public bool RayCast(out b2RayCastOutput output, b2RayCastInput input)
{
float tmin = -float.MaxValue;
float tmax = float.MaxValue;
b2Vec2 p = input.p1;
b2Vec2 d = input.p2 - input.p1;
b2Vec2 absD = b2Math.b2Abs(d);
b2Vec2 normal = new b2Vec2(0,0);
for (int i = 0; i < 2; ++i)
{
float p_i, lb, ub, d_i, absd_i;
p_i = (i == 0 ? p.x : p.y);
lb = (i == 0 ? m_lowerBound.x : m_lowerBound.y);
ub = (i == 0 ? m_upperBound.x : m_upperBound.y);
absd_i = (i == 0 ? absD.x : absD.y);
d_i = (i == 0 ? d.x : d.y);
if (absd_i < b2Settings.b2_epsilon)
{
// Parallel.
if (p_i < lb || ub < p_i)
{
output.fraction = 0f;
output.normal = new b2Vec2(0, 0);
return false;
}
}
else
{
float inv_d = 1.0f / d_i;
float t1 = (lb - p_i) * inv_d;
float t2 = (ub - p_i) * inv_d;
// Sign of the normal vector.
float s = -1.0f;
if (t1 > t2)
{
b2Math.b2Swap(t1, t2);
s = 1.0f;
}
// Push the min up
if (t1 > tmin)
{
normal.SetZero();
if (i == 0)
{
normal.x = s;
}
else
{
normal.y = s;
}
tmin = t1;
}
// Pull the max down
tmax = Math.Min(tmax, t2);
if (tmin > tmax)
{
output.fraction = 0f;
output.normal = new b2Vec2(0, 0);
return false;
}
}
}
// Does the ray start inside the box?
// Does the ray intersect beyond the max fraction?
if (tmin < 0.0f || input.maxFraction < tmin)
{
output.fraction = 0f;
output.normal = new b2Vec2(0, 0);
return false;
}
// Intersection.
output.fraction = tmin;
output.normal = normal;
return true;
}
public virtual bool RayCast(out b2RayCastOutput output, b2RayCastInput input, int childIndex)
{
return m_shape.RayCast(out output, input, m_body.Transform, childIndex);
}
public bool RayCast(out b2RayCastOutput output, b2RayCastInput input)
{
float tmin = -float.MaxValue;
float tmax = float.MaxValue;
b2Vec2 p = input.p1;
b2Vec2 d = input.p2 - input.p1;
b2Vec2 absD = b2Math.b2Abs(d);
b2Vec2 normal = new b2Vec2(0, 0);
for (int i = 0; i < 2; ++i)
{
float p_i, lb, ub, d_i, absd_i;
p_i = (i == 0 ? p.x : p.y);
lb = (i == 0 ? m_lowerBound.x : m_lowerBound.y);
ub = (i == 0 ? m_upperBound.x : m_upperBound.y);
absd_i = (i == 0 ? absD.x : absD.y);
d_i = (i == 0 ? d.x : d.y);
if (absd_i < b2Settings.b2_epsilon)
{
// Parallel.
if (p_i < lb || ub < p_i)
{
output.fraction = 0f;
output.normal = new b2Vec2(0, 0);
return(false);
}
}
else
{
float inv_d = 1.0f / d_i;
float t1 = (lb - p_i) * inv_d;
float t2 = (ub - p_i) * inv_d;
// Sign of the normal vector.
float s = -1.0f;
if (t1 > t2)
{
b2Math.b2Swap(t1, t2);
s = 1.0f;
}
// Push the min up
if (t1 > tmin)
{
normal.SetZero();
if (i == 0)
{
normal.x = s;
}
else
{
normal.y = s;
}
tmin = t1;
}
// Pull the max down
tmax = Math.Min(tmax, t2);
if (tmin > tmax)
{
output.fraction = 0f;
output.normal = new b2Vec2(0, 0);
return(false);
}
}
}
// Does the ray start inside the box?
// Does the ray intersect beyond the max fraction?
if (tmin < 0.0f || input.maxFraction < tmin)
{
output.fraction = 0f;
output.normal = new b2Vec2(0, 0);
return(false);
}
// Intersection.
output.fraction = tmin;
output.normal = normal;
return(true);
}
private void RayCast()
{
m_rayActor = null;
b2RayCastInput input = m_rayCastInput;
// Ray cast against the dynamic tree.
m_tree.RayCast(this, input);
// Brute force ray cast.
Actor bruteActor = null;
b2RayCastOutput bruteOutput = new b2RayCastOutput();
for (int i = 0; i < e_actorCount; ++i)
{
if (m_actors[i].proxyId == b2_nullNode)
{
continue;
}
b2RayCastOutput output;
bool hit = m_actors[i].aabb.RayCast(out output, input);
if (hit)
{
bruteActor = m_actors[i];
bruteOutput = output;
input.maxFraction = output.fraction;
}
}
if (bruteActor != null)
{
Debug.Assert(bruteOutput.fraction == m_rayCastOutput.fraction);
}
}
public float RayCastCallback(ref b2RayCastInput input, int proxyId)
{
Actor actor = (Actor) m_tree.GetUserData(proxyId);
b2RayCastOutput output = new b2RayCastOutput();
bool hit = actor.aabb.RayCast(out output, input);
if (hit)
{
m_rayCastOutput = output;
m_rayActor = actor;
m_rayActor.fraction = output.fraction;
return output.fraction;
}
return input.maxFraction;
}
// From Real-time Collision Detection, p179.
/**
* Perform a precise raycast against the AABB.
*/
public bool RayCast(b2RayCastOutput output, b2RayCastInput input)
{
float tmin = -float.MaxValue;
//float tmax = float.MaxValue;
float pX = input.p1.x;
float pY = input.p1.y;
float dX = input.p2.x - input.p1.x;
float dY = input.p2.y - input.p1.y;
float absDX = Mathf.Abs(dX);
float absDY = Mathf.Abs(dY);
b2Vec2 normal = output.normal;
float inv_d;
float t1;
float t2;
float t3;
float s;
//x
if (absDX < float.MinValue)
{
// Parallel.
if (pX < lowerBound.x || upperBound.x < pX)
{
return(false);
}
}
else
{
inv_d = 1.0f / dX;
t1 = (lowerBound.x - pX) * inv_d;
t2 = (upperBound.x - pX) * inv_d;
// Sign of the normal vector
s = -1.0f;
if (t1 > t2)
{
t3 = t1;
t1 = t2;
t2 = t3;
s = 1.0f;
}
// Push the min up
if (t1 > tmin)
{
normal.x = s;
normal.y = 0.0f;
tmin = t1;
}
// Pull the max down
float tmax = Mathf.Min(float.MaxValue, t2);
if (tmin > tmax)
{
return(false);
}
}
//y
if (absDY < float.MinValue)
{
// Parallel.
if (pY < lowerBound.y || upperBound.y < pY)
{
return(false);
}
}
else
{
inv_d = 1.0f / dY;
t1 = (lowerBound.y - pY) * inv_d;
t2 = (upperBound.y - pY) * inv_d;
// Sign of the normal vector
s = -1.0f;
if (t1 > t2)
{
t3 = t1;
t1 = t2;
t2 = t3;
s = 1.0f;
}
// Push the min up
if (t1 > tmin)
{
normal.y = s;
normal.x = 0.0f;
tmin = t1;
}
// Pull the max down
float tmax = Mathf.Min(float.MaxValue, t2);
if (tmin > tmax)
{
return(false);
}
}
output.fraction = tmin;
return(true);
}
