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Crafter.Math-Misc.cppm

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+
+module;
+
+#include <cstdint>
+#include <stdfloat>
+
+export module Crafter.Math:Misc;
+
+export namespace Crafter {
+    //-------------------------------------------------------------------------------------
+    // DirectXMathMisc.inl -- SIMD C++ Math library
+    //
+    // Copyright (c) Microsoft Corporation.
+    // Licensed under the MIT License.
+    //
+    // http://go.microsoft.com/fwlink/?LinkID=615560
+    //-------------------------------------------------------------------------------------
+    constexpr float XM_PI = 3.141592654f;
+    constexpr float XM_2PI = 6.283185307f;
+    constexpr float XM_1DIVPI = 0.318309886f;
+    constexpr float XM_1DIV2PI = 0.159154943f;
+    constexpr float XM_PIDIV2 = 1.570796327f;
+    constexpr float XM_PIDIV4 = 0.785398163f;
+
+
+    inline void XMScalarSinCos(float* pSin, float* pCos, float  Value) noexcept
+    {
+        // Map Value to y in [-pi,pi], x = 2*pi*quotient + remainder.
+        float quotient = XM_1DIV2PI * Value;
+        if (Value >= 0.0f)
+        {
+            quotient = static_cast<float>(static_cast<int>(quotient + 0.5f));
+        }
+        else
+        {
+            quotient = static_cast<float>(static_cast<int>(quotient - 0.5f));
+        }
+        float y = Value - XM_2PI * quotient;
+
+        // Map y to [-pi/2,pi/2] with sin(y) = sin(Value).
+        float sign;
+        if (y > XM_PIDIV2)
+        {
+            y = XM_PI - y;
+            sign = -1.0f;
+        }
+        else if (y < -XM_PIDIV2)
+        {
+            y = -XM_PI - y;
+            sign = -1.0f;
+        }
+        else
+        {
+            sign = +1.0f;
+        }
+
+        float y2 = y * y;
+
+        // 11-degree minimax approximation
+        *pSin = (((((-2.3889859e-08f * y2 + 2.7525562e-06f) * y2 - 0.00019840874f) * y2 + 0.0083333310f) * y2 - 0.16666667f) * y2 + 1.0f) * y;
+
+        // 10-degree minimax approximation
+        float p = ((((-2.6051615e-07f * y2 + 2.4760495e-05f) * y2 - 0.0013888378f) * y2 + 0.041666638f) * y2 - 0.5f) * y2 + 1.0f;
+        *pCos = sign * p;
+    }
+}