/// <summary>
/// Workhorse for circle-circle collisions, compares origin distance
/// to the sum of the two circles' radii, returns a Manifold.
/// </summary>
///
private static Manifold TestCircles(
VoltWorld world,
VoltCircle shapeA,
VoltShape shapeB,
Vector2 overrideBCenter, // For testing vertices in circles
float overrideBRadius)
{
Vector2 r = overrideBCenter - shapeA.worldSpaceOrigin;
float min = shapeA.radius + overrideBRadius;
float distSq = r.sqrMagnitude;
if (distSq >= min * min)
{
return(null);
}
float dist = Mathf.Sqrt(distSq);
float distInv = 1.0f / dist;
Vector2 pos =
shapeA.worldSpaceOrigin +
(0.5f + distInv * (shapeA.radius - min / 2.0f)) * r;
// Build the collision Manifold
Manifold manifold =
world.AllocateManifold().Assign(world, shapeA, shapeB);
manifold.AddContact(pos, distInv * r, dist - min);
return(manifold);
}
/// <summary>
/// Workhorse for circle-circle collisions, compares origin distance
/// to the sum of the two circles' radii, returns a Manifold.
/// </summary>
///
private static Manifold TestCircles(
VoltWorld world,
VoltCircle shapeA,
VoltShape shapeB,
VoltVector2 overrideBCenter, // For testing vertices in circles
Fix64 overrideBRadius)
{
VoltVector2 r = overrideBCenter - shapeA.worldSpaceOrigin;
Fix64 min = shapeA.radius + overrideBRadius;
Fix64 distSq = r.sqrMagnitude;
if (distSq >= min * min)
{
return(null);
}
Fix64 dist = VoltMath.Sqrt(distSq);
// 최소값을 지정하여 divide by zero 방지
Fix64 distInv = Fix64.One / VoltMath.Max(dist, min / (Fix64)10);
VoltVector2 pos =
shapeA.worldSpaceOrigin +
(Fix64.One / (Fix64)2 + distInv * (shapeA.radius - min / (Fix64)2)) * r;
// Build the collision Manifold
Manifold manifold =
world.AllocateManifold().Assign(world, shapeA, shapeB);
manifold.AddContact(pos, distInv * r, dist - min);
return(manifold);
}
/// <summary>
/// Creates a new circle shape from a world-space origin.
/// </summary>
public VoltCircle CreateCircleWorldSpace(
VoltVector2 worldSpaceOrigin, Fix64 radius, Fix64 density, Fix64 friction, Fix64 restitution)
{
VoltCircle circle = (VoltCircle)this.circlePool.Allocate();
circle.InitializeFromWorldSpace(
worldSpaceOrigin,
radius,
density,
friction,
restitution);
return(circle);
}
private static Manifold Circle_Circle(
VoltWorld world,
VoltCircle circA,
VoltCircle circB)
{
return
(TestCircles(
world,
circA,
circB,
circB.worldSpaceOrigin,
circB.radius));
}
/// <summary>
/// Creates a new circle shape from a world-space origin.
/// </summary>
public VoltCircle CreateCircleWorldSpace(
TSVector2 worldSpaceOrigin,
FP radius,
FP?density = null,
FP?friction = null,
FP?restitution = null)
{
VoltCircle circle = (VoltCircle)this.circlePool.Allocate();
circle.InitializeFromWorldSpace(
worldSpaceOrigin,
radius,
density ?? VoltConfig.DEFAULT_DENSITY,
friction ?? VoltConfig.DEFAULT_FRICTION,
restitution ?? VoltConfig.DEFAULT_RESTITUTION);
return(circle);
}
/// <summary>
/// Creates a new circle shape from a world-space origin.
/// </summary>
public VoltCircle CreateCircleWorldSpace(
Vector2 worldSpaceOrigin,
float radius,
float density = VoltConfig.DEFAULT_DENSITY,
float friction = VoltConfig.DEFAULT_FRICTION,
float restitution = VoltConfig.DEFAULT_RESTITUTION)
{
VoltCircle circle = (VoltCircle)this.circlePool.Allocate();
circle.InitializeFromWorldSpace(
worldSpaceOrigin,
radius,
density,
friction,
restitution);
return(circle);
}
private static Manifold Circle_Polygon(
VoltWorld world,
VoltCircle circ,
VoltPolygon poly)
{
// Get the axis on the polygon closest to the circle's origin
float penetration;
int index =
Collision.FindAxisMaxPenetration(
circ.worldSpaceOrigin,
circ.radius,
poly,
out penetration);
if (index < 0)
{
return(null);
}
Vector2 a, b;
poly.GetEdge(index, out a, out b);
Axis axis = poly.GetWorldAxis(index);
// If the circle is past one of the two vertices, check it like
// a circle-circle intersection where the vertex has radius 0
float d = VoltMath.Cross(axis.Normal, circ.worldSpaceOrigin);
if (d > VoltMath.Cross(axis.Normal, a))
{
return(Collision.TestCircles(world, circ, poly, a, 0.0f));
}
if (d < VoltMath.Cross(axis.Normal, b))
{
return(Collision.TestCircles(world, circ, poly, b, 0.0f));
}
// Build the collision Manifold
Manifold manifold = world.AllocateManifold().Assign(world, circ, poly);
Vector2 pos =
circ.worldSpaceOrigin - (circ.radius + penetration / 2) * axis.Normal;
manifold.AddContact(pos, -axis.Normal, penetration);
return(manifold);
}