25 lines
583 B
C++
25 lines
583 B
C++
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#include "vec3.h"
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Vec3 random_in_unit_sphere() {
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while (true) {
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auto p = Vec3::random(-1, 1);
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if (p.length_squared() >= 1) continue;
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return p;
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}
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}
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Vec3 random_unit_vector() {
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auto a = random_double(0, 2*pi);
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auto z = random_double(-1, 1);
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auto r = std::sqrt(1 - z*z);
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return Vec3(r*std::cos(a), r*std::sin(a), z);
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}
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Vec3 random_in_hemisphere(const Vec3& normal) {
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Vec3 in_unit_sphere = random_in_unit_sphere();
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if (dot(in_unit_sphere, normal) > 0.0)
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return in_unit_sphere;
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else
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return -in_unit_sphere;
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}
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