/**
* Determines if the given ball has collided with the paddle and returns true if it has and false
* if it has not. If the ball has collided with the paddle the balls movement vectors are modified
* so the ball will bounce back at the proper angle.
*
* @param ball is the ball to examine to see if it has collided with the paddle
* @return Returns true if ball collides with paddle and if so updates vectors
*/
public boolean collision(Ball ball) {
// Temp variables for paddle corner coordinates;
int pX1 = this.x;
int pX2 = pX1 + this.width - 1;
int pY1 = this.y;
int pY2 = pY1 + this.height - 1;
// Temp variables for ball coordinates, movement vectors, and radius
int bX = ball.getX();
int bY = ball.getY();
int vX = ball.getXVector();
int vY = ball.getYVector();
int bRad = ball.getRadius();
// Testing for collisions with the paddle edges and the Ball
if (bX < pX1 && bY >= pY1 && bY <= pY2 && vX > 0) // left edge
{
if (bX + bRad > pX1) // will collide with edge
{
ball.setX(pX1 - bRad);
ball.setXVector(-Math.abs(vX)); // Change x direction
return true;
}
} else if (bX > pX2 && bY >= pY1 && bY <= pY2 && vX < 0) // right edge
{
if (bX - bRad < pX2) // will collide with edge
{
ball.setX(pX2 + bRad);
ball.setXVector(Math.abs(vX)); // Change x direction
return true;
}
} else if (bY < pY1 && bX >= pX1 && bX <= pX2 && vY > 0) // top edge
{
if (bY + bRad > pY1) // will collide with edge
{
ball.setY(pY1 - bRad);
ball.setYVector(-Math.abs(vY)); // Change y direction
return true;
}
} else if (bY > pY2 && bX >= pX1 && bX <= pX2 && vY < 0) // bottom edge
{
if (bY - bRad < pY2) // will collide with edge
{
ball.setY(pY2 + bRad);
ball.setYVector(Math.abs(vY)); // Change y direction
return true;
}
} else // Otherwise test to see if the ball hits a corner of the paddle
{
if (ball.distance(pX1, pY1) <= bRad
&& ball.distance(pX1, pY1) <= ball.distance(pX2, pY1)) { // top-left corner collision
if (Math.abs(pX1 - bX) >= Math.abs(pY1 - bY)) if (vX > 0) ball.setXVector(-vX);
if (Math.abs(pX1 - bX) <= Math.abs(pY1 - bY)) if (vY > 0) ball.setYVector(-vY);
return true;
} else if (ball.distance(pX2, pY1) <= bRad) { // top-right corner collision
if (Math.abs(pX2 - bX) >= Math.abs(pY1 - bY)) if (vX < 0) ball.setXVector(-vX);
if (Math.abs(pX2 - bX) <= Math.abs(pY1 - bY)) if (vY > 0) ball.setYVector(-vY);
return true;
} else if (ball.distance(pX2, pY2) <= bRad
&& ball.distance(pX2, pY2) <= ball.distance(pX1, pY2)) { // bottom-right corner collision
if (Math.abs(pX2 - bX) >= Math.abs(pY2 - bY)) if (vX < 0) ball.setXVector(-vX);
if (Math.abs(pX2 - bX) <= Math.abs(pY2 - bY)) if (vY < 0) ball.setYVector(-vY);
return true;
} else if (ball.distance(pX1, pY2) <= bRad) { // bottom-left corner collision
if (Math.abs(pX1 - bX) >= Math.abs(pY2 - bY)) if (vX > 0) ball.setXVector(-vX);
if (Math.abs(pX1 - bX) <= Math.abs(pY2 - bY)) if (vY < 0) ball.setYVector(-vY);
return true;
}
}
return false;
}
