public bool IntersectsWith(IConvexShape shape)
{
//so it won't enter a call-loop of infinite proportions
if (shape.GetType() == typeof(Point))
{
return(this == (Point)shape);
}
else //call Shape's better suited sat check
{
return(shape.IntersectsWith(this));
}
}
/// <summary>
/// Returns whether this shape overlaps with another somewhere if it moves by relativeSpeed.
/// Returns the fraction of the speed given at which they touch and the axis closest to this touching point (from either shape).
/// The fraction will be -1f if there's an overlap but no collision caused by the relativeSpeed.
/// </summary>
public bool IntersectsWith(IConvexShape shape, Point relativeSpeed, out float touchingAtSpeedFraction, out Point intersectionAxis)
{
touchingAtSpeedFraction = float.PositiveInfinity;
intersectionAxis = Point.Zero;
Type shape1Type = GetType();
Type shape2Type = shape.GetType();
//2 AABB's or ComplexRectangles without a rotation (so basically AABB's)
if ((shape1Type == typeof(Rectangle) ||
shape1Type == typeof(ComplexRectangle) && _Rotation == 0f) &&
(shape2Type == typeof(Rectangle) ||
shape2Type == typeof(ComplexRectangle) && ((Shape)shape)._Rotation == 0f))
{
Rectangle rect1 = (Rectangle)this;
Rectangle rect2 = (Rectangle)shape;
float xTouchingFraction, yTouchingFraction;
if (relativeSpeed.X >= 0f)
{
if (rect1.Position2.X + relativeSpeed.X < rect2.Position.X || rect1.Position.X > rect2.Position2.X)
{
return(false);
}
xTouchingFraction = (rect2.Position.X - rect1.Position2.X) / relativeSpeed.X;
}
else
{
if (rect1.Position.X + relativeSpeed.X > rect2.Position2.X || rect1.Position2.X < rect2.Position.X)
{
return(false);
}
xTouchingFraction = (rect2.Position2.X - rect1.Position.X) / relativeSpeed.X;
}
if (relativeSpeed.Y >= 0f)
{
if (rect1.Position2.Y + relativeSpeed.Y < rect2.Position.Y || rect1.Position.Y > rect2.Position2.Y)
{
return(false);
}
yTouchingFraction = (rect2.Position.Y - rect1.Position2.Y) / relativeSpeed.Y;
}
else
{
if (rect1.Position.Y + relativeSpeed.Y > rect2.Position2.Y || rect1.Position2.Y < rect2.Position.Y)
{
return(false);
}
yTouchingFraction = (rect2.Position2.Y - rect1.Position.Y) / relativeSpeed.Y;
}
//decide which fraction and corresponding axis to return, if any
if (xTouchingFraction >= 0f &&
xTouchingFraction <= 1f)
{
touchingAtSpeedFraction = xTouchingFraction;
intersectionAxis = rect2.GetPerpAxes()[0];
}
if (yTouchingFraction >= 0f &&
yTouchingFraction <= 1f &&
yTouchingFraction < touchingAtSpeedFraction)
{
touchingAtSpeedFraction = yTouchingFraction;
intersectionAxis = rect2.GetPerpAxes()[1];
}
if (intersectionAxis == Point.Zero)
{
touchingAtSpeedFraction = -1f;
}
return(true);
}
else //other shapes
{
touchingAtSpeedFraction = float.PositiveInfinity;
Point[] shape1Points = GetPoints();
Point[] shape2Points = shape.GetPoints();
List <Point> allAxes = new List <Point>(GetPerpAxes());
allAxes.AddRange(shape.GetPerpAxes());
foreach (Point axis in allAxes)
{
float shape1ScalarMin = float.PositiveInfinity;
float shape1ScalarMax = float.NegativeInfinity;
float shape2ScalarMin = float.PositiveInfinity;
float shape2ScalarMax = float.NegativeInfinity;
//cast shape1's points to the axis
foreach (Point point in shape1Points)
{
float multiplier = (float)((point.X * axis.X + point.Y * axis.Y) / (axis.X * axis.X + axis.Y * axis.Y));
float scalar = multiplier * axis.X * axis.X + multiplier * axis.Y * axis.Y;
if (scalar < shape1ScalarMin)
{
shape1ScalarMin = scalar;
}
if (scalar > shape1ScalarMax)
{
shape1ScalarMax = scalar;
}
}
//cast shape2's points to the axis
foreach (Point point in shape2Points)
{
float multiplier = (float)((point.X * axis.X + point.Y * axis.Y) / (axis.X * axis.X + axis.Y * axis.Y));
float scalar = multiplier * axis.X * axis.X + multiplier * axis.Y * axis.Y;
if (scalar < shape2ScalarMin)
{
shape2ScalarMin = scalar;
}
if (scalar > shape2ScalarMax)
{
shape2ScalarMax = scalar;
}
}
//cast speed to axis
float speedMultiplier = (float)((relativeSpeed.X * axis.X + relativeSpeed.Y * axis.Y) / (axis.X * axis.X + axis.Y * axis.Y));
float speedScalar = speedMultiplier * axis.X * axis.X + speedMultiplier * axis.Y * axis.Y;
float thisTouchingAtSpeedFraction;
if (speedScalar >= 0)
{
if (shape1ScalarMax + speedScalar < shape2ScalarMin || shape1ScalarMin > shape2ScalarMax)
{
return(false);
}
thisTouchingAtSpeedFraction = (shape2ScalarMin - shape1ScalarMax) / speedScalar;
}
else
{
if (shape1ScalarMin + speedScalar > shape2ScalarMax || shape1ScalarMax < shape2ScalarMin)
{
return(false);
}
thisTouchingAtSpeedFraction = (shape2ScalarMax - shape1ScalarMin) / speedScalar;
}
if (thisTouchingAtSpeedFraction >= 0f &&
thisTouchingAtSpeedFraction <= 1f &&
thisTouchingAtSpeedFraction < touchingAtSpeedFraction)
{
touchingAtSpeedFraction = thisTouchingAtSpeedFraction;
intersectionAxis = axis;
}
}
if (intersectionAxis == Point.Zero)
{
touchingAtSpeedFraction = -1f;
}
else //this axis is still a perpendicular axis, revert!
{
intersectionAxis = new Point(intersectionAxis.Y, -intersectionAxis.X);
}
return(true);
}
}
/// <summary>
/// Returns whether this shape overlaps with another somewhere if it moves by relativeSpeed.
/// Returns the fraction of the speed given at which they touch and the axis closest to this touching point (from either shape).
/// The fraction will be -1f if there's an overlap but no collision caused by the relativeSpeed.
/// </summary>
public bool IntersectsWith(IConvexShape shape, Point relativeSpeed, out float touchingAtSpeedFraction, out Point intersectionAxis)
{
touchingAtSpeedFraction = float.PositiveInfinity;
intersectionAxis = Point.Zero;
Type shape1Type = GetType();
Type shape2Type = shape.GetType();
//2 AABB's or ComplexRectangles without a rotation (so basically AABB's)
if ((shape1Type == typeof(Rectangle)
|| shape1Type == typeof(ComplexRectangle) && _Rotation == 0f)
&& (shape2Type == typeof(Rectangle)
|| shape2Type == typeof(ComplexRectangle) && ((Shape)shape)._Rotation == 0f))
{
Rectangle rect1 = (Rectangle)this;
Rectangle rect2 = (Rectangle)shape;
float xTouchingFraction, yTouchingFraction;
if (relativeSpeed.X >= 0f)
{
if (rect1.Position2.X + relativeSpeed.X < rect2.Position.X || rect1.Position.X > rect2.Position2.X)
return false;
xTouchingFraction = (rect2.Position.X - rect1.Position2.X) / relativeSpeed.X;
}
else
{
if (rect1.Position.X + relativeSpeed.X > rect2.Position2.X || rect1.Position2.X < rect2.Position.X)
return false;
xTouchingFraction = (rect2.Position2.X - rect1.Position.X) / relativeSpeed.X;
}
if (relativeSpeed.Y >= 0f)
{
if (rect1.Position2.Y + relativeSpeed.Y < rect2.Position.Y || rect1.Position.Y > rect2.Position2.Y)
return false;
yTouchingFraction = (rect2.Position.Y - rect1.Position2.Y) / relativeSpeed.Y;
}
else
{
if (rect1.Position.Y + relativeSpeed.Y > rect2.Position2.Y || rect1.Position2.Y < rect2.Position.Y)
return false;
yTouchingFraction = (rect2.Position2.Y - rect1.Position.Y) / relativeSpeed.Y;
}
//decide which fraction and corresponding axis to return, if any
if (xTouchingFraction >= 0f
&& xTouchingFraction <= 1f)
{
touchingAtSpeedFraction = xTouchingFraction;
intersectionAxis = rect2.GetPerpAxes()[0];
}
if (yTouchingFraction >= 0f
&& yTouchingFraction <= 1f
&& yTouchingFraction < touchingAtSpeedFraction)
{
touchingAtSpeedFraction = yTouchingFraction;
intersectionAxis = rect2.GetPerpAxes()[1];
}
if (intersectionAxis == Point.Zero)
touchingAtSpeedFraction = -1f;
return true;
}
//other shapes
touchingAtSpeedFraction = float.PositiveInfinity;
Point[] shape1Points = GetPoints();
Point[] shape2Points = shape.GetPoints();
List<Point> allAxes = new List<Point>(GetPerpAxes());
allAxes.AddRange(shape.GetPerpAxes());
foreach (Point axis in allAxes)
{
float shape1ScalarMin = float.PositiveInfinity;
float shape1ScalarMax = float.NegativeInfinity;
float shape2ScalarMin = float.PositiveInfinity;
float shape2ScalarMax = float.NegativeInfinity;
//cast shape1's points to the axis
foreach (Point point in shape1Points)
{
float multiplier = (float)((point.X * axis.X + point.Y * axis.Y) / (axis.X * axis.X + axis.Y * axis.Y));
float scalar = multiplier * axis.X * axis.X + multiplier * axis.Y * axis.Y;
if (scalar < shape1ScalarMin)
shape1ScalarMin = scalar;
if (scalar > shape1ScalarMax)
shape1ScalarMax = scalar;
}
//cast shape2's points to the axis
foreach (Point point in shape2Points)
{
float multiplier = (float)((point.X * axis.X + point.Y * axis.Y) / (axis.X * axis.X + axis.Y * axis.Y));
float scalar = multiplier * axis.X * axis.X + multiplier * axis.Y * axis.Y;
if (scalar < shape2ScalarMin)
shape2ScalarMin = scalar;
if (scalar > shape2ScalarMax)
shape2ScalarMax = scalar;
}
//cast speed to axis
float speedMultiplier = (float)((relativeSpeed.X * axis.X + relativeSpeed.Y * axis.Y) / (axis.X * axis.X + axis.Y * axis.Y));
float speedScalar = speedMultiplier * axis.X * axis.X + speedMultiplier * axis.Y * axis.Y;
float thisTouchingAtSpeedFraction;
if (speedScalar >= 0)
{
if (shape1ScalarMax + speedScalar < shape2ScalarMin || shape1ScalarMin > shape2ScalarMax)
return false;
thisTouchingAtSpeedFraction = (shape2ScalarMin - shape1ScalarMax) / speedScalar;
}
else
{
if (shape1ScalarMin + speedScalar > shape2ScalarMax || shape1ScalarMax < shape2ScalarMin)
return false;
thisTouchingAtSpeedFraction = (shape2ScalarMax - shape1ScalarMin) / speedScalar;
}
if (thisTouchingAtSpeedFraction >= 0f
&& thisTouchingAtSpeedFraction <= 1f
&& thisTouchingAtSpeedFraction < touchingAtSpeedFraction)
{
touchingAtSpeedFraction = thisTouchingAtSpeedFraction;
intersectionAxis = axis;
}
}
if (intersectionAxis == Point.Zero)
touchingAtSpeedFraction = -1f;
else //this axis is still a perpendicular axis, revert!
intersectionAxis = new Point(intersectionAxis.Y, -intersectionAxis.X);
return true;
}