bool SquareCollisions::LineCollision(glm::vec2 & A1, glm::vec2 & A2,
glm::vec2 & B1, glm::vec2 & B2,
double* out)
{
glm::vec2 a(A2 - A1);
glm::vec2 b(B2 - B1);
double f = PerpDot(a, b);
if (!f) // lines are parallel
return false;
glm::vec2 c(B2 - A2);
double aa = PerpDot(a, c);
double bb = PerpDot(b, c);
if (f < 0)
{
if (aa > 0) return false;
if (bb > 0) return false;
if (aa < f) return false;
if (bb < f) return false;
}
else
{
if (aa < 0) return false;
if (bb < 0) return false;
if (aa > f) return false;
if (bb > f) return false;
}
if (out)
*out = 1.0 - (aa / f);
return true;
}
/*
Returns true if vector a collides with vector b
*/
bool LineCollision(double alx, double aly, double aux, double auy, double blx, double bly, double bux, double buy) {
if (alx < aux){
double ax = alx;
alx = aux;
aux = ax;
}
if (aly < auy){
double ay = aly;
aly = auy;
auy = ay;
}
double f = PerpDot(aux - alx, auy - aly, bux - blx, buy - bly);
if (f == 0.0) {
return false;
}
double r = PerpDot(aux - alx, auy - aly, bux - aux, buy - auy);
double s = PerpDot(bux - blx, buy - bly, bux - aux, buy - auy);
if ((f > 0.0 && r > 0.0 && s > 0.0 && f > r && f > s) ||
(f < 0.0 && r < 0.0 && s < 0.0 && f < r && f < s)) {
return true;
}
return false;
}
