/**
* Return the Vector's reflection direction
* @return The specular direction
*/
Vec SpecularDirection(Vec I, Vec N)
{
Vec r;
r = Vec.comb(1.0 / Math.Abs(Vec.dot(I, N)), I, 2.0, N);
r.normalize();
return(r);
}
/**
* Return the Vector's transmission direction
*/
Vec TransDir(Surface m1, Surface m2, Vec I, Vec N)
{
double n1, n2, eta, c1, cs2;
Vec r;
n1 = m1 == null ? 1.0 : m1.ior;
n2 = m2 == null ? 1.0 : m2.ior;
eta = n1 / n2;
c1 = -Vec.dot(I, N);
cs2 = 1.0 - eta * eta * (1.0 - c1 * c1);
if (cs2 < 0.0)
{
return(null);
}
r = Vec.comb(eta, I, eta * c1 - Math.Sqrt(cs2), N);
r.normalize();
return(r);
}
public void render(Interval interval)
{
int[] row = new int[interval.width * (interval.yto - interval.yfrom)];
int pixCounter = 0; //iterator
int x, y, red, green, blue;
double xlen, ylen;
Vec viewVec;
viewVec = Vec.sub(view.at, view.from);
viewVec.normalize();
Vec tmpVec = new Vec(viewVec);
tmpVec.scale(Vec.dot(view.up, viewVec));
Vec upVec = Vec.sub(view.up, tmpVec);
upVec.normalize();
Vec leftVec = Vec.cross(view.up, viewVec);
leftVec.normalize();
double frustrumwidth = view.dist * Math.Tan(view.angle);
upVec.scale(-frustrumwidth);
leftVec.scale(view.aspect * frustrumwidth);
Ray r = new Ray(view.from, voidVec);
Vec col = new Vec();
// For each line
for (y = interval.yfrom; y < interval.yto; y++)
{
ylen = (double)(2.0 * y) / (double)interval.width - 1.0;
for (x = 0; x < interval.width; x++)
{
xlen = (double)(2.0 * x) / (double)interval.width - 1.0;
r.D = Vec.comb(xlen, leftVec, ylen, upVec);
r.D.add(viewVec);
r.D.normalize();
col = trace(0, 1.0, r);
// computes the color of the ray
red = (int)(col.x * 255.0);
if (red > 255)
{
red = 255;
}
green = (int)(col.y * 255.0);
if (green > 255)
{
green = 255;
}
blue = (int)(col.z * 255.0);
if (blue > 255)
{
blue = 255;
}
checksum += red;
checksum += green;
checksum += blue;
// Sets the pixels
row [pixCounter] = alpha | (red << 16) | (green << 8) | (blue);
pixCounter++;
}
}
}