76 lines
1.6 KiB
C++
76 lines
1.6 KiB
C++
/*
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* DoRayMe - a quick and dirty Raytracer
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* Cube implementation
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*
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* Created by Manoël Trapier
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* Copyright (c) 2020 986-Studio.
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*
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*/
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#include <tuple.h>
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#include <ray.h>
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#include <shape.h>
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#include <cube.h>
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#include <math_helper.h>
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void Cube::checkAxis(double axeOrigin, double axeDirection, double *axeMin, double *axeMax)
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{
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double tMinNumerator = (-1 - axeOrigin);
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double tMaxNumerator = (1 - axeOrigin);
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if (fabs(axeDirection) >= getEpsilon())
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{
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*axeMin = tMinNumerator / axeDirection;
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*axeMax = tMaxNumerator / axeDirection;
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}
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else
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{
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*axeMin = tMinNumerator * INFINITY;
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*axeMax = tMaxNumerator * INFINITY;
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}
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if (*axeMin > *axeMax)
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{
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double swap = *axeMax;
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*axeMax = *axeMin;
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*axeMin = swap;
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}
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}
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Intersect Cube::localIntersect(Ray r)
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{
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Intersect ret;
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double xtMin, xtMax, ytMin, ytMax, ztMin, ztMax;
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double tMin, tMax;
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this->checkAxis(r.origin.x, r.direction.x, &xtMin, &xtMax);
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this->checkAxis(r.origin.y, r.direction.y, &ytMin, &ytMax);
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this->checkAxis(r.origin.z, r.direction.z, &ztMin, &ztMax);
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tMin = max3(xtMin, ytMin, ztMin);
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tMax = min3(xtMax, ytMax, ztMax);
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if (tMin <= tMax)
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{
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ret.add(Intersection(tMin, this));
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ret.add(Intersection(tMax, this));
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}
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return ret;
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}
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Tuple Cube::localNormalAt(Tuple point)
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{
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double maxC = max3(fabs(point.x), fabs(point.y), fabs(point.z));
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if (maxC == fabs(point.x))
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{
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return Vector(point.x, 0, 0);
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}
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else if (maxC == fabs(point.y))
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{
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return Vector(0, point.y, 0);
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}
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return Vector(0, 0, point.z);
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} |