void floating point error clipping courtessy higuy and hutch

This commit is contained in:
AzaezelX 2021-07-31 17:05:29 -05:00
parent 33e78fd8a8
commit 59e162abe5

View file

@ -344,22 +344,52 @@ void BitStream::writeInt(S32 val, S32 bitCount)
void BitStream::writeFloat(F32 f, S32 bitCount)
{
writeInt((S32)(f * ((1 << bitCount) - 1)), bitCount);
auto maxInt = (1U << bitCount) - 1;
U32 i;
if (f < POINT_EPSILON)
{
// Special case: <= 0 serializes to 0
i = 0.0f;
}
else if (f == 0.5)
{
// Special case: 0.5 serializes to maxInt / 2 + 1
i = maxInt / 2 + 1;
}
else if (f > (1.0f- POINT_EPSILON))
{
// Special case: >= 1 serializes to maxInt
i = maxInt;
}
else
{
// Serialize normally but round the number
i = static_cast<U32>(roundf(f * maxInt));
}
writeInt(i, bitCount);
}
F32 BitStream::readFloat(S32 bitCount)
{
return readInt(bitCount) / F32((1 << bitCount) - 1);
auto maxInt = (1U << bitCount) - 1;
auto i = static_cast<U32>(readInt(bitCount));
if (i == 0)
return 0;
if (i == maxInt / 2 + 1)
return 0.5;
if (i == maxInt)
return 1;
return i / static_cast<F32>(maxInt);
}
void BitStream::writeSignedFloat(F32 f, S32 bitCount)
{
writeInt((S32)(((f + 1) * .5) * ((1 << bitCount) - 1)), bitCount);
writeFloat((f + 1) / 2, bitCount);
}
F32 BitStream::readSignedFloat(S32 bitCount)
{
return readInt(bitCount) * 2 / F32((1 << bitCount) - 1) - 1.0f;
return readFloat(bitCount) * 2 - 1;
}
void BitStream::writeSignedInt(S32 value, S32 bitCount)