public static Pixel[] start()
{
Pixel[] pixels = new Pixel[Constants.WIN_X * Constants.WIN_Y];
Point3 viewPlane = new Point3(-Constants.WIN_X / 2, -Constants.WIN_X / 2, 0);
createScene();
for (int y = 0; y < Constants.WIN_Y; y++)
{
for (int x = 0; x < Constants.WIN_X; x++)
{
Pixel p = new Pixel();
p.rect.X = x;
p.rect.Y = Constants.WIN_Y - 1 - y;
Point3 viewPixel = new Point3();
viewPixel.x = viewPlane.x + x;
viewPixel.y = viewPlane.y + y;
viewPixel.z = viewPlane.z;
Ray r = new Ray();
r.direction = Point3.vectorize(layout.Cam.Eye, viewPixel);
r.start = layout.Cam.Eye;
p.color = fireRay(r, Constants.MIN_DEPTH, null);
pixels[y * Constants.WIN_X + x] = p;
}
}
return pixels;
}
public override Color3 colorNormal(Color3 existing, Ray r, Hit h, Shape s, Light bulb)
{
switch (shader)
{
case ProcShading.Circle:
return mapCircle(h);
case ProcShading.Texture:
return mapTexture(h);
default:
return mapSquare(h);
}
}
public override Hit intersect(Ray r)
{
Hit h = new Hit();
double denominator =
Vector3.DotProduct(normal, r.direction);
if (denominator == 0.0)
{
h.intersect.z = Constants.FAR_AWAY;
}
else
{
double numerator = normal.X * r.start.x +
normal.Y * r.start.y +
normal.Z * r.start.z +
distance;
h.omega = -numerator / denominator;
if (h.omega < 0)
{
h.intersect.z = Constants.FAR_AWAY;
}
else
{
h.intersect.x = r.start.x + r.direction.X * h.omega;
h.intersect.y = r.start.y + r.direction.Y * h.omega;
h.intersect.z = r.start.z + r.direction.Z * h.omega;
// Boundary hit testing.
if (h.intersect.x > Constants.RIGHT_PLANE_BOUNDARY || h.intersect.x < Constants.LEFT_PLANE_BOUNDARY)
{
h.intersect.x = h.intersect.y = h.intersect.z = Constants.FAR_AWAY;
}
}
}
return h;
}
private static Color3 fireRay(Ray incomingRay, int depth, Shape fromShape)
{
double closest = Constants.FAR_AWAY;
Color3 retColor = Constants.BGCOLOR;
int whichObject = 0, hitObject = 0;
Hit finalHit = new Hit();
foreach (Shape s in layout.Shapes)
{
Hit rayHit = s.intersect(incomingRay);
whichObject++;
if (rayHit.intersect.z == Constants.FAR_AWAY)
continue;
double dist = Point3.distance(layout.Cam.Eye, rayHit.intersect);
if (dist < closest && !s.Equals(fromShape))
{
closest = dist;
hitObject = whichObject;
finalHit = rayHit;
}
}
if (hitObject <= 0)
return Constants.BGCOLOR;
Shape hitShape = layout.Shapes[hitObject - 1];
retColor = Color3.ambient(hitShape);
// phongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphong
Color3 diffuseColor = Color3.Black, specularColor = Color3.Black;
foreach (Light bulb in layout.Lights)
{
if (spawnShadow(bulb, finalHit, hitShape, fromShape))
{
retColor = hitShape.colorShadow(retColor, finalHit, layout.Lights.Count * 3);
}
else
{
if (hitShape is Plane)
{
retColor = hitShape.colorNormal(retColor, incomingRay, finalHit, hitShape, bulb);
}
else
{
diffuseColor += Color3.diffuse(finalHit, hitShape, bulb);
specularColor += Color3.specular(incomingRay, finalHit, hitShape, bulb);
}
}
}
if (hitShape is Sphere)
{
retColor += diffuseColor * hitShape.Material.Kd;
retColor += specularColor * hitShape.Material.Ks;
}
if (depth < Constants.MAX_DEPTH)
{
Color3 reflectColor = Color3.Black;
if (hitShape.Material.Kr > 0)
{
Ray reflectRay = new Ray();
reflectRay.start = finalHit.intersect;
Vector3 normalVec = hitShape.calcNormal(finalHit);
double c = -Vector3.DotProduct(normalVec, incomingRay.direction);
reflectRay.direction = -(incomingRay.direction + (2 * normalVec * c));
reflectRay.direction.Normalize();
reflectColor = fireRay(reflectRay, depth + 1, hitShape);
retColor += reflectColor * hitShape.Material.Kr;
}
if (hitShape.Material.Kt > 0)
{
Ray transRay = new Ray();
double indexRefract;
Vector3 normalVec = Vector3.FaceForward(hitShape.calcNormal(finalHit), -incomingRay.direction);
if (Vector3.DotProduct(-incomingRay.direction, hitShape.calcNormal(finalHit)) < 0)
indexRefract = Constants.REFRACTION_INDEX_SPHERE / Constants.REFRACTION_INDEX_AIR;
else
indexRefract = Constants.REFRACTION_INDEX_AIR / Constants.REFRACTION_INDEX_SPHERE;
double discrim = 1 + (Math.Pow(indexRefract, 2) * (Math.Pow(Vector3.DotProduct(-incomingRay.direction, normalVec), 2) - 1));
// Total internal reflection!
if (discrim < 0)
{
retColor += reflectColor * hitShape.Material.Kt;
}
else
{
discrim = indexRefract * Vector3.DotProduct(-incomingRay.direction, normalVec) - Math.Sqrt(discrim);
transRay.direction = (indexRefract * incomingRay.direction) + (discrim * normalVec);
transRay.start = finalHit.intersect;
Color3 transColor = fireRay(transRay, depth + 1, hitShape);
retColor += transColor * hitShape.Material.Kt;
}
}
}
return retColor;
}
// spawn a shadow ray from the intersection point to the light source.
private static bool spawnShadow(Light bulb, Hit finalHit, Shape hitShape, Shape fromShape)
{
Ray shadowRay = new Ray();
shadowRay.start = finalHit.intersect;
shadowRay.direction = Point3.vectorize(shadowRay.start, bulb.Location);
double shadowDist = Point3.distance(shadowRay.start, bulb.Location);
foreach (Shape s in layout.Shapes)
{
// If this is the object we're checking from, ignore. Duh.
if (s.Equals(hitShape) || s.Equals(fromShape) || s.Material.Kt > 0)
continue;
Hit shadowHit = s.intersect(shadowRay);
if (shadowHit.intersect.z == Constants.FAR_AWAY)
continue;
// We need to check if hitShape object is in FRONT OF the current one. if it is, we need to ignore this current shape.
Vector3 frontTest = Point3.vectorize(shadowHit.intersect, finalHit.intersect);
if (frontTest.X > 0 && frontTest.Y > 0 && frontTest.Z > 0)
continue;
// something has to come between the light and the current shape.
double shapeDist = Point3.distance(shadowRay.start, shadowHit.intersect);
if (shapeDist < shadowDist)
{
return true;
}
}
return false;
}
public override Hit intersect(Ray r)
{
Hit h = new Hit();
double b = 2 * (r.direction.X * (r.start.x - center.x) +
r.direction.Y * (r.start.y - center.y) +
r.direction.Z * (r.start.z - center.z));
double c = Math.Pow(r.start.x - center.x, 2) +
Math.Pow(r.start.y - center.y, 2) +
Math.Pow(r.start.z - center.z, 2) -
Math.Pow(radius, radius);
double disc = Math.Pow(b, 2) - 4 * c;
if (disc < 0)
{
h.intersect.z = Constants.FAR_AWAY;
}
else
{
h.omega = (-b + Math.Sqrt(disc)) / 2;
h.intersect.x = r.start.x + r.direction.X * h.omega;
h.intersect.y = r.start.y + r.direction.Y * h.omega;
h.intersect.z = r.start.z + r.direction.Z * h.omega;
}
return h;
}
public override Color3 colorNormal(Color3 existing, Ray r, Hit h, Shape s, Light bulb)
{
return Color3.Black;
}
public abstract Hit intersect(Ray r);
public abstract Color3 colorNormal(Color3 existing, Ray r, Hit h, Shape s, Light bulb);
public static Color3 specular(Ray r, Hit h, Shape s, Light bulb)
{
Color3 specular = Black;
Vector3 normal = s.calcNormal(h);
Vector3 lightDir = Point3.vectorize(bulb.Location, h.intersect);
Vector3 refDir = lightDir - (2 * (Vector3.DotProduct(lightDir, normal) / Math.Pow(normal.Abs(), 2)) * normal);
double specularDot = Vector3.DotProduct(r.direction, refDir);
if (specularDot >= 0)
specular = (bulb.Color * s.Material.Specular) * Math.Pow(specularDot, s.Material.Ke);
return specular;
}
