private static void SolidSquareCollision(SquareCollisionBox ia, SquareCollisionBox ib,
out CollisionResolutionData dataA, out CollisionResolutionData dataB)
{
dataA = new CollisionResolutionData();
dataB = new CollisionResolutionData();
dataA.obj = ib;
dataB.obj = ia;
BasePhysObject objectA = ia;
BasePhysObject objectB = ib;
var av = objectA.GetVelocity();
var bv = objectB.GetVelocity();
//Get inverse vectors
var inverseA = Vector.Multiply(-1, av);
var inverseB = Vector.Multiply(-1, bv);
//Combined magnitude
var tXMag = Math.Abs(inverseA.X - inverseB.X);
var tYMag = Math.Abs(inverseA.Y - inverseB.Y);
var absXMag = Math.Abs(inverseA.X) + Math.Abs(inverseB.X);
var absYMag = Math.Abs(inverseA.Y) + Math.Abs(inverseB.Y);
double deltaX;
double deltaY;
if (av.X < 0 && bv.X < 0)
{
deltaX = av.X < bv.X ? Math.Abs(ib.Right - ia.Left) : Math.Abs(ib.Left - ia.Right);
}
else if (av.X > 0 && bv.X > 0)
{
deltaX = av.X > bv.X ? Math.Abs(ib.Left - ia.Right) : Math.Abs(ib.Right - ia.Left);
}
else
{
deltaX = av.X > 0 ? Math.Abs(ib.Left - ia.Right) : Math.Abs(ib.Right - ia.Left);
}
var aMount = false;
var bMount = false;
if (av.Y < 0 && bv.Y < 0)
{
if (av.Y > bv.Y)
{
deltaY = Math.Abs(ib.Bottem - ia.Top);
bMount = true;
}
else
{
deltaY = Math.Abs(ib.Top - ia.Bottem);
aMount = true;
}
}
else if (av.Y > 0 && bv.Y > 0)
{
if (av.Y < bv.Y)
{
deltaY = Math.Abs(ib.Top - ia.Bottem);
aMount = true;
}
else
{
deltaY = Math.Abs(ib.Bottem - ia.Top);
bMount = true;
}
}
else
{
if (av.Y > 0)
{
deltaY = Math.Abs(ib.Top - ia.Bottem);
aMount = true;
}
else
{
deltaY = Math.Abs(ib.Bottem - ia.Top);
bMount = true;
}
}
//What we do here is get the ratio of movement to distance
//between the closest edges of the two objects
double xRatio = 0;
double yRatio = 0;
xRatio = deltaX / tXMag;
yRatio = deltaY / tYMag;
//The distance between the colliding edges of the objects after collision resolution
//A buffer of 0.0 would result in the colliding edges still being ontop of eachother after collision resolution
var collisionBuffer = 0.01;
//The lower ratio indicates which side hit first
if (xRatio < yRatio)
{
var xa = 0.0;
var xb = 0.0;
//apply correction
if (ia.CollisionObjectType == CollisionObjectType.Static)
{
xb = inverseA.X / absXMag * (deltaX + collisionBuffer) + inverseB.X / absXMag * deltaX;
}
else if (ib.CollisionObjectType == CollisionObjectType.Static)
{
xa = inverseA.X / absXMag * (deltaX + collisionBuffer) + inverseB.X / absXMag * deltaX;
}
else
{
xa = inverseA.X / absXMag * (deltaX + collisionBuffer);
xb = inverseB.X / absXMag * (deltaX + collisionBuffer);
}
dataA.PositionChange = new Vector(xa, 0);
dataB.PositionChange = new Vector(xb, 0);
dataA.CollisionAxisX = true;
dataB.CollisionAxisX = true;
}
else
{
var ya = 0.0;
var yb = 0.0;
//apply correction
if (ia.CollisionObjectType == CollisionObjectType.Static)
{
yb = inverseA.Y / absYMag * (deltaY + collisionBuffer) + inverseB.Y / absYMag * deltaY;
}
else if (ib.CollisionObjectType == CollisionObjectType.Static)
{
ya = inverseA.Y / absYMag * (deltaY + collisionBuffer) + inverseB.Y / absYMag * deltaY;
}
else
{
ya = inverseA.Y / absYMag * (deltaY + collisionBuffer);
yb = inverseB.Y / absYMag * (deltaY + collisionBuffer);
}
dataA.PositionChange = new Vector(0, ya);
dataB.PositionChange = new Vector(0, yb);
dataA.CollisionAxisY = true;
dataB.CollisionAxisY = true;
//Do Mounting
if (aMount && ia.CollisionObjectType != CollisionObjectType.Static)
{
dataA.Mount = true;
}
if (bMount && ib.CollisionObjectType != CollisionObjectType.Static)
{
dataB.Mount = true;
}
}
}
/// <summary>
/// Axis-Aligned Bounding Box collision
/// </summary>
/// <param name="rectA">Box 1</param>
/// <param name="rectB">Box 2</param>
/// <returns></returns>
private static bool Aabb(SquareCollisionBox rectA, SquareCollisionBox rectB)
{
return(!(rectA.Right < rectB.Left) && !(rectA.Bottem < rectB.Top) && !(rectA.Left > rectB.Right) &&
!(rectA.Top > rectB.Bottem));
}