FiE-Game/Assets/Spine/SpineCSharp/MathUtils.cs
2023-07-25 00:52:50 +05:00

100 lines
4 KiB
C#

/******************************************************************************
* Spine Runtimes Software License v2.5
*
* Copyright (c) 2013-2016, Esoteric Software
* All rights reserved.
*
* You are granted a perpetual, non-exclusive, non-sublicensable, and
* non-transferable license to use, install, execute, and perform the Spine
* Runtimes software and derivative works solely for personal or internal
* use. Without the written permission of Esoteric Software (see Section 2 of
* the Spine Software License Agreement), you may not (a) modify, translate,
* adapt, or develop new applications using the Spine Runtimes or otherwise
* create derivative works or improvements of the Spine Runtimes or (b) remove,
* delete, alter, or obscure any trademarks or any copyright, trademark, patent,
* or other intellectual property or proprietary rights notices on or in the
* Software, including any copy thereof. Redistributions in binary or source
* form must include this license and terms.
*
* THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL ESOTERIC SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, BUSINESS INTERRUPTION, OR LOSS OF
* USE, DATA, OR PROFITS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*****************************************************************************/
using System;
namespace Spine {
public static class MathUtils {
public const float PI = 3.1415927f;
public const float PI2 = PI * 2;
public const float RadDeg = 180f / PI;
public const float DegRad = PI / 180;
const int SIN_BITS = 14; // 16KB. Adjust for accuracy.
const int SIN_MASK = ~(-1 << SIN_BITS);
const int SIN_COUNT = SIN_MASK + 1;
const float RadFull = PI * 2;
const float DegFull = 360;
const float RadToIndex = SIN_COUNT / RadFull;
const float DegToIndex = SIN_COUNT / DegFull;
static float[] sin = new float[SIN_COUNT];
static MathUtils () {
for (int i = 0; i < SIN_COUNT; i++)
sin[i] = (float)Math.Sin((i + 0.5f) / SIN_COUNT * RadFull);
for (int i = 0; i < 360; i += 90)
sin[(int)(i * DegToIndex) & SIN_MASK] = (float)Math.Sin(i * DegRad);
}
/// <summary>Returns the sine in radians from a lookup table.</summary>
static public float Sin (float radians) {
return sin[(int)(radians * RadToIndex) & SIN_MASK];
}
/// <summary>Returns the cosine in radians from a lookup table.</summary>
static public float Cos (float radians) {
return sin[(int)((radians + PI / 2) * RadToIndex) & SIN_MASK];
}
/// <summary>Returns the sine in radians from a lookup table.</summary>
static public float SinDeg (float degrees) {
return sin[(int)(degrees * DegToIndex) & SIN_MASK];
}
/// <summary>Returns the cosine in radians from a lookup table.</summary>
static public float CosDeg (float degrees) {
return sin[(int)((degrees + 90) * DegToIndex) & SIN_MASK];
}
/// <summary>Returns atan2 in radians, faster but less accurate than Math.Atan2. Average error of 0.00231 radians (0.1323
/// degrees), largest error of 0.00488 radians (0.2796 degrees).</summary>
static public float Atan2 (float y, float x) {
if (x == 0f) {
if (y > 0f) return PI / 2;
if (y == 0f) return 0f;
return -PI / 2;
}
float atan, z = y / x;
if (Math.Abs(z) < 1f) {
atan = z / (1f + 0.28f * z * z);
if (x < 0f) return atan + (y < 0f ? -PI : PI);
return atan;
}
atan = PI / 2 - z / (z * z + 0.28f);
return y < 0f ? atan - PI : atan;
}
static public float Clamp (float value, float min, float max) {
if (value < min) return min;
if (value > max) return max;
return value;
}
}
}