Jumping

package;

import flixel.FlxG;
import flixel.FlxObject;
import flixel.FlxSprite;
import flixel.FlxState;
import flixel.ui.FlxVirtualPad;

class PlayState extends FlxState
{
    var sprite:FlxSprite;
    var box:FlxSprite;
    var pad:FlxVirtualPad;

    var jumpTimer:Float = 0;
    var jumping:Bool = false;

    override public function create()
    {
        super.create();

        sprite = new FlxSprite("assets/sprite.png");
        sprite.x = FlxG.width / 2 - sprite.width / 2;
        sprite.acceleration.y = 900;
        sprite.maxVelocity.y = 300;
        add(sprite);

        box = new FlxSprite("assets/bigbox.png");
        box.x = FlxG.width / 2 - box.width / 2;
        box.y = FlxG.height * 0.75 - box.height / 2;
        box.immovable = true;
        add(box);

        pad = new FlxVirtualPad(FlxDPadMode.NONE, FlxActionMode.A);
        add(pad);
    }

    override public function update(elapsed:Float)
    {
        super.update(elapsed);

        FlxG.collide(box, sprite);

        var jumpPressed:Bool = pad.buttonA.pressed;

        if (jumping && !jumpPressed)
            jumping = false;

        // reset jumpTimer when touching the floor
        if (sprite.isTouching(FlxObject.DOWN) && !jumping)
            jumpTimer = 0;

        if (jumpTimer >= 0 && jumpPressed)
        {
            jumping = true;
            jumpTimer += elapsed;
        }
        else
            jumpTimer = -1;

        // hold button to jump higher (up to 0.25s)
        if (jumpTimer > 0 && jumpTimer < 0.25)
            sprite.velocity.y = -300;
    }
}