From 756c1242ad87fc749923ccb5dccdd0de1adffae9 Mon Sep 17 00:00:00 2001
From: Konstantinos Chatzilygeroudis <costashatz@gmail.com>
Date: Thu, 7 Nov 2019 13:17:51 +0100
Subject: [PATCH] GlfwApplication: add mainLoopIteration similar to
 Sdl2Application

---
 src/Magnum/Platform/GlfwApplication.cpp | 19 ++++++++++++-------
 src/Magnum/Platform/GlfwApplication.h   | 12 ++++++++++++
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/Magnum/Platform/GlfwApplication.cpp b/src/Magnum/Platform/GlfwApplication.cpp
index bb566f15e..bc73a5e23 100644
--- a/src/Magnum/Platform/GlfwApplication.cpp
+++ b/src/Magnum/Platform/GlfwApplication.cpp
@@ -603,16 +603,21 @@ void GlfwApplication::setSwapInterval(const Int interval) {
 int GlfwApplication::exec() {
     CORRADE_ASSERT(_window, "Platform::GlfwApplication::exec(): no window opened", {});
 
-    while(!glfwWindowShouldClose(_window)) {
-        if(_flags & Flag::Redraw) {
-            _flags &= ~Flag::Redraw;
-            drawEvent();
-        }
-        glfwPollEvents();
-    }
+    while(mainLoopIteration()) {}
+
     return _exitCode;
 }
 
+bool GlfwApplication::mainLoopIteration() {
+    if(_flags & Flag::Redraw) {
+        _flags &= ~Flag::Redraw;
+        drawEvent();
+    }
+    glfwPollEvents();
+
+    return !glfwWindowShouldClose(_window);
+}
+
 namespace {
 
 constexpr Int CursorMap[] {
diff --git a/src/Magnum/Platform/GlfwApplication.h b/src/Magnum/Platform/GlfwApplication.h
index 0d0d9135a..fcef716a1 100644
--- a/src/Magnum/Platform/GlfwApplication.h
+++ b/src/Magnum/Platform/GlfwApplication.h
@@ -238,6 +238,18 @@ class GlfwApplication {
          */
         int exec();
 
+        /**
+         * @brief Run one iteration of application main loop
+         * @return @cpp false @ce if @ref exit() was called and the application
+         *      should exit, @cpp true @ce otherwise
+         *
+         * Called internally from @ref exec(). If you want to have better
+         * control over how the main loop behaves, you can call this function
+         * yourself from your own `main()` function instead of it being called
+         * automatically from @ref exec().
+         */
+        bool mainLoopIteration();
+
         /**
          * @brief Exit application main loop
          * @param exitCode  The exit code the application should return