268 lines
9.6 KiB
C#
268 lines
9.6 KiB
C#
// Copyright (c) Xenko contributors (https://xenko.com) and Silicon Studio Corp. (https://www.siliconstudio.co.jp)
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// Distributed under the MIT license. See the LICENSE.md file in the project root for more information.
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//
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// Copyright (c) 2010-2011 SharpDX - Alexandre Mutel
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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using System;
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using System.ComponentModel;
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using System.Globalization;
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using System.Runtime.InteropServices;
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using System.Runtime.Serialization;
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namespace math
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{
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/// <summary>
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/// A half precision (16 bit) floating point value.
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/// </summary>
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[DataContract]
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[StructLayout(LayoutKind.Sequential, Pack = 2)]
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public struct Half
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{
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private ushort value;
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/// <summary>
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/// Number of decimal digits of precision.
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/// </summary>
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public const int PrecisionDigits = 3;
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/// <summary>
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/// Number of bits in the mantissa.
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/// </summary>
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public const int MantissaBits = 11;
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/// <summary>
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/// Maximum decimal exponent.
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/// </summary>
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public const int MaximumDecimalExponent = 4;
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/// <summary>
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/// Maximum binary exponent.
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/// </summary>
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public const int MaximumBinaryExponent = 15;
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/// <summary>
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/// Minimum decimal exponent.
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/// </summary>
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public const int MinimumDecimalExponent = -4;
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/// <summary>
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/// Minimum binary exponent.
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/// </summary>
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public const int MinimumBinaryExponent = -14;
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/// <summary>
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/// Exponent radix.
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/// </summary>
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public const int ExponentRadix = 2;
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/// <summary>
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/// Additional rounding.
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/// </summary>
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public const int AdditionRounding = 1;
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/// <summary>
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/// Smallest such that 1.0 + epsilon != 1.0
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/// </summary>
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public static readonly float Epsilon;
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/// <summary>
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/// Maximum value of the number.
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/// </summary>
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public static readonly float MaxValue;
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/// <summary>
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/// Minimum value of the number.
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/// </summary>
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public static readonly float MinValue;
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/// <summary>
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/// A <see cref="Half"/> whose value is 0.0f.
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/// </summary>
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public static readonly Half Zero;
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/// <summary>
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/// A <see cref="Half"/> whose value is 1.0f.
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/// </summary>
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public static readonly Half One;
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/// <summary>
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/// Initializes a new instance of the <see cref="Half"/> structure.
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/// </summary>
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/// <param name = "value">The floating point value that should be stored in 16 bit format.</param>
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public Half(float value)
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{
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this.value = HalfUtils.Pack(value);
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}
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/// <summary>
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/// Gets or sets the raw 16 bit value used to back this half-float.
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/// </summary>
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public ushort RawValue
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{
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get { return value; }
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set { this.value = value; }
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}
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/// <summary>
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/// Converts an array of half precision values into full precision values.
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/// </summary>
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/// <param name = "values">The values to be converted.</param>
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/// <returns>An array of converted values.</returns>
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public static float[] ConvertToFloat(Half[] values)
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{
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float[] results = new float[values.Length];
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for (int i = 0; i < results.Length; i++)
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results[i] = HalfUtils.Unpack(values[i].RawValue);
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return results;
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}
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/// <summary>
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/// Converts an array of full precision values into half precision values.
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/// </summary>
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/// <param name = "values">The values to be converted.</param>
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/// <returns>An array of converted values.</returns>
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public static Half[] ConvertToHalf(float[] values)
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{
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Half[] results = new Half[values.Length];
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for (int i = 0; i < results.Length; i++)
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results[i] = new Half(values[i]);
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return results;
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}
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/// <summary>
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/// Performs an explicit conversion from <see cref = "T:System.Single" /> to <see cref = "T:math.Half" />.
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/// </summary>
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/// <param name = "value">The value to be converted.</param>
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/// <returns>The converted value.</returns>
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public static explicit operator Half(float value)
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{
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return new Half(value);
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}
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/// <summary>
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/// Performs an implicit conversion from <see cref = "T:math.Half" /> to <see cref = "T:System.Single" />.
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/// </summary>
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/// <param name = "value">The value to be converted.</param>
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/// <returns>The converted value.</returns>
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public static implicit operator float(Half value)
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{
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return HalfUtils.Unpack(value.value);
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}
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/// <summary>
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/// Tests for equality between two objects.
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/// </summary>
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/// <param name = "left">The first value to compare.</param>
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/// <param name = "right">The second value to compare.</param>
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/// <returns>
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/// <c>true</c> if <paramref name = "left" /> has the same value as <paramref name = "right" />; otherwise, <c>false</c>.</returns>
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public static bool operator ==(Half left, Half right)
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{
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return left.value == right.value;
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}
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/// <summary>
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/// Tests for inequality between two objects.
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/// </summary>
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/// <param name = "left">The first value to compare.</param>
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/// <param name = "right">The second value to compare.</param>
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/// <returns>
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/// <c>true</c> if <paramref name = "left" /> has a different value than <paramref name = "right" />; otherwise, <c>false</c>.</returns>
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public static bool operator !=(Half left, Half right)
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{
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return left.value != right.value;
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}
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/// <summary>
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/// Converts the value of the object to its equivalent string representation.
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/// </summary>
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/// <returns>The string representation of the value of this instance.</returns>
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public override string ToString()
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{
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float num = this;
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return num.ToString(CultureInfo.CurrentCulture);
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}
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/// <summary>
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/// Returns the hash code for this instance.
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/// </summary>
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/// <returns>A 32-bit signed integer hash code.</returns>
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public override int GetHashCode()
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{
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ushort num = value;
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return ((num * 3) / 2) ^ num;
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}
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/// <summary>
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/// Determines whether the specified object instances are considered equal.
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/// </summary>
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/// <param name = "value1">The first value.</param>
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/// <param name = "value2">The second value.</param>
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/// <returns>
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/// <c>true</c> if <paramref name = "value1" /> is the same instance as <paramref name = "value2" /> or
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/// if both are <c>null</c> references or if <c>value1.Equals(value2)</c> returns <c>true</c>; otherwise, <c>false</c>.</returns>
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public static bool Equals(ref Half value1, ref Half value2)
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{
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return value1.value == value2.value;
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}
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/// <summary>
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/// Returns a value that indicates whether the current instance is equal to the specified object.
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/// </summary>
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/// <param name = "other">Object to make the comparison with.</param>
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/// <returns>
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/// <c>true</c> if the current instance is equal to the specified object; <c>false</c> otherwise.</returns>
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public bool Equals(Half other)
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{
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return other.value == value;
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}
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/// <summary>
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/// Returns a value that indicates whether the current instance is equal to a specified object.
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/// </summary>
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/// <param name = "obj">Object to make the comparison with.</param>
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/// <returns>
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/// <c>true</c> if the current instance is equal to the specified object; <c>false</c> otherwise.</returns>
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public override bool Equals(object obj)
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{
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if (obj == null)
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{
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return false;
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}
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if (obj.GetType() != GetType())
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{
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return false;
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}
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Half half = (Half)obj;
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return half.value == value;
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}
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static Half()
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{
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Epsilon = 0.0004887581f;
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MaxValue = 65504f;
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MinValue = 6.103516E-05f;
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Zero = (Half)0.0f;
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One = (Half)1.0f;
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}
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}
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}
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