You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
101 lines
4.0 KiB
101 lines
4.0 KiB
/******************************************************************************
|
|
* 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;
|
|
}
|
|
}
|
|
}
|