Gravity can be simulated by setting the y acceleration of a FlxObject. You can even use maxVelocity to set a ‘terminal velocity’.
// object will accelerate downwards by 400 pixels per second
object.acceleration.y = 400;
// object will not accelerate beyond 200 pixels per second
object.maxVelocity.y = 200;
package;
import flixel.FlxG;
import flixel.FlxSprite;
import flixel.FlxState;
class PlayState extends FlxState
{
var sprite:FlxSprite;
override public function create()
{
bgColor = 0;
super.create();
sprite = new FlxSprite("assets/sprite.png");
sprite.x = FlxG.width / 2 - sprite.width / 2;
sprite.acceleration.y = 600;
sprite.maxVelocity.y = 200;
add(sprite);
}
override public function update(elapsed:Float)
{
super.update(elapsed);
if (sprite.velocity.y > 0 && sprite.y >= FlxG.height + 8)
{
sprite.y = FlxG.height + 8;
sprite.acceleration.y = 0;
sprite.velocity.y = -100;
}
else if (sprite.velocity.y < 0 && sprite.y <= 0)
{
sprite.y = 0;
sprite.velocity.y = 0;
sprite.acceleration.y = 800;
}
}
}