// CCD via the local separating axis method. This seeks progression
// by computing the largest time at which separation is maintained.
public static void Compute(out b2TOIOutput output, ref b2TOIInput input)
{
++b2_toiCalls;
output.state = b2ImpactState.e_unknown;
output.t = input.tMax;
b2DistanceProxy proxyA = input.proxyA;
b2DistanceProxy proxyB = input.proxyB;
b2Sweep sweepA = input.sweepA;
b2Sweep sweepB = input.sweepB;
// Large rotations can make the root finder fail, so we normalize the
// sweep angles.
sweepA.Normalize();
sweepB.Normalize();
float tMax = input.tMax;
float totalRadius = proxyA.Radius + proxyB.Radius;
float target = Math.Max(b2Settings.b2_linearSlop, totalRadius - 3.0f * b2Settings.b2_linearSlop);
float tolerance = 0.25f * b2Settings.b2_linearSlop;
Debug.Assert(target > tolerance);
float t1 = 0.0f;
int k_maxIterations = 20; // TODO_ERIN b2Settings
int iter = 0;
// Prepare input for distance query.
b2SimplexCache cache = _cache;
b2DistanceInput distanceInput;
distanceInput.proxyA = input.proxyA;
distanceInput.proxyB = input.proxyB;
distanceInput.useRadii = false;
// The outer loop progressively attempts to compute new separating axes.
// This loop terminates when an axis is repeated (no progress is made).
while (true)
{
// Get the distance between shapes. We can also use the results
// to get a separating axis.
sweepA.GetTransform(out distanceInput.transformA, t1);
sweepB.GetTransform(out distanceInput.transformB, t1);
b2DistanceOutput distanceOutput;
b2Simplex.b2Distance(out distanceOutput, ref cache, ref distanceInput);
// If the shapes are overlapped, we give up on continuous collision.
if (distanceOutput.distance <= 0.0f)
{
// Failure!
output.state = b2ImpactState.e_overlapped;
output.t = 0.0f;
break;
}
if (distanceOutput.distance < target + tolerance)
{
// Victory!
output.state = b2ImpactState.e_touching;
output.t = t1;
break;
}
// Initialize the separating axis.
b2SeparationFunction fcn = new b2SeparationFunction();
fcn.Initialize(ref cache, proxyA, ref sweepA, proxyB, ref sweepB, t1,
ref distanceInput.transformA, ref distanceInput.transformB);
#if false
// Dump the curve seen by the root finder
{
int N = 100;
float dx = 1.0f / N;
float xs[N + 1];
// CCD via the local separating axis method. This seeks progression
// by computing the largest time at which separation is maintained.
public static void Compute(out b2TOIOutput output, ref b2TOIInput input)
{
++b2_toiCalls;
output.state = b2ImpactState.e_unknown;
output.t = input.tMax;
b2DistanceProxy proxyA = input.proxyA;
b2DistanceProxy proxyB = input.proxyB;
b2Sweep sweepA = input.sweepA;
b2Sweep sweepB = input.sweepB;
// Large rotations can make the root finder fail, so we normalize the
// sweep angles.
sweepA.Normalize();
sweepB.Normalize();
float tMax = input.tMax;
float totalRadius = proxyA.Radius + proxyB.Radius;
float target = Math.Max(b2Settings.b2_linearSlop, totalRadius - 3.0f * b2Settings.b2_linearSlop);
float tolerance = 0.25f * b2Settings.b2_linearSlop;
Debug.Assert(target > tolerance);
float t1 = 0.0f;
int k_maxIterations = 20; // TODO_ERIN b2Settings
int iter = 0;
// Prepare input for distance query.
b2SimplexCache cache = _cache;
b2DistanceInput distanceInput;
distanceInput.proxyA = input.proxyA;
distanceInput.proxyB = input.proxyB;
distanceInput.useRadii = false;
// The outer loop progressively attempts to compute new separating axes.
// This loop terminates when an axis is repeated (no progress is made).
while (true)
{
// Get the distance between shapes. We can also use the results
// to get a separating axis.
sweepA.GetTransform(out distanceInput.transformA, t1);
sweepB.GetTransform(out distanceInput.transformB, t1);
b2DistanceOutput distanceOutput;
b2Simplex.b2Distance(out distanceOutput, ref cache, ref distanceInput);
// If the shapes are overlapped, we give up on continuous collision.
if (distanceOutput.distance <= 0.0f)
{
// Failure!
output.state = b2ImpactState.e_overlapped;
output.t = 0.0f;
break;
}
if (distanceOutput.distance < target + tolerance)
{
// Victory!
output.state = b2ImpactState.e_touching;
output.t = t1;
break;
}
// Initialize the separating axis.
b2SeparationFunction fcn = new b2SeparationFunction();
fcn.Initialize(ref cache, proxyA, ref sweepA, proxyB, ref sweepB, t1,
ref distanceInput.transformA, ref distanceInput.transformB);
#if false
// Dump the curve seen by the root finder
{
int N = 100;
float dx = 1.0f / N;
float xs[N+1];