Debounce resize requests

kitty/child-monitor.c

@@ -627,6 +627,20 @@ wait_for_events() {
     maximum_wait = -1;
 }
 
+static inline void
+process_pending_resizes(double now) {
+    global_state.has_pending_resizes = false;
+    for (size_t i = 0; i < global_state.num_os_windows; i++) {
+        OSWindow *w = global_state.os_windows + i;
+        if (w->has_pending_resizes) {
+            if (now - w->last_resize_at >= RESIZE_DEBOUNCE_TIME) update_os_window_viewport(w, true);
+            else {
+                global_state.has_pending_resizes = true;
+                set_maximum_wait(RESIZE_DEBOUNCE_TIME - now + w->last_resize_at);
+            }
+        }
+    }
+}
 
 static PyObject*
 main_loop(ChildMonitor *self) {
@@ -635,6 +649,7 @@ main_loop(ChildMonitor *self) {
 
     while (has_open_windows) {
         double now = monotonic();
+        if (global_state.has_pending_resizes) process_pending_resizes(now);
         render(now);
         wait_for_events();
         parse_input(self);

kitty/glfw.c

@@ -29,16 +29,22 @@ extern bool cocoa_make_window_resizable(void *w);
 
 static GLFWcursor *standard_cursor = NULL, *click_cursor = NULL, *arrow_cursor = NULL;
 
-static void 
-update_viewport(OSWindow *window) {
+void
+update_os_window_viewport(OSWindow *window, bool notify_boss) {
     int w, h;
     glfwGetFramebufferSize(window->handle, &window->viewport_width, &window->viewport_height);
     glfwGetWindowSize(window->handle, &w, &h);
     window->viewport_x_ratio = (double)window->viewport_width / (double)w;
     window->viewport_y_ratio = (double)window->viewport_height / (double)h;
     window->viewport_size_dirty = true;
+    window->has_pending_resizes = false;
+    if (notify_boss) {
+        call_boss(on_window_resize, "Kii", window->id, window->viewport_width, window->viewport_height);
+    }
+    window->last_resize_at = monotonic();
 }
 
+
 // callbacks {{{
 
 void
@@ -85,11 +91,13 @@ static void
 framebuffer_size_callback(GLFWwindow *w, int width, int height) {
     if (!set_callback_window(w)) return;
     if (width > 100 && height > 100) {
-        update_viewport(global_state.callback_os_window);
-        if (is_window_ready_for_callbacks()) { 
-            WINDOW_CALLBACK(on_window_resize, "ii", width, height);
+        double now = monotonic();
+        OSWindow *window = global_state.callback_os_window;
+        if (now - window->last_resize_at < RESIZE_DEBOUNCE_TIME) { window->has_pending_resizes = true; global_state.has_pending_resizes = true; }
+        else {
+            update_os_window_viewport(global_state.callback_os_window, is_window_ready_for_callbacks());
+            glfwPostEmptyEvent();
         }
-        glfwPostEmptyEvent();
     } else fprintf(stderr, "Ignoring resize request for tiny size: %dx%d\n", width, height);
     global_state.callback_os_window = NULL;
 }
@@ -247,7 +255,7 @@ create_os_window(PyObject UNUSED *self, PyObject *args) {
     update_os_window_references();
     if (logo.pixels && logo.width && logo.height) glfwSetWindowIcon(glfw_window, 1, &logo);
     glfwSetCursor(glfw_window, standard_cursor);
-    update_viewport(w);
+    update_os_window_viewport(w, false);
     glfwSetFramebufferSizeCallback(glfw_window, framebuffer_size_callback);
     glfwSetCharModsCallback(glfw_window, char_mods_callback);
     glfwSetMouseButtonCallback(glfw_window, mouse_button_callback);

kitty/state.h

@@ -98,6 +98,8 @@ typedef struct {
     PyObject *window_title;
     bool is_key_pressed[MAX_KEY_COUNT];
     bool viewport_size_dirty;
+    double last_resize_at;
+    bool has_pending_resizes;
 } OSWindow;
 
 
@@ -115,6 +117,7 @@ typedef struct {
     bool close_all_windows;
     bool is_wayland;
     bool debug_gl;
+    bool has_pending_resizes;
 } GlobalState;
 
 extern GlobalState global_state;
@@ -125,11 +128,14 @@ extern GlobalState global_state;
     else Py_DECREF(cret_); \
 }
 
+#define RESIZE_DEBOUNCE_TIME 0.2
+
 void gl_init();
 void remove_vao(ssize_t vao_idx);
 bool remove_os_window(id_type os_window_id);
 void remove_os_window_reference(OSWindow *w);
 void mark_os_window_for_close(OSWindow* w, bool yes);
+void update_os_window_viewport(OSWindow *window, bool);
 bool should_os_window_close(OSWindow* w);
 bool should_os_window_be_rendered(OSWindow* w);
 void wakeup_main_loop();