public override void setCenter(Vec c)
{
this.c = c;
}
public Surface()
{
color = new Vec(1, 0, 0);
kd = 1.0;
ks = 0.0;
shine = 0.0;
kt = 0.0;
ior = 1.0;
}
/**
* Adds vector such as:
* this+=sB
* @param: s The multiplier
* @param: b The vector to be added
*/
public void adds(double s, Vec b)
{
x += s * b.x;
y += s * b.y;
z += s * b.z;
}
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 static double dot(Vec a, Vec b)
{
return a.x * b.x + a.y * b.y + a.z * b.z;
}
/**
* Substracs two vectors
*/
public static Vec sub(Vec a, Vec b)
{
return new Vec(a.x - b.x, a.y - b.y, a.z - b.z);
}
public void render(Interval interval)
{
// Screen variables
int[] row = new int[interval.width * (interval.yto - interval.yfrom)];
int pixCounter = 0; //iterator
// Rendering variables
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();
// Header for .ppm file
// System.out.println("P3");
// System.out.println(width + " " + height);
// System.out.println("255");
// All loops are reversed for 'speedup' (cf. thinking in java p331)
// For each line
for (y = interval.yfrom; y < interval.yto; y++)
{
ylen = (double)(2.0 * y) / (double)interval.width - 1.0;
// System.out.println("Doing line " + y);
// For each pixel of the line
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;
// RGB values for .ppm file
// System.out.println(red + " " + green + " " + blue);
// Sets the pixels
row[pixCounter++] = alpha | (red << 16) | (green << 8) | (blue);
} // end for (x)
} // end for (y)
}
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 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();
}
public Ray()
{
P = new Vec();
D = new Vec();
}
public abstract void setCenter(Vec c);
public abstract Vec normal(Vec pnt);
public Light(double x, double y, double z, double brightness)
{
this.pos = new Vec(x, y, z);
this.brightness = brightness;
}
/**
* Copy constructor
*/
public Vec(Vec a)
{
x = a.x;
y = a.y;
z = a.z;
}
/**
* 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)
{
double n1, n2, eta, c1, cs2;
Vec r;
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;
}
}
}
} // if
} // for
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;
}
/**
* adds: Returns a new vector such as
* new = sA + B
*/
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);
}
/**
* 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 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);
}
/**
* 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 static Vec mult(Vec a, Vec b)
{
return new Vec(a.x * b.x, a.y * b.y, a.z * b.z);
}
Vec v, b; // temporary vecs used to minimize the memory load
#endregion Fields
#region Constructors
public Sphere(Vec center, double radius)
{
c = center;
r = radius;
r2 = r * r;
v = new Vec();
b = new Vec();
}
/**
* Add a vector to the current vector
* @param: a The vector to be added
*/
public void add(Vec a)
{
x += a.x;
y += a.y;
z += a.z;
}
public override Vec normal(Vec p)
{
Vec r;
r = Vec.sub(p, c);
r.normalize();
return r;
}
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;
}
/**
* Substracts two vects and places the results in the current vector
* Used for speedup with local variables -there were too much Vec to be gc'ed
* Consumes about 10 units, whether sub consumes nearly 999 units!!
* cf thinking in java p. 831,832
*/
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;
}
