120 lines
3.5 KiB
C#
120 lines
3.5 KiB
C#
//-----------------------------------------------------------------------
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//-----------------------------------------------------------------------
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// file="ATan.cs"
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// Project: StgSharp
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// AuthorGroup: Nitload Space
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// Copyright (c) Nitload Space. All rights reserved.
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//
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// Permission is hereby granted, free of charge, to any person
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// obtaining a copy of this software and associated documentation
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// files (the “Software”), to deal in the Software without restriction,
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// including without limitation the rights to use, copy, modify, merge,
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// publish, distribute, sublicense, and/or sell copies of the Software,
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// and to permit persons to whom the Software is furnished to do so,
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// subject to the following conditions:
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//
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// The above copyright notice and
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// this permission notice shall be included in all copies
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// or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED “AS IS”,
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// WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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// ARISING FROM, OUT OF OR IN CONNECTION WITH
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// THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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//
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//-----------------------------------------------------------------------
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//-----------------------------------------------------------------------
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using System;
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using System.Runtime.CompilerServices;
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namespace StgSharp.Math
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{
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public static unsafe partial class Scaler
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{
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[MethodImpl( MethodImplOptions.AggressiveInlining )]
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public static unsafe float ATan( float x )
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{
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return MathF.Atan( x );
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/*
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float sign = 1, angle = 0;
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if (x < 0)
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{
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sign = -1;
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x = -x;
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}
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uint xBit = *(uint*)&x;
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int xExp = (int)(xBit >> 23) - 127;
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if (xExp >= 26)
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{
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return 1;
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}
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if (xExp <= -15)
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{
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return x;
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}
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if (xExp >= 0)
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{
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x = (x - 1) / (x + 1);
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angle = 0.7853981634f;
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}
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float v = 0.7853981634f * x + x * (1 - x) * (0.2447f + 0.0663f * x);
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v += angle;
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v *= sign;
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return v;
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}
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public static unsafe float ATan(float x, float y)
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{
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float z = y / x;
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float sign = 1, angle = 0, angle2 = 0;
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if (x < 0)
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{
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angle = -3.1415926535f;
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}
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if (z < 0)
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{
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sign = -1;
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z = -z;
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}
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uint zBit = *(uint*)&z;
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int zExp = (int)(zBit >> 23) - 127;
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if (zExp >= 26)
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{
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return 1;
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}
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if (zExp <= -15)
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{
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return z;
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}
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if (zExp >= 0)
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{
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z = (z - 1) / (z + 1);
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angle2 = 0.7853981634f;
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}
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float v = 0.7853981634f * z + z * (1 - z) * (0.2447f + 0.0663f * z);
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v *= 57.29577951f;
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v += angle2;
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v += angle;
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v *= sign;
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return v;
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*/
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}
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}
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}
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