From d593ccba2f7fd176649a79990489a403bd512f2b Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 26 Feb 2019 10:29:46 +0530
Subject: [PATCH] Add a loop tick callback

---
 glfw/glfw3.h         |  4 +++-
 glfw/init.c          | 13 ++++++++++---
 glfw/internal.h      |  3 ++-
 glfw/x11_init.c      | 13 +++++++++++--
 kitty/glfw-wrapper.c |  3 +++
 kitty/glfw-wrapper.h |  7 ++++++-
 kitty/glfw.c         | 15 +++++++++++++++
 kitty/state.h        |  4 ++++
 8 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/glfw/glfw3.h b/glfw/glfw3.h
index 1ee5394b5..96b2c8a41 100644
--- a/glfw/glfw3.h
+++ b/glfw/glfw3.h
@@ -1510,6 +1510,7 @@ typedef void (* GLFWmonitorfun)(GLFWmonitor*,int);
 typedef void (* GLFWjoystickfun)(int,int);
 
 typedef void (* GLFWuserdatafun)(unsigned long long, void*);
+typedef void (* GLFWtickcallback)(void*);
 
 /*! @brief Video mode type.
  *
@@ -1657,8 +1658,9 @@ typedef struct GLFWgamepadstate
  *  @ingroup init
  */
 GLFWAPI int glfwInit(void);
-GLFWAPI void glfwRunMainLoop(void);
+GLFWAPI void glfwRunMainLoop(GLFWtickcallback callback, void *callback_data);
 GLFWAPI void glfwStopMainLoop(void);
+GLFWAPI void glfwRequestTickCallback(void);
 GLFWAPI unsigned long long glfwAddTimer(double interval, bool repeats, GLFWuserdatafun callback, void * callback_data, GLFWuserdatafun free_callback);
 GLFWAPI void glfwRemoveTimer(unsigned long long);
 
diff --git a/glfw/init.c b/glfw/init.c
index 3f554c6cd..6e9fe4db2 100644
--- a/glfw/init.c
+++ b/glfw/init.c
@@ -322,10 +322,14 @@ GLFWAPI GLFWerrorfun glfwSetErrorCallback(GLFWerrorfun cbfun)
 }
 
 
-GLFWAPI void glfwRunMainLoop(void)
+GLFWAPI void glfwRunMainLoop(GLFWtickcallback callback, void *data)
 {
     _GLFW_REQUIRE_INIT();
-    _glfwPlatformRunMainLoop();
+    _glfwPlatformRunMainLoop(callback, data);
+}
+
+GLFWAPI void glfwRequestTickCallback(void) {
+    _glfwPlatformRequestTickCallback();
 }
 
 GLFWAPI void glfwStopMainLoop(void) {
@@ -333,7 +337,10 @@ GLFWAPI void glfwStopMainLoop(void) {
     _glfwPlatformStopMainLoop();
 }
 
-GLFWAPI unsigned long long glfwAddTimer(double interval, bool repeats, GLFWuserdatafun callback, void *callback_data, GLFWuserdatafun free_callback) {
+GLFWAPI unsigned long long glfwAddTimer(
+        double interval, bool repeats, GLFWuserdatafun callback,
+        void *callback_data, GLFWuserdatafun free_callback)
+{
     return _glfwPlatformAddTimer(interval, repeats, callback, callback_data, free_callback);
 }
 
diff --git a/glfw/internal.h b/glfw/internal.h
index 333f52643..e09e29959 100644
--- a/glfw/internal.h
+++ b/glfw/internal.h
@@ -783,7 +783,8 @@ void _glfwTerminateVulkan(void);
 const char* _glfwGetVulkanResultString(VkResult result);
 _GLFWwindow* _glfwFocusedWindow();
 _GLFWwindow* _glfwWindowForId(GLFWid id);
-void _glfwPlatformRunMainLoop(void);
+void _glfwPlatformRunMainLoop(GLFWtickcallback, void*);
+void _glfwPlatformRequestTickCallback();
 void _glfwPlatformStopMainLoop(void);
 unsigned long long _glfwPlatformAddTimer(double interval, bool repeats, GLFWuserdatafreefun callback, void *callback_data, GLFWuserdatafreefun free_callback);
 void _glfwPlatformRemoveTimer(unsigned long long timer_id);
diff --git a/glfw/x11_init.c b/glfw/x11_init.c
index c793176c0..399dceec2 100644
--- a/glfw/x11_init.c
+++ b/glfw/x11_init.c
@@ -770,7 +770,11 @@ const char* _glfwPlatformGetVersionString(void)
         ;
 }
 
-static GLFWbool keep_going;
+static GLFWbool keep_going = GLFW_FALSE, tick_callback_requested = GLFW_FALSE;
+
+void _glfwPlatformRequestTickCallback() {
+    tick_callback_requested = GLFW_TRUE;
+}
 
 void _glfwPlatformStopMainLoop(void) {
     if (keep_going) {
@@ -779,9 +783,14 @@ void _glfwPlatformStopMainLoop(void) {
     }
 }
 
-void _glfwPlatformRunMainLoop(void) {
+void _glfwPlatformRunMainLoop(GLFWtickcallback callback, void* data) {
     keep_going = GLFW_TRUE;
+    tick_callback_requested = GLFW_FALSE;
     while(keep_going) {
+        if (tick_callback_requested) {
+            tick_callback_requested = GLFW_FALSE;
+            callback(data);
+        }
         _glfwPlatformWaitEvents();
     }
 }
diff --git a/kitty/glfw-wrapper.c b/kitty/glfw-wrapper.c
index 733d734a9..08d2b76b8 100644
--- a/kitty/glfw-wrapper.c
+++ b/kitty/glfw-wrapper.c
@@ -23,6 +23,9 @@ load_glfw(const char* path) {
     *(void **) (&glfwStopMainLoop_impl) = dlsym(handle, "glfwStopMainLoop");
     if (glfwStopMainLoop_impl == NULL) fail("Failed to load glfw function glfwStopMainLoop with error: %s", dlerror());
 
+    *(void **) (&glfwRequestTickCallback_impl) = dlsym(handle, "glfwRequestTickCallback");
+    if (glfwRequestTickCallback_impl == NULL) fail("Failed to load glfw function glfwRequestTickCallback with error: %s", dlerror());
+
     *(void **) (&glfwAddTimer_impl) = dlsym(handle, "glfwAddTimer");
     if (glfwAddTimer_impl == NULL) fail("Failed to load glfw function glfwAddTimer with error: %s", dlerror());
 
diff --git a/kitty/glfw-wrapper.h b/kitty/glfw-wrapper.h
index 5d808264b..f060b3ecc 100644
--- a/kitty/glfw-wrapper.h
+++ b/kitty/glfw-wrapper.h
@@ -1267,6 +1267,7 @@ typedef void (* GLFWmonitorfun)(GLFWmonitor*,int);
 typedef void (* GLFWjoystickfun)(int,int);
 
 typedef void (* GLFWuserdatafun)(unsigned long long, void*);
+typedef void (* GLFWtickcallback)(void*);
 
 /*! @brief Video mode type.
  *
@@ -1426,7 +1427,7 @@ typedef int (*glfwInit_func)();
 glfwInit_func glfwInit_impl;
 #define glfwInit glfwInit_impl
 
-typedef void (*glfwRunMainLoop_func)();
+typedef void (*glfwRunMainLoop_func)(GLFWtickcallback, void*);
 glfwRunMainLoop_func glfwRunMainLoop_impl;
 #define glfwRunMainLoop glfwRunMainLoop_impl
 
@@ -1434,6 +1435,10 @@ typedef void (*glfwStopMainLoop_func)();
 glfwStopMainLoop_func glfwStopMainLoop_impl;
 #define glfwStopMainLoop glfwStopMainLoop_impl
 
+typedef void (*glfwRequestTickCallback_func)();
+glfwRequestTickCallback_func glfwRequestTickCallback_impl;
+#define glfwRequestTickCallback glfwRequestTickCallback_impl
+
 typedef unsigned long long (*glfwAddTimer_func)(double, bool, GLFWuserdatafun, void *, GLFWuserdatafun);
 glfwAddTimer_func glfwAddTimer_impl;
 #define glfwAddTimer glfwAddTimer_impl
diff --git a/kitty/glfw.c b/kitty/glfw.c
index 1dda8a455..9de6882ca 100644
--- a/kitty/glfw.c
+++ b/kitty/glfw.c
@@ -1123,6 +1123,21 @@ remove_main_loop_timer(id_type timer_id) {
     glfwRemoveTimer(timer_id);
 }
 
+void
+run_main_loop(tick_callback_fun cb, void* cb_data) {
+    glfwRunMainLoop(cb, cb_data);
+}
+
+void
+request_tick_callback(void) {
+    glfwRequestTickCallback();
+}
+
+void
+stop_main_loop(void) {
+    glfwStopMainLoop();
+}
+
 // Boilerplate {{{
 
 static PyMethodDef module_methods[] = {
diff --git a/kitty/state.h b/kitty/state.h
index 488a37f71..ac0be71b2 100644
--- a/kitty/state.h
+++ b/kitty/state.h
@@ -222,5 +222,9 @@ void request_application_quit();
 #endif
 void request_frame_render(OSWindow *w);
 typedef void (* timer_callback_fun)(id_type, void*);
+typedef void (* tick_callback_fun)(void*);
 id_type add_main_loop_timer(double interval, bool repeats, timer_callback_fun callback, void *callback_data, timer_callback_fun free_callback);
 void remove_main_loop_timer(id_type timer_id);
+void run_main_loop(tick_callback_fun, void*);
+void request_tick_callback(void);
+void stop_main_loop(void);