RPG Maker MV: Airship like FF4

HajimeHoshi_Airship_alpha.js

// This script is old and deprecated: Please see https://github.com/hajimehoshi/rpgmmv for the latest version.

(function() {
    var MAX_SCALE = 1.5;

    var Tilemap_initialize = Tilemap.prototype.initialize;
    Tilemap.prototype.initialize = function() {
        Tilemap_initialize.call(this);
        this.width *= MAX_SCALE;
        this.height *= MAX_SCALE;
    };

    Game_Vehicle.prototype.altitude = function() {
        return this._altitude;
    };

    // TODO: This should be in $game* as a saved state.
    var scale = 1;

    var Game_Player_centerX = Game_Player.prototype.centerX;
    Game_Player.prototype.centerX = function() {
        return Game_Player_centerX.call(this) * scale;
    };

    var Game_Player_centerY = Game_Player.prototype.centerY;
    Game_Player.prototype.centerY = function() {
        return Game_Player_centerY.call(this) * scale;
    };

    var Scene_Map_updateMain = Scene_Map.prototype.updateMain;
    Scene_Map.prototype.updateMain = function() {
        var airship = $gameMap.airship();
        var wasHighest = airship.isHighest();
        var wasInAirship = $gamePlayer.isInAirship();
        Scene_Map_updateMain.call(this);
        scale = 1;
        if ($gamePlayer.isInAirship()) {
            if (!airship.isHighest()) {
                var alpha = (airship.altitude() / airship.maxAltitude());
                scale = alpha * MAX_SCALE + (1 - alpha) * 1;
                $gamePlayer.center($gamePlayer.x, $gamePlayer.y);
            } else {
                scale = MAX_SCALE;
                if (!wasHighest) {
                    $gamePlayer.center($gamePlayer.x, $gamePlayer.y);
                }
            }
        } else if (wasInAirship) {
            $gamePlayer.center($gamePlayer.x, $gamePlayer.y);
        }
        this._spriteset._tilemap.scale.x = 1 / scale;
        this._spriteset._tilemap.scale.y = 1 / scale;
    };

})();