Creating a knockback effect

Question

I'm fairly new to creating a 2D game in java and I'd love some help. I'm trying to create a sort of knock back effect the enemies have on you. So when you are touched by a enemy you will:

1. lose life

2. be knocked back a few pixels

I thought about saying something simple such as:

    if ((player.x & player.y) == (enemy.x & enemy.y)){  
        player.x += 8;
        player.y += 8;
    }

But seeing as this will only push you back with no hope of moving while being pushed, I didn't want to use it. Is there any simple, yet effective way for going about this?

Answer 1

Usually this is done by changing velocity.

If you simply change position, there is danger of stucking in walls (and other solid objects, including enemises) or falling/jumping through them (depends on your collision system and level design).

Also you need to configure friction and/or gravity accordingly, so player will not fly into open space after one kick.

If inertial sliding will be too smooth for you, some engines allowing to attach short-living constant-power pushing forces to objects.

Honestly, it is hard to answer without knowing anything about your physics engine and its capabilities.