RNBoolean R3Contains(const R3Halfspace& halfspace, const R3Triangle& triangle)
{
// Check whether halfspace contains triangle bounding shape
if (R3Contains(halfspace, triangle.Box())) return TRUE;
// Check whether halfspace contains all vertices of triangle
if (!R3Contains(halfspace, triangle.Vertex(0)->Position())) return FALSE;
if (!R3Contains(halfspace, triangle.Vertex(1)->Position())) return FALSE;
if (!R3Contains(halfspace, triangle.Vertex(2)->Position())) return FALSE;
// Passed all tests
return TRUE;
}
RNBoolean R3Contains(const R3Triangle& triangle, const R3Point& point)
{
// Check whether triangle bounding shape contains point
if (!R3Contains(triangle.Box(), point)) return FALSE;
// Check whether triangle plane contains point
if (!R3Contains(triangle.Plane(), point)) return FALSE;
// Compute whether point is on correct side of each edge
const R3Point& p0 = triangle.Vertex(0)->Position();
const R3Point& p1 = triangle.Vertex(1)->Position();
const R3Point& p2 = triangle.Vertex(2)->Position();
R3Plane h01(p1, triangle.Normal(), p1 - p0);
if (RNIsNegative(R3SignedDistance(h01, point))) return FALSE;
R3Plane plane01(p1, triangle.Normal(), p1 - p0);
if (RNIsNegative(R3SignedDistance(plane01, point))) return FALSE;
R3Plane plane12(p2, triangle.Normal(), p2 - p1);
if (RNIsNegative(R3SignedDistance(plane12, point))) return FALSE;
R3Plane plane20(p0, triangle.Normal(), p0 - p2);
if (RNIsNegative(R3SignedDistance(plane20, point))) return FALSE;
// Triangle contains point
return TRUE;
}