pixelstream-cn/gamepad.js

基于虚幻引擎的像素流平台

let haveEvents = 'GamepadEvent' in window;
let haveWebkitEvents = 'WebKitGamepadEvent' in window;


let rAF = window.mozRequestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.requestAnimationFrame;


class gamepad{
    controllers = {};
    sendFunction=null;
    init(send){
        this.sendFunction=send;
        //Gamepad events
        if (haveEvents) {
            window.addEventListener("gamepadconnected", this.gamepadConnectHandler.bind(this));
            window.addEventListener("gamepaddisconnected", this.gamepadDisconnectHandler.bind(this));
        } else if (haveWebkitEvents) {
            window.addEventListener("webkitgamepadconnected", this.gamepadConnectHandler.bind(this));
            window.addEventListener("webkitgamepaddisconnected", this.gamepadDisconnectHandler.bind(this));
        }
    }


    gamepadConnectHandler(e){
        console.log("Gamepad connect handler");
        let gamepad = e.gamepad;
        this.controllers[gamepad.index] = {};
        this.controllers[gamepad.index].currentState = gamepad;
        this.controllers[gamepad.index].prevState = gamepad;
        console.log("gamepad: " + gamepad.id + " connected");
        rAF(this.updateStatus.bind(this));
    }

    gamepadDisconnectHandler(e) {
        console.log("Gamepad disconnect handler");
        console.log("gamepad: " + e.gamepad.id + " disconnected");
        delete this.controllers[e.gamepad.index];
    }

    scanGamepads() {
        let gamepads = navigator.getGamepads ? navigator.getGamepads() : (navigator.webkitGetGamepads ? navigator.webkitGetGamepads() : []);
        for (let i = 0; i < gamepads.length; i++) {
            if (gamepads[i] && (gamepads[i].index in this.controllers)) {
                this.controllers[gamepads[i].index].currentState = gamepads[i];
            }
        }
    }
    updateStatus() {
        this.scanGamepads();
        console.log("updateStatus",this.controllers);
        // Iterate over multiple controllers in the case the mutiple gamepads are connected
        for (let j in this.controllers) {
            let controller = this.controllers[j];
            let currentState = controller.currentState;
            let prevState = controller.prevState;
            // Iterate over buttons
            for (let i = 0; i < currentState.buttons.length; i++) {
                let currButton = currentState.buttons[i];
                let prevButton = prevState.buttons[i];
                // Button 6 is actually the left trigger, send it to UE as an analog axis
                // Button 7 is actually the right trigger, send it to UE as an analog axis
                // The rest are normal buttons. Treat as such
                if (currButton.pressed && !prevButton.pressed) {
                    // New press
                    if (i == 6) {
                        this.emitControllerAxisMove(j, 5, currButton.value);
                    } else if (i == 7) {
                        this.emitControllerAxisMove(j, 6, currButton.value);
                    } else {
                        this.emitControllerButtonPressed(j, i, 0);
                    }
                } else if (!currButton.pressed && prevButton.pressed) {
                    // release
                    if (i == 6) {
                        this.emitControllerAxisMove(j, 5, 0);
                    } else if (i == 7) {
                        this.emitControllerAxisMove(j, 6, 0);
                    } else {
                        this.emitControllerButtonReleased(j, i);
                    }
                } else if (currButton.pressed && prevButton.pressed) {
                    // repeat press / hold
                    if (i == 6) {
                        this.emitControllerAxisMove(j, 5, currButton.value);
                    } else if (i == 7) {
                        this.emitControllerAxisMove(j, 6, currButton.value);
                    } else {
                        this.emitControllerButtonPressed(j, i, 1);
                    }
                }
                // Last case is button isn't currently pressed and wasn't pressed before. This doesn't need an else block
            }
            // Iterate over gamepad axes
            for (let i = 0; i < currentState.axes.length; i += 2) {
                let x = parseFloat(currentState.axes[i].toFixed(4));
                // https://w3c.github.io/gamepad/#remapping Gamepad broweser side standard mapping has positive down, negative up. This is downright disgusting. So we fix it.
                let y = -parseFloat(currentState.axes[i + 1].toFixed(4));
                if (i === 0) {
                    // left stick
                    // axis 1 = left horizontal
                    this.emitControllerAxisMove(j, 1, x);
                    // axis 2 = left vertical
                    this.emitControllerAxisMove(j, 2, y);
                } else if (i === 2) {
                    // right stick
                    // axis 3 = right horizontal
                    this.emitControllerAxisMove(j, 3, x);
                    // axis 4 = right vertical
                    this.emitControllerAxisMove(j, 4, y);
                }
            }
            this.controllers[j].prevState = currentState;
        }
        rAF(this.updateStatus.bind(this));
    }

    emitControllerAxisMove(controllerIndex, axisIndex, analogValue) {
        console.log("emitAxisMove");
        this.emitAxisMove(controllerIndex, axisIndex, analogValue);
    }
    emitControllerButtonPressed(controllerIndex, buttonIndex, isRepeat) {
        console.log("emitButtonPressed");
        this.emitButtonPressed(controllerIndex, buttonIndex, isRepeat);
    }
    emitControllerButtonReleased(controllerIndex, buttonIndex) {
        console.log("emitButtonReleased");
        this.emitButtonReleased(controllerIndex, buttonIndex);
    }
}

export default gamepad;