//package comp557.a5;
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import javax.vecmath.Point3d;
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public class BBox
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{
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public Point3d max;
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public Point3d min;
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public BBox()
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{
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this.max = new Point3d(1, 1, 1);
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this.min = new Point3d(-1, -1, -1);
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}
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public boolean intersect0(Ray ray, IntersectResult result)
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{
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// Reference: http://people.csail.mit.edu/amy/papers/box-jgt.pdf
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double tmin, tmax, tymin, tymax, tzmin, tzmax;
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double invDirX = 1 / ray.viewDirection.x;
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double invDirY = 1 / ray.viewDirection.y;
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double invDirZ = 1 / ray.viewDirection.z;
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if (ray.viewDirection.x >= 1e-9)
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{
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tmin = (min.x - ray.eyePoint.x) * invDirX;
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tmax = (max.x - ray.eyePoint.x) * invDirX;
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} else
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{
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tmax = (min.x - ray.eyePoint.x) * invDirX;
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tmin = (max.x - ray.eyePoint.x) * invDirX;
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}
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if (ray.viewDirection.y >= 1e-9)
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{
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tymin = (min.y - ray.eyePoint.y) * invDirY;
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tymax = (max.y - ray.eyePoint.y) * invDirY;
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} else
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{
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tymax = (min.y - ray.eyePoint.y) * invDirY;
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tymin = (max.y - ray.eyePoint.y) * invDirY;
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}
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if ((tmin > tymax) || (tymin > tmax))
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{
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return false;
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}
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if (tymin > tmin)
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{
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tmin = tymin;
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}
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if (tymax < tmax)
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{
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tmax = tymax;
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}
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if (ray.viewDirection.z >= 1e-9)
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{
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tzmin = (min.z - ray.eyePoint.z) * invDirZ;
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tzmax = (max.z - ray.eyePoint.z) * invDirZ;
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} else
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{
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tzmax = (min.z - ray.eyePoint.z) * invDirZ;
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tzmin = (max.z - ray.eyePoint.z) * invDirZ;
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}
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if ((tmin > tzmax) || (tzmin > tmax))
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{
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return false;
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}
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// result.isIntersected = true;
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//
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// if (tzmin > tmin)
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// {
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// tmin = tzmin;
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// }
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//
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// if (tzmax < tmax)
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// {
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// tmax = tzmax;
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// }
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//
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// if (tmin > 1e-9)
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// {
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// result.t = tmin;
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// } else
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// {
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// result.t = tmax;
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// }
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return true;
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}
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public boolean intersect(Ray ray, IntersectResult result)
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{
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double tmin = Double.NEGATIVE_INFINITY, tmax = Double.POSITIVE_INFINITY;
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double t1 = (min.x - ray.eyePoint.x) / ray.viewDirection.x;
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double t2 = (max.x - ray.eyePoint.x) / ray.viewDirection.x;
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if (ray.viewDirection.x == 0)
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{
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if (ray.eyePoint.x <= min.x || ray.eyePoint.x >= max.x)
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return false;
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}
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else
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{
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if (t1 > t2)
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{
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double t = t1;
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t1 = t2;
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t2 = t;
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}
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if (tmin > t1) tmin = t1;
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if (tmax < t2) tmax = t2;
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}
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if (ray.viewDirection.y == 0)
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{
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if (ray.eyePoint.y <= min.y || ray.eyePoint.y >= max.y)
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return false;
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}
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else
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{
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t1 = (min.y - ray.eyePoint.y) / ray.viewDirection.y;
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t2 = (max.y - ray.eyePoint.y) / ray.viewDirection.y;
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if (t1 > t2)
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{
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double t = t1;
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t1 = t2;
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t2 = t;
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}
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if (tmin > t1) tmin = t1;
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if (tmax < t2) tmax = t2;
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}
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if (ray.viewDirection.z == 0)
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{
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if (ray.eyePoint.z <= min.z || ray.eyePoint.z >= max.z)
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return false;
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}
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else
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{
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t1 = (min.z - ray.eyePoint.z) / ray.viewDirection.z;
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t2 = (max.z - ray.eyePoint.z) / ray.viewDirection.z;
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if (t1 > t2)
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{
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double t = t1;
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t1 = t2;
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t2 = t;
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}
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if (tmin > t1) tmin = t1;
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if (tmax < t2) tmax = t2;
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}
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return tmax >= tmin && tmax > 0.0;
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}
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}
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