1 files changed, 132 insertions, 0 deletions
diff --git a/src/vec3.cc b/src/vec3.cc
new file mode 100644
index 0000000..d01f90a
--- /dev/null
+++ b/src/vec3.cc
@@ -0,0 +1,132 @@
+/*
+ * 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/>.
+ */
+#include "vec3.h"
+
+double vec3::x() const
+{
+  return e[0];
+}
+double vec3::y() const
+{
+  return e[1];
+}
+double vec3::z() const
+{
+  return e[2];
+}
+
+vec3 vec3::operator-() const
+{
+  return { -e[0], -e[1], -e[2] };
+}
+
+double vec3::operator[]( int i ) const
+{
+  return e.at( i );
+}
+
+double& vec3::operator[]( int i )
+{
+  return e.at( i );
+}
+
+vec3& vec3::operator+=( const vec3& other )
+{
+  e[0] += other.e[0];
+  e[1] += other.e[1];
+  e[2] += other.e[2];
+  return *this;
+}
+
+vec3& vec3::operator*=( double t )
+{
+  e[0] *= t;
+  e[1] *= t;
+  e[2] *= t;
+  return *this;
+}
+
+vec3& vec3::operator/=( double t )
+{
+  return *this *= 1 / t;
+}
+
+double vec3::length() const
+{
+  return std::sqrt( length_squared() );
+}
+
+double vec3::length_squared() const
+{
+  return e[0] * e[0] + e[1] * e[1] + e[2] * e[2];
+}
+
+// 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();
+}