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#include "texusint.h"
#include "sst2fxt1.h"
#include "fx64.h"
#define REMOVE(d, b, n) { d = (FxU32) (b & ((1 << (n)) - 1)); b >>= n; }
#define INSERT(b, d, n) { b <<= n; b |= ((d) & ((1 << (n)) - 1)); }
/*
* The following 4 procedures read and write 2 or 3 bit indices into
* the bit bucket
*/
static void
encode2(int *index, FxU32 bits[4] )
{
FxU32 lo = 0, hi = 0;
int i;
for (i=15; i >= 0; i--) {
lo = (lo << 2) | (index[i ] & 3);
hi = (hi << 2) | (index[i + 16] & 3);
}
bits[0] = lo;
bits[1] = hi;
}
static void
encode3(int *index, FxU32 bits[4] )
{
FxU64 lo = 0, hi = 0;
int i;
for (i=15; i >= 0; i--) {
lo = (lo << 3) | (index[i ] & 7);
hi = (hi << 3) | (index[i + 16] & 7);
}
bits[0] = (FxU32) lo;
bits[1] = (FxU32) ((lo >> 32) | (hi << 16));
bits[2] = (FxU32) (hi >> 16);
}
static void
decode2(FxU32 bits[4], int *index)
{
FxU32 lo, hi;
int i;
lo = bits[0];
hi = bits[1];
for (i=0; i<16; i++) {
index[i + 0] = lo & 3; lo >>= 2;
index[i + 16] = hi & 3; hi >>= 2;
}
}
static void
decode3(FxU32 bits[4], int *index)
{
FxU64 lo, hi;
int i;
lo = bits[0] | (((FxU64) bits[1]) << 32);
hi = (bits[1] >> 16) | (((FxU64) bits[2]) << 16);
for (i=0; i<16; i++) {
index[i + 0] = (int) (lo & 7); lo >>= 3;
index[i + 16] = (int) (hi & 7); hi >>= 3;
}
}
/* decode variable length mode field */
static int
getMode(FxU32 bits3)
{
int mode;
bits3 >>= 29;
if ( bits3 & 4 ) { // 1XX
mode = TCC_MIXED;
} else if (( bits3 & 6 ) == 0 ) { // 00X
mode = TCC_HI;
} else {
switch ( bits3 ) {
case TCC_CHROMA:
case TCC_ALPHA:
mode = bits3;
break;
default:
txError("FXT1 bad mode\n");
break;
}
}
return mode;
}
int
bitDecoder( void *bits128, FxU32 c[4], int index[32], FxU32 *alpha )
{
FxU32 *bits = (FxU32 *) bits128;
int mode = getMode(bits[3]);
FxU64 d;
d = bits[3];
d = (d << 32) | bits[2];
switch(mode & 3) {
case TCC_HI:
{
d >>= 32;
REMOVE(c[0], d, 15);
REMOVE(c[1], d, 15);
c[2] = 0;
c[3] = 0;
decode3( bits, index);
*alpha = 0;
}
break;
case TCC_MIXED:
{
REMOVE(c[0], d, 15);
REMOVE(c[1], d, 15);
REMOVE(c[2], d, 15);
REMOVE(c[3], d, 15);
REMOVE(*alpha, d, 3);
decode2( bits, index);
}
break;
case TCC_CHROMA:
{
REMOVE(c[0], d, 15);
REMOVE(c[1], d, 15);
REMOVE(c[2], d, 15);
REMOVE(c[3], d, 15);
*alpha = 0;
decode2( bits, index);
}
break;
case TCC_ALPHA:
{
FxU32 a;
REMOVE(c[0], d, 15);
REMOVE(c[1], d, 15);
REMOVE(c[2], d, 15);
REMOVE(a, d, 5); c[0] |= a << 15;
REMOVE(a, d, 5); c[1] |= a << 15;
REMOVE(a, d, 5); c[2] |= a << 15;
c[3] = 0;
REMOVE(*alpha, d, 1); // interpolate
decode2( bits, index);
}
break;
}
return mode;
}
void
bitEncoder( int mode, FxU32 c[4], FxU32 alpha, int index[32], void *bits128 )
{
FxU32 *bits = (FxU32 *) bits128;
FxU64 d = 0;
// mode has variable length encoding to fit alpha bits
switch(mode & 3) {
case TCC_HI:
{
encode3( index, bits);
INSERT( d, mode, 2);
INSERT( d, c[1], 15);
INSERT( d, c[0], 15);
bits[3] = (FxU32) d;
}
break;
case TCC_MIXED:
{
encode2( index, bits);
INSERT(d, mode, 1);
INSERT(d, alpha, 3);
INSERT(d, c[3], 15);
INSERT(d, c[2], 15);
INSERT(d, c[1], 15);
INSERT(d, c[0], 15);
bits[2] = (FxU32) d;
bits[3] = (FxU32) (d >> 32);
}
break;
case TCC_CHROMA:
{
encode2( index, bits);
INSERT(d, mode, 3);
INSERT(d, 0, 1); // pad
INSERT(d, c[3], 15);
INSERT(d, c[2], 15);
INSERT(d, c[1], 15);
INSERT(d, c[0], 15);
bits[2] = (FxU32) d;
bits[3] = (FxU32) (d >> 32);
}
break;
case TCC_ALPHA:
{
encode2( index, bits);
INSERT(d, mode, 3);
INSERT(d, alpha, 1); // interpolate
INSERT(d, (c[2]>>15), 5);
INSERT(d, (c[1]>>15), 5);
INSERT(d, (c[0]>>15), 5);
INSERT(d, (c[2]&0x7fff), 15);
INSERT(d, (c[1]&0x7fff), 15);
INSERT(d, (c[0]&0x7fff), 15);
bits[2] = (FxU32) d;
bits[3] = (FxU32) (d >> 32);
}
break;
}
}
#if 0
/* For testing low level encoding */
int
rand32() { return (rand() << 16) | (rand() & 0xffff); }
main()
{
FxU32 imode, icol[4], iindex[32], bits[4];
FxU32 omode, ocol[4], oindex[32];
int n, i, mask, passed;
int stats[4] = {0};
for (n=0; n<1000000; n++) {
imode = rand() & 3;
switch(imode) {
case 0:
icol[0] = rand32() & 0x7fff;
icol[1] = rand32() & 0x7fff;
icol[2] = 0;
icol[3] = 0;
mask = 7;
break;
case 1:
icol[0] = rand32() & 0x7fffffff;
icol[1] = rand32() & 0x7fffffff;
icol[2] = 0;
icol[3] = 0;
mask = 3;
break;
case 2:
icol[0] = rand32() & 0x7fff;
icol[1] = rand32() & 0x7fff;
icol[2] = rand32() & 0x7fff;
icol[3] = rand32() & 0x7fff;
mask = 3;
break;
case 3:
icol[0] = rand32() & 0xfffff;
icol[1] = rand32() & 0xfffff;
icol[2] = rand32() & 0xfffff;
icol[3] = 0;
mask = 3;
break;
}
stats[imode]++;
for (i=0; i<32; i++) iindex[i] = rand() & mask;
/* encode this block, decode */
encoder( imode, icol, iindex, bits);
omode = decoder( bits, ocol, oindex);
/* verify */
passed = 1;
for (i=0; i<4; i++) passed &= (icol[i] == ocol[i]);
if (!passed) printf("Failed colors\n");
for (i=0; i<32; i++) passed &= (iindex[i] == oindex[i]);
if (!passed) printf("Failed index\n");
passed &= (imode == omode);
if (!passed) printf("Failed mode\n");
if (!passed) {
for (i=0; i<32; i++) printf("%d", iindex[i]); printf("\n");
for (i=0; i<32; i++) printf("%d", oindex[i]); printf("\n");
for (i=0; i< 4; i++) printf("%.08x ", icol[i]); printf("\n");
for (i=0; i< 4; i++) printf("%.08x ", ocol[i]); printf("\n");
printf("imode = %d, omode = %d\n", imode, omode);
exit(0);
}
if ((n % 100000) == 0) printf("%8d %8d %8d %8d %8d\n", n,
stats[0], stats[1], stats[2], stats[3]);
}
}
#endif
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