Put the whole vtable in backend_list

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

src/backend/backend.c

@@ -10,10 +10,15 @@
 #include "region.h"
 #include "win.h"
 
-backend_init_fn backend_list[NUM_BKEND] = {
-    [BKEND_XRENDER] = backend_xrender_init,
+extern struct backend_operations xrender_ops;
 #ifdef CONFIG_OPENGL
-    [BKEND_GLX] = backend_glx_init,
+extern struct backend_operations glx_ops;
+#endif
+
+struct backend_operations *backend_list[NUM_BKEND] = {
+    [BKEND_XRENDER] = &xrender_ops,
+#ifdef CONFIG_OPENGL
+    [BKEND_GLX] = &glx_ops,
 #endif
 };
 
@@ -240,7 +245,7 @@ void paint_all_new(session_t *ps, win *const t, bool ignore_damage) {
 	}
 	pixman_region32_fini(&reg_damage);
 
-	if (ps->o.monitor_repaint && ps->backend_data->ops->fill_rectangle) {
+	if (ps->o.monitor_repaint) {
 		reg_damage = get_damage(ps, false);
 		auto extent = pixman_region32_extents(&reg_damage);
 		ps->backend_data->ops->fill_rectangle(

src/backend/backend.h

@@ -43,6 +43,7 @@ struct backend_operations {
 	///    1) if ps->overlay is not XCB_NONE, use that
 	///    2) use ps->root otherwise
 	/// XXX make the target window a parameter
+	backend_t *(*init)(session_t *) attr_nonnull(1);
 	void (*deinit)(backend_t *backend_data) __attribute__((nonnull(1)));
 
 	/// Called when rendering will be stopped for an unknown amount of
@@ -172,11 +173,9 @@ struct backend_operations {
 	/// Let the backend hook into the event handling queue
 };
 
-typedef backend_t *(*backend_init_fn)(session_t *ps) __attribute__((nonnull(1)));
+typedef backend_t *(*backend_init_fn)(session_t *ps) attr_nonnull(1);
 
-extern backend_t *backend_xrender_init(session_t *ps);
-extern backend_t *backend_glx_init(session_t *ps);
-extern backend_init_fn backend_list[];
+extern struct backend_operations *backend_list[];
 
 bool default_is_win_transparent(void *, win *, void *);
 bool default_is_frame_transparent(void *, win *, void *);

src/backend/gl/glx.c

@@ -532,6 +532,8 @@ void glx_compose(void *backend_data, session_t *ps, win *w, void *win_data,
 	pixman_region32_fini(&region_yflipped);
 }
 
+struct backend_operations glx_ops;
+
 /* backend_info_t glx_backend = { */
 /*     .init = glx_init, */
 /*     .deinit = glx_deinit, */

src/backend/xrender.c

@@ -453,31 +453,11 @@ static void *copy(backend_t *base, const void *image, const region_t *reg) {
 	return new_img;
 }
 
-static struct backend_operations xrender_ops = {
-    .deinit = deinit,
-    .blur = blur,
-    .present = present,
-    .compose = compose,
-    .fill_rectangle = fill_rectangle,
-    .bind_pixmap = bind_pixmap,
-    .release_image = release_image,
-    .render_shadow = default_backend_render_shadow,
-    //.prepare_win = prepare_win,
-    //.release_win = release_win,
-    .is_image_transparent = is_image_transparent,
-    .buffer_age = buffer_age,
-    .max_buffer_age = 2,
-
-    .image_op = image_op,
-    .copy = copy,
-};
-
 backend_t *backend_xrender_init(session_t *ps) {
 	auto xd = ccalloc(1, struct _xrender_data);
 
 	xd->base.c = ps->c;
 	xd->base.root = ps->root;
-	xd->base.ops = &xrender_ops;
 
 	for (int i = 0; i < 256; ++i) {
 		double o = (double)i / 255.0;
@@ -567,4 +547,24 @@ err:
 	return NULL;
 }
 
+struct backend_operations xrender_ops = {
+    .init = backend_xrender_init,
+    .deinit = deinit,
+    .blur = blur,
+    .present = present,
+    .compose = compose,
+    .fill_rectangle = fill_rectangle,
+    .bind_pixmap = bind_pixmap,
+    .release_image = release_image,
+    .render_shadow = default_backend_render_shadow,
+    //.prepare_win = prepare_win,
+    //.release_win = release_win,
+    .is_image_transparent = is_image_transparent,
+    .buffer_age = buffer_age,
+    .max_buffer_age = 2,
+
+    .image_op = image_op,
+    .copy = copy,
+};
+
 // vim: set noet sw=8 ts=8:

src/compton.c

@@ -838,7 +838,8 @@ void configure_root(session_t *ps, int width, int height) {
     if (has_root_change) {
       ps->backend_data->ops->root_change(ps->backend_data, ps);
     } else {
-      ps->backend_data = backend_list[ps->o.backend](ps);
+      ps->backend_data = backend_list[ps->o.backend]->init(ps);
+      ps->backend_data->ops = backend_list[ps->o.backend];
       if (!ps->backend_data) {
         log_fatal("Failed to re-initialize backend after root change, aborting...");
         ps->quit = true;
@@ -1991,7 +1992,8 @@ redir_start(session_t *ps) {
 
     if (ps->o.experimental_backends) {
       // Reinitialize win_data
-      ps->backend_data = backend_list[ps->o.backend](ps);
+      ps->backend_data = backend_list[ps->o.backend]->init(ps);
+      ps->backend_data->ops = backend_list[ps->o.backend];
       if (!ps->backend_data) {
         log_fatal("Failed to initialize backend, aborting...");
         ps->quit = true;
@@ -2721,6 +2723,13 @@ session_init(int argc, char **argv, Display *dpy, const char *config_file,
     }
   }
 
+  if (ps->o.experimental_backends) {
+    if (ps->o.monitor_repaint && !backend_list[ps->o.backend]->fill_rectangle) {
+      log_warn("--monitor-repaint is not supported by the backend, disabling");
+      ps->o.monitor_repaint = false;
+    }
+  }
+
   // Initialize software optimization
   if (ps->o.sw_opti)
     ps->o.sw_opti = swopti_init(ps);