58 lines
1.7 KiB
C++
58 lines
1.7 KiB
C++
#ifndef AABB_H
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#define AABB_H
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#include "rayTracer.h"
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class aabb {
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public:
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interval x, y, z;
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aabb() {} // The default AABB is empty, since intervals are empty by default.
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aabb(const interval& x, const interval& y, const interval& z) : x(x), y(y), z(z) {}
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aabb(const point3& a, const point3& b) {
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// Treat the two points a and b as extrema for the bounding box, so we don't require a particular minimum/maximum coordinate order.
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x = (a[0] <= b[0]) ? interval(a[0], b[0]) : interval(b[0], a[0]);
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y = (a[1] <= b[1]) ? interval(a[1], b[1]) : interval(b[1], a[1]);
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z = (a[2] <= b[2]) ? interval(a[2], b[2]) : interval(b[2], a[2]);
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}
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aabb(const aabb& box0, const aabb& box1) {
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x = interval(box0.x, box1.x);
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y = interval(box0.y, box1.y);
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z = interval(box0.z, box1.z);
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}
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const interval& axisInterval(int n) const {
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if (n == 1) return y;
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if (n == 2) return z;
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return x;
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}
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bool hit(const ray& r, interval rayT) const {
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const point3& rayOrigin = r.origin();
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const vec3& rayDirection = r.direction();
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for (int axis = 0; axis < 3; axis++) {
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const interval& ax = axisInterval(axis);
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const double adInv = 1.0 / rayDirection[axis];
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auto t0 = (ax.min - rayOrigin[axis]) * adInv;
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auto t1 = (ax.max - rayOrigin[axis]) * adInv;
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if (t0 < t1) {
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if (t0 > rayT.min) rayT.min = t0;
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if (t1 < rayT.max) rayT.max = t1;
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} else {
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if (t1 > rayT.min) rayT.min = t1;
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if (t0 < rayT.max) rayT.max = t0;
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}
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if (rayT.max <= rayT.min) return false;
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}
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return true;
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}
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};
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#endif |