三角形の内包判定　多分間違ってる 無駄に頑張ってみた

gistfile1.cpp

//http://www5d.biglobe.ne.jp/~tomoya03/shtml/algorithm/IntersectionEX.htm

bool IL::ILZBuffer::IsTriangleInPoint(const ILVECTOR2 &A, const ILVECTOR2 &B, const ILVECTOR2 &C, const ILVECTOR2 &P)
{
	return IsCross(ILSEGMENT2(A,B),ILSEGMENT2(C,P)) && IsCross(ILSEGMENT2(B,C),ILSEGMENT2(A,P)) && IsCross(ILSEGMENT2(C,A),ILSEGMENT2(B,P));
}

bool IL::ILZBuffer::IsCross(const ILSEGMENT2 &A,const ILSEGMENT2 &B)
{
	return !((IsCrossSub(A.a.x,A.b.x,B.a.x,B.b.x)) || (IsCrossSub(A.a.y,A.b.y,B.a.y,B.b.y))) && (((((A.a.x - A.b.x) * (B.a.y - A.a.y) + (A.a.y - A.b.y) * (A.a.x - B.a.x)) * ((A.a.x - A.b.x) * (B.b.y - A.a.y) + (A.a.y - A.b.y) * (A.a.x - B.b.x))) > 0.0F) && (((B.a.x - B.b.x) * (A.a.y - B.a.y) + (B.a.y - B.b.y) * (B.a.x - A.a.x)) * ((B.a.x - B.b.x) * (A.b.y - B.a.y) + (B.a.y - B.b.y) * (B.a.x - A.b.x)) > 0.0F));
}

bool IL::ILZBuffer::IsCrossSub(const double &p1, const double &p2, const double &p3, const double &p4)
{
	return (p1 < p2)?IsCrossSub2(p1,p2,p3,p4):IsCrossSub2(p2,p1,p3,p4);
}

bool IL::ILZBuffer::IsCrossSub2(const double &p1, const double &p2, const double &p3, const double &p4)
{
	return (p1 < p3 && p1 < p4) || (p2 < p3 && p2 < p4);
}