From af78d5dbb8641bf38334d180cd56fc5d51f75315 Mon Sep 17 00:00:00 2001
From: Martin Vladic <martin.vladic@gmail.com>
Date: Sat, 21 Mar 2020 12:10:47 +0100
Subject: [PATCH] improved touch responsiveness

---
 src/eez/gui/gui.cpp   |   1 +
 src/eez/gui/touch.cpp | 161 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 142 insertions(+), 20 deletions(-)

diff --git a/src/eez/gui/gui.cpp b/src/eez/gui/gui.cpp
index 2a92c54e5..e8fd9647c 100644
--- a/src/eez/gui/gui.cpp
+++ b/src/eez/gui/gui.cpp
@@ -61,6 +61,7 @@ osMessageQId g_guiMessageQueueId;
 void startThread() {
     decompressAssets();
     mcu::display::onThemeChanged();
+    touch::init();
     g_guiMessageQueueId = osMessageCreate(osMessageQ(g_guiMessageQueue), NULL);
     g_guiTaskHandle = osThreadCreate(osThread(g_guiTask), nullptr);
 }
diff --git a/src/eez/gui/touch.cpp b/src/eez/gui/touch.cpp
index c598cd442..0e701c580 100644
--- a/src/eez/gui/touch.cpp
+++ b/src/eez/gui/touch.cpp
@@ -27,23 +27,72 @@ namespace eez {
 namespace gui {
 namespace touch {
 
-EventType g_eventType = EVENT_TYPE_TOUCH_NONE;
+static EventType g_lastEventType = EVENT_TYPE_TOUCH_NONE;
 
-int g_x;
-int g_y;
-bool g_pressed;
+static int g_x = -1;
+static int g_y = -1;
+static bool g_pressed = false;
 
-int g_calibratedX = -1;
-int g_calibratedY = -1;
-bool g_calibratedPressed;
+static int g_calibratedX = -1;
+static int g_calibratedY = -1;
+static bool g_calibratedPressed = false;
 
-int g_filteredX = -1;
-int g_filteredY = -1;
-bool g_filteredPressed;
+static int g_filteredX = -1;
+static int g_filteredY = -1;
+static bool g_filteredPressed = false;
 
 ////////////////////////////////////////////////////////////////////////////////
 
-void tick() {
+EventType g_eventType = EVENT_TYPE_TOUCH_NONE;
+int g_eventX = -1;
+int g_eventY = -1;
+
+////////////////////////////////////////////////////////////////////////////////
+
+#if defined(EEZ_PLATFORM_STM32)
+
+static const int EVENT_QUEUE_MAX_SIZE = 50;
+struct Event {
+    EventType type;
+    int x;
+    int y;
+};
+static Event g_eventQueue[EVENT_QUEUE_MAX_SIZE];
+static uint8_t g_eventQueueHead = 0;
+static uint8_t g_eventQueueTail = 0;
+static bool g_eventQueueFull;
+osMutexId(g_eventQueueMutexId);
+osMutexDef(g_eventQueueMutex);
+
+void mainLoop(const void *);
+
+#if defined(EEZ_PLATFORM_STM32)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wwrite-strings"
+#endif
+
+osThreadDef(g_touchTask, mainLoop, osPriorityNormal, 0, 1024);
+
+#if defined(EEZ_PLATFORM_STM32)
+#pragma GCC diagnostic pop
+#endif
+
+void oneIter();
+
+void mainLoop(const void *) {
+#ifdef __EMSCRIPTEN__
+	oneIter();
+#else
+    while (1) {
+        oneIter();
+        osDelay(10);
+    }
+#endif
+}
+
+#endif
+
+void oneIter() {
     bool pressed;
     int x;
     int y;
@@ -69,28 +118,100 @@ void tick() {
 #endif
 
     if (g_pressed) {
-        if (g_eventType == EVENT_TYPE_TOUCH_NONE || g_eventType == EVENT_TYPE_TOUCH_UP) {
-            g_eventType = EVENT_TYPE_TOUCH_DOWN;
+        if (g_lastEventType == EVENT_TYPE_TOUCH_NONE || g_lastEventType == EVENT_TYPE_TOUCH_UP) {
+            g_lastEventType = EVENT_TYPE_TOUCH_DOWN;
         } else {
-            if (g_eventType == EVENT_TYPE_TOUCH_DOWN) {
-                g_eventType = EVENT_TYPE_TOUCH_MOVE;
+            if (g_lastEventType == EVENT_TYPE_TOUCH_DOWN) {
+                g_lastEventType = EVENT_TYPE_TOUCH_MOVE;
             }
         }
     } else {
-        if (g_eventType == EVENT_TYPE_TOUCH_DOWN || g_eventType == EVENT_TYPE_TOUCH_MOVE) {
-            g_eventType = EVENT_TYPE_TOUCH_UP;
-        } else if (g_eventType == EVENT_TYPE_TOUCH_UP) {
+        if (g_lastEventType == EVENT_TYPE_TOUCH_DOWN || g_lastEventType == EVENT_TYPE_TOUCH_MOVE) {
+            g_lastEventType = EVENT_TYPE_TOUCH_UP;
+        } else if (g_lastEventType == EVENT_TYPE_TOUCH_UP) {
+            g_lastEventType = EVENT_TYPE_TOUCH_NONE;
+        }
+    }
+
+#if defined(EEZ_PLATFORM_STM32)
+    if (g_lastEventType != EVENT_TYPE_TOUCH_NONE) {
+        if (osMutexWait(g_eventQueueMutexId, 5) == osOK) {
+		    if (g_eventQueueFull || g_eventQueueTail != g_eventQueueHead) {
+			    uint32_t previousEventQueueHead = g_eventQueueHead == 0 ? EVENT_QUEUE_MAX_SIZE - 1 : g_eventQueueHead - 1;
+                Event &event = g_eventQueue[previousEventQueueHead];
+                if (event.type == g_lastEventType) {
+                	g_eventQueueHead = previousEventQueueHead;
+                }
+            }
+
+			Event &event = g_eventQueue[g_eventQueueHead];
+
+			event.type = g_lastEventType;
+			event.x = g_x;
+			event.y = g_y;
+
+			if (g_eventQueueFull) {
+				g_eventQueueTail = (g_eventQueueTail + 1) % EVENT_QUEUE_MAX_SIZE;
+			}
+
+			g_eventQueueHead = (g_eventQueueHead + 1) % EVENT_QUEUE_MAX_SIZE;
+
+			if (g_eventQueueHead == g_eventQueueTail) {
+				g_eventQueueFull = true;
+			}
+
+            osMutexRelease(g_eventQueueMutexId);
+        }
+    }
+#endif
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+void init() {
+#if defined(EEZ_PLATFORM_STM32)
+    g_eventQueueMutexId = osMutexCreate(osMutex(g_eventQueueMutex));
+    osThreadCreate(osThread(g_touchTask), nullptr);
+#endif
+}
+
+void tick() {
+#if defined(EEZ_PLATFORM_STM32)
+    if (osMutexWait(g_eventQueueMutexId, 5) == osOK) {
+		if (g_eventQueueFull || g_eventQueueTail != g_eventQueueHead) {
+			Event &event = g_eventQueue[g_eventQueueTail];
+
+            g_eventType = event.type;
+            g_eventX = event.x;
+            g_eventY = event.y;
+
+			g_eventQueueTail = (g_eventQueueTail + 1) % EVENT_QUEUE_MAX_SIZE;
+			g_eventQueueFull = false;
+		} else {
             g_eventType = EVENT_TYPE_TOUCH_NONE;
+            g_eventX = -1;
+            g_eventY = -1;
         }
+
+        osMutexRelease(g_eventQueueMutexId);
     }
+#endif
+
+#if defined(EEZ_PLATFORM_SIMULATOR)
+    oneIter();
+
+    g_eventType = g_lastEventType;
+    g_eventX = g_x;
+    g_eventY = g_y;
+#endif
 }
 
 int getX() {
-    return g_x;
+    return g_eventX;
 }
 
 int getY() {
-    return g_y;
+    return g_eventY;
 }
 
 } // namespace touch