float3 Triangle::RandomPointInside(LCG &rng) const
{
float epsilon = 1e-3f;
///@todo rng.Float() returns [0,1[, but to be completely uniform, we'd need [0,1] here.
float s = rng.Float(epsilon, 1.f - epsilon);//1e-2f, 1.f - 1e-2f);
float t = rng.Float(epsilon, 1.f - epsilon);//1e-2f, 1.f - 1e-2f
if (s + t >= 1.f)
{
s = 1.f - s;
t = 1.f - t;
}
#ifdef MATH_ASSERT_CORRECTNESS
float3 pt = Point(s, t);
float2 uv = BarycentricUV(pt);
assert(uv.x >= 0.f);
assert(uv.y >= 0.f);
assert(uv.x + uv.y <= 1.f);
float3 uvw = BarycentricUVW(pt);
assert(uvw.x >= 0.f);
assert(uvw.y >= 0.f);
assert(uvw.z >= 0.f);
assert(EqualAbs(uvw.x + uvw.y + uvw.z, 1.f));
#endif
return Point(s, t);
}
float3 Triangle::ClosestPointToTriangleEdge(const LineSegment &lineSegment, float *outU, float *outV, float *outD) const
{
///@todo Optimize!
// The line is parallel to the triangle.
float d1, d2, d3;
float3 pt1 = Edge(0).ClosestPoint(lineSegment, 0, &d1);
float3 pt2 = Edge(1).ClosestPoint(lineSegment, 0, &d2);
float3 pt3 = Edge(2).ClosestPoint(lineSegment, 0, &d3);
float dist1 = pt1.DistanceSq(lineSegment.GetPoint(d1));
float dist2 = pt2.DistanceSq(lineSegment.GetPoint(d2));
float dist3 = pt3.DistanceSq(lineSegment.GetPoint(d3));
if (dist1 <= dist2 && dist1 <= dist3)
{
if (outU) *outU = BarycentricUV(pt1).x;
if (outV) *outV = BarycentricUV(pt1).y;
if (outD) *outD = d1;
return pt1;
}
else if (dist2 <= dist3)
{
if (outU) *outU = BarycentricUV(pt2).x;
if (outV) *outV = BarycentricUV(pt2).y;
if (outD) *outD = d2;
return pt2;
}
else
{
if (outU) *outU = BarycentricUV(pt3).x;
if (outV) *outV = BarycentricUV(pt3).y;
if (outD) *outD = d3;
return pt3;
}
}
