macOS: Render OS windows during windowDidResize for even smoother live resize rendering

glfw/cocoa_platform.h

@@ -157,6 +157,7 @@ typedef struct _GLFWwindowNS
     GLFWcocoarenderframefun renderFrameCallback;
     // update cursor after switching desktops with Mission Control
     bool delayed_cursor_update_requested;
+    GLFWcocoarenderframefun resizeCallback;
 } _GLFWwindowNS;
 
 typedef struct _GLFWDisplayLinkNS

glfw/cocoa_window.m

@@ -646,6 +646,7 @@ - (void)windowDidResize:(NSNotification *)notification
         window->ns.height = (int)contentRect.size.height;
         _glfwInputWindowSize(window, (int)contentRect.size.width, (int)contentRect.size.height);
     }
+    if (window->ns.resizeCallback) window->ns.resizeCallback((GLFWwindow*)window);
 }
 
 - (void)windowDidMove:(NSNotification *)notification
@@ -2964,6 +2965,13 @@ GLFWAPI int glfwCocoaSetBackgroundBlur(GLFWwindow *w, int radius) {
     return orig;
 }
 
+GLFWAPI GLFWcocoarenderframefun glfwCocoaSetWindowResizeCallback(GLFWwindow *w, GLFWcocoarenderframefun cb) {
+    _GLFWwindow* window = (_GLFWwindow*)w;
+    GLFWcocoarenderframefun current = window->ns.resizeCallback;
+    window->ns.resizeCallback = cb;
+    return current;
+}
+
 GLFWAPI void glfwCocoaSetWindowChrome(GLFWwindow *w, unsigned int color, bool use_system_color, unsigned int system_color, int background_blur, unsigned int hide_window_decorations, bool show_text_in_titlebar, int color_space, float background_opacity, bool resizable) { @autoreleasepool {
     _GLFWwindow* window = (_GLFWwindow*)w;
     const bool is_transparent = ![window->ns.object isOpaque];

glfw/glfw.py

@@ -248,6 +248,7 @@ def generate_wrappers(glfw_header: str) -> None:
     GLFWapplicationwillfinishlaunchingfun glfwSetApplicationWillFinishLaunching(GLFWapplicationwillfinishlaunchingfun callback)
     uint32_t glfwGetCocoaKeyEquivalent(uint32_t glfw_key, int glfw_mods, int* cocoa_mods)
     void glfwCocoaRequestRenderFrame(GLFWwindow *w, GLFWcocoarenderframefun callback)
+    GLFWcocoarenderframefun glfwCocoaSetWindowResizeCallback(GLFWwindow *w, GLFWcocoarenderframefun callback)
     int glfwCocoaSetBackgroundBlur(GLFWwindow *w, int blur_radius)
     bool glfwSetX11WindowBlurred(GLFWwindow *w, bool enable_blur)
     void* glfwGetX11Display(void)

kitty/child-monitor.c

@@ -841,6 +841,10 @@ render(monotonic_t now, bool input_read) {
 
     for (size_t i = 0; i < global_state.num_os_windows; i++) {
         OSWindow *w = global_state.os_windows + i;
+#ifdef __APPLE__
+        // rendering is done in cocoa_os_window_resized()
+        if (w->live_resize.in_progress) continue;
+#endif
         if (!render_os_window(w, now, false, scan_for_animated_images)) {
             // since we didn't scan the window for animations, force a rescan on next wakeup/render frame
             if (scan_for_animated_images) global_state.check_for_active_animated_images = true;

kitty/glfw-wrapper.c

@@ -440,6 +440,9 @@ load_glfw(const char* path) {
     *(void **) (&glfwCocoaRequestRenderFrame_impl) = dlsym(handle, "glfwCocoaRequestRenderFrame");
     if (glfwCocoaRequestRenderFrame_impl == NULL) dlerror(); // clear error indicator
 
+    *(void **) (&glfwCocoaSetWindowResizeCallback_impl) = dlsym(handle, "glfwCocoaSetWindowResizeCallback");
+    if (glfwCocoaSetWindowResizeCallback_impl == NULL) dlerror(); // clear error indicator
+
     *(void **) (&glfwCocoaSetBackgroundBlur_impl) = dlsym(handle, "glfwCocoaSetBackgroundBlur");
     if (glfwCocoaSetBackgroundBlur_impl == NULL) dlerror(); // clear error indicator
 

kitty/glfw-wrapper.h

@@ -2217,6 +2217,10 @@ typedef void (*glfwCocoaRequestRenderFrame_func)(GLFWwindow*, GLFWcocoarenderfra
 GFW_EXTERN glfwCocoaRequestRenderFrame_func glfwCocoaRequestRenderFrame_impl;
 #define glfwCocoaRequestRenderFrame glfwCocoaRequestRenderFrame_impl
 
+typedef GLFWcocoarenderframefun (*glfwCocoaSetWindowResizeCallback_func)(GLFWwindow*, GLFWcocoarenderframefun);
+GFW_EXTERN glfwCocoaSetWindowResizeCallback_func glfwCocoaSetWindowResizeCallback_impl;
+#define glfwCocoaSetWindowResizeCallback glfwCocoaSetWindowResizeCallback_impl
+
 typedef int (*glfwCocoaSetBackgroundBlur_func)(GLFWwindow*, int);
 GFW_EXTERN glfwCocoaSetBackgroundBlur_func glfwCocoaSetBackgroundBlur_impl;
 #define glfwCocoaSetBackgroundBlur glfwCocoaSetBackgroundBlur_impl

kitty/glfw.c

@@ -289,11 +289,38 @@ window_iconify_callback(GLFWwindow *window, int iconified) {
     global_state.callback_os_window = NULL;
 }
 
+#ifdef __APPLE__
+static void
+cocoa_out_of_sequence_render(OSWindow *window) {
+    make_os_window_context_current(window);
+    window->needs_render = true;
+    bool rendered = render_os_window(window, monotonic(), true, true);
+    if (!rendered) {
+        blank_os_window(window);
+        swap_window_buffers(window);
+    }
+    window->needs_render = true;
+}
+
+static void
+cocoa_os_window_resized(GLFWwindow *w) {
+    if (!set_callback_window(w)) return;
+    cocoa_out_of_sequence_render(global_state.callback_os_window);
+    global_state.callback_os_window = NULL;
+}
+#endif
+
+
+
 void
 change_live_resize_state(OSWindow *w, bool in_progress) {
     if (in_progress != w->live_resize.in_progress) {
         w->live_resize.in_progress = in_progress;
+        w->live_resize.num_of_resize_events = 0;
         apply_swap_interval(in_progress ? 0 : -1);
+#ifdef __APPLE__
+        cocoa_out_of_sequence_render(w);
+#endif
     }
 }
 
@@ -1083,6 +1110,7 @@ create_os_window(PyObject UNUSED *self, PyObject *args, PyObject *kw) {
 #ifdef __APPLE__
     if (OPT(macos_option_as_alt)) glfwSetCocoaTextInputFilter(glfw_window, filter_option);
     glfwSetCocoaToggleFullscreenIntercept(glfw_window, intercept_cocoa_fullscreen);
+    glfwCocoaSetWindowResizeCallback(glfw_window, cocoa_os_window_resized);
 #endif
     send_prerendered_sprites_for_window(w);
     if (logo.pixels && logo.width && logo.height) glfwSetWindowIcon(glfw_window, 1, &logo);