From 9a62b97a6727acfb43a2c9c8dd7d58cedad6ea41 Mon Sep 17 00:00:00 2001
From: Benau <Benau@users.noreply.github.com>
Date: Tue, 16 Jul 2019 00:55:25 +0800
Subject: [PATCH] Fix multitouch in iOS

---
 lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.h  | 38 +++++++++++++++++++
 lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.mm | 24 ++++++------
 2 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.h b/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.h
index 1b76b8807..0e4840f18 100644
--- a/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.h
+++ b/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.h
@@ -14,6 +14,8 @@
 #include "CIrrDeviceStub.h"
 #include "IrrlichtDevice.h"
 #include "IImagePresenter.h"
+#include <map>
+#include <set>
 
 namespace irr
 {
@@ -75,6 +77,40 @@ namespace irr
 
         //! Returns true if system has native on screen keyboard
         virtual bool hasOnScreenKeyboard() const  { return false; }
+
+        //! Get a unique touch id per touch, create one if it's a new touch
+        size_t getTouchId(void* touch)
+        {
+            auto it = m_touch_id_map.find(touch);
+            if (it == m_touch_id_map.end())
+            {
+                std::set<size_t> ids;
+                for (auto& p : m_touch_id_map)
+                    ids.insert(p.second);
+                size_t cur_id = 0;
+                while (true)
+                {
+                    if (ids.find(cur_id) == ids.end())
+                        break;
+                    cur_id++;
+                }
+                m_touch_id_map[touch] = cur_id;
+                return cur_id;
+            }
+            return it->second;
+        }
+
+        //! Remove a unique touch id, free it for future usage
+        void removeTouchId(void* touch)
+        {
+            m_touch_id_map.erase(touch);
+        }
+
+        //! Clear all unique touch ids, used when the app out focused
+        void clearAllTouchIds()
+        {
+            m_touch_id_map.clear();
+        }
     private:
         void createWindow();
         void createViewAndDriver();
@@ -82,6 +118,8 @@ namespace irr
         void* DataStorage;
 
         bool Close;
+
+        std::map<void*, size_t> m_touch_id_map;
     };
 
 }
diff --git a/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.mm b/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.mm
index 7bc6a3c0c..a31b74e14 100644
--- a/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.mm
+++ b/lib/irrlicht/source/Irrlicht/CIrrDeviceiOS.mm
@@ -90,6 +90,7 @@ namespace irr
 {
     if (Device != nil)
     {
+        Device->clearAllTouchIds();
         irr::SEvent ev;
         ev.EventType = irr::EET_APPLICATION_EVENT;
         ev.ApplicationEvent.EventType = irr::EAET_WILL_PAUSE;
@@ -104,6 +105,7 @@ namespace irr
 {
     if (Device != nil)
     {
+        Device->clearAllTouchIds();
         irr::SEvent ev;
         ev.EventType = irr::EET_APPLICATION_EVENT;
         ev.ApplicationEvent.EventType = irr::EAET_DID_PAUSE;
@@ -118,6 +120,7 @@ namespace irr
 {
     if (Device != nil)
     {
+        Device->clearAllTouchIds();
         irr::SEvent ev;
         ev.EventType = irr::EET_APPLICATION_EVENT;
         ev.ApplicationEvent.EventType = irr::EAET_WILL_RESUME;
@@ -132,6 +135,7 @@ namespace irr
 {
     if (Device != nil)
     {
+        Device->clearAllTouchIds();
         irr::SEvent ev;
         ev.EventType = irr::EET_APPLICATION_EVENT;
         ev.ApplicationEvent.EventType = irr::EAET_DID_RESUME;
@@ -178,6 +182,7 @@ namespace irr
 @implementation CIrrViewiOS
 {
     irr::CIrrDeviceiOS* Device;
+    std::map<void*, size_t> m_touch_id_map;
 }
 
 - (id)initWithFrame:(CGRect)frame forDevice:(irr::CIrrDeviceiOS*)device forContext:(EAGLContext*)eagl_context
@@ -187,16 +192,13 @@ namespace irr
     {
         self.drawableDepthFormat = GLKViewDrawableDepthFormat24;
         self.drawableStencilFormat = GLKViewDrawableStencilFormat8;
+        self.multipleTouchEnabled = YES;
         Device = device;
     }
 
     return self;
 }
 
-- (BOOL)isMultipleTouchEnabled
-{
-    return YES;
-}
 
 - (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
 {
@@ -206,11 +208,10 @@ namespace irr
 
     irr::core::position2d<irr::s32> mouse_pos = irr::core::position2d<irr::s32>(0, 0);
     bool simulate_mouse = false;
-    size_t id = 0;
 
     for (UITouch* touch in touches)
     {
-        ev.TouchInput.ID = id++;
+        ev.TouchInput.ID = Device->getTouchId(touch);
 
         CGPoint touchPoint = [touch locationInView:self];
 
@@ -237,11 +238,10 @@ namespace irr
 
     irr::core::position2d<irr::s32> mouse_pos = irr::core::position2d<irr::s32>(0, 0);
     bool simulate_mouse = false;
-    size_t id = 0;
 
     for (UITouch* touch in touches)
     {
-        ev.TouchInput.ID = id++;
+        ev.TouchInput.ID = Device->getTouchId(touch);
 
         CGPoint touchPoint = [touch locationInView:self];
 
@@ -268,11 +268,11 @@ namespace irr
 
     irr::core::position2d<irr::s32> mouse_pos = irr::core::position2d<irr::s32>(0, 0);
     bool simulate_mouse = false;
-    size_t id = 0;
 
     for (UITouch* touch in touches)
     {
-        ev.TouchInput.ID = id++;
+        ev.TouchInput.ID = Device->getTouchId(touch);
+        Device->removeTouchId(touch);
 
         CGPoint touchPoint = [touch locationInView:self];
 
@@ -299,11 +299,11 @@ namespace irr
 
     irr::core::position2d<irr::s32> mouse_pos = irr::core::position2d<irr::s32>(0, 0);
     bool simulate_mouse = false;
-    size_t id = 0;
 
     for (UITouch* touch in touches)
     {
-        ev.TouchInput.ID = id++;
+        ev.TouchInput.ID = Device->getTouchId(touch);
+        Device->removeTouchId(touch);
 
         CGPoint touchPoint = [touch locationInView:self];