3D Tutorial - Step 16 - Controller Support
by Monstrous Software
Step 16 - Controller Support
Game controllers are, for the moment, not supported by gdx-teavm (and can actually crash the application) so this is an option that will only be available on the desktop version. Let us add a field in Settings to enable/disable controller support:
static public boolean supportControllers = true; // disable in case it causes issues
To automatically set this field we can add the following line to the create() method in the Main class:
Settings.supportControllers = (Gdx.app.getType() == Desktop);
Add the following to GameScreen.show():
if (Settings.supportControllers && Controllers.getCurrent() != null) {
MyControllerAdapter controllerAdapter = new MyControllerAdapter(world.getPlayerController(), this);
Controllers.addListener(controllerAdapter);
}
Create an extension of ControllerAdapter to process the inputs from the controller and
forward them mostly to the PlayerController or sometimes to the GameScreen.
For example, the so-called DPad buttons are mapped to the WASD keys. The left stick is used for
player movement and the right stick for camera rotation.
This code is for an XBox compatible controller.
There is very poor standardization for game controller buttons and sticks. If you want to support many types
of controllers you may need to add a setup screen where the player can map their controller inputs to actions.
public class MyControllerAdapter extends ControllerAdapter {
private final static int L2_AXIS = 4;
private final static int R2_AXIS = 5;
private final PlayerController playerController;
private final GameScreen gameScreen;
public MyControllerAdapter(PlayerController playerController, GameScreen gameScreen) {
this.gameScreen = gameScreen;
this.playerController = playerController;
}
@Override
public boolean buttonDown(Controller controller, int buttonIndex) {
processButtonEvent(controller, buttonIndex, true);
return false;
}
@Override
public boolean buttonUp(Controller controller, int buttonIndex) {
processButtonEvent(controller, buttonIndex, false);
return false;
}
private void processButtonEvent(Controller controller, int buttonIndex, boolean down) {
// map Dpad to WASD
if (buttonIndex == controller.getMapping().buttonDpadUp)
buttonChange(playerController.forwardKey, down);
if (buttonIndex == controller.getMapping().buttonDpadDown)
buttonChange(playerController.backwardKey, down);
if (buttonIndex == controller.getMapping().buttonDpadLeft)
buttonChange(playerController.strafeLeftKey, down);
if (buttonIndex == controller.getMapping().buttonDpadRight)
buttonChange(playerController.strafeRightKey, down);
if (buttonIndex == controller.getMapping().buttonR1 )
playerController.setScopeMode(down);
if (buttonIndex == controller.getMapping().buttonL1 )
playerController.setRunning(down);
if (buttonIndex == controller.getMapping().buttonStart && down)
gameScreen.restart();
if (buttonIndex == controller.getMapping().buttonX)
buttonChange(playerController.switchWeaponKey, down);
if (buttonIndex == controller.getMapping().buttonY && down)
gameScreen.toggleViewMode();
}
private void buttonChange(int keyCode, boolean down){
if(down)
playerController.keyDown(keyCode);
else
playerController.keyUp(keyCode);
}
@Override
public boolean axisMoved(Controller controller, int axisIndex, float value) {
if(Math.abs(value) < 0.02f ) // dead zone to cope with neutral not being exactly zero
value = 0;
// right stick for looking
if(axisIndex == controller.getMapping().axisRightX) // right stick for looking around (X-axis)
playerController.stickLookX(-value); // rotate view left/right
if(axisIndex == controller.getMapping().axisRightY) // right stick for looking around (Y-axis)
playerController.stickLookY(-value); // rotate view up/down
// left stick for moving
if(axisIndex == controller.getMapping().axisLeftX) // left stick for strafing (X-axis)
playerController.stickMoveX(value);
if(axisIndex == controller.getMapping().axisLeftY) // right stick for forward/backwards (Y-axis)
playerController.stickMoveY(-value);
if(axisIndex == L2_AXIS) // left trigger
buttonChange(playerController.jumpKey, (value > 0.4f));
if(axisIndex == R2_AXIS) // right trigger
if(value > 0.8f)
playerController.fireWeapon();
return false;
}
}
In PlayerController we need to add a few methods to support this:
private final Vector2 stickMove = new Vector2();
private final Vector2 stickLook = new Vector2();
public void stickMoveX(float value){
stickMove.x = value;
}
public void stickMoveY(float value){
stickMove.y = value;
}
public void stickLookX(float value){
stickLook.x = value;
}
public void stickLookY(float value){
stickLook.y = value;
}
And in PlayerController.update() we add the following lines to move the player and rotate the view
based on controller input. The trickiest bit is for rotating the view up and down. We want the view
to automatically drift back to a level view when the joystick is released. In scope mode however we use the
joystick to nudge the view up or down in small steps.
// controller stick inputs
moveForward(stickMove.y*deltaTime * moveSpeed);
strafe(stickMove.x * deltaTime * Settings.walkSpeed);
float delta = 0;
float speedFactor;
if(world.weaponState.scopeMode) {
speedFactor = 0.2f;
delta = (stickLook.y * 30f );
}
else {
speedFactor = 1f;
delta = (stickLook.y * 90f - stickViewAngle);
}
delta *= deltaTime*Settings.verticalReadjustSpeed*speedFactor;
stickViewAngle += delta;
rotateView(stickLook.x * deltaTime * Settings.turnSpeed*speedFactor, delta );
This concludes step 16 which added game controller support to the game.