巧用触控打造出色的游戏

2:04 - GCController polling vs. change handlers

// Polling
if (button.isPressed) {
    // ...
}

// Change handlers
pressedInput.pressedDidChangeHandler = { (element: any GCPhysicalInputElement,
                                           input: any GCPressedStateInput,
                                           pressed: Bool)
    // ...
}

3:14 - Set up a TCTouchController

// Set up a TCTouchController
private(set) var touchController: TCTouchController?

let descriptor = TCTouchControllerDescriptor(mtkView: mtkView)
if TCTouchController.isSupported {
    touchController = TCTouchController(descriptor: descriptor)
}
touchController?.connect()
touchController?.render(using: renderEncoder)

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch in touches {
        touchControls.handleTouchBegan(at: touch.location(in: view), index: touch.hash)
    }
}

buttonA?.valueChangedHandler = { (_ button: GCControllerButtonInput, _ value: Float,
                                  _ pressed: Bool) in
    // ...
}

8:33 - Create a standard circular button B

// Create a standard circular button B
let buttonBDesc = TCButtonDescriptor()
buttonBDesc.label = TCControlLabel.buttonB
buttonBDesc.anchor = .bottomRight
buttonBDesc.offset = adjustedOffset(CGPoint(x: -35, y: -106), for: buttonBDesc.anchor)
buttonBDesc.contents = .buttonContents(forSystemImageNamed: "b.circle",
                                       size: buttonBDesc.size, shape: .circle,
                                       controller: touchController)
// Set other properties ...
touchController.addButton(descriptor: buttonBDesc)

func adjustedOffset(_ offset: CGPoint, for anchor: TCControlLayoutAnchor) -> CGPoint {
    // Adjust offset for other anchors ...
    case .bottomRight:
        x -= safeArea.right
        y -= safeArea.bottom
}

10:48 - Change icon image

// Change icon image
buttonBDesc.contents = .buttonContents(forSystemImageNamed: "figure.fencing",
                                       size: buttonBDesc.size,
                                       shape: .circle,
                                       controller: touchController)

11:51 - Update contents for button B based on context

// Update contents for button B based on context
func setButtonBContents(symbolName: String) {
    for button in touchController.buttons {
        if button.label == TCControlLabel.buttonB {
            button.contents = .buttonContents(forSystemImageNamed: symbolName, size: buttonSize,
                                              shape: .circle, controller: touchController)
        }
    }
}

func cyclePower() {
    // Get the current power type ...
    switch currentPower {
        case .strike:       touchControls?.setButtonBContents(symbolName: "figure.fencing")
        case .fireball:     touchControls?.setButtonBContents(symbolName: "flame.fill")
        case .waterBlaster: touchControls?.setButtonBContents(symbolName: "drop.fill")
    }
}

13:01 - Hide left thumbstick when not touched

// Hide left thumbstick when it is not touched
let leftStickDesc = TCThumbstickDescriptor()
leftStickDesc.hidesWhenNotPressed = true
// Set other properties ...
touchController.addThumbstick(descriptor: leftStickDesc)

13:19 - Show/hide the pick-up button

// Show pickup button when there's an item nearby
func showPickupButton(at projectedPosition: CGPoint) {
    // Calculate the position(ptX, ptY) for pickup button ...
    descriptor.offset = CGPoint(x: ptX, y: ptY)
    // Set other properties ...
    touchController.addButton(descriptor: descriptor)
}

func hidePickupButton() {
    for button in touchController.buttons {
        if button.label == TCControlLabel.buttonY {
            touchController.removeControl(button)
        }
    }
}

13:56 - Show power options as touch controls

// Show power options as touch controls
buttonX?.pressedChangedHandler = { (_ button: GCControllerButtonInput, _ value: Float,
                                    _ pressed: Bool) -> Void in
    if pressed {
        self.openPowerWheel()
    }
}

func openPowerWheel() {
    touchControls?.showPowerWheelButtons(fireballCount: fireballCount, has: hasWaterBlaster)
    wirePowerWheelHandlers()
    DispatchQueue.main.asyncAfter(deadline: .now() + 3.0) { [weak self] in
        guard let self = self, self.powerWheelActive else { return }
        self.closePowerWheel()
    }
}

15:34 - Use the left half of the screen for character movement

// Use the left half of the screen for character movement
let leftStickDesc = TCThumbstickDescriptor()
leftStickDesc.colliderShape = .leftSide // Don't set as .circle
// Set other properties ...
touchController.addThumbstick(descriptor: leftStickDesc)

16:39 - Calculate thumbstick tilt magnitude to trigger sprint

// Calculate left thumbstick's tilt magnitude to trigger sprint
func pollInput() {
    if let gamePad = gameController.extendedGamepad {
        let gamePadLeft = gamePad.leftThumbstick
        var moveInput = simd_make_float2(gamePadLeft.xAxis.value, -gamePadLeft.yAxis.value)
        let magnitude = simd_length(moveInput)
        if magnitude > 0.8 {
            self.runModifier = 1.3
        }
        self.characterDirection = moveInput
    }
}

17:36 - Replace right thumbstick with a touchpad

// Replace right thumbstick with touchpad
let touchpadDesc = TCTouchpadDescriptor()
touchpadDesc.label = TCControlLabel.rightThumbstick
touchpadDesc.colliderShape = .rightSide
touchpadDesc.reportsRelativeValues = true
// Set other properties ...
touchController.addTouchpad(descriptor: touchpadDesc)

19:30 - Collapse two QTE buttons into one

// Collapse 2 QTE buttons into 1 single button
func setupControls() {
    let desc = TCButtonDescriptor()
    desc.label = TCControlLabel(name: "escape_button", role: .button)
    // Set up other properties ...
    touchController.addButton(descriptor: desc)
}

func showEscapeButton() {
    // Find escape button in touchController ...
    escapeButton.isEnabled = true
}

func hideEscapeButton() {
    // Find escape button in touchController ...
    escapeButton.isEnabled = false
}

20:28 - Use button B to aim, move, and release power

// Use button B to aim, move, and release power
buttonB?.valueChangedHandler = { (_ button: GCControllerButtonInput, _ value: Float,
                                  _ pressed: Bool) -> Void in
    self.releasePower(pressed: pressed)
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch in touches {
        let point = touch.location(in: metalView)
        // Handle touch input ...
        if let gc = gameController, gc.isAiming {
            let prev = touch.previousLocation(in: metalView)
            gc.aimTouchDelta += simd_float2(Float(point.x - prev.x), Float(point.y - prev.y))
        }
    }
}

21:52 - Add a halo effect with custom TCControlContents

// Add a halo effect around left thumbstick with customized TCControlContents
let haloLayer = TCControlImage(texture: haloTexture, size: haloSize, highlight: nil,
                               offset: .zero, tintColor: tint)
let normalBgImages = TCControlContents.thumbstickStickBackgroundContents(size: bgSize,
                                                                         controller: controller).images
haloThumbstickBg = TCControlContents(images: [haloLayer] + normalBgImages)
thumbstick.backgroundContents = active ? haloThumbstickBg : normalThumbstickBg