mirror of
https://github.com/scratchfoundation/bgfx.git
synced 2024-11-28 18:45:54 -05:00
324 lines
8.4 KiB
C++
324 lines
8.4 KiB
C++
/*
|
|
Copyright 2007 nVidia, Inc.
|
|
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
|
|
|
|
You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
|
|
See the License for the specific language governing permissions and limitations under the License.
|
|
*/
|
|
|
|
// Utility and common routines
|
|
|
|
#include "zoh_utils.h"
|
|
#include "nvmath/Vector.inl"
|
|
#include <math.h>
|
|
|
|
using namespace nv;
|
|
using namespace ZOH;
|
|
|
|
static const int denom7_weights_64[] = {0, 9, 18, 27, 37, 46, 55, 64}; // divided by 64
|
|
static const int denom15_weights_64[] = {0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64}; // divided by 64
|
|
|
|
/*static*/ Format Utils::FORMAT;
|
|
|
|
int Utils::lerp(int a, int b, int i, int denom)
|
|
{
|
|
nvDebugCheck (denom == 3 || denom == 7 || denom == 15);
|
|
nvDebugCheck (i >= 0 && i <= denom);
|
|
|
|
int round = 32, shift = 6;
|
|
const int *weights;
|
|
|
|
switch(denom)
|
|
{
|
|
case 3: denom *= 5; i *= 5; // fall through to case 15
|
|
case 15: weights = denom15_weights_64; break;
|
|
case 7: weights = denom7_weights_64; break;
|
|
default: nvDebugCheck(0);
|
|
}
|
|
|
|
return (a*weights[denom-i] +b*weights[i] + round) >> shift;
|
|
}
|
|
|
|
Vector3 Utils::lerp(const Vector3& a, const Vector3 &b, int i, int denom)
|
|
{
|
|
nvDebugCheck (denom == 3 || denom == 7 || denom == 15);
|
|
nvDebugCheck (i >= 0 && i <= denom);
|
|
|
|
int shift = 6;
|
|
const int *weights;
|
|
|
|
switch(denom)
|
|
{
|
|
case 3: denom *= 5; i *= 5; // fall through to case 15
|
|
case 15: weights = denom15_weights_64; break;
|
|
case 7: weights = denom7_weights_64; break;
|
|
default: nvUnreachable();
|
|
}
|
|
|
|
// no need to round these as this is an exact division
|
|
return (a*float(weights[denom-i]) +b*float(weights[i])) / float(1 << shift);
|
|
}
|
|
|
|
|
|
/*
|
|
For unsigned f16, clamp the input to [0,F16MAX]. Thus u15.
|
|
For signed f16, clamp the input to [-F16MAX,F16MAX]. Thus s16.
|
|
|
|
The conversions proceed as follows:
|
|
|
|
unsigned f16: get bits. if high bit set, clamp to 0, else clamp to F16MAX.
|
|
signed f16: get bits. extract exp+mantissa and clamp to F16MAX. return -value if sign bit was set, else value
|
|
unsigned int: get bits. return as a positive value.
|
|
signed int. get bits. return as a value in -32768..32767.
|
|
|
|
The inverse conversions are just the inverse of the above.
|
|
*/
|
|
|
|
// clamp the 3 channels of the input vector to the allowable range based on FORMAT
|
|
// note that each channel is a float storing the allowable range as a bit pattern converted to float
|
|
// that is, for unsigned f16 say, we would clamp each channel to the range [0, F16MAX]
|
|
|
|
void Utils::clamp(Vector3 &v)
|
|
{
|
|
for (int i=0; i<3; ++i)
|
|
{
|
|
switch(Utils::FORMAT)
|
|
{
|
|
case UNSIGNED_F16:
|
|
if (v.component[i] < 0.0) v.component[i] = 0;
|
|
else if (v.component[i] > F16MAX) v.component[i] = F16MAX;
|
|
break;
|
|
|
|
case SIGNED_F16:
|
|
if (v.component[i] < -F16MAX) v.component[i] = -F16MAX;
|
|
else if (v.component[i] > F16MAX) v.component[i] = F16MAX;
|
|
break;
|
|
|
|
default:
|
|
nvUnreachable();
|
|
}
|
|
}
|
|
}
|
|
|
|
// convert a u16 value to s17 (represented as an int) based on the format expected
|
|
int Utils::ushort_to_format(unsigned short input)
|
|
{
|
|
int out, s;
|
|
|
|
// clamp to the valid range we are expecting
|
|
switch (Utils::FORMAT)
|
|
{
|
|
case UNSIGNED_F16:
|
|
if (input & F16S_MASK) out = 0;
|
|
else if (input > F16MAX) out = F16MAX;
|
|
else out = input;
|
|
break;
|
|
|
|
case SIGNED_F16:
|
|
s = input & F16S_MASK;
|
|
input &= F16EM_MASK;
|
|
if (input > F16MAX) out = F16MAX;
|
|
else out = input;
|
|
out = s ? -out : out;
|
|
break;
|
|
}
|
|
return out;
|
|
}
|
|
|
|
// convert a s17 value to u16 based on the format expected
|
|
unsigned short Utils::format_to_ushort(int input)
|
|
{
|
|
unsigned short out;
|
|
|
|
// clamp to the valid range we are expecting
|
|
switch (Utils::FORMAT)
|
|
{
|
|
case UNSIGNED_F16:
|
|
nvDebugCheck (input >= 0 && input <= F16MAX);
|
|
out = input;
|
|
break;
|
|
|
|
case SIGNED_F16:
|
|
nvDebugCheck (input >= -F16MAX && input <= F16MAX);
|
|
// convert to sign-magnitude
|
|
int s;
|
|
if (input < 0) { s = F16S_MASK; input = -input; }
|
|
else { s = 0; }
|
|
out = s | input;
|
|
break;
|
|
}
|
|
return out;
|
|
}
|
|
|
|
// quantize the input range into equal-sized bins
|
|
int Utils::quantize(float value, int prec)
|
|
{
|
|
int q, ivalue, s;
|
|
|
|
nvDebugCheck (prec > 1); // didn't bother to make it work for 1
|
|
|
|
value = (float)floor(value + 0.5);
|
|
|
|
int bias = (prec > 10) ? ((1<<(prec-1))-1) : 0; // bias precisions 11..16 to get a more accurate quantization
|
|
|
|
switch (Utils::FORMAT)
|
|
{
|
|
case UNSIGNED_F16:
|
|
nvDebugCheck (value >= 0 && value <= F16MAX);
|
|
ivalue = (int)value;
|
|
q = ((ivalue << prec) + bias) / (F16MAX+1);
|
|
nvDebugCheck (q >= 0 && q < (1 << prec));
|
|
break;
|
|
|
|
case SIGNED_F16:
|
|
nvDebugCheck (value >= -F16MAX && value <= F16MAX);
|
|
// convert to sign-magnitude
|
|
ivalue = (int)value;
|
|
if (ivalue < 0) { s = 1; ivalue = -ivalue; } else s = 0;
|
|
|
|
q = ((ivalue << (prec-1)) + bias) / (F16MAX+1);
|
|
if (s)
|
|
q = -q;
|
|
nvDebugCheck (q > -(1 << (prec-1)) && q < (1 << (prec-1)));
|
|
break;
|
|
}
|
|
|
|
return q;
|
|
}
|
|
|
|
int Utils::finish_unquantize(int q, int prec)
|
|
{
|
|
if (Utils::FORMAT == UNSIGNED_F16)
|
|
return (q * 31) >> 6; // scale the magnitude by 31/64
|
|
else if (Utils::FORMAT == SIGNED_F16)
|
|
return (q < 0) ? -(((-q) * 31) >> 5) : (q * 31) >> 5; // scale the magnitude by 31/32
|
|
else
|
|
return q;
|
|
}
|
|
|
|
// unquantize each bin to midpoint of original bin range, except
|
|
// for the end bins which we push to an endpoint of the bin range.
|
|
// we do this to ensure we can represent all possible original values.
|
|
// the asymmetric end bins do not affect PSNR for the test images.
|
|
//
|
|
// code this function assuming an arbitrary bit pattern as the encoded block
|
|
int Utils::unquantize(int q, int prec)
|
|
{
|
|
int unq, s;
|
|
|
|
nvDebugCheck (prec > 1); // not implemented for prec 1
|
|
|
|
switch (Utils::FORMAT)
|
|
{
|
|
// modify this case to move the multiplication by 31 after interpolation.
|
|
// Need to use finish_unquantize.
|
|
|
|
// since we have 16 bits available, let's unquantize this to 16 bits unsigned
|
|
// thus the scale factor is [0-7c00)/[0-10000) = 31/64
|
|
case UNSIGNED_F16:
|
|
if (prec >= 15)
|
|
unq = q;
|
|
else if (q == 0)
|
|
unq = 0;
|
|
else if (q == ((1<<prec)-1))
|
|
unq = U16MAX;
|
|
else
|
|
unq = (q * (U16MAX+1) + (U16MAX+1)/2) >> prec;
|
|
break;
|
|
|
|
// here, let's stick with S16 (no apparent quality benefit from going to S17)
|
|
// range is (-7c00..7c00)/(-8000..8000) = 31/32
|
|
case SIGNED_F16:
|
|
// don't remove this test even though it appears equivalent to the code below
|
|
// as it isn't -- the code below can overflow for prec = 16
|
|
if (prec >= 16)
|
|
unq = q;
|
|
else
|
|
{
|
|
if (q < 0) { s = 1; q = -q; } else s = 0;
|
|
|
|
if (q == 0)
|
|
unq = 0;
|
|
else if (q >= ((1<<(prec-1))-1))
|
|
unq = s ? -S16MAX : S16MAX;
|
|
else
|
|
{
|
|
unq = (q * (S16MAX+1) + (S16MAX+1)/2) >> (prec-1);
|
|
if (s)
|
|
unq = -unq;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
return unq;
|
|
}
|
|
|
|
|
|
|
|
// pick a norm!
|
|
#define NORM_EUCLIDEAN 1
|
|
|
|
float Utils::norm(const Vector3 &a, const Vector3 &b)
|
|
{
|
|
#ifdef NORM_EUCLIDEAN
|
|
return lengthSquared(a - b);
|
|
#endif
|
|
#ifdef NORM_ABS
|
|
Vector3 err = a - b;
|
|
return fabs(err.x) + fabs(err.y) + fabs(err.z);
|
|
#endif
|
|
}
|
|
|
|
// parse <name>[<start>{:<end>}]{,}
|
|
// the pointer starts here ^
|
|
// name is 1 or 2 chars and matches field names. start and end are decimal numbers
|
|
void Utils::parse(const char *encoding, int &ptr, Field &field, int &endbit, int &len)
|
|
{
|
|
if (ptr <= 0) return;
|
|
--ptr;
|
|
if (encoding[ptr] == ',') --ptr;
|
|
nvDebugCheck (encoding[ptr] == ']');
|
|
--ptr;
|
|
endbit = 0;
|
|
int scale = 1;
|
|
while (encoding[ptr] != ':' && encoding[ptr] != '[')
|
|
{
|
|
nvDebugCheck(encoding[ptr] >= '0' && encoding[ptr] <= '9');
|
|
endbit += (encoding[ptr--] - '0') * scale;
|
|
scale *= 10;
|
|
}
|
|
int startbit = 0; scale = 1;
|
|
if (encoding[ptr] == '[')
|
|
startbit = endbit;
|
|
else
|
|
{
|
|
ptr--;
|
|
while (encoding[ptr] != '[')
|
|
{
|
|
nvDebugCheck(encoding[ptr] >= '0' && encoding[ptr] <= '9');
|
|
startbit += (encoding[ptr--] - '0') * scale;
|
|
scale *= 10;
|
|
}
|
|
}
|
|
len = startbit - endbit + 1; // startbit>=endbit note
|
|
--ptr;
|
|
if (encoding[ptr] == 'm') field = FIELD_M;
|
|
else if (encoding[ptr] == 'd') field = FIELD_D;
|
|
else {
|
|
// it's wxyz
|
|
nvDebugCheck (encoding[ptr] >= 'w' && encoding[ptr] <= 'z');
|
|
int foo = encoding[ptr--] - 'w';
|
|
// now it is r g or b
|
|
if (encoding[ptr] == 'r') foo += 10;
|
|
else if (encoding[ptr] == 'g') foo += 20;
|
|
else if (encoding[ptr] == 'b') foo += 30;
|
|
else nvDebugCheck(0);
|
|
field = (Field) foo;
|
|
}
|
|
}
|
|
|
|
|