PtexHalfTableGen.cpp
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#include "PtexHalf.h"
#include <stdio.h>
static bool PtexHalfInit(uint32_t* h2fTable, uint16_t* f2hTable)
{
union { int i; float f; } u;
for (int h = 0; h < 65536; h++) {
int s = (h & 0x8000)<<16;
int m = h & 0x03ff;
int e = h&0x7c00;
if (unsigned(e-1) < ((31<<10)-1)) {
// normal case
u.i = s|(((e+0x1c000)|m)<<13);
}
else if (e == 0) {
// denormalized
if (!(h&0x8000)) u.f = float(5.9604644775390625e-08*m);
else u.f = float(-5.9604644775390625e-08*m);
}
else {
// inf/nan, preserve low bits of m for nan code
u.i = s|0x7f800000|(m<<13);
}
h2fTable[h] = u.i;
}
for (int i = 0; i < 512; i++) {
int f = i << 23;
int e = (f & 0x7f800000) - 0x38000000;
// normalized iff (0 < e < 31)
if (unsigned(e-1) < ((31<<23)-1)) {
int s = ((f>>16) & 0x8000);
int m = f & 0x7fe000;
// add bit 12 to round
f2hTable[i] = (uint16_t)((s|((e|m)>>13))+((f>>12)&1));
}
}
return 1;
}
int main()
{
FILE* fp = fopen("PtexHalfTables.h", "w");
if (!fp) {
perror("Can't write PtexHalfTable.h");
return 1;
}
uint32_t h2fTable[65536];
uint16_t f2hTable[512];
PtexHalfInit(h2fTable, f2hTable);
fprintf(fp, "PTEXAPI uint32_t PtexHalf::h2fTable[65536] = {");
for (int i = 0; i < 65536; i++) {
if (i % 8 == 0) fprintf(fp, "\n");
fprintf(fp, " 0x%08x", h2fTable[i]);
if (i != 65535) fprintf(fp, ",");
}
fprintf(fp, "\n};\n");
fprintf(fp, "PTEXAPI uint16_t PtexHalf::f2hTable[512] = {");
for (int i = 0; i < 512; i++) {
if (i % 8 == 0) fprintf(fp, "\n");
fprintf(fp, " 0x%04x", f2hTable[i]);
if (i != 511) fprintf(fp, ",");
}
fprintf(fp, "\n};\n");
fclose(fp);
return 0;
}
PtexHalfInit
static bool PtexHalfInit(uint32_t *h2fTable, uint16_t *f2hTable)
Table initializations.
Definition PtexHalfTableGen.cpp:5
main
int main()
Definition PtexHalfTableGen.cpp:46
PtexHalf.h
Half-precision floating-point type.