add from giga-device, new branch added

2025-08-21 16:51:25 +08:00
commit 43bbc06bbb
1296 changed files with 264186 additions and 0 deletions
@@ -0,0 +1,112 @@
+//-----------------------------------------------------------------------
+// -----------------------------------------------------------------------
+// file="Exp.cs"
+// Project: StgSharp
+// AuthorGroup: Nitload Space
+// Copyright (c) Nitload Space. All rights reserved.
+//     
+// Permission is hereby granted, free of charge, to any person 
+// obtaining a copy of this software and associated documentation 
+// files (the “Software”), to deal in the Software without restriction, 
+// including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, 
+// and to permit persons to whom the Software is furnished to do so, 
+// subject to the following conditions:
+//     
+// The above copyright notice and 
+// this permission notice shall be included in all copies 
+// or substantial portions of the Software.
+//     
+// THE SOFTWARE IS PROVIDED “AS IS”, 
+// WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
+// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
+// ARISING FROM, OUT OF OR IN CONNECTION WITH 
+// THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//     
+// -----------------------------------------------------------------------
+// -----------------------------------------------------------------------
+using System;
+using System.Runtime.CompilerServices;
+
+namespace StgSharp.Mathematics
+{
+    public static unsafe partial class Scaler
+    {
+
+        public const float E = 2.718281828f;
+        public const double EDouble = System.Math.E;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float Exp(float x)
+        {
+            return MathF.Exp(x);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static double Exp(double x)
+        {
+            return System.Math.Exp(x);
+        }
+
+        /// <summary>
+        ///   Get the value of E ^ x;
+        /// </summary>
+        /// <param _label="x">
+        ///
+        /// </param>
+        /// <returns>
+        ///
+        /// </returns>
+        public static unsafe float ExpSlow(float x)
+        {
+            if (x == 1) {
+                return E;
+            }
+            if (x == 0) {
+                return 1;
+            }
+
+            bool sign = false;
+            if (x < 0)
+            {
+                sign = true;
+                x = -x;
+            }
+
+            float z = x, t;
+            if (x < 0.5f)
+            {
+                t = 1.0f + (x * (1.0f + (x * (0.5f + (x * (0.1666666667f + (x * (0.0416666666667f + (x * 8.333333333e-3f)))))))));
+            } else
+            {
+                /*
+                 * define z =  n * 2 ^ m
+                 * n is between 0 and 0.5
+                 */
+                uint zBit = *(uint*)&z;
+                uint zBitAbs = zBit & 0b_0111_1111_1111_1111_1111_1111_1111_1111;
+                uint uintm = zBitAbs >> 23;
+                int m = (*(int*)&uintm) - 126;
+
+
+                uint nBit = (zBitAbs & 0b_0000_0000_0111_1111_1111_1111_1111_1111) + 0b_0011_1111_0000_0000_0000_0000_0000_0000;
+                float n = (*(float*)&nBit) - 1;
+
+                t = 2.718281828f + (n * (2.718281828f + (n * (1.359140914f + (n * (0.4530469714f + (n * (0.1132617429f + (n * 0.02265234857f)))))))));
+
+                for (int i = 0; i < m; i++) {
+                    t = t * t;
+                }
+            }
+
+            if (sign) {
+                t = 1 / t;
+            }
+            return t;
+        }
+
+    }
+}