bool DoesLineAndBoxCollide( const CVector2< PointType >& p1, const CVector2< PointType >& p2,
const CVector2< PointType >& rect_low, const CVector2< PointType >& rect_high )
{
if( IsPointInsideRect( p1, rect_low, rect_high ) )
return true;
if( IsPointInsideRect( p2, rect_low, rect_high ) )
return true;
CVector2< PointType > result;
typedef CVector2< PointType > vec2;
if( LineIntersection( p1, p2, rect_low, vec2( rect_low.x, rect_high.y ), result ) )
return true;
if( LineIntersection( p1, p2, vec2( rect_low.x, rect_high.y ), rect_high, result ) )
return true;
if( LineIntersection( p1, p2, rect_high, vec2( rect_high.x, rect_low.x ), result ) )
return true;
if( LineIntersection( p1, p2, vec2( rect_high.x, rect_low.x ), rect_low, result ) )
return true;
return false;
}
bool CIRect::Intersect(const CIPoint& C, const CIPoint& D) // line intersection
{
if (Sector((int)A.x, (int)A.y)&Sector((int)B.x, (int)B.y)) return false;
CXPoint X;
if (LineIntersection(C,D, CIPoint(A.x, DBL_MIN), CIPoint(A.x, DBL_MAX), &X)) return true;
if (LineIntersection(C,D, CIPoint(B.x, DBL_MIN), CIPoint(B.x, DBL_MAX), &X)) return true;
if (LineIntersection(C,D, CIPoint(DBL_MIN, A.y), CIPoint(DBL_MAX, A.y), &X)) return true;
if (LineIntersection(C,D, CIPoint(DBL_MIN, B.y), CIPoint(DBL_MAX, B.y), &X)) return true;
return false;
}
/* Returns true if the given point is in the given domain */
static int PointInDomain(struct Domain *d, int x, int y)
{
int i, xi;
int intersections = 0;
/* Point-in-polygon algorithm. We check for intersection with
a horizontal line going through (x, y). */
for (i = 0; i < d->num_borders; ++i) {
if (LineIntersection(d->borders[i], &xi, y) && xi < x) {
++intersections;
}
}
/* Odd number of intersections to the left of (x, y) implies the
point is inside the domain. */
return (intersections % 2) == 1;
}
bool IsSegmentIntersect(float Ax, float Ay, float Bx, float By, float Cx, float Cy, float Dx, float Dy, bool TestSegEnd) {
if (!IsLineIntersect(Ax, Ay, Bx, By, Cx, Cy, Dx, Dy)) {
return false;
}
Coord pos = LineIntersection(Ax, Ay, Bx, By, Cx, Cy, Dx, Dy);
pos = Coord(round(pos.x),round(pos.y));
bool res = false;
if (Bx >= Ax) {
res= (pos.x <= Bx) && (pos.x >= Ax);
} else {
res = (pos.x <= Ax) && (pos.x >= Bx);
}
if (By >= Ay) {
res= res && (pos.y <= By) && (pos.y >= Ay);
} else {
res = res && (pos.y <= Ay) && (pos.y >= By);
}
if (Dx >= Cx) {
res = res && (pos.x <= Dx) && (pos.x >= Cx);
} else {
res = res && (pos.x <= Cx) && (pos.x >= Dx);
}
if (Dy >= Cy) {
res = res && (pos.y <= Dy) && (pos.y >= Cy);
} else {
res = res && (pos.y <= Cy) && (pos.y >= Dy);
}
if (!TestSegEnd) { // Prise de marge pour absorber les arrondis
if (Distance(pos, Coord(Ax,Ay)) <= 1 ||
Distance(pos, Coord(Bx,By)) <= 1 ||
Distance(pos, Coord(Cx,Cy)) <= 1 ||
Distance(pos, Coord(Dx,Dy)) <= 1)
res = false;
}
return res;
}
Coord LineIntersection(Coord A, Coord B, Coord C, Coord D) {
return LineIntersection(A.x, A.y, B.x, B.y, C.x, C.y, D.x, D.y);
}
