Elysian Shadows

A Person wrote:I'm not quite sure exactly what your doing here but what i would do would be to have a point in circle function where you pass in the soccer position and the circle origin and radius or something. Then if the point is not in the circle undo the last movement of the ball. I'm not going to explain point in circle function just google it.

Sorry about the objective-c

Code: Select all

if(![collisionDetection pointIsInCircle:soccerPosition circleOrigin:circlePosition withRadius:circleRadius]) {
soccerPosition.x -= ballVelocity.x;
soccerPosition.y -= ballVelocity.y;

ballVelocity.x = 0;
ballVelocity.y = 0;
}

X Abstract X wrote:So this isn't a realtime simulation where the ball has a speed and it's position is adjusted over time? You just want to do a calculation and move the ball to it's new position instantaneously?

X Abstract X wrote:I think I'm really close to solving this, as long as I understand correctly. Ok, here we go hope this can help but maybe not, it's 6:00am and I haven't slept yet. Warning: messy solution follows.

First, we need to see if the ball would land out of the circle.

Code: Select all

ballPotentialX = playerX + cos(playerToBallAngle) * circleRadius
ballPotentialY = playerY + sin(playerToBallAngle) * circleRadius

distanceFromCenterOfCircleToBall = sqrt{[absolute(ballPotentialX - circleCenterX)]^2 + [absolute(ballPotentialY - circleCenterY)]^2}

if (distanceFromCenterOfCircleToBall > circleRadius)
    placeBallOnCircumference();

Example picture of how to calculate the position of the ball on the circumference of the circle


Direct link because the picture gets cut off in my browser: http://img707.imageshack.us/img707/4897/circlek.png

X Abstract X wrote:I look forward to hearing back with your results.

X Abstract X wrote:Hey that's too bad, ye I should have used greek letters to distinguish but I couldn't remember the alt-codes for any lol. Anyway, I'm completely confused by your situation. How can you have a player shoot a soccer ball in your game if you don't know the angle at which the ball gets kicked? I'm really confused about what your doing overall.

X += (SHOOT_DIST * floatsin(-A,degrees));
Y += (SHOOT_DIST * floatcos(-A,degrees));

Scoody wrote:The angle will not always be 90 degrees at the player to make use of pythagoras ...

X Abstract X wrote:It's almost 8:00am now, my head is spinning in all these sketches I'm making, I'm probably overcomplicating this. I'm going to bed, I'll have another look tomorow. I'm pretty sure I have this all worked out if I can figure out how to calculate one angle that I'm missing.