Initial attempt at supporting Wayland frame events

Does not actually work because the wayland frame callback is not called
at all, fo rsome reason I cannot determine.

glfw/glfw.py

@@ -211,6 +211,7 @@ def generate_wrappers(glfw_header):
     void glfwSetX11SelectionString(const char* string)
     const char* glfwGetX11SelectionString(void)
     int glfwGetXKBScancode(const char* key_name, int case_sensitive)
+    void glfwRequestWaylandFrameEvent(GLFWwindow *handle, unsigned long long id, GLFWwaylandframecallbackfunc callback)
 '''.splitlines():
         if line:
             functions.append(Function(line.strip(), check_fail=False))
@@ -229,7 +230,7 @@ def generate_wrappers(glfw_header):
 typedef int (* GLFWcocoatextinputfilterfun)(int,int,unsigned int);
 typedef int (* GLFWapplicationshouldhandlereopenfun)(int);
 typedef int (* GLFWcocoatogglefullscreenfun)(GLFWwindow*);
-
+typedef void (*GLFWwaylandframecallbackfunc)(unsigned long long id);
 {}
 
 const char* load_glfw(const char* path);

glfw/wl_window.c

@@ -1929,6 +1929,18 @@ _glfwPlatformUpdateIMEState(_GLFWwindow *w, int which, int a, int b, int c, int
     glfw_xkb_update_ime_state(w, &_glfw.wl.xkb, which, a, b, c, d);
 }
 
+struct frame_callback_data {
+    unsigned long long id;
+    void(*callback)(unsigned long long id);
+};
+
+static void
+frame_handle_redraw(void *data, struct wl_callback *callback, uint32_t time) {
+    struct frame_callback_data *cbdata = (struct frame_callback_data*)data;
+    cbdata->callback(cbdata->id);
+    free(cbdata);
+    wl_callback_destroy(callback);
+}
 
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////
@@ -1950,3 +1962,12 @@ GLFWAPI struct wl_surface* glfwGetWaylandWindow(GLFWwindow* handle)
 GLFWAPI int glfwGetXKBScancode(const char* keyName, GLFWbool caseSensitive) {
     return glfw_xkb_keysym_from_name(keyName, caseSensitive);
 }
+
+GLFWAPI void glfwRequestWaylandFrameEvent(GLFWwindow *handle, unsigned long long id, void(*callback)(unsigned long long id)) {
+    _GLFWwindow* window = (_GLFWwindow*) handle;
+    struct frame_callback_data *cbdata = malloc(sizeof(struct frame_callback_data));
+    cbdata->callback = callback; cbdata->id = id;
+    static const struct wl_callback_listener frame_listener = { .done = frame_handle_redraw };
+    struct wl_callback *wlcallback = wl_surface_frame(window->wl.surface);
+    wl_callback_add_listener(wlcallback, &frame_listener, cbdata);
+}

kitty/child-monitor.c

@@ -623,6 +623,7 @@ render_os_window(OSWindow *os_window, double now, unsigned int active_window_id,
     os_window->last_active_tab = os_window->active_tab; os_window->last_num_tabs = os_window->num_tabs; os_window->last_active_window_id = active_window_id;
     os_window->focused_at_last_render = os_window->is_focused;
     os_window->is_damaged = false;
+    if (global_state.is_wayland) os_window->wayland_render_state = RENDER_FRAME_NOT_REQUESTED;
 #undef WD
 #undef TD
 }
@@ -638,6 +639,12 @@ render(double now) {
     for (size_t i = 0; i < global_state.num_os_windows; i++) {
         OSWindow *w = global_state.os_windows + i;
         if (!w->num_tabs || !should_os_window_be_rendered(w)) continue;
+        if (global_state.is_wayland && w->wayland_render_state != RENDER_FRAME_READY) {
+            if (w->wayland_render_state == RENDER_FRAME_NOT_REQUESTED) {
+                wayland_request_frame_render(w);
+            }
+            return;
+        }
         bool needs_render = w->is_damaged;
         make_os_window_context_current(w);
         if (w->viewport_size_dirty) {

kitty/glfw-wrapper.c

@@ -380,6 +380,8 @@ load_glfw(const char* path) {
 
     *(void **) (&glfwGetXKBScancode_impl) = dlsym(handle, "glfwGetXKBScancode");
 
+    *(void **) (&glfwRequestWaylandFrameEvent_impl) = dlsym(handle, "glfwRequestWaylandFrameEvent");
+
     return NULL;
 }
 

kitty/glfw-wrapper.h

@@ -1387,7 +1387,7 @@ typedef struct GLFWgamepadstate
 typedef int (* GLFWcocoatextinputfilterfun)(int,int,unsigned int);
 typedef int (* GLFWapplicationshouldhandlereopenfun)(int);
 typedef int (* GLFWcocoatogglefullscreenfun)(GLFWwindow*);
-
+typedef void (*GLFWwaylandframecallbackfunc)(unsigned long long id);
 typedef int (*glfwInit_func)();
 glfwInit_func glfwInit_impl;
 #define glfwInit glfwInit_impl
@@ -1892,4 +1892,8 @@ typedef int (*glfwGetXKBScancode_func)(const char*, int);
 glfwGetXKBScancode_func glfwGetXKBScancode_impl;
 #define glfwGetXKBScancode glfwGetXKBScancode_impl
 
+typedef void (*glfwRequestWaylandFrameEvent_func)(GLFWwindow*, unsigned long long, GLFWwaylandframecallbackfunc);
+glfwRequestWaylandFrameEvent_func glfwRequestWaylandFrameEvent_impl;
+#define glfwRequestWaylandFrameEvent glfwRequestWaylandFrameEvent_impl
+
 const char* load_glfw(const char* path);

kitty/glfw.c

@@ -559,7 +559,7 @@ create_os_window(PyObject UNUSED *self, PyObject *args) {
     w->fonts_data = fonts_data;
     w->shown_once = true;
     push_focus_history(w);
-    glfwSwapInterval(OPT(sync_to_monitor) ? 1 : 0);
+    glfwSwapInterval(OPT(sync_to_monitor) && !global_state.is_wayland ? 1 : 0);
 #ifdef __APPLE__
     if (OPT(macos_option_as_alt)) glfwSetCocoaTextInputFilter(glfw_window, filter_option);
     glfwSetCocoaToggleFullscreenIntercept(glfw_window, intercept_cocoa_fullscreen);
@@ -982,6 +982,23 @@ get_cocoa_key_equivalent(int key, int mods, unsigned short *cocoa_key, int *coco
     glfwGetCocoaKeyEquivalent(key, mods, cocoa_key, cocoa_mods);
 }
 #endif
+
+void
+wayland_frame_request_callback(id_type os_window_id) {
+    for (size_t i = 0; i < global_state.num_os_windows; i++) {
+        if (global_state.os_windows[i].id == os_window_id) {
+            global_state.os_windows[i].wayland_render_state = RENDER_FRAME_READY;
+            break;
+        }
+    }
+}
+
+void
+wayland_request_frame_render(OSWindow *w) {
+    glfwRequestWaylandFrameEvent(w->handle, w->id, wayland_frame_request_callback);
+    w->wayland_render_state = RENDER_FRAME_REQUESTED;
+}
+
 // Boilerplate {{{
 
 static PyMethodDef module_methods[] = {

kitty/state.h

@@ -98,6 +98,7 @@ typedef struct {
     bool is_set;
 } OSWindowGeometry;
 
+enum WAYLAND_RENDER_STATE { RENDER_FRAME_NOT_REQUESTED, RENDER_FRAME_REQUESTED, RENDER_FRAME_READY };
 
 typedef struct {
     void *handle;
@@ -127,6 +128,7 @@ typedef struct {
     FONTS_DATA_HANDLE fonts_data;
     id_type temp_font_group_id;
     double pending_scroll_pixels;
+    enum WAYLAND_RENDER_STATE wayland_render_state;
 } OSWindow;
 
 
@@ -204,3 +206,4 @@ typedef enum {
 void set_cocoa_pending_action(CocoaPendingAction action);
 bool application_quit_requested();
 #endif
+void wayland_request_frame_render(OSWindow *w);