SDL: Fix erratic analog pointer + control options

Fixes erratic speeds in analog pointer motion
Implemented option to set analog/keyboard pointer speed
and control the analog joystick deadzone. The deadzone option appears
only if the build supports analog joystick (via JOY_ANALOG define)

2 files changed, 61 insertions, 16 deletions

diff --git a/backends/events/sdl/sdl-events.cpp b/backends/events/sdl/sdl-events.cpp
index 469f1d5a44..8c1194419f 100644
--- a/backends/events/sdl/sdl-events.cpp
+++ b/backends/events/sdl/sdl-events.cpp
@@ -231,18 +231,59 @@ bool SdlEventSource::handleKbdMouse(Common::Event &event) {
 				}
 			}
 
+			int16 speedFactor = 25;
+
+			if (g_system->hasFeature(OSystem::kFeatureKbdMouseSpeed)) {
+				switch (ConfMan.getInt("kbdmouse_speed")) {
+				// 0.25 keyboard pointer speed
+				case 0:
+					speedFactor = 100;
+					break;
+				// 0.5 speed
+				case 1:
+					speedFactor = 50;
+					break;
+				// 0.75 speed
+				case 2:
+					speedFactor = 37;
+					break;
+				// 1.0 speed
+				case 3:
+					speedFactor = 25;
+					break;
+				// 1.25 speed
+				case 4:
+					speedFactor = 20;
+					break;
+				// 1.5 speed
+				case 5:
+					speedFactor = 17;
+					break;
+				// 1.75 speed
+				case 6:
+					speedFactor = 14;
+					break;
+				// 2.0 speed
+				case 7:
+					speedFactor = 12;
+					break;
+				default:
+					speedFactor = 25;
+				}
+			}
+
 			// - The modifier key makes the mouse movement slower
-			// - The extra factor "delay/25" ensures velocities 
+			// - The extra factor "delay/speedFactor" ensures velocities 
 			// are independent of the kbdMouse update rate
 			// - all velocities were originally chosen
 			// at a delay of 25, so that is the reference used here
 			// - note: operator order is important to avoid overflow
 			if (_km.modifier) {
-				_km.x += ((_km.x_vel / 10) * ((int16)_km.delay_time)) / 25;
-				_km.y += ((_km.y_vel / 10) * ((int16)_km.delay_time)) / 25;
+				_km.x += ((_km.x_vel / 10) * ((int16)_km.delay_time)) / speedFactor;
+				_km.y += ((_km.y_vel / 10) * ((int16)_km.delay_time)) / speedFactor;
 			} else {
-				_km.x += (_km.x_vel * ((int16)_km.delay_time)) / 25;
-				_km.y += (_km.y_vel * ((int16)_km.delay_time)) / 25;
+				_km.x += (_km.x_vel * ((int16)_km.delay_time)) / speedFactor;
+				_km.y += (_km.y_vel * ((int16)_km.delay_time)) / speedFactor;
 			}
 
 			if (_km.x < 0) {
@@ -826,8 +867,7 @@ bool SdlEventSource::handleJoyAxisMotion(SDL_Event &ev, Common::Event &event) {
 
 	if (ev.jaxis.axis == JOY_XAXIS) {
 #ifdef JOY_ANALOG
-		_km.x_vel = axis / vel_to_axis;
-		_km.x_down_count = 0;
+		_km.joy_x = axis;
 #else
 		if (axis != 0) {
 			_km.x_vel = (axis > 0) ? 1 * MULTIPLIER:-1 * MULTIPLIER;
@@ -842,8 +882,7 @@ bool SdlEventSource::handleJoyAxisMotion(SDL_Event &ev, Common::Event &event) {
 		axis = -axis;
 #endif
 #ifdef JOY_ANALOG
-		_km.y_vel = -axis / vel_to_axis;
-		_km.y_down_count = 0;
+		_km.joy_y = -axis;
 #else
 		if (axis != 0) {
 			_km.y_vel = (-axis > 0) ? 1 * MULTIPLIER: -1 * MULTIPLIER;
@@ -856,21 +895,25 @@ bool SdlEventSource::handleJoyAxisMotion(SDL_Event &ev, Common::Event &event) {
 	}
 #ifdef JOY_ANALOG
 	// radial and scaled analog joystick deadzone
-	float analogX = (float) (_km.x_vel * vel_to_axis);
-	float analogY = (float) (_km.y_vel * vel_to_axis);
-	float deadZone = (float) JOY_DEADZONE;
+	float analogX = (float)_km.joy_x;
+	float analogY = (float)_km.joy_y;
+	float deadZone = (float)JOY_DEADZONE;
+	if (g_system->hasFeature(OSystem::kFeatureJoystickDeadzone))
+		deadZone = (float)ConfMan.getInt("joystick_deadzone") * 1000.0f;
 	float scalingFactor = 1.0f;
 	float magnitude = 0.0f;
 
 	magnitude = sqrt(analogX * analogX + analogY * analogY);
 
 	if (magnitude >= deadZone) {
+		_km.x_down_count = 0;
+		_km.y_down_count = 0;
 		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);
+		_km.x_vel = (int16)(analogX * scalingFactor * 32768.0f / vel_to_axis);
+		_km.y_vel = (int16)(analogY * scalingFactor * 32768.0f / vel_to_axis);
 	} else {
-		_km.y_vel = 0;
 		_km.x_vel = 0;
+		_km.y_vel = 0;
 	}
 #endif
 
@@ -951,6 +994,8 @@ void SdlEventSource::resetKeyboardEmulation(int16 x_max, int16 y_max) {
 	_km.delay_time = 12;
 	_km.last_time = 0;
 	_km.modifier = false;
+	_km.joy_x = 0;
+	_km.joy_y = 0;
 }
 
 bool SdlEventSource::handleResizeEvent(Common::Event &event, int w, int h) {
diff --git a/backends/events/sdl/sdl-events.h b/backends/events/sdl/sdl-events.h
index 334bf8acfc..cf445e9e2c 100644
--- a/backends/events/sdl/sdl-events.h
+++ b/backends/events/sdl/sdl-events.h
@@ -60,7 +60,7 @@ protected:
 	//@{
 
 	struct KbdMouse {
-		int16 x, y, x_vel, y_vel, x_max, y_max, x_down_count, y_down_count;
+		int16 x, y, x_vel, y_vel, x_max, y_max, x_down_count, y_down_count, joy_x, joy_y;
 		uint32 last_time, delay_time, x_down_time, y_down_time;
 		bool modifier;
 	};