public bool intersectionTriangle(ray r, Vector2 v, primitives p)
{
//box pixelcoordinates to world coordinates
float tx = TX(p.X);
float ty = TY(p.Y);
float tw = TW(p.W);
float th = TW(p.H);
//3 vectors, for every line of the triangle 1
Vector2 blc = new Vector2(tx, ty + th);
Vector2 brc = new Vector2(tx + tw, ty + th);
Vector2 tc = new Vector2(tx + (tw / 2), ty);
////ensure that it is not inside the triangle. Else you have an intersection immediatly.
//if (p.X > blc.X && p.X < trc.X && p.Y < blc.Y && p.Y > trc.Y && r.o.X > blc.X && r.o.X < trc.X && r.o.Y < blc.Y && r.o.Y > trc.Y)
//{
// return true;
//}
// check for intersection for every vector of the triangle.
if (intersectionLine(r, v, blc, tc))
{
return(true);
}
if (intersectionLine(r, v, tc, brc))
{
return(true);
}
if (intersectionLine(r, v, brc, blc))
{
return(true);
}
return(false);
}
public bool intersectionBox(ray r, Vector2 p, primitives b)
{
//box pixelcoordinates to world coordinates
float bx1 = TX(b.X);
float by1 = TY(b.Y);
float bx2 = (TX(b.X)) + (TW(b.W));
float by2 = (TY(b.Y)) + (TW(b.H));
//4 vectors, for every line of the box 1
Vector2 blc = new Vector2(bx1, by2);
Vector2 brc = new Vector2(bx2, by2);
Vector2 tlc = new Vector2(bx1, by1);
Vector2 trc = new Vector2(bx2, by1);
//ensure that it is not inside the box. Else you have an intersection immediatly.
if (p.X > blc.X && p.X < trc.X && p.Y < blc.Y && p.Y > trc.Y && r.o.X > blc.X && r.o.X < trc.X && r.o.Y < blc.Y && r.o.Y > trc.Y)
{
return(true);
}
// check for intersection for every vector of the box.
if (intersectionLine(r, p, tlc, blc))
{
return(true);
}
if (intersectionLine(r, p, blc, brc))
{
return(true);
}
if (intersectionLine(r, p, tlc, trc))
{
return(true);
}
if (intersectionLine(r, p, trc, brc))
{
return(true);
}
return(false);
}
public bool intersectionCircle(ray r, Vector2 v, primitives p)
{
float radius = ((TW(p.W) / 2));
Vector2 vec = new Vector2(TX(p.X), TY(p.Y));
Vector2 c = vec - r.o;
float t = Vector2.Dot(c, r.d);
Vector2 q = c - (t * r.d);
float p2 = Vector2.Dot(q, q);
float tocircle = t - (float)Math.Sqrt(((radius * radius) - p2));
if (tocircle > r.t || t < 0)
{
return(false);
}
if ((radius * radius) < p2)
{
return(false);
}
else
{
r.t = t;
return(true);
}
}
