private void CalcHitVelocity(PhysicsCircle circle1, PhysicsCircle circle2)
{
double distance = circle1.CenterPoint.GetDistance(circle2.CenterPoint);
// mormal
double nx = (circle2.CenterPoint.X - circle1.CenterPoint.X) / distance;
double ny = (circle2.CenterPoint.Y - circle1.CenterPoint.Y) / distance;
// tangent
double tx = -ny;
double ty = nx;
//dot product tangent
double dpTan1 = circle1.Velocity.X * tx + circle1.Velocity.y * ty;
double dpTan2 = circle2.Velocity.X * tx + circle2.Velocity.y * ty;
dpTan1 *= 1.3;
dpTan2 *= 1.3;
circle1.Velocity.X = tx * dpTan1;
circle1.Velocity.y = ty * dpTan1;
circle2.Velocity.X = tx * dpTan2;
circle2.Velocity.y = tx * dpTan2;
}
public static bool pointInCircle(Vector2 point, PhysicsCircle circle)
{
var dx = point.X - circle.origin.X;
var dy = point.Y - circle.origin.Y;
return(((dx * dx) + (dy * dy)) <= (circle.radius * circle.radius));
}
public static bool CirclevsCircleOptimized(PhysicsCircle a, PhysicsCircle b)
{
float r = a.Radius + b.Radius;
float X = (a.Origin.X + b.Origin.X);
float Y = (a.Origin.Y + b.Origin.Y);
r *= r;
return(r < ((X * X) + (Y * Y)));
}
public Projectile(Game1 game, Vector2 origin, int size, int initialVelocity, double initialAngle, Texture2D texture)
{
active = true;
circle = new PhysicsCircle(origin, size / 2);
this.texture = texture;
var radians = initialAngle * (Math.PI / 180.0);
xVelocity = (float)(initialVelocity * Math.Cos(radians));
yVelocity = (float)(initialVelocity * Math.Sin(radians));
this.game = game;
game.particleEngine.rocketSystem.Emitter.Add(circle.origin);
}
public static Vector2 pointOnCircle(Vector2 point, PhysicsCircle circle)
{
var dx = point.X - circle.origin.X;
var dy = point.Y - circle.origin.Y;
var d = Math.Sqrt((dx * dx) + (dy * dy));
if (d <= circle.radius)
{
return(point);
}
return(new Vector2(((float)(dx / d * circle.radius) + circle.origin.X), ((float)(dy / d * circle.radius) + circle.origin.Y)));
}
public void CircleCollision(PhysicsCircle circle1, PhysicsCircle circle2)
{
//todo: implement entitiyCollision
double xDistance = circle1.CenterPoint.X - circle2.CenterPoint.X;
double yDistance = circle1.CenterPoint.Y - circle2.CenterPoint.Y;
double radiusSum = circle1.Radius + circle2.Radius;
if (xDistance * xDistance + yDistance * yDistance <= radiusSum * radiusSum)
{
FixOverlap(circle1, circle2);
CalcHitVelocity(circle1, circle2);
}
}
private void FixOverlap(PhysicsCircle circle1, PhysicsCircle circle2)
{
double xDistance = circle1.CenterPoint.X - circle2.CenterPoint.X;
double yDistance = circle1.CenterPoint.Y - circle2.CenterPoint.Y;
double cDistance = Math.Sqrt(xDistance * xDistance + yDistance * yDistance);
double Overlap = 0.5f * (cDistance - circle1.Radius - circle2.Radius);
//fix pos of first circle
double newX = circle1.CenterPoint.X - Overlap * (circle1.CenterPoint.X - circle2.CenterPoint.X) / cDistance;
double newY = circle1.CenterPoint.Y - Overlap * (circle1.CenterPoint.Y - circle2.CenterPoint.Y) / cDistance;
circle1.SetCenterPoint(newX, newY);
//fix pos of second circle
newX = circle2.CenterPoint.X + Overlap * (circle1.CenterPoint.X - circle2.CenterPoint.X) / cDistance;
newY = circle2.CenterPoint.Y + Overlap * (circle1.CenterPoint.Y - circle2.CenterPoint.Y) / cDistance;
circle2.SetCenterPoint(newX, newY);
}
public static bool Collides(PhysicsCircle circle1, PhysicsCircle circle2)
{
return(Within.pointInCircle(circle1.origin, new PhysicsCircle(circle2.origin, circle1.radius + circle2.radius)));
}
public static bool Collides(PhysicsCircle circle, PhysicsRectangle rect)
{
var point = Nearest.pointOnRectangle(circle.origin, rect);
return(Within.pointInCircle(point, circle));
}
public static bool IsColliding(PhysicsCircle circle1, PhysicsCircle circle2)
{
return(Within.pointInCircle(circle1.Origin, new PhysicsCircle(circle2.Origin, circle1.Radius + circle2.Radius)));
}
