| public GetVertex ( int index ) : Vector2 | ||
| index | int | The index. |
| return | Vector2 | |
internal void ReadCache(ref SimplexCache cache,
ref DistanceProxy proxyA, ref Transform transformA,
ref DistanceProxy proxyB, ref Transform transformB)
{
Debug.Assert(cache.Count <= 3);
// Copy data from cache.
Count = cache.Count;
for (int i = 0; i < Count; ++i)
{
SimplexVertex v = V[i];
v.IndexA = cache.IndexA[i];
v.IndexB = cache.IndexB[i];
Vector2 wALocal = proxyA.GetVertex(v.IndexA);
Vector2 wBLocal = proxyB.GetVertex(v.IndexB);
v.WA = MathUtils.Multiply(ref transformA, wALocal);
v.WB = MathUtils.Multiply(ref transformB, wBLocal);
v.W = v.WB - v.WA;
v.A = 0.0f;
V[i] = v;
}
// Compute the new simplex metric, if it is substantially different than
// old metric then flush the simplex.
if (Count > 1)
{
float metric1 = cache.Metric;
float metric2 = GetMetric();
if (metric2 < 0.5f * metric1 || 2.0f * metric1 < metric2 || metric2 < Settings.Epsilon)
{
// Reset the simplex.
Count = 0;
}
}
// If the cache is empty or invalid ...
if (Count == 0)
{
SimplexVertex v = V[0];
v.IndexA = 0;
v.IndexB = 0;
Vector2 wALocal = proxyA.GetVertex(0);
Vector2 wBLocal = proxyB.GetVertex(0);
v.WA = MathUtils.Multiply(ref transformA, wALocal);
v.WB = MathUtils.Multiply(ref transformB, wBLocal);
v.W = v.WB - v.WA;
V[0] = v;
Count = 1;
}
}
public SeparationFunction(ref SimplexCache cache,
ref DistanceProxy proxyA, ref Sweep sweepA,
ref DistanceProxy proxyB, ref Sweep sweepB,
float t1)
{
_localPoint = Vector2.Zero;
_proxyA = proxyA;
_proxyB = proxyB;
int count = cache.Count;
Debug.Assert(0 < count && count < 3);
_sweepA = sweepA;
_sweepB = sweepB;
Transform xfA, xfB;
_sweepA.GetTransform(out xfA, t1);
_sweepB.GetTransform(out xfB, t1);
if (count == 1)
{
_type = SeparationFunctionType.Points;
Vector2 localPointA = _proxyA.GetVertex(cache.IndexA[0]);
Vector2 localPointB = _proxyB.GetVertex(cache.IndexB[0]);
Vector2 pointA = MathUtils.Multiply(ref xfA, localPointA);
Vector2 pointB = MathUtils.Multiply(ref xfB, localPointB);
_axis = pointB - pointA;
_axis.Normalize();
return;
}
else if (cache.IndexA[0] == cache.IndexA[1])
{
// Two points on B and one on A.
_type = SeparationFunctionType.FaceB;
Vector2 localPointB1 = proxyB.GetVertex(cache.IndexB[0]);
Vector2 localPointB2 = proxyB.GetVertex(cache.IndexB[1]);
Vector2 a = localPointB2 - localPointB1;
_axis = new Vector2(a.Y, -a.X);
_axis.Normalize();
Vector2 normal = MathUtils.Multiply(ref xfB.R, _axis);
_localPoint = 0.5f * (localPointB1 + localPointB2);
Vector2 pointB = MathUtils.Multiply(ref xfB, _localPoint);
Vector2 localPointA = proxyA.GetVertex(cache.IndexA[0]);
Vector2 pointA = MathUtils.Multiply(ref xfA, localPointA);
float s = Vector2.Dot(pointA - pointB, normal);
if (s < 0.0f)
{
_axis = -_axis;
s = -s;
}
return;
}
else
{
// Two points on A and one or two points on B.
_type = SeparationFunctionType.FaceA;
Vector2 localPointA1 = _proxyA.GetVertex(cache.IndexA[0]);
Vector2 localPointA2 = _proxyA.GetVertex(cache.IndexA[1]);
Vector2 a = localPointA2 - localPointA1;
_axis = new Vector2(a.Y, -a.X);
_axis.Normalize();
Vector2 normal = MathUtils.Multiply(ref xfA.R, _axis);
_localPoint = 0.5f * (localPointA1 + localPointA2);
Vector2 pointA = MathUtils.Multiply(ref xfA, _localPoint);
Vector2 localPointB = _proxyB.GetVertex(cache.IndexB[0]);
Vector2 pointB = MathUtils.Multiply(ref xfB, localPointB);
float s = Vector2.Dot(pointB - pointA, normal);
if (s < 0.0f)
{
_axis = -_axis;
s = -s;
}
return;
}
}
public float FindMinSeparation(out int indexA, out int indexB, float t)
{
Transform xfA, xfB;
_sweepA.GetTransform(out xfA, t);
_sweepB.GetTransform(out xfB, t);
switch (_type)
{
case SeparationFunctionType.Points:
{
Vector2 axisA = MathUtils.MultiplyT(ref xfA.R, _axis);
Vector2 axisB = MathUtils.MultiplyT(ref xfB.R, -_axis);
indexA = _proxyA.GetSupport(axisA);
indexB = _proxyB.GetSupport(axisB);
Vector2 localPointA = _proxyA.GetVertex(indexA);
Vector2 localPointB = _proxyB.GetVertex(indexB);
Vector2 pointA = MathUtils.Multiply(ref xfA, localPointA);
Vector2 pointB = MathUtils.Multiply(ref xfB, localPointB);
float separation = Vector2.Dot(pointB - pointA, _axis);
return(separation);
}
case SeparationFunctionType.FaceA:
{
Vector2 normal = MathUtils.Multiply(ref xfA.R, _axis);
Vector2 pointA = MathUtils.Multiply(ref xfA, _localPoint);
Vector2 axisB = MathUtils.MultiplyT(ref xfB.R, -normal);
indexA = -1;
indexB = _proxyB.GetSupport(axisB);
Vector2 localPointB = _proxyB.GetVertex(indexB);
Vector2 pointB = MathUtils.Multiply(ref xfB, localPointB);
float separation = Vector2.Dot(pointB - pointA, normal);
return(separation);
}
case SeparationFunctionType.FaceB:
{
Vector2 normal = MathUtils.Multiply(ref xfB.R, _axis);
Vector2 pointB = MathUtils.Multiply(ref xfB, _localPoint);
Vector2 axisA = MathUtils.MultiplyT(ref xfA.R, -normal);
indexB = -1;
indexA = _proxyA.GetSupport(axisA);
Vector2 localPointA = _proxyA.GetVertex(indexA);
Vector2 pointA = MathUtils.Multiply(ref xfA, localPointA);
float separation = Vector2.Dot(pointA - pointB, normal);
return(separation);
}
default:
Debug.Assert(false);
indexA = -1;
indexB = -1;
return(0.0f);
}
}
public SeparationFunction(ref SimplexCache cache,
ref DistanceProxy proxyA, ref Sweep sweepA,
ref DistanceProxy proxyB, ref Sweep sweepB,
float t1)
{
_localPoint = Vector2.Zero;
_proxyA = proxyA;
_proxyB = proxyB;
int count = cache.Count;
Debug.Assert(0 < count && count < 3);
_sweepA = sweepA;
_sweepB = sweepB;
Transform xfA, xfB;
_sweepA.GetTransform(out xfA, t1);
_sweepB.GetTransform(out xfB, t1);
if (count == 1)
{
_type = SeparationFunctionType.Points;
Vector2 localPointA = _proxyA.GetVertex(cache.IndexA[0]);
Vector2 localPointB = _proxyB.GetVertex(cache.IndexB[0]);
Vector2 pointA = MathUtils.Multiply(ref xfA, localPointA);
Vector2 pointB = MathUtils.Multiply(ref xfB, localPointB);
_axis = pointB - pointA;
_axis.Normalize();
return;
}
else if (cache.IndexA[0] == cache.IndexA[1])
{
// Two points on B and one on A.
_type = SeparationFunctionType.FaceB;
Vector2 localPointB1 = proxyB.GetVertex(cache.IndexB[0]);
Vector2 localPointB2 = proxyB.GetVertex(cache.IndexB[1]);
Vector2 a = localPointB2 - localPointB1;
_axis = new Vector2(a.Y, -a.X);
_axis.Normalize();
Vector2 normal = MathUtils.Multiply(ref xfB.R, _axis);
_localPoint = 0.5f*(localPointB1 + localPointB2);
Vector2 pointB = MathUtils.Multiply(ref xfB, _localPoint);
Vector2 localPointA = proxyA.GetVertex(cache.IndexA[0]);
Vector2 pointA = MathUtils.Multiply(ref xfA, localPointA);
float s = Vector2.Dot(pointA - pointB, normal);
if (s < 0.0f)
{
_axis = -_axis;
s = -s;
}
return;
}
else
{
// Two points on A and one or two points on B.
_type = SeparationFunctionType.FaceA;
Vector2 localPointA1 = _proxyA.GetVertex(cache.IndexA[0]);
Vector2 localPointA2 = _proxyA.GetVertex(cache.IndexA[1]);
Vector2 a = localPointA2 - localPointA1;
_axis = new Vector2(a.Y, -a.X);
_axis.Normalize();
Vector2 normal = MathUtils.Multiply(ref xfA.R, _axis);
_localPoint = 0.5f*(localPointA1 + localPointA2);
Vector2 pointA = MathUtils.Multiply(ref xfA, _localPoint);
Vector2 localPointB = _proxyB.GetVertex(cache.IndexB[0]);
Vector2 pointB = MathUtils.Multiply(ref xfB, localPointB);
float s = Vector2.Dot(pointB - pointA, normal);
if (s < 0.0f)
{
_axis = -_axis;
s = -s;
}
return;
}
}
internal void ReadCache(ref SimplexCache cache,
ref DistanceProxy proxyA, ref Transform transformA,
ref DistanceProxy proxyB, ref Transform transformB)
{
Debug.Assert(cache.Count <= 3);
// Copy data from cache.
Count = cache.Count;
for (int i = 0; i < Count; ++i)
{
SimplexVertex v = V[i];
v.IndexA = cache.IndexA[i];
v.IndexB = cache.IndexB[i];
Vector2 wALocal = proxyA.GetVertex(v.IndexA);
Vector2 wBLocal = proxyB.GetVertex(v.IndexB);
v.WA = MathUtils.Multiply(ref transformA, wALocal);
v.WB = MathUtils.Multiply(ref transformB, wBLocal);
v.W = v.WB - v.WA;
v.A = 0.0f;
V[i] = v;
}
// Compute the new simplex metric, if it is substantially different than
// old metric then flush the simplex.
if (Count > 1)
{
float metric1 = cache.Metric;
float metric2 = GetMetric();
if (metric2 < 0.5f*metric1 || 2.0f*metric1 < metric2 || metric2 < Settings.Epsilon)
{
// Reset the simplex.
Count = 0;
}
}
// If the cache is empty or invalid ...
if (Count == 0)
{
SimplexVertex v = V[0];
v.IndexA = 0;
v.IndexB = 0;
Vector2 wALocal = proxyA.GetVertex(0);
Vector2 wBLocal = proxyB.GetVertex(0);
v.WA = MathUtils.Multiply(ref transformA, wALocal);
v.WB = MathUtils.Multiply(ref transformB, wBLocal);
v.W = v.WB - v.WA;
V[0] = v;
Count = 1;
}
}