minor rewrite

interfaces/Crafter.Math-Ray.cppm

@@ -0,0 +1,62 @@
+/*
+Crafter®.Math
+Copyright (C) 2026 Catcrafts®
+catcrafts.net
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License version 3.0 as published by the Free Software Foundation;
+
+This library 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
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+*/
+
+export module Crafter.Math:Ray;
+import :Vector;
+import std;
+
+namespace Crafter {
+    export template<typename T>
+	T IntersectionTestRayTriangle(Vector<T, 3, 0> vert0, Vector<T, 3, 0> vert1, Vector<T, 3, 0> vert2, Vector<T, 3, 0> rayOrigin, Vector<T, 3, 0> rayDir) {
+        constexpr float EPSILON = 0.0000001;
+        Vector<T, 3, 0> edge1 = vert1 - vert0;
+        Vector<T, 3, 0> edge2 = vert2 - vert0;
+
+        Vector<T, 3, 0> h = Vector<T, 3, 0>::Cross(rayDir, edge2);
+        float determinant = Vector<T, 3, 0>::Dot(edge1, h);
+
+
+        if(determinant < 0) {
+            return -1;
+        }
+
+        if (determinant > -EPSILON && determinant < EPSILON)  {
+            return -1;
+        }
+
+        float inverse_determinant = 1.0 / determinant;
+
+        Vector<T, 3, 0> origins_diff_vector = rayOrigin - vert0;
+        float u =  Vector<T, 3, 0>::Dot(origins_diff_vector, h) * inverse_determinant;
+
+        if (u < 0.0 || u > 1.0)
+        {
+            return false;
+        }
+
+        Vector<T, 3, 0> q = Vector<T, 3, 0>::Cross(origins_diff_vector, edge1);
+        float v = inverse_determinant * Vector<T, 3, 0>::Dot(rayDir, q);
+
+        if (v < 0.0 || u + v > 1.0) {
+            return -1;
+        }
+
+        return inverse_determinant * Vector<T, 3, 0>::Dot(edge2, q);
+    }
+}