shoot ball in opposite direction

[mironcaius]

Hi,

I am building a football game. When the player presses space and he is next to the ball, i want to apply a force in the opposite direction. With flash and NAPE physics I did something like this:

if (!ballHit && Vec2.distance( ball.body.position, playerBody.position ) <= ball.radius + extra )
{
	ballHit = true;
	difference = ball.body.position.sub( playerBody.position );
	difference.length = BALL_SPEED;
	ball.body.velocity.addeq( difference );
}

With Phaser, I have the following but I am kinda stuck

 distance = Phaser.Point.distance(player.position, ball.position);

        if (distance < 30) {
            difference = Phaser.Point.subtract(player.position, ball.position);
            difference.length = 500;
            console.log(difference);
        }

Could you help me?

[samid737]

Hi, if you are using physics (arcade or P2), then the syntax for adding velocity to a body is:

            ball.body.velocity.x+=-difference.x;
            ball.body.velocity.y+=-difference.y;

Here is an extra example in case you might be stuck (including drag to slow down ball):

 

[mironcaius]

Hi,

Thanks for the sample. I tested it and it acted odd. If the player was close to the ball the velocity increased slowly than if the player was farther from the ball.

distance = Phaser.Point.distance(player.position, ball.position);
        if (player.getShooting() && !ballHit && distance < player.width) {
            ballHit = true;
            var angle = Phaser.Math.angleBetweenPoints(player.position, ball.position);
            ball.body.velocity.x += Math.cos(angle) * BALL_SPEED;
            ball.body.velocity.y += Math.sin(angle) * BALL_SPEED;
        }

This code here seems to be more accurate to what I was expecting. If the player is closer to the ball, it increases the velocity much more than if the player would be farther.

[samid737]

 

 

I see your point, I was approaching it kind of differently.. sort of like kicking the ball from larger distance would give you a higher kick strength (more like a free kick/penalty).. But your solution would be the right way now that I think of it (if your BALL_SPEED is a function of the distance , that is).

[samme]

I think you may be looking for

difference.setMagnitude(500);

 

[mironcaius]

@samme

Yes, you are right.

distance = Phaser.Point.distance(player.position, ball.position);
       if (player.getShooting() && !ballHit && distance < player.width) {
            ballHit = true;
            var angle = Phaser.Math.angleBetweenPoints(player.position, ball.position);
            ball.body.velocity.x += Math.cos(angle) * BALL_SPEED;
            ball.body.velocity.y += Math.sin(angle) * BALL_SPEED;

            // difference = Phaser.Point.subtract(player.position, ball.position);
            // difference.setMagnitude(BALL_SPEED);
            // ball.body.velocity.x += -difference.x;
            // ball.body.velocity.y += -difference.y;
        }

Both solutions output the same result.

[samid737]

 

 

@sammenice one I did not know about setting the magnitude.... @mironcaius a little bit of nitpicking, but setMagnitude() boils down to one Math.sqrt function call , so I would pick that one if it produces the exact same result.