bool Vector2::isLineOverlap(const Vector2& A, const Vector2& B, const Vector2& C, const Vector2& D)
{
if( (A.x == B.x && A.y == B.y) || (C.x == D.x && C.y == D.y))
return false;
if (crossProduct2Vector(A, B, C, D) == 0 && (crossProduct2Vector(C, D, C, A) == 0 || crossProduct2Vector(A, B, C, A) == 0))
return true;
return false;
}
// TODO: 'denom 이하' 부터 이해하기.
bool Vector2::isLineIntersect(const Vector2& A, const Vector2& B, const Vector2& C, const Vector2& D, double *T1, double *T2)
{
if( (A.x == B.x && A.y == B.y) || (C.x == D.x && C.y == D.y))
return false;
const double denom = crossProduct2Vector(A, B, C, D);
if (denom == 0)
{
return false;
}
if (T1 != nullptr) *T1 = crossProduct2Vector(C, D, C, A) / denom;
if (T2 != nullptr) *T2 = crossProduct2Vector(A, B, C, A) / denom;
return true;
}
bool Point::isLineOverlap(const Point& A, const Point& B,
const Point& C, const Point& D)
{
// FAIL: Line undefined
if ( (A.x==B.x && A.y==B.y) || (C.x==D.x && C.y==D.y) )
{
return false;
}
if (crossProduct2Vector(A, B, C, D) == 0 &&
(crossProduct2Vector(C, D, C, A) == 0 || crossProduct2Vector(A, B, C, A) == 0))
{
return true;
}
return false;
}
bool Vector2::isLineParallel(const Vector2& A, const Vector2& B, const Vector2& C, const Vector2& D)
{
if ( (A.x==B.x && A.y==B.y) || (C.x==D.x && C.y==D.y) )
{
return false;
}
if (crossProduct2Vector(A, B, C, D) == 0)
{
// line overlap
if (crossProduct2Vector(C, D, C, A) == 0 || crossProduct2Vector(A, B, C, A) == 0)
{
return false;
}
return true;
}
return false;
}
bool Point::isLineIntersect(const Point& A, const Point& B,
const Point& C, const Point& D,
float *S, float *T)
{
// FAIL: Line undefined
if ( (A.x==B.x && A.y==B.y) || (C.x==D.x && C.y==D.y) )
{
return false;
}
const float denom = crossProduct2Vector(A, B, C, D);
if (denom == 0)
{
// Lines parallel or overlap
return false;
}
if (S != nullptr) *S = crossProduct2Vector(C, D, C, A) / denom;
if (T != nullptr) *T = crossProduct2Vector(A, B, C, A) / denom;
return true;
}
