mirror of
https://github.com/baldurk/renderdoc.git
synced 2026-07-16 20:47:12 +00:00
baldurk
133 lines
3.7 KiB
C
133 lines
3.7 KiB
C
///////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// 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.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////
|
|
|
|
#pragma once
|
|
|
|
inline uint16_t ConvertToHalf(float comp)
|
|
{
|
|
int *alias = (int *)∁
|
|
int i = *alias;
|
|
|
|
int sign = (i >> 16) & 0x00008000;
|
|
int exponent = ((i >> 23) & 0x000000ff) - (127 - 15);
|
|
int mantissa = i & 0x007fffff;
|
|
|
|
if(exponent <= 0)
|
|
{
|
|
if(exponent < -10)
|
|
return sign & 0xffff;
|
|
|
|
mantissa |= 0x00800000;
|
|
|
|
int t = 14 - exponent;
|
|
int a = (1 << (t - 1)) - 1;
|
|
int b = (mantissa >> t) & 1;
|
|
|
|
mantissa = (mantissa + a + b) >> t;
|
|
|
|
return (sign | mantissa) & 0xffff;
|
|
}
|
|
else if(exponent == 0xff - (127 - 15))
|
|
{
|
|
if(mantissa == 0)
|
|
return (sign | 0x7c00) & 0xffff;
|
|
|
|
mantissa >>= 13;
|
|
return (sign | 0x7c00 | mantissa | (mantissa == 0)) & 0xffff;
|
|
}
|
|
else
|
|
{
|
|
mantissa = mantissa + 0x00000fff + ((mantissa >> 13) & 1);
|
|
|
|
if(mantissa & 0x00800000)
|
|
{
|
|
mantissa = 0;
|
|
exponent += 1;
|
|
}
|
|
|
|
if(exponent > 30)
|
|
{
|
|
return (sign | 0x7c00) & 0xffff;
|
|
}
|
|
|
|
return (sign | (exponent << 10) | (mantissa >> 13)) & 0xffff;
|
|
}
|
|
}
|
|
|
|
inline float ConvertFromHalf(uint16_t comp)
|
|
{
|
|
bool sign = (comp & 0x8000) != 0;
|
|
int exponent = (comp & 0x7C00) >> 10;
|
|
int mantissa = comp & 0x03FF;
|
|
|
|
if(exponent == 0x00)
|
|
{
|
|
if(mantissa == 0)
|
|
return 0.0f;
|
|
|
|
// subnormal
|
|
float ret = (float)mantissa;
|
|
int *alias = (int *)&ret;
|
|
|
|
// set sign bit and set exponent to 2^-24
|
|
// (2^-14 from spec for subnormals * 2^-10 to convert (float)mantissa to 0.mantissa)
|
|
*alias = (sign ? 0x80000000 : 0) | (*alias - (24 << 23));
|
|
|
|
return ret;
|
|
}
|
|
else if(exponent < 0x1f)
|
|
{
|
|
exponent -= 15;
|
|
|
|
float ret = 0.0f;
|
|
int *alias = (int *)&ret;
|
|
|
|
// convert to float. Put sign bit in the right place, convert exponent to be
|
|
// [-128,127] and put in the right place, then shift mantissa up.
|
|
*alias = (sign ? 0x80000000 : 0) | (exponent + 127) << 23 | (mantissa << 13);
|
|
|
|
return ret;
|
|
}
|
|
else // if(exponent = 0x1f)
|
|
{
|
|
union
|
|
{
|
|
int i;
|
|
float f;
|
|
} nan;
|
|
nan.i = 0x7F800001;
|
|
return nan.f;
|
|
}
|
|
}
|