further sse simd additions

avx2 float3 added
added normalize_magnitude
added divide fast to float3 may copy to float4

move static spheremesh to drawSphere (initialize on first use) so platform has a chance to load the math backend

Engine/source/math/public/float3_dispatch.h

@@ -0,0 +1,38 @@
+#pragma once
+#ifndef _FLOAT3_DISPATCH_H_
+#define _FLOAT3_DISPATCH_H_
+
+
+#include <cstdint>
+
+namespace math_backend::float3::dispatch
+{
+   struct Float3Funcs
+   {
+      void (*add)(const float*, const float*, float*) = nullptr;
+      void (*sub)(const float*, const float*, float*) = nullptr;
+      void (*mul)(const float*, const float*, float*) = nullptr;
+      void (*mul_scalar)(const float*, float, float*) = nullptr;
+      void (*div)(const float*, const float*, float*) = nullptr;
+      void (*div_scalar)(const float*, float, float*) = nullptr;
+      float (*dot)(const float*, const float*) = nullptr;
+      float (*length)(const float*) = nullptr;
+      float (*lengthSquared)(const float*) = nullptr;
+      void (*normalize)(float*) = nullptr;
+      void (*normalize_mag)(float*, float) = nullptr;
+      void (*lerp)(const float*, const float*, float, float*) = nullptr;
+   };
+
+   // Global dispatch table
+   extern Float3Funcs gFloat3;
+
+   // Backend installers (defined in ISA libraries)
+   void install_scalar();
+   void install_sse2();
+   void install_sse41();
+   void install_avx();
+   void install_avx2();
+   void install_neon();
+}
+
+#endif // !_FLOAT4_DISPATCH_H_