ray sphere test

interfaces/Crafter.Math-Ray.cppm

@@ -54,4 +54,25 @@ namespace Crafter {
 
         return inverse_determinant * Vector<T, 3, 0>::Dot(edge2, q);
     }
+
+    export template<typename T>
+    constexpr T IntersectionTestRaySphere(Vector<T, 3, 0> position, T radius, Vector<T, 3, 0> rayOrigin, Vector<T, 3, 0> rayDir) {
+        T a = Vector<T, 3, 0>::Dot(rayDir, rayDir);
+        T b = Vector<T, 3, 0>::Dot(rayDir, (T(2) * (rayOrigin - position)));
+        T c = Vector<T, 3, 0>::Dot(position, position) + Vector<T, 3, 0>::Dot(rayOrigin, rayOrigin) - T(2) * Vector<T, 3, 0>::Dot(rayOrigin, position) - radius * radius;
+        T d = b * b + (T(-4)) * a * c;
+
+        if (d < 0) {
+            return std::numeric_limits<T>::max();
+        }
+
+        d = std::sqrt(d);
+
+        float t = (T(-0.5)) * (b + d) / a;
+        if (t > T(0)) {
+            return t;
+        } else {
+            return std::numeric_limits<T>::max();
+        }
+    }
 }

interfaces/Crafter.Math-Vector.cppm

@@ -347,4 +347,10 @@ struct std::formatter<Crafter::Vector<T, 4, Aligment>> : std::formatter<std::str
 			obj.x, obj.y, obj.z, obj.w
 		), ctx);
     }
-};
+};
+
+
+template <typename T, std::uint32_t Len, std::uint32_t Aligment, typename BT>
+constexpr Crafter::Vector<T, Len, Aligment> operator*(BT b, const Crafter::Vector<T, Len, Aligment>& v) {
+    return v * b;
+}

interfaces/main.cpp

@@ -4,10 +4,5 @@ import std;
 using namespace Crafter;
 
 int main() {
-    Vector<float, 3, 0> test(1,2,3);
-    Vector<float, 3, 0> test2(1,2,3);
-        Vector<float, 3, 0> test3(1,2,3);
-            Vector<float, 3, 0> test4(1,2,3);
-            Vector<float, 3, 0> test5(1,2,3);
-    std::cout << IntersectionTestRayTriangle(test, test2, test3, test4, test5) << std::endl;
+    std::cout << IntersectionTestRaySphere<float>({0,0,0}, 10, {0,0,-100}, {0,1,0}) << std::endl;
 }