mirror of
https://github.com/Ryujinx/Opentk.git
synced 2024-12-23 20:15:31 +00:00
588 lines
23 KiB
C#
588 lines
23 KiB
C#
#region --- License ---
|
|
/*
|
|
Copyright (c) 2006 - 2008 The Open Toolkit library.
|
|
|
|
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.
|
|
*/
|
|
/*
|
|
The conversion functions are derived from OpenEXR's implementation and are
|
|
governed by the following license:
|
|
|
|
Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
|
|
Digital Ltd. LLC
|
|
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above
|
|
copyright notice, this list of conditions and the following disclaimer
|
|
in the documentation and/or other materials provided with the
|
|
distribution.
|
|
* Neither the name of Industrial Light & Magic nor the names of
|
|
its contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
"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 THE COPYRIGHT
|
|
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 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.
|
|
*/
|
|
#endregion --- License ---
|
|
|
|
using System;
|
|
using System.IO;
|
|
using System.Runtime.InteropServices;
|
|
using System.Runtime.Serialization;
|
|
|
|
namespace OpenTK
|
|
{
|
|
|
|
/// <summary>
|
|
/// The name Half is derived from half-precision floating-point number.
|
|
/// It occupies only 16 bits, which are split into 1 Sign bit, 5 Exponent bits and 10 Mantissa bits.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// Quote from ARB_half_float_pixel specification:
|
|
/// Any representable 16-bit floating-point value is legal as input to a GL command that accepts 16-bit floating-point data. The
|
|
/// result of providing a value that is not a floating-point number (such as infinity or NaN) to such a command is unspecified,
|
|
/// but must not lead to GL interruption or termination. Providing a denormalized number or negative zero to GL must yield
|
|
/// predictable results.
|
|
/// </remarks>
|
|
[Serializable, StructLayout(LayoutKind.Sequential)]
|
|
public struct Half : ISerializable, IComparable<Half>, IFormattable, IEquatable<Half>
|
|
{
|
|
#region Internal Field
|
|
|
|
UInt16 bits;
|
|
|
|
#endregion Internal Field
|
|
|
|
#region Properties
|
|
|
|
/// <summary>Returns true if the Half is zero.</summary>
|
|
public bool IsZero { get { return (bits == 0) || (bits == 0x8000); } }
|
|
|
|
/// <summary>Returns true if the Half represents Not A Number (NaN)</summary>
|
|
public bool IsNaN { get { return (((bits & 0x7C00) == 0x7C00) && (bits & 0x03FF) != 0x0000); } }
|
|
|
|
/// <summary>Returns true if the Half represents positive infinity.</summary>
|
|
public bool IsPositiveInfinity { get { return (bits == 31744); } }
|
|
|
|
/// <summary>Returns true if the Half represents negative infinity.</summary>
|
|
public bool IsNegativeInfinity { get { return (bits == 64512); } }
|
|
|
|
#endregion Properties
|
|
|
|
#region Constructors
|
|
|
|
/// <summary>
|
|
/// The new Half instance will convert the parameter into 16-bit half-precision floating-point.
|
|
/// </summary>
|
|
/// <param name="f">32-bit single-precision floating-point number.</param>
|
|
public Half(Single f)
|
|
: this()
|
|
{
|
|
unsafe
|
|
{
|
|
bits = SingleToHalf(*(int*)&f);
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// The new Half instance will convert the parameter into 16-bit half-precision floating-point.
|
|
/// </summary>
|
|
/// <param name="f">32-bit single-precision floating-point number.</param>
|
|
/// <param name="throwOnError">Enable checks that will throw if the conversion result is not meaningful.</param>
|
|
public Half(Single f, bool throwOnError)
|
|
: this(f)
|
|
{
|
|
if (throwOnError)
|
|
{
|
|
// handle cases that cause overflow rather than silently ignoring it
|
|
if (f > Half.MaxValue) throw new ArithmeticException("Half: Positive maximum value exceeded.");
|
|
if (f < -Half.MaxValue) throw new ArithmeticException("Half: Negative minimum value exceeded.");
|
|
|
|
// handle cases that make no sense
|
|
if (Single.IsNaN(f)) throw new ArithmeticException("Half: Input is not a number (NaN).");
|
|
if (Single.IsPositiveInfinity(f)) throw new ArithmeticException("Half: Input is positive infinity.");
|
|
if (Single.IsNegativeInfinity(f)) throw new ArithmeticException("Half: Input is negative infinity.");
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// The new Half instance will convert the parameter into 16-bit half-precision floating-point.
|
|
/// </summary>
|
|
/// <param name="d">64-bit double-precision floating-point number.</param>
|
|
public Half(Double d) : this((Single)d) { }
|
|
|
|
/// <summary>
|
|
/// The new Half instance will convert the parameter into 16-bit half-precision floating-point.
|
|
/// </summary>
|
|
/// <param name="d">64-bit double-precision floating-point number.</param>
|
|
/// <param name="throwOnError">Enable checks that will throw if the conversion result is not meaningful.</param>
|
|
public Half(Double d, bool throwOnError) : this((Single)d, throwOnError) { }
|
|
|
|
#endregion Constructors
|
|
|
|
#region Single -> Half
|
|
|
|
/// <summary>Ported from OpenEXR's IlmBase 1.0.1</summary>
|
|
private UInt16 SingleToHalf(Int32 si32)
|
|
{
|
|
// Our floating point number, F, is represented by the bit pattern in integer i.
|
|
// Disassemble that bit pattern into the sign, S, the exponent, E, and the significand, M.
|
|
// Shift S into the position where it will go in in the resulting half number.
|
|
// Adjust E, accounting for the different exponent bias of float and half (127 versus 15).
|
|
|
|
Int32 sign = (si32 >> 16) & 0x00008000;
|
|
Int32 exponent = ((si32 >> 23) & 0x000000ff) - (127 - 15);
|
|
Int32 mantissa = si32 & 0x007fffff;
|
|
|
|
// Now reassemble S, E and M into a half:
|
|
|
|
if (exponent <= 0)
|
|
{
|
|
if (exponent < -10)
|
|
{
|
|
// E is less than -10. The absolute value of F is less than Half.MinValue
|
|
// (F may be a small normalized float, a denormalized float or a zero).
|
|
//
|
|
// We convert F to a half zero with the same sign as F.
|
|
|
|
return (UInt16)sign;
|
|
}
|
|
|
|
// E is between -10 and 0. F is a normalized float whose magnitude is less than Half.MinNormalizedValue.
|
|
//
|
|
// We convert F to a denormalized half.
|
|
|
|
// Add an explicit leading 1 to the significand.
|
|
|
|
mantissa = mantissa | 0x00800000;
|
|
|
|
// Round to M to the nearest (10+E)-bit value (with E between -10 and 0); in case of a tie, round to the nearest even value.
|
|
//
|
|
// Rounding may cause the significand to overflow and make our number normalized. Because of the way a half's bits
|
|
// are laid out, we don't have to treat this case separately; the code below will handle it correctly.
|
|
|
|
Int32 t = 14 - exponent;
|
|
Int32 a = (1 << (t - 1)) - 1;
|
|
Int32 b = (mantissa >> t) & 1;
|
|
|
|
mantissa = (mantissa + a + b) >> t;
|
|
|
|
// Assemble the half from S, E (==zero) and M.
|
|
|
|
return (UInt16)(sign | mantissa);
|
|
}
|
|
else if (exponent == 0xff - (127 - 15))
|
|
{
|
|
if (mantissa == 0)
|
|
{
|
|
// F is an infinity; convert F to a half infinity with the same sign as F.
|
|
|
|
return (UInt16)(sign | 0x7c00);
|
|
}
|
|
else
|
|
{
|
|
// F is a NAN; we produce a half NAN that preserves the sign bit and the 10 leftmost bits of the
|
|
// significand of F, with one exception: If the 10 leftmost bits are all zero, the NAN would turn
|
|
// into an infinity, so we have to set at least one bit in the significand.
|
|
|
|
mantissa >>= 13;
|
|
return (UInt16)(sign | 0x7c00 | mantissa | ((mantissa == 0) ? 1 : 0));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// E is greater than zero. F is a normalized float. We try to convert F to a normalized half.
|
|
|
|
// Round to M to the nearest 10-bit value. In case of a tie, round to the nearest even value.
|
|
|
|
mantissa = mantissa + 0x00000fff + ((mantissa >> 13) & 1);
|
|
|
|
if ((mantissa & 0x00800000) == 1)
|
|
{
|
|
mantissa = 0; // overflow in significand,
|
|
exponent += 1; // adjust exponent
|
|
}
|
|
|
|
// exponent overflow
|
|
if (exponent > 30) throw new ArithmeticException("Half: Hardware floating-point overflow.");
|
|
|
|
// Assemble the half from S, E and M.
|
|
|
|
return (UInt16)(sign | (exponent << 10) | (mantissa >> 13));
|
|
}
|
|
}
|
|
|
|
#endregion Single -> Half
|
|
|
|
#region Half -> Single
|
|
|
|
/// <summary>Converts the 16-bit half to 32-bit floating-point.</summary>
|
|
/// <returns>A single-precision floating-point number.</returns>
|
|
public Single ToSingle()
|
|
{
|
|
int i = HalfToFloat(bits);
|
|
|
|
unsafe
|
|
{
|
|
return *(float*)&i;
|
|
}
|
|
}
|
|
|
|
/// <summary>Ported from OpenEXR's IlmBase 1.0.1</summary>
|
|
private Int32 HalfToFloat(UInt16 ui16)
|
|
{
|
|
|
|
Int32 sign = (ui16 >> 15) & 0x00000001;
|
|
Int32 exponent = (ui16 >> 10) & 0x0000001f;
|
|
Int32 mantissa = ui16 & 0x000003ff;
|
|
|
|
if (exponent == 0)
|
|
{
|
|
if (mantissa == 0)
|
|
{
|
|
// Plus or minus zero
|
|
|
|
return sign << 31;
|
|
}
|
|
else
|
|
{
|
|
// Denormalized number -- renormalize it
|
|
|
|
while ((mantissa & 0x00000400) == 0)
|
|
{
|
|
mantissa <<= 1;
|
|
exponent -= 1;
|
|
}
|
|
|
|
exponent += 1;
|
|
mantissa &= ~0x00000400;
|
|
}
|
|
}
|
|
else if (exponent == 31)
|
|
{
|
|
if (mantissa == 0)
|
|
{
|
|
// Positive or negative infinity
|
|
|
|
return (sign << 31) | 0x7f800000;
|
|
}
|
|
else
|
|
{
|
|
// Nan -- preserve sign and significand bits
|
|
|
|
return (sign << 31) | 0x7f800000 | (mantissa << 13);
|
|
}
|
|
}
|
|
|
|
// Normalized number
|
|
|
|
exponent = exponent + (127 - 15);
|
|
mantissa = mantissa << 13;
|
|
|
|
// Assemble S, E and M.
|
|
|
|
return (sign << 31) | (exponent << 23) | mantissa;
|
|
}
|
|
|
|
#endregion Half -> Single
|
|
|
|
#region Conversions
|
|
|
|
/// <summary>
|
|
/// Converts a System.Single to a OpenTK.Half.
|
|
/// </summary>
|
|
/// <param name="f">The value to convert.
|
|
/// A <see cref="System.Single"/>
|
|
/// </param>
|
|
/// <returns>The result of the conversion.
|
|
/// A <see cref="Half"/>
|
|
/// </returns>
|
|
public static explicit operator Half(float f)
|
|
{
|
|
return new Half(f);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Converts a System.Double to a OpenTK.Half.
|
|
/// </summary>
|
|
/// <param name="d">The value to convert.
|
|
/// A <see cref="System.Double"/>
|
|
/// </param>
|
|
/// <returns>The result of the conversion.
|
|
/// A <see cref="Half"/>
|
|
/// </returns>
|
|
public static explicit operator Half(double d)
|
|
{
|
|
return new Half(d);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Converts a OpenTK.Half to a System.Single.
|
|
/// </summary>
|
|
/// <param name="h">The value to convert.
|
|
/// A <see cref="Half"/>
|
|
/// </param>
|
|
/// <returns>The result of the conversion.
|
|
/// A <see cref="System.Single"/>
|
|
/// </returns>
|
|
public static implicit operator float(Half h)
|
|
{
|
|
return h.ToSingle();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Converts a OpenTK.Half to a System.Double.
|
|
/// </summary>
|
|
/// <param name="h">The value to convert.
|
|
/// A <see cref="Half"/>
|
|
/// </param>
|
|
/// <returns>The result of the conversion.
|
|
/// A <see cref="System.Double"/>
|
|
/// </returns>
|
|
public static implicit operator double(Half h)
|
|
{
|
|
return (double)h.ToSingle();
|
|
}
|
|
|
|
#endregion Conversions
|
|
|
|
#region Constants
|
|
|
|
/// <summary>The size in bytes for an instance of the Half struct.</summary>
|
|
public static readonly Int32 SizeInBytes = 2;
|
|
|
|
/// <summary>Smallest positive half</summary>
|
|
public static readonly Single MinValue = 5.96046448e-08f;
|
|
|
|
/// <summary>Smallest positive normalized half</summary>
|
|
public static readonly Single MinNormalizedValue = 6.10351562e-05f;
|
|
|
|
/// <summary>Largest positive half</summary>
|
|
public static readonly Single MaxValue = 65504.0f;
|
|
|
|
/// <summary>Smallest positive e for which half (1.0 + e) != half (1.0)</summary>
|
|
public static readonly Single Epsilon = 0.00097656f;
|
|
|
|
#endregion Constants
|
|
|
|
#region ISerializable
|
|
|
|
/// <summary>Constructor used by ISerializable to deserialize the object.</summary>
|
|
/// <param name="info"></param>
|
|
/// <param name="context"></param>
|
|
public Half(SerializationInfo info, StreamingContext context)
|
|
{
|
|
this.bits = (ushort)info.GetValue("bits", typeof(ushort));
|
|
}
|
|
|
|
/// <summary>Used by ISerialize to serialize the object.</summary>
|
|
/// <param name="info"></param>
|
|
/// <param name="context"></param>
|
|
public void GetObjectData(SerializationInfo info, StreamingContext context)
|
|
{
|
|
info.AddValue("bits", this.bits);
|
|
}
|
|
|
|
#endregion ISerializable
|
|
|
|
#region Binary dump
|
|
|
|
/// <summary>Updates the Half by reading from a Stream.</summary>
|
|
/// <param name="bin">A BinaryReader instance associated with an open Stream.</param>
|
|
public void FromBinaryStream(BinaryReader bin)
|
|
{
|
|
this.bits = bin.ReadUInt16();
|
|
|
|
}
|
|
|
|
/// <summary>Writes the Half into a Stream.</summary>
|
|
/// <param name="bin">A BinaryWriter instance associated with an open Stream.</param>
|
|
public void ToBinaryStream(BinaryWriter bin)
|
|
{
|
|
bin.Write(this.bits);
|
|
}
|
|
|
|
#endregion Binary dump
|
|
|
|
#region IEquatable<Half> Members
|
|
|
|
const int maxUlps = 1;
|
|
|
|
/// <summary>
|
|
/// Returns a value indicating whether this instance is equal to a specified OpenTK.Half value.
|
|
/// </summary>
|
|
/// <param name="other">OpenTK.Half object to compare to this instance..</param>
|
|
/// <returns>True, if other is equal to this instance; false otherwise.</returns>
|
|
public bool Equals(Half other)
|
|
{
|
|
short aInt, bInt;
|
|
unchecked { aInt = (short)other.bits; }
|
|
unchecked { bInt = (short)this.bits; }
|
|
|
|
// Make aInt lexicographically ordered as a twos-complement int
|
|
if (aInt < 0)
|
|
aInt = (short)(0x8000 - aInt);
|
|
|
|
// Make bInt lexicographically ordered as a twos-complement int
|
|
if (bInt < 0)
|
|
bInt = (short)(0x8000 - bInt);
|
|
|
|
short intDiff = System.Math.Abs((short)(aInt - bInt));
|
|
|
|
if (intDiff <= maxUlps)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
#endregion
|
|
|
|
#region IComparable<Half> Members
|
|
|
|
/// <summary>
|
|
/// Compares this instance to a specified half-precision floating-point number
|
|
/// and returns an integer that indicates whether the value of this instance
|
|
/// is less than, equal to, or greater than the value of the specified half-precision
|
|
/// floating-point number.
|
|
/// </summary>
|
|
/// <param name="other">A half-precision floating-point number to compare.</param>
|
|
/// <returns>
|
|
/// A signed number indicating the relative values of this instance and value. If the number is:
|
|
/// <para>Less than zero, then this instance is less than other, or this instance is not a number
|
|
/// (OpenTK.Half.NaN) and other is a number.</para>
|
|
/// <para>Zero: this instance is equal to value, or both this instance and other
|
|
/// are not a number (OpenTK.Half.NaN), OpenTK.Half.PositiveInfinity, or
|
|
/// OpenTK.Half.NegativeInfinity.</para>
|
|
/// <para>Greater than zero: this instance is greater than othrs, or this instance is a number
|
|
/// and other is not a number (OpenTK.Half.NaN).</para>
|
|
/// </returns>
|
|
public int CompareTo(Half other)
|
|
{
|
|
return ((float)this).CompareTo((float)other);
|
|
}
|
|
|
|
#endregion IComparable<Half> Members
|
|
|
|
#region IFormattable Members
|
|
|
|
/// <summary>Converts this Half into a human-legible string representation.</summary>
|
|
/// <returns>The string representation of this instance.</returns>
|
|
public override string ToString()
|
|
{
|
|
return this.ToSingle().ToString();
|
|
}
|
|
|
|
/// <summary>Converts this Half into a human-legible string representation.</summary>
|
|
/// <param name="format">Formatting for the output string.</param>
|
|
/// <param name="formatProvider">Culture-specific formatting information.</param>
|
|
/// <returns>The string representation of this instance.</returns>
|
|
public string ToString(string format, IFormatProvider formatProvider)
|
|
{
|
|
return this.ToSingle().ToString(format, formatProvider);
|
|
}
|
|
|
|
#endregion IFormattable Members
|
|
|
|
#region String -> Half
|
|
|
|
/// <summary>Converts the string representation of a number to a half-precision floating-point equivalent.</summary>
|
|
/// <param name="s">String representation of the number to convert.</param>
|
|
/// <returns>A new Half instance.</returns>
|
|
public static Half Parse(string s)
|
|
{
|
|
return (Half)Single.Parse(s);
|
|
}
|
|
|
|
/// <summary>Converts the string representation of a number to a half-precision floating-point equivalent.</summary>
|
|
/// <param name="s">String representation of the number to convert.</param>
|
|
/// <param name="style">Specifies the format of s.</param>
|
|
/// <param name="provider">Culture-specific formatting information.</param>
|
|
/// <returns>A new Half instance.</returns>
|
|
public static Half Parse(string s, System.Globalization.NumberStyles style, IFormatProvider provider)
|
|
{
|
|
return (Half)Single.Parse(s, style, provider);
|
|
}
|
|
|
|
/// <summary>Converts the string representation of a number to a half-precision floating-point equivalent. Returns success.</summary>
|
|
/// <param name="s">String representation of the number to convert.</param>
|
|
/// <param name="result">The Half instance to write to.</param>
|
|
/// <returns>Success.</returns>
|
|
public static bool TryParse(string s, out Half result)
|
|
{
|
|
float f;
|
|
bool b = Single.TryParse(s, out f);
|
|
result = (Half)f;
|
|
return b;
|
|
}
|
|
|
|
/// <summary>Converts the string representation of a number to a half-precision floating-point equivalent. Returns success.</summary>
|
|
/// <param name="s">String representation of the number to convert.</param>
|
|
/// <param name="style">Specifies the format of s.</param>
|
|
/// <param name="provider">Culture-specific formatting information.</param>
|
|
/// <param name="result">The Half instance to write to.</param>
|
|
/// <returns>Success.</returns>
|
|
public static bool TryParse(string s, System.Globalization.NumberStyles style, IFormatProvider provider, out Half result)
|
|
{
|
|
float f;
|
|
bool b = Single.TryParse(s, style, provider, out f);
|
|
result = (Half)f;
|
|
return b;
|
|
}
|
|
|
|
#endregion String -> Half
|
|
|
|
#region BitConverter
|
|
|
|
/// <summary>Returns the Half as an array of bytes.</summary>
|
|
/// <param name="h">The Half to convert.</param>
|
|
/// <returns>The input as byte array.</returns>
|
|
public static byte[] GetBytes(Half h)
|
|
{
|
|
return BitConverter.GetBytes(h.bits);
|
|
}
|
|
|
|
/// <summary>Converts an array of bytes into Half.</summary>
|
|
/// <param name="value">A Half in it's byte[] representation.</param>
|
|
/// <param name="startIndex">The starting position within value.</param>
|
|
/// <returns>A new Half instance.</returns>
|
|
public static Half FromBytes(byte[] value, int startIndex)
|
|
{
|
|
Half h;
|
|
h.bits = BitConverter.ToUInt16(value, startIndex);
|
|
return h;
|
|
}
|
|
|
|
#endregion BitConverter
|
|
}
|
|
} |