERTY_INVERTED: tex->color_inverted = bargs[0]; break;
 	case IMAGE_PROPERTY_DIM_LEVEL: tex->dim = dargs[0]; break;

src/backend/backend_common.h

@@ -75,5 +75,5 @@ struct dual_kawase_params *generate_dual_kawase_params(void *args);
 image_handle default_clone_image(backend_t *base, image_handle image, const region_t *reg);
 bool default_is_image_transparent(backend_t *base attr_unused, image_handle image);
 bool default_set_image_property(backend_t *base attr_unused, enum image_properties op,
-                                image_handle image, void *arg);
+                                image_handle image, const void *arg);
 struct backend_image *default_new_backend_image(int w, int h);

src/backend/dummy/dummy.c

@@ -148,7 +148,7 @@ image_handle dummy_make_mask(struct backend_base *base, geometry_t size attr_unu
 }
 
 bool dummy_set_image_property(struct backend_base *base, enum image_properties prop attr_unused,
-                              image_handle image, void *arg attr_unused) {
+                              image_handle image, const void *arg attr_unused) {
 	dummy_check_image(base, image);
 	return true;
 }

src/backend/gl/gl_common.c

@@ -1242,7 +1242,7 @@ bool gl_image_op(backend_t *base, enum image_operations op, image_handle image,
 }
 
 bool gl_set_image_property(backend_t *backend_data, enum image_properties prop,
-                           image_handle image, void *args) {
+                           image_handle image, const void *args) {
 	if (prop != IMAGE_PROPERTY_CUSTOM_SHADER) {
 		return default_set_image_property(backend_data, prop, image, args);
 	}

src/backend/gl/gl_common.h

@@ -86,7 +86,7 @@ struct gl_texture {
 
 	// Textures for auxiliary uses.
 	GLuint auxiliary_texture[2];
-	gl_win_shader_t *shader;
+	const gl_win_shader_t *shader;
 	void *user_data;
 };
 
@@ -144,7 +144,7 @@ void *gl_create_window_shader(backend_t *backend_data, const char *source);
 void gl_destroy_window_shader(backend_t *backend_data, void *shader);
 uint64_t gl_get_shader_attributes(backend_t *backend_data, void *shader);
 bool gl_set_image_property(backend_t *backend_data, enum image_properties prop,
-                           image_handle image, void *args);
+                           image_handle image, const void *args);
 bool gl_last_render_time(backend_t *backend_data, struct timespec *time);
 
 /**

src/backend/xrender/xrender.c

@@ -986,10 +986,10 @@ image_handle xrender_clone_image(backend_t *base attr_unused, image_handle image
 }
 
 static bool xrender_set_image_property(backend_t *base, enum image_properties op,
-                                       image_handle image, void *args) {
+                                       image_handle image, const void *args) {
 	auto xrimg = (struct xrender_image *)image;
 	if (op == IMAGE_PROPERTY_CORNER_RADIUS &&
-	    ((double *)args)[0] != xrimg->base.corner_radius) {
+	    ((const double *)args)[0] != xrimg->base.corner_radius) {
 		// Free cached rounded rectangle if corner radius changed
 		xrender_release_rounded_corner_cache(base, xrimg->rounded_rectangle);
 		xrimg->rounded_rectangle = NULL;