From 75004c429c2eb114b28cbb8adb10c6e34b2716c0 Mon Sep 17 00:00:00 2001
From: rsn8887
Date: Sat, 18 Feb 2017 11:54:39 -0600
Subject: SDL: improved internal joystick event handling

---
 backends/events/sdl/sdl-events.cpp | 49 ++++++++++++++++++++------------------
 backends/events/sdl/sdl-events.h   |  3 ++-
 2 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/backends/events/sdl/sdl-events.cpp b/backends/events/sdl/sdl-events.cpp
index 78092f8fc1..dccdef971b 100644
--- a/backends/events/sdl/sdl-events.cpp
+++ b/backends/events/sdl/sdl-events.cpp
@@ -205,12 +205,12 @@ bool SdlEventSource::handleKbdMouse(Common::Event &event) {
 
 		if (_km.x_vel || _km.y_vel) {
 			if (_km.x_down_count) {
-				if (curTime > _km.x_down_time + _km.delay_time * 12) {
+				if (curTime > _km.x_down_time + 300) {
 					if (_km.x_vel > 0)
-						_km.x_vel+=_km.multiplier;
+						_km.x_vel += _km.multiplier;
 					else
-						_km.x_vel-=_km.multiplier;
-				} else if (curTime > _km.x_down_time + _km.delay_time * 8) {
+						_km.x_vel -= _km.multiplier;
+				} else if (curTime > _km.x_down_time + 200) {
 					if (_km.x_vel > 0)
 						_km.x_vel = 5 * _km.multiplier;
 					else
@@ -218,27 +218,33 @@ bool SdlEventSource::handleKbdMouse(Common::Event &event) {
 				}
 			}
 			if (_km.y_down_count) {
-				if (curTime > _km.y_down_time + _km.delay_time * 12) {
+				if (curTime > _km.y_down_time + 300) {
 					if (_km.y_vel > 0)
 						_km.y_vel += _km.multiplier;
 					else
 						_km.y_vel -= _km.multiplier;
-				} else if (curTime > _km.y_down_time + _km.delay_time * 8) {
+				} else if (curTime > _km.y_down_time + 200) {
 					if (_km.y_vel > 0)
 						_km.y_vel = 5 * _km.multiplier;
 					else
 						_km.y_vel = -5 * _km.multiplier;
 				}
 			}
+
 			// The modifier key makes the mouse movement slower
+			// The extra factor of delay/25 makes velocities 
+			// independent of kbdMouse update rate
+			// all velovities were originally chosen
+			// at a delay of 25, so that is the reference
+			// operator order is important to avoid overflow
 			if (_km.modifier) {
-				_km.x += _km.x_vel / 10;
-				_km.y += _km.y_vel / 10;
+				_km.x += ((_km.x_vel / 10) * ((int16)_km.delay_time)) / 25;
+				_km.y += ((_km.y_vel / 10) * ((int16)_km.delay_time)) / 25;
 			} else {
-				_km.x += _km.x_vel;
-				_km.y += _km.y_vel;
+				_km.x += (_km.x_vel * ((int16)_km.delay_time)) / 25;
+				_km.y += (_km.y_vel * ((int16)_km.delay_time)) / 25;
 			}
-			
+
 			if (_km.x < 0) {
 				_km.x = 0;
 				_km.x_vel = -1 * _km.multiplier;
@@ -260,7 +266,7 @@ bool SdlEventSource::handleKbdMouse(Common::Event &event) {
 			}
 
 			if (_graphicsManager) {
-				_graphicsManager->getWindow()->warpMouseInWindow((Uint16) (_km.x / _km.multiplier), (Uint16) (_km.y / _km.multiplier));
+				_graphicsManager->getWindow()->warpMouseInWindow((Uint16)(_km.x / _km.multiplier), (Uint16)(_km.y / _km.multiplier));
 			}
 
 			if (_km.x != oldKmX || _km.y != oldKmY) {
@@ -446,9 +452,6 @@ Common::KeyCode SdlEventSource::SDLToOSystemKeycode(const SDLKey key) {
 }
 
 bool SdlEventSource::pollEvent(Common::Event &event) {
-	if (handleKbdMouse(event)) {
-		return true;
-	}
 
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 	// In case we still need to send a key up event for a key down from a
@@ -474,6 +477,12 @@ bool SdlEventSource::pollEvent(Common::Event &event) {
 		if (dispatchSDLEvent(ev, event))
 			return true;
 	}
+
+	// Handle mouse control via analog joystick and keyboard
+	if (handleKbdMouse(event)) {
+		return true;
+	}
+
 	return false;
 }
 
@@ -799,14 +808,12 @@ bool SdlEventSource::handleJoyAxisMotion(SDL_Event &ev, Common::Event &event) {
 	int axis = ev.jaxis.value;
 #ifdef JOY_ANALOG
 	// conversion factor between keyboard mouse and joy axis value
-	int vel_to_axis = (3000 / _km.multiplier);
+	int vel_to_axis = (1500 / _km.multiplier);
 #else
 	if (axis > JOY_DEADZONE) {
 		axis -= JOY_DEADZONE;
-		event.type = Common::EVENT_MOUSEMOVE;
 	} else if (axis < -JOY_DEADZONE) {
 		axis += JOY_DEADZONE;
-		event.type = Common::EVENT_MOUSEMOVE;
 	} else
 		axis = 0;
 #endif
@@ -855,16 +862,13 @@ bool SdlEventSource::handleJoyAxisMotion(SDL_Event &ev, Common::Event &event) {
 		scalingFactor = 1.0f / magnitude * (magnitude - deadZone) / (32769.0f - deadZone);
 		_km.x_vel = (int16) (analogX * scalingFactor * 32768.0f / vel_to_axis);
 		_km.y_vel = (int16) (analogY * scalingFactor * 32768.0f / vel_to_axis);
-		event.type = Common::EVENT_MOUSEMOVE;
 	} else {
 		_km.y_vel = 0;
 		_km.x_vel = 0;
 	}
 #endif
 
-	processMouseEvent(event, _km.x / _km.multiplier, _km.y / _km.multiplier);
-
-	return true;
+	return false;
 }
 
 bool SdlEventSource::remapKey(SDL_Event &ev, Common::Event &event) {
@@ -940,7 +944,6 @@ void SdlEventSource::resetKeyboardEmulation(int16 x_max, int16 y_max) {
 	_km.y_max = y_max;
 	_km.delay_time = 12;
 	_km.last_time = 0;
-	_km.multiplier = 16;
 	_km.modifier = false;
 }
 
diff --git a/backends/events/sdl/sdl-events.h b/backends/events/sdl/sdl-events.h
index ecbf62c464..c1d6057dac 100644
--- a/backends/events/sdl/sdl-events.h
+++ b/backends/events/sdl/sdl-events.h
@@ -58,7 +58,8 @@ protected:
 	//@{
 
 	struct KbdMouse {
-		int16 x, y, x_vel, y_vel, x_max, y_max, x_down_count, y_down_count, multiplier;
+		int16 x, y, x_vel, y_vel, x_max, y_max, x_down_count, y_down_count;
+		static const int16 multiplier = 16;
 		uint32 last_time, delay_time, x_down_time, y_down_time;
 		bool modifier;
 	};
-- 
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