Joystick sensitivity for player movement (#11262)

This commit deprecates the forward, backward, left, and right binary
inputs currently used for player movement in the PlayerControl struct.
In their place, it adds the movement_speed and movement_direction
values, which represents the player movement is a polar coordinate
system.

movement_speed is a scalar from 0.0 to 1.0. movement_direction is
an angle from 0 to +-Pi:

	       FWD
	        0
	        _
	 LFT   / \   RGT
	-Pi/2 |   | +Pi/2
	       \_/
	       +-Pi
	       BCK

Boolean movement bits will still be set for server telegrams and
Lua script invocations to provide full backward compatibility.
When generating these values from an analog input, a direction is
considered active when it is 22.5 degrees away from either
orthogonal axis.

Co-authored-by: Markus Koch <markus@notsyncing.net>
Co-authored-by: sfan5 <sfan5@live.de>

1 files changed, 21 insertions, 3 deletions

diff --git a/src/client/joystick_controller.cpp b/src/client/joystick_controller.cpp
index 919db5315..630565d8d 100644
--- a/src/client/joystick_controller.cpp
+++ b/src/client/joystick_controller.cpp
@@ -160,6 +160,7 @@ JoystickController::JoystickController() :
 	for (float &i : m_past_pressed_time) {
 		i = 0;
 	}
+	m_layout.axes_deadzone = 0;
 	clear();
 }
 
@@ -251,10 +252,27 @@ void JoystickController::clear()
 	memset(m_axes_vals, 0, sizeof(m_axes_vals));
 }
 
-s16 JoystickController::getAxisWithoutDead(JoystickAxis axis)
+float JoystickController::getAxisWithoutDead(JoystickAxis axis)
 {
 	s16 v = m_axes_vals[axis];
+
 	if (abs(v) < m_layout.axes_deadzone)
-		return 0;
-	return v;
+		return 0.0f;
+
+	v += (v < 0 ? m_layout.axes_deadzone : -m_layout.axes_deadzone);
+
+	return (float)v / ((float)(INT16_MAX - m_layout.axes_deadzone));
+}
+
+float JoystickController::getMovementDirection()
+{
+	return atan2(getAxisWithoutDead(JA_SIDEWARD_MOVE), -getAxisWithoutDead(JA_FORWARD_MOVE));
+}
+
+float JoystickController::getMovementSpeed()
+{
+	float speed = sqrt(pow(getAxisWithoutDead(JA_FORWARD_MOVE), 2) + pow(getAxisWithoutDead(JA_SIDEWARD_MOVE), 2));
+	if (speed > 1.0f)
+		speed = 1.0f;
+	return speed;
 }