gamepads.js

define(['utils'],
    function (utils) {
        "use strict";

        var BBC = utils.BBC;

        function GamePad() {
            this.gamepad0 = null;

            //this.gamepadMapping = [BBC.COLON_STAR, BBC.X, BBC.SLASH, BBC.Z,
            //    BBC.SPACE, BBC.SPACE, BBC.SPACE, BBC.SPACE,
            //    BBC.SPACE, BBC.SPACE, BBC.SPACE, BBC.SPACE,
            //    BBC.SPACE, BBC.SPACE, BBC.SPACE, BBC.SPACE];

            this.gamepadMapping = [];

            // default: "snapper" keys
            this.gamepadMapping[14] = BBC.Z;
            this.gamepadMapping[15] = BBC.X;
            this.gamepadMapping[13] = BBC.SLASH;
            this.gamepadMapping[12] = BBC.COLON_STAR;

            // often <Return> = "Fire"
            this.gamepadMapping[0] = BBC.RETURN;
            // "start" (often <Space> to start game)
            this.gamepadMapping[9] = BBC.SPACE;


            // Gamepad joysticks
            this.gamepadAxisMapping = [
                [],
                [],
                [],
                []
            ];
        }

        /*
         this.gamepadAxisMapping[0][-1] = BBC.Z;          // left
         this.gamepadAxisMapping[0][1] = BBC.X;          // right
         this.gamepadAxisMapping[1][-1] = BBC.COLON_STAR; // up
         this.gamepadAxisMapping[1][1] = BBC.SLASH;      // down
         this.gamepadAxisMapping[2][-1] = BBC.Z;          // left
         this.gamepadAxisMapping[2][1] = BBC.X;          // right
         this.gamepadAxisMapping[3][-1] = BBC.COLON_STAR; // up
         this.gamepadAxisMapping[3][1] = BBC.SLASH;      // down
         */
        GamePad.prototype.remap = function (gamepadKey, bbcKey) {
            // convert "1" into "K1"
            if ("0123456789".indexOf(bbcKey) > 0) {
                bbcKey = "K" + bbcKey;
            }

            var mappedBbcKey = BBC[bbcKey];
            if (!mappedBbcKey) {
                console.log("unknown BBC key: " + bbcKey);
                return;
            }

            switch (gamepadKey) {
                case "LEFT":
                    this.gamepadMapping[3] = mappedBbcKey;
                    this.gamepadAxisMapping[0][-1] = mappedBbcKey;
                    this.gamepadAxisMapping[2][-1] = mappedBbcKey;
                    break;
                case "RIGHT":
                    this.gamepadMapping[1] = mappedBbcKey;
                    this.gamepadAxisMapping[0][1] = mappedBbcKey;
                    this.gamepadAxisMapping[2][1] = mappedBbcKey;
                    break;
                case "UP":
                    this.gamepadMapping[0] = mappedBbcKey;
                    this.gamepadAxisMapping[1][-1] = mappedBbcKey;
                    this.gamepadAxisMapping[3][-1] = mappedBbcKey;
                    break;
                case "DOWN":
                    this.gamepadMapping[2] = mappedBbcKey;
                    this.gamepadAxisMapping[1][1] = mappedBbcKey;
                    this.gamepadAxisMapping[3][1] = mappedBbcKey;
                    break;
                case "FIRE":
                    for (var i = 0; i < 16; i++) {
                        this.gamepadMapping[i] = mappedBbcKey;
                    }
                    break;

                // XBox 360 Controller names
                case "UP2":
                    this.gamepadAxisMapping[3][-1] = mappedBbcKey;
                    break;
                case "UP1":
                    this.gamepadAxisMapping[1][-1] = mappedBbcKey;
                    break;
                case "UP3":
                    this.gamepadMapping[0] = mappedBbcKey;
                    break;
                case "DOWN2":
                    this.gamepadAxisMapping[3][1] = mappedBbcKey;
                    break;
                case "DOWN1":
                    this.gamepadAxisMapping[1][1] = mappedBbcKey;
                    break;
                case "DOWN3":
                    this.gamepadMapping[2] = mappedBbcKey;
                    break;
                case "LEFT2":
                    this.gamepadAxisMapping[2][-1] = mappedBbcKey;
                    break;
                case "LEFT1":
                    this.gamepadAxisMapping[0][-1] = mappedBbcKey;
                    break;
                case "LEFT3":
                    this.gamepadMapping[3] = mappedBbcKey;
                    break;
                case "RIGHT2":
                    this.gamepadAxisMapping[2][1] = mappedBbcKey;
                    break;
                case "RIGHT1":
                    this.gamepadAxisMapping[0][1] = mappedBbcKey;
                    break;
                case "RIGHT3":
                    this.gamepadMapping[1] = mappedBbcKey;
                    break;
                case "FIRE2":
                    this.gamepadMapping[11] = mappedBbcKey;
                    break;
                case "FIRE1":
                    this.gamepadMapping[10] = mappedBbcKey;
                    break;
                case "A":
                    this.gamepadMapping[0] = mappedBbcKey;
                    break;
                case "B":
                    this.gamepadMapping[1] = mappedBbcKey;
                    break;
                case "X":
                    this.gamepadMapping[2] = mappedBbcKey;
                    break;
                case "Y":
                    this.gamepadMapping[3] = mappedBbcKey;
                    break;
                case "START":
                    this.gamepadMapping[9] = mappedBbcKey;
                    break;
                case "BACK":
                    this.gamepadMapping[8] = mappedBbcKey;
                    break;
                case "RB":
                    this.gamepadMapping[5] = mappedBbcKey;
                    break;
                case "RT":
                    this.gamepadMapping[7] = mappedBbcKey;
                    break;
                case "LB":
                    this.gamepadMapping[4] = mappedBbcKey;
                    break;
                case "LT":
                    this.gamepadMapping[6] = mappedBbcKey;
                    break;
                default:
                    console.log("unknown gamepad key: " + gamepadKey);
            }
        };

        GamePad.prototype.update = function (sysvia) {
            // init gamepad
            // gamepad not necessarily available until a button press
            // so need to check gamepads[0] continuously
            if (navigator.getGamepads && !this.gamepad0) {
                var gamepads = navigator.getGamepads();
                this.gamepad0 = gamepads[0];

                if (this.gamepad0) {
                    console.log("initing gamepad");
                    // 16 buttons
                    this.gamepadButtons = [false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false];

                    // two joysticks (so 4 axes)
                    this.gamepadAxes = [0, 0, 0, 0];
                }
            }

            // process gamepad buttons
            if (this.gamepad0) {
                // these two lines needed in Chrome to update state, not Firefox
                // TODO: what about IE? (can't get Gamepads to work in IE11/IE12. Mike)
                if (!utils.isFirefox()) {
                    this.gamepad0 = navigator.getGamepads()[0];
                }

                for (var i = 0; i < 4; i++) {
                    var axisRaw = this.gamepad0.axes[i];
                    var axis;

                    // Mike's XBox 360 controller, zero positions
                    // console.log(i, axisRaw, axis);
                    //0 -0.03456169366836548 -1
                    //1 -0.037033677101135254 -1
                    //2 0.055374979972839355 1
                    //3 0.06575113534927368 1
                    var threshold = 0.15;

                    // normalize to -1, 0, 1
                    if (axisRaw < -threshold) {
                        axis = -1;
                    } else if (axisRaw > threshold) {
                        axis = 1;
                    } else {
                        axis = 0;
                    }

                    if (axis !== this.gamepadAxes[i]) {

                        // tricky because transition can be
                        // -1 to 0
                        // -1 to 1
                        // 0 to 1
                        // 0 to -1
                        // 1 to 0
                        // 1 to -1
                        var oldKey = this.gamepadAxisMapping[i][this.gamepadAxes[i]];
                        if (oldKey) {
                            sysvia.keyUpRaw(oldKey);
                        }

                        var newKey = this.gamepadAxisMapping[i][axis];
                        if (newKey) {
                            sysvia.keyDownRaw(newKey);
                        }

                    }

                    // store new state
                    this.gamepadAxes[i] = axis;
                }

                for (i = 0; i < 16; i++) {
                    if (this.gamepad0.buttons[i]) {
                        var button = this.gamepad0.buttons[i];

                        if (button.pressed !== this.gamepadButtons[i]) {
                            // different to last time

                            if (this.gamepadMapping[i]) {
                                if (button.pressed) {
                                    sysvia.keyDownRaw(this.gamepadMapping[i]);
                                } else {
                                    sysvia.keyUpRaw(this.gamepadMapping[i]);
                                }
                            }
                        }

                        // store new state
                        this.gamepadButtons[i] = button.pressed;
                    }
                }
            }
        };

        return GamePad;
    }
);