public void growBy(CollisionVolume other) {
final float maxX;
final float minX;
final float maxY;
final float minY;
if (mRadius > 0) {
maxX = Math.max(getMaxX(), other.getMaxX());
minX = Math.min(getMinX(), other.getMinX());
maxY = Math.max(getMaxY(), other.getMaxY());
minY = Math.min(getMinY(), other.getMinY());
} else {
maxX = other.getMaxX();
minX = other.getMinX();
maxY = other.getMaxY();
minY = other.getMinY();
}
final float horizontalDelta = maxX - minX;
final float verticalDelta = maxY - minY;
final float diameter = Math.max(horizontalDelta, verticalDelta);
final float newCenterX = minX + (horizontalDelta / 2.0f);
final float newCenterY = minY + (verticalDelta / 2.0f);
final float newRadius = diameter / 2.0f;
mCenter.set(newCenterX, newCenterY);
mRadius = newRadius;
}
@Override
public boolean intersects(
Vector2 position,
FlipInfo flip,
CollisionVolume other,
Vector2 otherPosition,
FlipInfo otherFlip) {
boolean result = false;
if (other instanceof AABoxCollisionVolume) {
// It's more accurate to do a sphere-as-box test than a box-as-sphere test.
result = other.intersects(otherPosition, otherFlip, this, position, flip);
} else {
mWorkspaceVector.set(position);
offsetByCenter(mWorkspaceVector, mCenter, flip);
float otherRadius = 0;
if (other instanceof SphereCollisionVolume) {
SphereCollisionVolume sphereOther = (SphereCollisionVolume) other;
mWorkspaceVector2.set(otherPosition);
offsetByCenter(mWorkspaceVector2, sphereOther.getCenter(), otherFlip);
mWorkspaceVector.subtract(mWorkspaceVector2);
otherRadius = sphereOther.getRadius();
} else {
// Whatever this volume is, pretend it's a sphere.
final float deltaX = other.getMaxXPosition(otherFlip) - other.getMinXPosition(otherFlip);
final float deltaY = other.getMaxYPosition(otherFlip) - other.getMinYPosition(otherFlip);
final float centerX = deltaX / 2.0f;
final float centerY = deltaY / 2.0f;
mWorkspaceVector2.set(otherPosition);
mWorkspaceVector2.x += centerX;
mWorkspaceVector2.y += centerY;
otherRadius = Math.max(deltaX, deltaY);
}
final float maxDistance = mRadius + otherRadius;
final float distance2 = mWorkspaceVector.length2();
final float maxDistance2 = (maxDistance * maxDistance);
if (distance2 < maxDistance2) {
result = true;
}
}
return result;
}
