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Math: functions for half-float (un)packing. 

Most of the code is in the actual test where I'm comparing and
benchmarking three different implementations (a
naive/straightforward/ground-truth one, the chosen one and a fast though
cache-spilling table-based one) to ensure the behavior is consistent
across all of them and that the performance is within reasonable bounds.

The Corrade::TestSuite benchmarking stuff needs serious improvements,
though.
pull/190/head
Vladimír Vondruš 9 years ago
parent
c8cc1dc88e
commit
16ef1ae0b6
8 changed files with 629 additions and 1 deletions
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  1. 1
      src/Magnum/CMakeLists.txt
  2. 104
      src/Magnum/Math/Packing.cpp
  3. 43
      src/Magnum/Math/Packing.h
  4. 1
      src/Magnum/Math/Test/CMakeLists.txt
  5. 472
      src/Magnum/Math/Test/HalfTest.cpp
  6. 4
      src/Magnum/Math/Test/PackingTest.cpp
  7. 1
      src/Magnum/PixelFormat.h
  8. 4
      src/Magnum/TextureFormat.h

1
src/Magnum/CMakeLists.txt
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@ -231,6 +231,7 @@ endif()
set(MagnumMath_SRCS set(MagnumMath_SRCS
Math/Color.cpp Math/Color.cpp
Math/Functions.cpp Math/Functions.cpp
Math/Packing.cpp
Math/instantiation.cpp) Math/instantiation.cpp)
# Objects shared between main and test library # Objects shared between main and test library

104
src/Magnum/Math/Packing.cpp
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@ -0,0 +1,104 @@
/*
This file is part of Magnum.
Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016
Vladimír Vondruš <mosra@centrum.cz>
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.
*/
#include "Packing.h"
namespace Magnum { namespace Math {
namespace {
union FloatBits {
UnsignedInt u;
Float f;
};
}
/* half_to_float_fast4() from https://gist.github.com/rygorous/2144712 */
Float unpackHalf(const UnsignedShort value) {
constexpr const FloatBits Magic{113 << 23};
/* Exponent mask after shift */
constexpr const UnsignedInt ShiftedExp = 0x7c00 << 13;
const UnsignedShort h{value};
FloatBits o;
o.u = (h & 0x7fff) << 13; /* exponent/mantissa bits */
const UnsignedInt exp = ShiftedExp & o.u; /* just the exponent */
o.u += (127 - 15) << 23; /* exponent adjust */
/* handle exponent special cases */
if(exp == ShiftedExp) { /* Inf/NaN? */
o.u += (128 - 16) << 23; /* Extra exp adjust */
} else if(exp == 0) { /* Zero/Denormal */
o.u += 1 << 23; /* Extra exp adjust */
o.f -= Magic.f; /* Renormalize */
}
o.u |= (h & 0x8000) << 16; /* sign bit */
return o.f;
}
/* float_to_half_fast3() from https://gist.github.com/rygorous/2156668 */
UnsignedShort packHalf(const Float value) {
constexpr const FloatBits FloatInfinity{255 << 23};
constexpr const FloatBits HalfInfinity{31 << 23};
constexpr const FloatBits Magic{15 << 23};
constexpr const UnsignedInt SignMask = 0x80000000u;
constexpr const UnsignedInt RoundMask = ~0xfffu;
FloatBits f;
f.f = value;
UnsignedShort h;
const UnsignedInt sign = f.u & SignMask;
f.u ^= sign;
/* Note: all the integer compares in this function can be safely compiled
into signed compares since all operands are below 0x80000000. Important
if you want fast straight SSE2 code (since there's no unsigned PCMPGTD). */
/* Inf or NaN (all exponent bits set): NaN->qNaN and Inf->Inf */
if(f.u >= FloatInfinity.u) {
h = (f.u > FloatInfinity.u) ? 0x7e00 : 0x7c00;
/* (De)normalized number or zero */
} else {
f.u &= RoundMask;
f.f *= Magic.f;
f.u -= RoundMask;
/* Clamp to signed infinity if overflowed */
if (f.u > HalfInfinity.u) f.u = HalfInfinity.u;
/* Take the bits! */
h = f.u >> 13;
}
h |= sign >> 16;
return h;
}
}}

43
src/Magnum/Math/Packing.h
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@ -187,6 +187,49 @@ template<class Integral, class FloatingPoint> CORRADE_DEPRECATED("use pack() ins
} }
#endif #endif
/**
@brief Pack 32-bit float value into 16-bit half-float representation
See [Wikipedia](https://en.wikipedia.org/wiki/Half-precision_floating-point_format)
for more information about half floats. NaNs are converted to NaNs and
infinities to infinities, though their exact bit pattern is not preserved. Note
that rounding mode is unspecified in order to save some cycles.
Implementation based on CC0 / public domain code by *Fabian Giesen*,
https://fgiesen.wordpress.com/2012/03/28/half-to-float-done-quic/ .
@see @ref unpackHalf()
*/
MAGNUM_EXPORT UnsignedShort packHalf(Float value);
/** @overload */
template<std::size_t size> Vector<size, UnsignedShort> packHalf(const Vector<size, Float>& value) {
Vector<size, UnsignedShort> out{NoInit};
for(std::size_t i = 0; i != size; ++i)
out[i] = packHalf(value[i]);
return out;
}
/**
@brief Unpack 16-bit half-float value into 32-bit float representation
See [Wikipedia](https://en.wikipedia.org/wiki/Half-precision_floating-point_format)
for more information about half floats. NaNs are converted to NaNs and
infinities to infinities, though their exact bit pattern is not preserved.
Implementation based on CC0 / public domain code by *Fabian Giesen*,
https://fgiesen.wordpress.com/2012/03/28/half-to-float-done-quic/ .
@see @ref packHalf()
*/
MAGNUM_EXPORT Float unpackHalf(UnsignedShort value);
/** @overload */
template<std::size_t size> Vector<size, Float> unpackHalf(const Vector<size, UnsignedShort>& value) {
Vector<size, Float> out{NoInit};
for(std::size_t i = 0; i != size; ++i)
out[i] = unpackHalf(value[i]);
return out;
}
}} }}
#endif #endif

1
src/Magnum/Math/Test/CMakeLists.txt
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@ -26,6 +26,7 @@
corrade_add_test(MathBoolVectorTest BoolVectorTest.cpp LIBRARIES MagnumMathTestLib) corrade_add_test(MathBoolVectorTest BoolVectorTest.cpp LIBRARIES MagnumMathTestLib)
corrade_add_test(MathConstantsTest ConstantsTest.cpp LIBRARIES MagnumMathTestLib) corrade_add_test(MathConstantsTest ConstantsTest.cpp LIBRARIES MagnumMathTestLib)
corrade_add_test(MathFunctionsTest FunctionsTest.cpp LIBRARIES MagnumMathTestLib) corrade_add_test(MathFunctionsTest FunctionsTest.cpp LIBRARIES MagnumMathTestLib)
corrade_add_test(MathHalfTest HalfTest.cpp LIBRARIES MagnumMathTestLib)
corrade_add_test(MathPackingTest PackingTest.cpp LIBRARIES MagnumMathTestLib) corrade_add_test(MathPackingTest PackingTest.cpp LIBRARIES MagnumMathTestLib)
corrade_add_test(MathTagsTest TagsTest.cpp LIBRARIES MagnumMathTestLib) corrade_add_test(MathTagsTest TagsTest.cpp LIBRARIES MagnumMathTestLib)
corrade_add_test(MathTypeTraitsTest TypeTraitsTest.cpp LIBRARIES MagnumMathTestLib) corrade_add_test(MathTypeTraitsTest TypeTraitsTest.cpp LIBRARIES MagnumMathTestLib)

472
src/Magnum/Math/Test/HalfTest.cpp
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@ -0,0 +1,472 @@
/*
This file is part of Magnum.
Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016
Vladimír Vondruš <mosra@centrum.cz>
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.
*/
#include <Corrade/TestSuite/Tester.h>
#include "Magnum/Math/Packing.h"
#include "Magnum/Math/Vector3.h"
namespace Magnum { namespace Math { namespace Test {
struct HalfTest: Corrade::TestSuite::Tester {
explicit HalfTest();
void unpack();
void pack();
void repack();
void unpack1k();
void unpack1kNaive();
void unpack1kTable();
void pack1k();
void pack1kNaive();
void pack1kTable();
private:
/* Naive / ground-truth packing helpers */
UnsignedShort packNaive(Float value);
Float unpackNaive(UnsignedShort value);
/* Table-based packing helpers */
UnsignedInt convertMantissa(UnsignedInt i);
UnsignedShort packTable(Float value);
Float unpackTable(UnsignedShort value);
UnsignedInt _mantissaTable[2048];
UnsignedInt _exponentTable[64];
UnsignedShort _offsetTable[64];
UnsignedShort _baseTable[512];
UnsignedByte _shiftTable[512];
};
typedef Math::Constants<Float> Constants;
HalfTest::HalfTest() {
addTests({&HalfTest::unpack,
&HalfTest::pack});
addRepeatedTests({&HalfTest::repack}, 65536);
addBenchmarks({
&HalfTest::unpack1k,
&HalfTest::unpack1kNaive,
&HalfTest::unpack1kTable,
&HalfTest::pack1k,
&HalfTest::pack1kNaive,
&HalfTest::pack1kTable}, 100);
/* Calculate tables for table-based benchmark */
_mantissaTable[0] = 0;
for(std::size_t i = 1; i != 1024; ++i)
_mantissaTable[i] = convertMantissa(i);
for(std::size_t i = 1024; i != 2048; ++i)
_mantissaTable[i] = 0x38000000 + ((i - 1024) << 13);
_exponentTable[0] = 0;
for(std::size_t i = 1; i != 31; ++i)
_exponentTable[i] = i << 23;
_exponentTable[31] = 0x47800000;
_exponentTable[32] = 0x80000000;
for(std::size_t i = 33; i != 63; ++i)
_exponentTable[i] = 0x80000000 + ((i - 32) << 23);
_exponentTable[63] = 0xc7800000;
for(std::size_t i = 0; i != 64; ++i)
_offsetTable[i] = 1024;
_offsetTable[0] = 0;
_offsetTable[32] = 0;
for(std::int_fast32_t i = 0; i != 256; ++i) {
std::int_fast32_t e = i - 127;
if(e < -24) {
_baseTable[i | 0x000] = 0x0000;
_baseTable[i | 0x100] = 0x8000;
_shiftTable[i | 0x000] = 24;
_shiftTable[i | 0x100] = 24;
} else if(e < -14) {
_baseTable[i | 0x000] = (0x0400 >> (-e - 14));
_baseTable[i | 0x100] = (0x0400 >> (-e - 14)) | 0x8000;
_shiftTable[i | 0x000] = -e - 1;
_shiftTable[i | 0x100] = -e - 1;
} else if(e <= 15) {
_baseTable[i | 0x000] = ((e + 15) << 10);
_baseTable[i | 0x100] = ((e + 15) << 10) | 0x8000;
_shiftTable[i | 0x000] = 13;
_shiftTable[i | 0x100] = 13;
} else if(e < 128) {
_baseTable[i | 0x000] = 0x7c00;
_baseTable[i | 0x100] = 0xfc00;
_shiftTable[i | 0x000] = 24;
_shiftTable[i | 0x100] = 24;
} else {
_baseTable[i | 0x000] = 0x7c00;
_baseTable[i | 0x100] = 0xfc00;
_shiftTable[i | 0x000] = 13;
_shiftTable[i | 0x100] = 13;
}
}
}
namespace {
union FloatBits {
UnsignedInt u;
Float f;
struct {
UnsignedInt mantissa:23;
UnsignedInt exponent:8;
UnsignedInt sign:1;
} bits;
};
union HalfBits {
UnsignedShort u;
struct {
UnsignedShort mantissa:10;
UnsignedShort exponent:5;
UnsignedShort sign:1;
} bits;
};
}
/* float_to_half_full() from https://gist.github.com/rygorous/2156668,
originally from ISPC */
UnsignedShort HalfTest::packNaive(Float value) {
FloatBits f;
f.f = value;
HalfBits o{};
/* Signed zero/denormal (which will underflow) */
if(f.bits.exponent == 0) {
o.bits.exponent = 0;
/* Inf or NaN (all exponent bits set): NaN->qNaN and Inf->Inf */
} else if(f.bits.exponent == 255) {
o.bits.exponent = 31;
o.bits.mantissa = f.bits.mantissa ? 0x200 : 0;
/* Normalized number */
} else {
/* Exponent unbias the single, then bias the halfp */
Int newexp = f.bits.exponent - 127 + 15;
/* Overflow, return signed infinity */
if(newexp >= 31) {
o.bits.exponent = 31;
/* Underflow */
} else if(newexp <= 0) {
/* Mantissa might be non-zero */
if((14 - newexp) <= 24) {
/* Hidden 1 bit */
UnsignedInt mant = f.bits.mantissa | 0x800000;
o.bits.mantissa = mant >> (14 - newexp);
/* Check for rounding */
if((mant >> (13 - newexp)) & 1) {
/* Round, might overflow into exp bit, but this is OK */
o.u++;
}
}
} else {
o.bits.exponent = newexp;
o.bits.mantissa = f.bits.mantissa >> 13;
/* Check for rounding */
if(f.bits.mantissa & 0x1000) {
/* Round, might overflow to inf, this is OK */
o.u++;
}
}
}
o.bits.sign = f.bits.sign;
return o.u;
}
/* half_to_float_full() from https://gist.github.com/rygorous/2144712,
originally from ISPC */
Float HalfTest::unpackNaive(UnsignedShort value) {
HalfBits h{value};
FloatBits o{};
/* (Signed) zero */
if(h.bits.exponent == 0 && h.bits.mantissa == 0) {
o.bits.sign = h.bits.sign;
} else {
/* Denormal (will convert to normalized) */
if(h.bits.exponent == 0) {
/* Adjust mantissa so it's normalized (and keep track of exp
adjust) */
Int e = -1;
UnsignedInt m = h.bits.mantissa;
do {
e++;
m <<= 1;
} while((m & 0x400) == 0);
o.bits.mantissa = (m & 0x3ff) << 13;
o.bits.exponent = 127 - 15 - e;
o.bits.sign = h.bits.sign;
/* Inf/NaN */
} else if(h.bits.exponent == 0x1f) {
/* Note: it's safe to treat both with the same code path by just
truncating lower Mantissa bits in NaNs (this is valid). */
o.bits.mantissa = h.bits.mantissa << 13;
o.bits.exponent = 255;
o.bits.sign = h.bits.sign;
/* Normalized number */
} else {
o.bits.mantissa = h.bits.mantissa << 13;
o.bits.exponent = 127 - 15 + h.bits.exponent;
o.bits.sign = h.bits.sign;
}
}
return o.f;
}
/* Jeroen van der Zijp -- Fast Half Float Conversions, 2008,
ftp://ftp.fox-toolkit.org/pub/fasthalffloatconversion.pdf */
UnsignedInt HalfTest::convertMantissa(UnsignedInt i) {
UnsignedInt m = i << 13;
UnsignedInt e = 0;
while(!(m & 0x00800000)) {
e -= 0x00800000;
m <<= 1;
}
m &= ~0x00800000;
e += 0x38800000;
return m | e;
}
UnsignedShort HalfTest::packTable(Float value) {
const UnsignedInt v = reinterpret_cast<const UnsignedInt&>(value);
return _baseTable[(v >> 23) & 0x1ff] + ((v & 0x007fffff) >> _shiftTable[(v >> 23) & 0x1ff]);
}
Float HalfTest::unpackTable(UnsignedShort value) {
UnsignedInt result = _mantissaTable[_offsetTable[value >> 10] + (value & 0x3ff)] + _exponentTable[value >> 10];
return reinterpret_cast<Float&>(result);
}
void HalfTest::unpack() {
CORRADE_COMPARE(Math::unpackHalf(0x0000), 0.0f);
CORRADE_COMPARE(Math::unpackHalf(0x3c00), 1.0f);
CORRADE_COMPARE(Math::unpackHalf(0x4000), 2.0f);
CORRADE_COMPARE(Math::unpackHalf(0x4200), 3.0f);
CORRADE_COMPARE(unpackNaive(0x0000), 0.0f);
CORRADE_COMPARE(unpackNaive(0x3c00), 1.0f);
CORRADE_COMPARE(unpackNaive(0x4000), 2.0f);
CORRADE_COMPARE(unpackNaive(0x4200), 3.0f);
CORRADE_COMPARE(unpackTable(0x0000), 0.0f);
CORRADE_COMPARE(unpackTable(0x3c00), 1.0f);
CORRADE_COMPARE(unpackTable(0x4000), 2.0f);
CORRADE_COMPARE(unpackTable(0x4200), 3.0f);
/* Normals, denormals, specials */
CORRADE_COMPARE(Math::unpackHalf(0x8dc2), -0.000351f);
CORRADE_COMPARE(Math::unpackHalf(0x57bc), 123.75f);
CORRADE_COMPARE(Math::unpackHalf(0xfe00), -Constants::nan());
CORRADE_COMPARE(Math::unpackHalf(0x7e00), +Constants::nan());
CORRADE_COMPARE(Math::unpackHalf(0xfc00), -Constants::inf());
CORRADE_COMPARE(Math::unpackHalf(0x7c00), +Constants::inf());
CORRADE_COMPARE(unpackNaive(0x8dc2), -0.000351f);
CORRADE_COMPARE(unpackNaive(0x57bc), 123.75f);
CORRADE_COMPARE(unpackNaive(0xfe00), -Constants::nan());
CORRADE_COMPARE(unpackNaive(0x7e00), +Constants::nan());
CORRADE_COMPARE(unpackNaive(0xfc00), -Constants::inf());
CORRADE_COMPARE(unpackNaive(0x7c00), +Constants::inf());
CORRADE_COMPARE(unpackTable(0x8dc2), -0.000351f);
CORRADE_COMPARE(unpackTable(0x57bc), 123.75f);
CORRADE_COMPARE(unpackTable(0xfe00), -Constants::nan());
CORRADE_COMPARE(unpackTable(0x7e00), +Constants::nan());
CORRADE_COMPARE(unpackTable(0xfc00), -Constants::inf());
CORRADE_COMPARE(unpackTable(0x7c00), +Constants::inf());
/* Vector */
CORRADE_COMPARE(Math::unpackHalf(Math::Vector3<UnsignedShort>{0x0000, 0x4200, 0x3c00}),
(Math::Vector3<Float>{0.0f, 3.0f, 1.0f}));
}
void HalfTest::pack() {
CORRADE_COMPARE(Math::packHalf(0.0f), 0x0000);
CORRADE_COMPARE(Math::packHalf(1.0f), 0x3c00);
CORRADE_COMPARE(Math::packHalf(2.0f), 0x4000);
CORRADE_COMPARE(Math::packHalf(3.0f), 0x4200);
CORRADE_COMPARE(packNaive(0.0f), 0x0000);
CORRADE_COMPARE(packNaive(1.0f), 0x3c00);
CORRADE_COMPARE(packNaive(2.0f), 0x4000);
CORRADE_COMPARE(packNaive(3.0f), 0x4200);
CORRADE_COMPARE(packTable(0.0f), 0x0000);
CORRADE_COMPARE(packTable(1.0f), 0x3c00);
CORRADE_COMPARE(packTable(2.0f), 0x4000);
CORRADE_COMPARE(packTable(3.0f), 0x4200);
/* Rounding */
CORRADE_COMPARE(Math::unpackHalf(Math::packHalf(-1024.01f)), -1024.0f);
CORRADE_COMPARE(Math::unpackHalf(Math::packHalf(-1024.50f)), -1025.0f);
CORRADE_COMPARE(Math::unpackHalf(Math::packHalf(-1024.99f)), -1025.0f);
CORRADE_COMPARE(Math::unpackHalf(Math::packHalf(+1024.01f)), +1024.0f);
CORRADE_COMPARE(Math::unpackHalf(Math::packHalf(+1024.50f)), +1025.0f);
CORRADE_COMPARE(Math::unpackHalf(Math::packHalf(+1024.99f)), +1025.0f);
/* Don't care about rounding behavior of the others */
/* Normals, denormals, specials */
CORRADE_COMPARE(Math::packHalf(-0.000351512f), 0x8dc2);
CORRADE_COMPARE(Math::packHalf(123.7567f), 0x57bc);
/* Emscripten doesn't differentiate NaNs and treats their sign slightly
differently on different optimization levels. On MSVC they are somehow
flipped around, so I'm testing w/o the sign. */
CORRADE_COMPARE(Math::packHalf(-Constants::nan()) & ~0x8000, 0x7e00);
CORRADE_COMPARE(Math::packHalf(+Constants::nan()) & ~0x8000, 0x7e00);
CORRADE_COMPARE(Math::packHalf(-Constants::inf()), 0xfc00);
CORRADE_COMPARE(Math::packHalf(+Constants::inf()), 0x7c00);
CORRADE_COMPARE(packNaive(-0.000351512f), 0x8dc2);
CORRADE_COMPARE(packNaive(123.7567f), 0x57bc);
/* Emscripten doesn't differentiate NaNs and treats their sign slightly
differently on different optimization levels. On MSVC they are somehow
flipped around, so I'm testing w/o the sign. */
CORRADE_COMPARE(packNaive(-Constants::nan()) & ~0x8000, 0x7e00);
CORRADE_COMPARE(packNaive(+Constants::nan()) & ~0x8000, 0x7e00);
CORRADE_COMPARE(packNaive(-Constants::inf()), 0xfc00);
CORRADE_COMPARE(packNaive(+Constants::inf()), 0x7c00);
CORRADE_COMPARE(packTable(-0.000351512f), 0x8dc2);
CORRADE_COMPARE(packTable(123.7567f), 0x57bc);
/* Emscripten doesn't differentiate NaNs and treats their sign slightly
differently on different optimization levels. On MSVC they are somehow
flipped around, so I'm testing w/o the sign. */
CORRADE_COMPARE(packTable(-Constants::nan()) & ~0x8000, 0x7e00);
CORRADE_COMPARE(packTable(+Constants::nan()) & ~0x8000, 0x7e00);
CORRADE_COMPARE(packTable(-Constants::inf()), 0xfc00);
CORRADE_COMPARE(packTable(+Constants::inf()), 0x7c00);
/* Vector */
CORRADE_COMPARE(Math::packHalf(Math::Vector3<Float>{0.0f, 3.0f, 1.0f}),
(Math::Vector3<UnsignedShort>{0x0000, 0x4200, 0x3c00}));
}
void HalfTest::repack() {
UnsignedShort in = testCaseRepeatId();
Float result = Math::unpackHalf(in);
Float resultNaive = unpackNaive(in);
Float resultTable = unpackTable(in);
/* NaNs don't rountrip, but that's okay */
if(result != result) {
CORRADE_VERIFY(result != result);
CORRADE_VERIFY(resultNaive != resultNaive);
CORRADE_VERIFY(resultTable != resultTable);
/* Otherwise verify that both algos give the same results */
} else {
CORRADE_COMPARE(result, resultTable);
CORRADE_COMPARE(result, resultNaive);
CORRADE_COMPARE(Math::packHalf(result), in);
CORRADE_COMPARE(packTable(result), in);
CORRADE_COMPARE(packNaive(result), in);
}
}
void HalfTest::pack1k() {
UnsignedInt out = 0;
CORRADE_BENCHMARK(100)
for(std::uint_fast16_t i = 0; i != 1000; ++i)
out += Math::packHalf(Float(i)*65);
/* To avoid optimizing things out */
CORRADE_VERIFY(out);
}
void HalfTest::pack1kNaive() {
UnsignedInt out = 0;
CORRADE_BENCHMARK(100)
for(std::uint_fast16_t i = 0; i != 1000; ++i)
out += packNaive(Float(i)*65);
/* To avoid optimizing things out */
CORRADE_VERIFY(out);
}
void HalfTest::pack1kTable() {
UnsignedInt out = 0;
CORRADE_BENCHMARK(100)
for(std::uint_fast16_t i = 0; i != 1000; ++i)
out += packTable(Float(i)*65);
/* To avoid optimizing things out */
CORRADE_VERIFY(out);
}
void HalfTest::unpack1k() {
Float out = 0.0f;
CORRADE_BENCHMARK(100)
for(std::uint_fast16_t i = 0; i != 1000; ++i)
out += Math::unpackHalf(i*65);
/* To avoid optimizing things out */
CORRADE_VERIFY(out);
}
void HalfTest::unpack1kNaive() {
Float out = 0.0f;
CORRADE_BENCHMARK(100)
for(std::uint_fast16_t i = 0; i != 1000; ++i)
out += unpackNaive(i*65);
/* To avoid optimizing things out */
CORRADE_VERIFY(out);
}
void HalfTest::unpack1kTable() {
Float out = 0.0f;
CORRADE_BENCHMARK(100)
for(std::uint_fast16_t i = 0; i != 1000; ++i)
out += unpackTable(i*65);
/* To avoid optimizing things out */
CORRADE_VERIFY(out);
}
}}}
CORRADE_TEST_MAIN(Magnum::Math::Test::HalfTest)

4
src/Magnum/Math/Test/PackingTest.cpp
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@ -43,6 +43,9 @@ struct PackingTest: Corrade::TestSuite::Tester {
void reunpackUnsinged(); void reunpackUnsinged();
void reunpackSinged(); void reunpackSinged();
void unpackTypeDeduction(); void unpackTypeDeduction();
/* Half (un)pack functions are tested and benchmarked in HalfTest.cpp,
because there's involved comparison and benchmarks to ground truth */
}; };
typedef Math::Vector3<Float> Vector3; typedef Math::Vector3<Float> Vector3;
@ -279,4 +282,3 @@ void PackingTest::unpackTypeDeduction() {
}}} }}}
CORRADE_TEST_MAIN(Magnum::Math::Test::PackingTest) CORRADE_TEST_MAIN(Magnum::Math::Test::PackingTest)

1
src/Magnum/PixelFormat.h
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@ -375,6 +375,7 @@ enum class PixelType: GLenum {
/** /**
* Each component half float. * Each component half float.
* @see @ref Math::packHalf(), @ref Math::unpackHalf()
* @requires_gl30 Extension @extension{ARB,half_float_pixel} * @requires_gl30 Extension @extension{ARB,half_float_pixel}
* @requires_gles30 For texture data only, extension * @requires_gles30 For texture data only, extension
* @es_extension2{OES,texture_half_float,OES_texture_float} in OpenGL * @es_extension2{OES,texture_half_float,OES_texture_float} in OpenGL

4
src/Magnum/TextureFormat.h
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@ -513,6 +513,7 @@ enum class TextureFormat: GLenum {
/** /**
* Red component, half float. * Red component, half float.
* @see @ref Math::packHalf(), @ref Math::unpackHalf()
* @requires_gl30 Extension @extension{ARB,texture_rg} and @extension{ARB,texture_float} * @requires_gl30 Extension @extension{ARB,texture_rg} and @extension{ARB,texture_float}
* @requires_gles30 Only normalized integral formats are available in * @requires_gles30 Only normalized integral formats are available in
* OpenGL ES 2.0. * OpenGL ES 2.0.
@ -523,6 +524,7 @@ enum class TextureFormat: GLenum {
/** /**
* Red and green component, each half float. * Red and green component, each half float.
* @see @ref Math::packHalf(), @ref Math::unpackHalf()
* @requires_gl30 Extension @extension{ARB,texture_rg} and @extension{ARB,texture_float} * @requires_gl30 Extension @extension{ARB,texture_rg} and @extension{ARB,texture_float}
* @requires_gles30 Only normalized integral formats are available in * @requires_gles30 Only normalized integral formats are available in
* OpenGL ES 2.0. * OpenGL ES 2.0.
@ -533,6 +535,7 @@ enum class TextureFormat: GLenum {
/** /**
* RGB, each component half float. * RGB, each component half float.
* @see @ref Math::packHalf(), @ref Math::unpackHalf()
* @requires_gl30 Extension @extension{ARB,texture_float} * @requires_gl30 Extension @extension{ARB,texture_float}
* @requires_gles30 Only normalized integral formats are available in * @requires_gles30 Only normalized integral formats are available in
* OpenGL ES 2.0. * OpenGL ES 2.0.
@ -543,6 +546,7 @@ enum class TextureFormat: GLenum {
/** /**
* RGBA, each component half float. * RGBA, each component half float.
* @see @ref Math::packHalf(), @ref Math::unpackHalf()
* @requires_gl30 Extension @extension{ARB,texture_float} * @requires_gl30 Extension @extension{ARB,texture_float}
* @requires_gles30 Only normalized integral formats are available in * @requires_gles30 Only normalized integral formats are available in
* OpenGL ES 2.0. * OpenGL ES 2.0.

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