1 files changed, 102 insertions, 0 deletions
diff --git a/raytracing/src/vec3.h b/raytracing/src/vec3.h
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+++ b/raytracing/src/vec3.h
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+/*
+ * Copyright (C) 2026 Richard
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#ifndef VEC_3
+#define VEC_3
+
+#include <array>
+#include <cmath>
+#include <iostream>
+
+class vec3
+{
+public:
+  std::array<double, 3> e;
+
+  vec3() : e { 0, 0, 0 } {}
+  vec3( double e0, double e1, double e2 ) : e { e0, e1, e2 } {}
+
+  double x() const;
+  double y() const;
+  double z() const;
+
+  vec3 operator-() const;
+  double operator[]( int i ) const;
+  double& operator[]( int i );
+  vec3& operator+=( const vec3& other );
+  vec3& operator*=( double t );
+  vec3& operator/=( double t );
+  double length() const;
+  double length_squared() const;
+};
+
+// point3 is just an alias for vec3, but useful for geometric clarity in the code.
+using point3 = vec3;
+
+// Vector Utility Functions
+
+inline std::ostream& operator<<( std::ostream& out, const vec3& v )
+{
+  return out << v.e[0] << ' ' << v.e[1] << ' ' << v.e[2];
+}
+
+inline vec3 operator+( const vec3& u, const vec3& v )
+{
+  return { u.e[0] + v.e[0], u.e[1] + v.e[1], u.e[2] + v.e[2] };
+}
+
+inline vec3 operator-( const vec3& u, const vec3& v )
+{
+  return { u.e[0] - v.e[0], u.e[1] - v.e[1], u.e[2] - v.e[2] };
+}
+
+inline vec3 operator*( const vec3& u, const vec3& v )
+{
+  return { u.e[0] * v.e[0], u.e[1] * v.e[1], u.e[2] * v.e[2] };
+}
+
+inline vec3 operator*( double t, const vec3& v )
+{
+  return { t * v.e[0], t * v.e[1], t * v.e[2] };
+}
+
+inline vec3 operator*( const vec3& v, double t )
+{
+  return t * v;
+}
+
+inline vec3 operator/( const vec3& v, double t )
+{
+  return ( 1 / t ) * v;
+}
+
+inline double dot( const vec3& u, const vec3& v )
+{
+  return u.e[0] * v.e[0] + u.e[1] * v.e[1] + u.e[2] * v.e[2];
+}
+
+inline vec3 cross( const vec3& u, const vec3& v )
+{
+  return {
+    u.e[1] * v.e[2] - u.e[2] * v.e[1], u.e[2] * v.e[0] - u.e[0] * v.e[2], u.e[0] * v.e[1] - u.e[1] * v.e[0] };
+}
+
+inline vec3 unit_vector( const vec3& v )
+{
+  return v / v.length();
+}
+
+#endif