public static Vec cross (Vec a, Vec b)
{
return
new Vec (a.y * b.z - a.z * b.y,
a.z * b.x - a.x * b.z,
a.x * b.y - a.y * b.x);
}
public override Vec normal (Vec p)
{
Vec r;
r = Vec.sub (p, c);
r.normalize ();
return r;
}
// temporary vecs used to minimize the memory load
public Sphere (Vec center, double radius)
{
c = center;
r = radius;
r2 = r * r;
v = new Vec ();
b = new Vec ();
}
public View (Vec from, Vec at, Vec up, double dist, double angle, double aspect)
{
this.from = from;
this.at = at;
this.up = up;
this.dist = dist;
this.angle = angle;
this.aspect = aspect;
}
public Surface ()
{
color = new Vec (1, 0, 0);
kd = 1.0;
ks = 0.0;
shine = 0.0;
kt = 0.0;
ior = 1.0;
}
/**
* Returns the shaded color
* @return The color in Vec form (rgb)
*/
Vec shade(int level, double weight, Vec P, Vec N, Vec I, Isect hit)
{
Vec tcol;
Vec R;
double t, diff, spec;
Surface surf;
Vec col;
int l;
col = new Vec();
surf = hit.surf;
R = new Vec();
if (surf.shine > 1e-6)
{
R = SpecularDirection(I, N);
}
// Computes the effectof each light
for (l = 0; l < lights.Length; l++)
{
L.sub2(lights [l].pos, P);
if (Vec.dot(N, L) >= 0.0)
{
t = L.normalize();
tRay.P = P;
tRay.D = L;
// Checks if there is a shadow
if (Shadow(tRay, t) > 0)
{
diff = Vec.dot(N, L) * surf.kd *
lights [l].brightness;
col.adds(diff, surf.color);
if (surf.shine > 1e-6)
{
spec = Vec.dot(R, L);
if (spec > 1e-6)
{
spec = Math.Pow(spec, surf.shine);
col.x += spec;
col.y += spec;
col.z += spec;
}
}
}
}
}
tRay.P = P;
if (surf.ks * weight > 1e-3)
{
tRay.D = SpecularDirection(I, N);
tcol = trace(level + 1, surf.ks * weight, tRay);
col.adds(surf.ks, tcol);
}
if (surf.kt * weight > 1e-3)
{
if (hit.enter > 0)
{
tRay.D = TransDir(null, surf, I, N);
}
else
{
tRay.D = TransDir(surf, null, I, N);
}
tcol = trace(level + 1, surf.kt * weight, tRay);
col.adds(surf.kt, tcol);
}
// garbaging...
tcol = null;
surf = null;
return(col);
}
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++;
}
}
}
public abstract void setCenter(Vec c);
public Ray ()
{
P = new Vec ();
D = new Vec ();
}
/**
* Returns the shaded color
* @return The color in Vec form (rgb)
*/
Vec shade (int level, double weight, Vec P, Vec N, Vec I, Isect hit)
{
Vec tcol;
Vec R;
double t, diff, spec;
Surface surf;
Vec col;
int l;
col = new Vec ();
surf = hit.surf;
R = new Vec ();
if (surf.shine > 1e-6) {
R = SpecularDirection (I, N);
}
// Computes the effectof each light
for (l = 0; l < lights.Length; l++) {
L.sub2 (lights [l].pos, P);
if (Vec.dot (N, L) >= 0.0) {
t = L.normalize ();
tRay.P = P;
tRay.D = L;
// Checks if there is a shadow
if (Shadow (tRay, t) > 0) {
diff = Vec.dot (N, L) * surf.kd *
lights [l].brightness;
col.adds (diff, surf.color);
if (surf.shine > 1e-6) {
spec = Vec.dot (R, L);
if (spec > 1e-6) {
spec = Math.Pow (spec, surf.shine);
col.x += spec;
col.y += spec;
col.z += spec;
}
}
}
}
}
tRay.P = P;
if (surf.ks * weight > 1e-3) {
tRay.D = SpecularDirection (I, N);
tcol = trace (level + 1, surf.ks * weight, tRay);
col.adds (surf.ks, tcol);
}
if (surf.kt * weight > 1e-3) {
if (hit.enter > 0)
tRay.D = TransDir (null, surf, I, N);
else
tRay.D = TransDir (surf, null, I, N);
tcol = trace (level + 1, surf.kt * weight, tRay);
col.adds (surf.kt, tcol);
}
// garbaging...
tcol = null;
surf = null;
return col;
}
public void adds (double s, Vec b)
{
x += s * b.x;
y += s * b.y;
z += s * b.z;
}
public Vec (Vec a)
{
x = a.x;
y = a.y;
z = a.z;
}
public override void setCenter (Vec c)
{
this.c = c;
}
public static double dot (Vec a, Vec b)
{
return a.x * b.x + a.y * b.y + a.z * b.z;
}
public void add (Vec a)
{
x += a.x;
y += a.y;
z += a.z;
}
public static Vec mult (Vec a, Vec b)
{
return new Vec (a.x * b.x, a.y * b.y, a.z * b.z);
}
public void sub2 (Vec a, Vec b)
{
this.x = a.x - b.x;
this.y = a.y - b.y;
this.z = a.z - b.z;
}
public static Vec sub (Vec a, Vec b)
{
return new Vec (a.x - b.x, a.y - b.y, a.z - b.z);
}
public Light (double x, double y, double z, double brightness)
{
this.pos = new Vec (x, y, z);
this.brightness = brightness;
}
public abstract void setCenter (Vec c);
/**
* 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;
}
public static Vec comb (double a, Vec A, double b, Vec B)
{
return
new Vec (a * A.x + b * B.x,
a * A.y + b * B.y,
a * A.z + b * B.z);
}
public static Vec adds (double s, Vec a, Vec b)
{
return new Vec (s * a.x + b.x, s * a.y + b.y, s * a.z + b.z);
}
public abstract Vec normal (Vec pnt);
public void comb2 (double a, Vec A, double b, Vec B)
{
x = a * A.x + b * B.x;
y = a * A.y + b * B.y;
z = a * A.z + b * B.z;
}
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++;
}
}
}
public Ray(Vec pnt, Vec dir)
{
P = new Vec(pnt.x, pnt.y, pnt.z);
D = new Vec(dir.x, dir.y, dir.z);
D.normalize();
}
/**
* 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 Ray()
{
P = new Vec();
D = new Vec();
}
public abstract Vec normal(Vec pnt);
public Ray (Vec pnt, Vec dir)
{
P = new Vec (pnt.x, pnt.y, pnt.z);
D = new Vec (dir.x, dir.y, dir.z);
D.normalize ();
}
