Restricting joystick within a radius of center
- by Phil
I'm using Unity3d iOs and am using the example joysticks that came with one of the packages. It works fine but the area the joystick moves in is a rectangle which is unintuitive for my type of game. I can figure out how to see if the distance between the center and the current point is too far but I can't figure out how to constrain it to a certain distance without interrupting the finger tracking.
Here's the relevant code:
using UnityEngine;
using System.Collections;
public class Boundary
{
public Vector2 min = Vector2.zero;
public Vector2 max = Vector2.zero;
}
public class Joystick : MonoBehaviour{
static private Joystick[] joysticks; // A static collection of all joysticks
static private bool enumeratedJoysticks=false;
static private float tapTimeDelta = 0.3f; // Time allowed between taps
public bool touchPad; // Is this a TouchPad?
public Rect touchZone;
public Vector2 deadZone = Vector2.zero; // Control when position is output
public bool normalize = false; // Normalize output after the dead-zone?
public Vector2 position; // [-1, 1] in x,y
public int tapCount; // Current tap count
private int lastFingerId = -1; // Finger last used for this joystick
private float tapTimeWindow; // How much time there is left for a tap to occur
private Vector2 fingerDownPos;
private float fingerDownTime;
private float firstDeltaTime = 0.5f;
private GUITexture gui; // Joystick graphic
private Rect defaultRect; // Default position / extents of the joystick graphic
private Boundary guiBoundary = new Boundary(); // Boundary for joystick graphic
public Vector2 guiTouchOffset; // Offset to apply to touch input
private Vector2 guiCenter; // Center of joystick
private Vector3 tmpv3;
private Rect tmprect;
private Color tmpclr;
public float allowedDistance;
public enum JoystickType
{
movement, rotation
}
public JoystickType joystickType;
public void Start()
{
// Cache this component at startup instead of looking up every frame
gui = (GUITexture) GetComponent( typeof(GUITexture) );
// Store the default rect for the gui, so we can snap back to it
defaultRect = gui.pixelInset;
if ( touchPad )
{
// If a texture has been assigned, then use the rect ferom the gui as our touchZone
if ( gui.texture )
touchZone = gui.pixelInset;
}
else
{
// This is an offset for touch input to match with the top left
// corner of the GUI
guiTouchOffset.x = defaultRect.width * 0.5f;
guiTouchOffset.y = defaultRect.height * 0.5f;
// Cache the center of the GUI, since it doesn't change
guiCenter.x = defaultRect.x + guiTouchOffset.x;
guiCenter.y = defaultRect.y + guiTouchOffset.y;
// Let's build the GUI boundary, so we can clamp joystick movement
guiBoundary.min.x = defaultRect.x - guiTouchOffset.x;
guiBoundary.max.x = defaultRect.x + guiTouchOffset.x;
guiBoundary.min.y = defaultRect.y - guiTouchOffset.y;
guiBoundary.max.y = defaultRect.y + guiTouchOffset.y;
}
}
public void Disable()
{
gameObject.active = false;
enumeratedJoysticks = false;
}
public void ResetJoystick()
{
if (joystickType != JoystickType.rotation)
{
//Don't do anything if turret mode
// Release the finger control and set the joystick back to the default position
gui.pixelInset = defaultRect;
lastFingerId = -1;
position = Vector2.zero;
fingerDownPos = Vector2.zero;
if ( touchPad ){
tmpclr = gui.color;
tmpclr.a = 0.025f;
gui.color = tmpclr;
}
}
else {
//gui.pixelInset = defaultRect;
lastFingerId = -1;
position = position;
fingerDownPos = fingerDownPos;
if ( touchPad ){
tmpclr = gui.color;
tmpclr.a = 0.025f;
gui.color = tmpclr;
}
}
}
public bool IsFingerDown()
{
return (lastFingerId != -1);
}
public void LatchedFinger( int fingerId )
{
// If another joystick has latched this finger, then we must release it
if ( lastFingerId == fingerId )
ResetJoystick();
}
public void Update()
{
if ( !enumeratedJoysticks )
{
// Collect all joysticks in the game, so we can relay finger latching messages
joysticks = (Joystick[]) FindObjectsOfType( typeof(Joystick) );
enumeratedJoysticks = true;
}
//CHeck if distance is over the allowed amount
//Get centerPosition
//Get current position
//Get distance
//If over, don't allow
int count = iPhoneInput.touchCount;
// Adjust the tap time window while it still available
if ( tapTimeWindow > 0 )
tapTimeWindow -= Time.deltaTime;
else
tapCount = 0;
if ( count == 0 )
ResetJoystick();
else
{
for(int i = 0;i < count; i++)
{
iPhoneTouch touch = iPhoneInput.GetTouch(i);
Vector2 guiTouchPos = touch.position - guiTouchOffset;
bool shouldLatchFinger = false;
if ( touchPad )
{
if ( touchZone.Contains( touch.position ) )
shouldLatchFinger = true;
}
else if ( gui.HitTest( touch.position ) )
{
shouldLatchFinger = true;
}
// Latch the finger if this is a new touch
if ( shouldLatchFinger && ( lastFingerId == -1 || lastFingerId != touch.fingerId ) )
{
if ( touchPad )
{
tmpclr = gui.color;
tmpclr.a = 0.15f;
gui.color = tmpclr;
lastFingerId = touch.fingerId;
fingerDownPos = touch.position;
fingerDownTime = Time.time;
}
lastFingerId = touch.fingerId;
// Accumulate taps if it is within the time window
if ( tapTimeWindow > 0 )
{
tapCount++;
print("tap" + tapCount.ToString());
}
else
{
tapCount = 1;
print("tap" + tapCount.ToString());
//Tell gameobject that player has tapped turret joystick
if (joystickType == JoystickType.rotation) {
//TODO: Call!
}
tapTimeWindow = tapTimeDelta;
}
// Tell other joysticks we've latched this finger
foreach ( Joystick j in joysticks )
{
if ( j != this )
j.LatchedFinger( touch.fingerId );
}
}
if ( lastFingerId == touch.fingerId )
{
// Override the tap count with what the iPhone SDK reports if it is greater
// This is a workaround, since the iPhone SDK does not currently track taps
// for multiple touches
if ( touch.tapCount > tapCount )
tapCount = touch.tapCount;
if ( touchPad )
{
// For a touchpad, let's just set the position directly based on distance from initial touchdown
position.x = Mathf.Clamp( ( touch.position.x - fingerDownPos.x ) / ( touchZone.width / 2 ), -1, 1 );
position.y = Mathf.Clamp( ( touch.position.y - fingerDownPos.y ) / ( touchZone.height / 2 ), -1, 1 );
}
else
{
// Change the location of the joystick graphic to match where the touch is
tmprect = gui.pixelInset;
tmprect.x = Mathf.Clamp( guiTouchPos.x, guiBoundary.min.x, guiBoundary.max.x );
tmprect.y = Mathf.Clamp( guiTouchPos.y, guiBoundary.min.y, guiBoundary.max.y );
//Check distance
float distance = Vector2.Distance(new Vector2(defaultRect.x, defaultRect.y), new Vector2(tmprect.x, tmprect.y));
float angle = Vector2.Angle(new Vector2(defaultRect.x, defaultRect.y), new Vector2(tmprect.x, tmprect.y));
if (distance < allowedDistance) {
//Ok
gui.pixelInset = tmprect;
}
else {
//This is where I don't know what to do...
}
}
if ( touch.phase == iPhoneTouchPhase.Ended || touch.phase == iPhoneTouchPhase.Canceled )
ResetJoystick();
}
}
}
if ( !touchPad )
{
// Get a value between -1 and 1 based on the joystick graphic location
position.x = ( gui.pixelInset.x + guiTouchOffset.x - guiCenter.x ) / guiTouchOffset.x;
position.y = ( gui.pixelInset.y + guiTouchOffset.y - guiCenter.y ) / guiTouchOffset.y;
}
// Adjust for dead zone
float absoluteX = Mathf.Abs( position.x );
float absoluteY = Mathf.Abs( position.y );
if ( absoluteX < deadZone.x )
{
// Report the joystick as being at the center if it is within the dead zone
position.x = 0;
}
else if ( normalize )
{
// Rescale the output after taking the dead zone into account
position.x = Mathf.Sign( position.x ) * ( absoluteX - deadZone.x ) / ( 1 - deadZone.x );
}
if ( absoluteY < deadZone.y )
{
// Report the joystick as being at the center if it is within the dead zone
position.y = 0;
}
else if ( normalize )
{
// Rescale the output after taking the dead zone into account
position.y = Mathf.Sign( position.y ) * ( absoluteY - deadZone.y ) / ( 1 - deadZone.y );
}
}
}
So the later portion of the code handles the updated position of the joystick thumb. This is where I'd like it to track the finger position in a direction it still is allowed to move (like if the finger is too far up and slightly to the +X I'd like to make sure the joystick is as close in X and Y as allowed within the radius)
Thanks for reading!
