mirror of
https://github.com/python-pillow/Pillow.git
synced 2024-12-25 17:36:18 +03:00
0477278c68
BC5 decoding uses only 2 channels instead of 4. The current algorithm did not initialize the RGBA struct which resulted in random values in the output image. This commit should initialize the decoded RGBA struct, thus setting B and A values to default (0).
857 lines
22 KiB
C
857 lines
22 KiB
C
/*
|
|
* The Python Imaging Library
|
|
*
|
|
* decoder for DXTn-compressed data
|
|
*
|
|
* Format documentation:
|
|
* http://oss.sgi.com/projects/ogl-sample/registry/EXT/texture_compression_s3tc.txt
|
|
*
|
|
* The contents of this file are in the public domain (CC0)
|
|
* Full text of the CC0 license:
|
|
* https://creativecommons.org/publicdomain/zero/1.0/
|
|
*/
|
|
|
|
|
|
#include "Imaging.h"
|
|
|
|
|
|
typedef struct {
|
|
UINT8 r, g, b, a;
|
|
} rgba;
|
|
|
|
typedef struct {
|
|
UINT8 l;
|
|
} lum;
|
|
|
|
typedef struct {
|
|
FLOAT32 r, g, b;
|
|
} rgb32f;
|
|
|
|
typedef struct {
|
|
UINT16 c0, c1;
|
|
UINT32 lut;
|
|
} bc1_color;
|
|
|
|
typedef struct {
|
|
UINT8 a0, a1;
|
|
UINT8 lut[6];
|
|
} bc3_alpha;
|
|
|
|
#define LOAD16(p) \
|
|
(p)[0] | ((p)[1] << 8)
|
|
|
|
#define LOAD32(p) \
|
|
(p)[0] | ((p)[1] << 8) | ((p)[2] << 16) | ((p)[3] << 24)
|
|
|
|
static void bc1_color_load(bc1_color *dst, const UINT8 *src) {
|
|
dst->c0 = LOAD16(src);
|
|
dst->c1 = LOAD16(src + 2);
|
|
dst->lut = LOAD32(src + 4);
|
|
}
|
|
|
|
static void bc3_alpha_load(bc3_alpha *dst, const UINT8 *src) {
|
|
memcpy(dst, src, sizeof(bc3_alpha));
|
|
}
|
|
|
|
static rgba decode_565(UINT16 x) {
|
|
rgba c;
|
|
int r, g, b;
|
|
r = (x & 0xf800) >> 8;
|
|
r |= r >> 5;
|
|
c.r = r;
|
|
g = (x & 0x7e0) >> 3;
|
|
g |= g >> 6;
|
|
c.g = g;
|
|
b = (x & 0x1f) << 3;
|
|
b |= b >> 5;
|
|
c.b = b;
|
|
c.a = 0xff;
|
|
return c;
|
|
}
|
|
|
|
static void decode_bc1_color(rgba *dst, const UINT8 *src) {
|
|
bc1_color col;
|
|
rgba p[4];
|
|
int n, cw;
|
|
UINT16 r0, g0, b0, r1, g1, b1;
|
|
bc1_color_load(&col, src);
|
|
|
|
p[0] = decode_565(col.c0);
|
|
r0 = p[0].r;
|
|
g0 = p[0].g;
|
|
b0 = p[0].b;
|
|
p[1] = decode_565(col.c1);
|
|
r1 = p[1].r;
|
|
g1 = p[1].g;
|
|
b1 = p[1].b;
|
|
if (col.c0 > col.c1) {
|
|
p[2].r = (2*r0 + 1*r1) / 3;
|
|
p[2].g = (2*g0 + 1*g1) / 3;
|
|
p[2].b = (2*b0 + 1*b1) / 3;
|
|
p[2].a = 0xff;
|
|
p[3].r = (1*r0 + 2*r1) / 3;
|
|
p[3].g = (1*g0 + 2*g1) / 3;
|
|
p[3].b = (1*b0 + 2*b1) / 3;
|
|
p[3].a = 0xff;
|
|
} else {
|
|
p[2].r = (r0 + r1) / 2;
|
|
p[2].g = (g0 + g1) / 2;
|
|
p[2].b = (b0 + b1) / 2;
|
|
p[2].a = 0xff;
|
|
p[3].r = 0;
|
|
p[3].g = 0;
|
|
p[3].b = 0;
|
|
p[3].a = 0;
|
|
}
|
|
for (n = 0; n < 16; n++) {
|
|
cw = 3 & (col.lut >> (2 * n));
|
|
dst[n] = p[cw];
|
|
}
|
|
}
|
|
|
|
static void decode_bc3_alpha(char *dst, const UINT8 *src, int stride, int o) {
|
|
bc3_alpha b;
|
|
UINT16 a0, a1;
|
|
UINT8 a[8];
|
|
int n, lut, aw;
|
|
bc3_alpha_load(&b, src);
|
|
|
|
a0 = b.a0;
|
|
a1 = b.a1;
|
|
a[0] = (UINT8)a0;
|
|
a[1] = (UINT8)a1;
|
|
if (a0 > a1) {
|
|
a[2] = (6*a0 + 1*a1) / 7;
|
|
a[3] = (5*a0 + 2*a1) / 7;
|
|
a[4] = (4*a0 + 3*a1) / 7;
|
|
a[5] = (3*a0 + 4*a1) / 7;
|
|
a[6] = (2*a0 + 5*a1) / 7;
|
|
a[7] = (1*a0 + 6*a1) / 7;
|
|
} else {
|
|
a[2] = (4*a0 + 1*a1) / 5;
|
|
a[3] = (3*a0 + 2*a1) / 5;
|
|
a[4] = (2*a0 + 3*a1) / 5;
|
|
a[5] = (1*a0 + 4*a1) / 5;
|
|
a[6] = 0;
|
|
a[7] = 0xff;
|
|
}
|
|
lut = b.lut[0] | (b.lut[1] << 8) | (b.lut[2] << 16);
|
|
for (n = 0; n < 8; n++) {
|
|
aw = 7 & (lut >> (3 * n));
|
|
dst[stride * n + o] = a[aw];
|
|
}
|
|
lut = b.lut[3] | (b.lut[4] << 8) | (b.lut[5] << 16);
|
|
for (n = 0; n < 8; n++) {
|
|
aw = 7 & (lut >> (3 * n));
|
|
dst[stride * (8+n) + o] = a[aw];
|
|
}
|
|
}
|
|
|
|
static void decode_bc1_block(rgba *col, const UINT8* src) {
|
|
decode_bc1_color(col, src);
|
|
}
|
|
|
|
static void decode_bc2_block(rgba *col, const UINT8* src) {
|
|
int n, bitI, byI, av;
|
|
decode_bc1_color(col, src + 8);
|
|
for (n = 0; n < 16; n++) {
|
|
bitI = n * 4;
|
|
byI = bitI >> 3;
|
|
av = 0xf & (src[byI] >> (bitI & 7));
|
|
av = (av << 4) | av;
|
|
col[n].a = av;
|
|
}
|
|
}
|
|
|
|
static void decode_bc3_block(rgba *col, const UINT8* src) {
|
|
decode_bc1_color(col, src + 8);
|
|
decode_bc3_alpha((char *)col, src, sizeof(col[0]), 3);
|
|
}
|
|
|
|
static void decode_bc4_block(lum *col, const UINT8* src) {
|
|
decode_bc3_alpha((char *)col, src, sizeof(col[0]), 0);
|
|
}
|
|
|
|
static void decode_bc5_block(rgba *col, const UINT8* src) {
|
|
decode_bc3_alpha((char *)col, src, sizeof(col[0]), 0);
|
|
decode_bc3_alpha((char *)col, src + 8, sizeof(col[0]), 1);
|
|
}
|
|
|
|
/* BC6 and BC7 are described here:
|
|
https://www.opengl.org/registry/specs/ARB/texture_compression_bptc.txt */
|
|
|
|
static UINT8 get_bit(const UINT8* src, int bit) {
|
|
int by = bit >> 3;
|
|
bit &= 7;
|
|
return (src[by] >> bit) & 1;
|
|
}
|
|
|
|
static UINT8 get_bits(const UINT8* src, int bit, int count) {
|
|
UINT8 v;
|
|
int x;
|
|
int by = bit >> 3;
|
|
bit &= 7;
|
|
if (!count) {
|
|
return 0;
|
|
}
|
|
if (bit + count <= 8) {
|
|
v = (src[by] >> bit) & ((1 << count) - 1);
|
|
} else {
|
|
x = src[by] | (src[by+1] << 8);
|
|
v = (x >> bit) & ((1 << count) - 1);
|
|
}
|
|
return v;
|
|
}
|
|
|
|
/* BC7 */
|
|
typedef struct {
|
|
char ns;
|
|
char pb;
|
|
char rb;
|
|
char isb;
|
|
char cb;
|
|
char ab;
|
|
char epb;
|
|
char spb;
|
|
char ib;
|
|
char ib2;
|
|
} bc7_mode_info;
|
|
|
|
static const bc7_mode_info bc7_modes[] = {
|
|
{3, 4, 0, 0, 4, 0, 1, 0, 3, 0},
|
|
{2, 6, 0, 0, 6, 0, 0, 1, 3, 0},
|
|
{3, 6, 0, 0, 5, 0, 0, 0, 2, 0},
|
|
{2, 6, 0, 0, 7, 0, 1, 0, 2, 0},
|
|
{1, 0, 2, 1, 5, 6, 0, 0, 2, 3},
|
|
{1, 0, 2, 0, 7, 8, 0, 0, 2, 2},
|
|
{1, 0, 0, 0, 7, 7, 1, 0, 4, 0},
|
|
{2, 6, 0, 0, 5, 5, 1, 0, 2, 0}
|
|
};
|
|
|
|
/* Subset indices:
|
|
Table.P2, 1 bit per index */
|
|
static const UINT16 bc7_si2[] = {
|
|
0xcccc, 0x8888, 0xeeee, 0xecc8, 0xc880, 0xfeec, 0xfec8, 0xec80,
|
|
0xc800, 0xffec, 0xfe80, 0xe800, 0xffe8, 0xff00, 0xfff0, 0xf000,
|
|
0xf710, 0x008e, 0x7100, 0x08ce, 0x008c, 0x7310, 0x3100, 0x8cce,
|
|
0x088c, 0x3110, 0x6666, 0x366c, 0x17e8, 0x0ff0, 0x718e, 0x399c,
|
|
0xaaaa, 0xf0f0, 0x5a5a, 0x33cc, 0x3c3c, 0x55aa, 0x9696, 0xa55a,
|
|
0x73ce, 0x13c8, 0x324c, 0x3bdc, 0x6996, 0xc33c, 0x9966, 0x0660,
|
|
0x0272, 0x04e4, 0x4e40, 0x2720, 0xc936, 0x936c, 0x39c6, 0x639c,
|
|
0x9336, 0x9cc6, 0x817e, 0xe718, 0xccf0, 0x0fcc, 0x7744, 0xee22};
|
|
|
|
/* Table.P3, 2 bits per index */
|
|
static const UINT32 bc7_si3[] = {
|
|
0xaa685050, 0x6a5a5040, 0x5a5a4200, 0x5450a0a8,
|
|
0xa5a50000, 0xa0a05050, 0x5555a0a0, 0x5a5a5050,
|
|
0xaa550000, 0xaa555500, 0xaaaa5500, 0x90909090,
|
|
0x94949494, 0xa4a4a4a4, 0xa9a59450, 0x2a0a4250,
|
|
0xa5945040, 0x0a425054, 0xa5a5a500, 0x55a0a0a0,
|
|
0xa8a85454, 0x6a6a4040, 0xa4a45000, 0x1a1a0500,
|
|
0x0050a4a4, 0xaaa59090, 0x14696914, 0x69691400,
|
|
0xa08585a0, 0xaa821414, 0x50a4a450, 0x6a5a0200,
|
|
0xa9a58000, 0x5090a0a8, 0xa8a09050, 0x24242424,
|
|
0x00aa5500, 0x24924924, 0x24499224, 0x50a50a50,
|
|
0x500aa550, 0xaaaa4444, 0x66660000, 0xa5a0a5a0,
|
|
0x50a050a0, 0x69286928, 0x44aaaa44, 0x66666600,
|
|
0xaa444444, 0x54a854a8, 0x95809580, 0x96969600,
|
|
0xa85454a8, 0x80959580, 0xaa141414, 0x96960000,
|
|
0xaaaa1414, 0xa05050a0, 0xa0a5a5a0, 0x96000000,
|
|
0x40804080, 0xa9a8a9a8, 0xaaaaaa44, 0x2a4a5254};
|
|
|
|
/* Anchor indices:
|
|
Table.A2 */
|
|
static const char bc7_ai0[] = {
|
|
15,15,15,15,15,15,15,15,
|
|
15,15,15,15,15,15,15,15,
|
|
15, 2, 8, 2, 2, 8, 8,15,
|
|
2, 8, 2, 2, 8, 8, 2, 2,
|
|
15,15, 6, 8, 2, 8,15,15,
|
|
2, 8, 2, 2, 2,15,15, 6,
|
|
6, 2, 6, 8,15,15, 2, 2,
|
|
15,15,15,15,15, 2, 2,15};
|
|
|
|
/* Table.A3a */
|
|
static const char bc7_ai1[] = {
|
|
3, 3,15,15, 8, 3,15,15,
|
|
8, 8, 6, 6, 6, 5, 3, 3,
|
|
3, 3, 8,15, 3, 3, 6,10,
|
|
5, 8, 8, 6, 8, 5,15,15,
|
|
8,15, 3, 5, 6,10, 8,15,
|
|
15, 3,15, 5,15,15,15,15,
|
|
3,15, 5, 5, 5, 8, 5,10,
|
|
5,10, 8,13,15,12, 3, 3};
|
|
|
|
/* Table.A3b */
|
|
static const char bc7_ai2[] = {
|
|
15, 8, 8, 3,15,15, 3, 8,
|
|
15,15,15,15,15,15,15, 8,
|
|
15, 8,15, 3,15, 8,15, 8,
|
|
3,15, 6,10,15,15,10, 8,
|
|
15, 3,15,10,10, 8, 9,10,
|
|
6,15, 8,15, 3, 6, 6, 8,
|
|
15, 3,15,15,15,15,15,15,
|
|
15,15,15,15, 3,15,15, 8};
|
|
|
|
/* Interpolation weights */
|
|
static const char bc7_weights2[] = {0, 21, 43, 64};
|
|
static const char bc7_weights3[] = {0, 9, 18, 27, 37, 46, 55, 64};
|
|
static const char bc7_weights4[] = {
|
|
0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64};
|
|
|
|
static const char *bc7_get_weights(int n) {
|
|
if (n == 2) {
|
|
return bc7_weights2;
|
|
}
|
|
if (n == 3) {
|
|
return bc7_weights3;
|
|
}
|
|
return bc7_weights4;
|
|
}
|
|
|
|
static int bc7_get_subset(int ns, int partition, int n) {
|
|
if (ns == 2) {
|
|
return 1 & (bc7_si2[partition] >> n);
|
|
}
|
|
if (ns == 3) {
|
|
return 3 & (bc7_si3[partition] >> (2 * n));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static UINT8 expand_quantized(UINT8 v, int bits) {
|
|
v = v << (8 - bits);
|
|
return v | (v >> bits);
|
|
}
|
|
|
|
static void bc7_lerp(rgba *dst, const rgba *e, int s0, int s1) {
|
|
int t0 = 64 - s0;
|
|
int t1 = 64 - s1;
|
|
dst->r = (UINT8)((t0 * e[0].r + s0 * e[1].r + 32) >> 6);
|
|
dst->g = (UINT8)((t0 * e[0].g + s0 * e[1].g + 32) >> 6);
|
|
dst->b = (UINT8)((t0 * e[0].b + s0 * e[1].b + 32) >> 6);
|
|
dst->a = (UINT8)((t1 * e[0].a + s1 * e[1].a + 32) >> 6);
|
|
}
|
|
|
|
static void decode_bc7_block(rgba *col, const UINT8* src) {
|
|
rgba endpoints[6];
|
|
int bit = 0, cibit, aibit;
|
|
int mode = src[0];
|
|
int i, j;
|
|
int numep, cb, ab, ib, ib2, i0, i1, s;
|
|
UINT8 index_sel, partition, rotation, val;
|
|
const char *cw, *aw;
|
|
const bc7_mode_info *info;
|
|
|
|
/* mode is the number of unset bits before the first set bit: */
|
|
if (!mode) {
|
|
/* degenerate case when no bits set */
|
|
for (i = 0; i < 16; i++) {
|
|
col[i].r = col[i].g = col[i].b = 0;
|
|
col[i].a = 255;
|
|
}
|
|
return;
|
|
}
|
|
while (!(mode & (1 << bit++))) ;
|
|
mode = bit - 1;
|
|
info = &bc7_modes[mode];
|
|
/* color selection bits: {subset}{endpoint} */
|
|
cb = info->cb;
|
|
ab = info->ab;
|
|
cw = bc7_get_weights(info->ib);
|
|
aw = bc7_get_weights((ab && info->ib2) ? info->ib2 : info->ib);
|
|
|
|
#define LOAD(DST, N) \
|
|
DST = get_bits(src, bit, N); \
|
|
bit += N;
|
|
LOAD(partition, info->pb);
|
|
LOAD(rotation, info->rb);
|
|
LOAD(index_sel, info->isb);
|
|
numep = info->ns << 1;
|
|
|
|
/* red */
|
|
for (i = 0; i < numep; i++) {
|
|
LOAD(val, cb);
|
|
endpoints[i].r = val;
|
|
}
|
|
|
|
/* green */
|
|
for (i = 0; i < numep; i++) {
|
|
LOAD(val, cb);
|
|
endpoints[i].g = val;
|
|
}
|
|
|
|
/* blue */
|
|
for (i = 0; i < numep; i++) {
|
|
LOAD(val, cb);
|
|
endpoints[i].b = val;
|
|
}
|
|
|
|
/* alpha */
|
|
for (i = 0; i < numep; i++) {
|
|
if (ab) {
|
|
LOAD(val, ab);
|
|
} else {
|
|
val = 255;
|
|
}
|
|
endpoints[i].a = val;
|
|
}
|
|
|
|
/* p-bits */
|
|
#define ASSIGN_P(x) x = (x << 1) | val
|
|
if (info->epb) {
|
|
/* per endpoint */
|
|
cb++;
|
|
if (ab) {
|
|
ab++;
|
|
}
|
|
for (i = 0; i < numep; i++) {
|
|
LOAD(val, 1);
|
|
ASSIGN_P(endpoints[i].r);
|
|
ASSIGN_P(endpoints[i].g);
|
|
ASSIGN_P(endpoints[i].b);
|
|
if (ab) {
|
|
ASSIGN_P(endpoints[i].a);
|
|
}
|
|
}
|
|
}
|
|
if (info->spb) {
|
|
/* per subset */
|
|
cb++;
|
|
if (ab) {
|
|
ab++;
|
|
}
|
|
for (i = 0; i < numep; i+=2) {
|
|
LOAD(val, 1);
|
|
for (j = 0; j < 2; j++) {
|
|
ASSIGN_P(endpoints[i+j].r);
|
|
ASSIGN_P(endpoints[i+j].g);
|
|
ASSIGN_P(endpoints[i+j].b);
|
|
if (ab) {
|
|
ASSIGN_P(endpoints[i+j].a);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#undef ASSIGN_P
|
|
#define EXPAND(x, b) x = expand_quantized(x, b)
|
|
for (i = 0; i < numep; i++) {
|
|
EXPAND(endpoints[i].r, cb);
|
|
EXPAND(endpoints[i].g, cb);
|
|
EXPAND(endpoints[i].b, cb);
|
|
if (ab) {
|
|
EXPAND(endpoints[i].a, ab);
|
|
}
|
|
}
|
|
#undef EXPAND
|
|
#undef LOAD
|
|
cibit = bit;
|
|
aibit = cibit + 16 * info->ib - info->ns;
|
|
for (i = 0; i < 16; i++) {
|
|
s = bc7_get_subset(info->ns, partition, i) << 1;
|
|
ib = info->ib;
|
|
if (i == 0) {
|
|
ib--;
|
|
} else if (info->ns == 2) {
|
|
if (i == bc7_ai0[partition]) {
|
|
ib--;
|
|
}
|
|
} else if (info->ns == 3) {
|
|
if (i == bc7_ai1[partition]) {
|
|
ib--;
|
|
} else if (i == bc7_ai2[partition]) {
|
|
ib--;
|
|
}
|
|
}
|
|
i0 = get_bits(src, cibit, ib);
|
|
cibit += ib;
|
|
|
|
if (ab && info->ib2) {
|
|
ib2 = info->ib2;
|
|
if (ib2 && i == 0) {
|
|
ib2--;
|
|
}
|
|
i1 = get_bits(src, aibit, ib2);
|
|
aibit += ib2;
|
|
if (index_sel) {
|
|
bc7_lerp(&col[i], &endpoints[s], aw[i1], cw[i0]);
|
|
} else {
|
|
bc7_lerp(&col[i], &endpoints[s], cw[i0], aw[i1]);
|
|
}
|
|
} else {
|
|
bc7_lerp(&col[i], &endpoints[s], cw[i0], cw[i0]);
|
|
}
|
|
#define ROTATE(x, y) \
|
|
val = x; \
|
|
x = y; \
|
|
y = val
|
|
if (rotation == 1) {
|
|
ROTATE(col[i].r, col[i].a);
|
|
} else if (rotation == 2) {
|
|
ROTATE(col[i].g, col[i].a);
|
|
} else if (rotation == 3) {
|
|
ROTATE(col[i].b, col[i].a);
|
|
}
|
|
#undef ROTATE
|
|
}
|
|
}
|
|
|
|
/* BC6 */
|
|
typedef struct {
|
|
char ns; /* number of subsets (also called regions) */
|
|
char tr; /* whether endpoints are delta-compressed */
|
|
char pb; /* partition bits */
|
|
char epb; /* endpoint bits */
|
|
char rb; /* red bits (delta) */
|
|
char gb; /* green bits (delta) */
|
|
char bb; /* blue bits (delta) */
|
|
} bc6_mode_info;
|
|
|
|
static const bc6_mode_info bc6_modes[] = {
|
|
// 00
|
|
{2, 1, 5, 10, 5, 5, 5},
|
|
// 01
|
|
{2, 1, 5, 7, 6, 6, 6},
|
|
// 10
|
|
{2, 1, 5, 11, 5, 4, 4},
|
|
{2, 1, 5, 11, 4, 5, 4},
|
|
{2, 1, 5, 11, 4, 4, 5},
|
|
{2, 1, 5, 9, 5, 5, 5},
|
|
{2, 1, 5, 8, 6, 5, 5},
|
|
{2, 1, 5, 8, 5, 6, 5},
|
|
{2, 1, 5, 8, 5, 5, 6},
|
|
{2, 0, 5, 6, 6, 6, 6},
|
|
// 11
|
|
{1, 0, 0, 10, 10, 10, 10},
|
|
{1, 1, 0, 11, 9, 9, 9},
|
|
{1, 1, 0, 12, 8, 8, 8},
|
|
{1, 1, 0, 16, 4, 4, 4}
|
|
};
|
|
|
|
/* Table.F, encoded as a sequence of bit indices */
|
|
static const UINT8 bc6_bit_packings[][75] = {
|
|
{116, 132, 176, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22,
|
|
23, 24, 25, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52,
|
|
164, 112, 113, 114, 115, 64, 65, 66, 67, 68, 172, 160, 161, 162, 163, 80,
|
|
81, 82, 83, 84, 173, 128, 129, 130, 131, 96, 97, 98, 99, 100, 174, 144,
|
|
145, 146, 147, 148, 175},
|
|
{117, 164, 165, 0, 1, 2, 3, 4, 5, 6, 172, 173, 132, 16, 17, 18, 19, 20, 21,
|
|
22, 133, 174, 116, 32, 33, 34, 35, 36, 37, 38, 175, 177, 176, 48, 49, 50,
|
|
51, 52, 53, 112, 113, 114, 115, 64, 65, 66, 67, 68, 69, 160, 161, 162, 163,
|
|
80, 81, 82, 83, 84, 85, 128, 129, 130, 131, 96, 97, 98, 99, 100, 101, 144,
|
|
145, 146, 147, 148, 149},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 32,
|
|
33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 10, 112, 113, 114,
|
|
115, 64, 65, 66, 67, 26, 172, 160, 161, 162, 163, 80, 81, 82, 83, 42, 173,
|
|
128, 129, 130, 131, 96, 97, 98, 99, 100, 174, 144, 145, 146, 147, 148,
|
|
175},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 32,
|
|
33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 10, 164, 112, 113, 114,
|
|
115, 64, 65, 66, 67, 68, 26, 160, 161, 162, 163, 80, 81, 82, 83, 42, 173,
|
|
128, 129, 130, 131, 96, 97, 98, 99, 172, 174, 144, 145, 146, 147, 116,
|
|
175},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 32,
|
|
33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 10, 132, 112, 113, 114,
|
|
115, 64, 65, 66, 67, 26, 172, 160, 161, 162, 163, 80, 81, 82, 83, 84, 42,
|
|
128, 129, 130, 131, 96, 97, 98, 99, 173, 174, 144, 145, 146, 147, 176,
|
|
175},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 132, 16, 17, 18, 19, 20, 21, 22, 23, 24, 116,
|
|
32, 33, 34, 35, 36, 37, 38, 39, 40, 176, 48, 49, 50, 51, 52, 164, 112, 113,
|
|
114, 115, 64, 65, 66, 67, 68, 172, 160, 161, 162, 163, 80, 81, 82, 83, 84,
|
|
173, 128, 129, 130, 131, 96, 97, 98, 99, 100, 174, 144, 145, 146, 147, 148,
|
|
175},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 164, 132, 16, 17, 18, 19, 20, 21, 22, 23, 174, 116,
|
|
32, 33, 34, 35, 36, 37, 38, 39, 175, 176, 48, 49, 50, 51, 52, 53, 112, 113,
|
|
114, 115, 64, 65, 66, 67, 68, 172, 160, 161, 162, 163, 80, 81, 82, 83, 84,
|
|
173, 128, 129, 130, 131, 96, 97, 98, 99, 100, 101, 144, 145, 146, 147, 148,
|
|
149},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 172, 132, 16, 17, 18, 19, 20, 21, 22, 23, 117, 116,
|
|
32, 33, 34, 35, 36, 37, 38, 39, 165, 176, 48, 49, 50, 51, 52, 164, 112,
|
|
113, 114, 115, 64, 65, 66, 67, 68, 69, 160, 161, 162, 163, 80, 81, 82, 83,
|
|
84, 173, 128, 129, 130, 131, 96, 97, 98, 99, 100, 174, 144, 145, 146, 147,
|
|
148, 175},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 173, 132, 16, 17, 18, 19, 20, 21, 22, 23, 133, 116,
|
|
32, 33, 34, 35, 36, 37, 38, 39, 177, 176, 48, 49, 50, 51, 52, 164, 112,
|
|
113, 114, 115, 64, 65, 66, 67, 68, 172, 160, 161, 162, 163, 80, 81, 82, 83,
|
|
84, 85, 128, 129, 130, 131, 96, 97, 98, 99, 100, 174, 144, 145, 146, 147,
|
|
148, 175},
|
|
{0, 1, 2, 3, 4, 5, 164, 172, 173, 132, 16, 17, 18, 19, 20, 21, 117, 133,
|
|
174, 116, 32, 33, 34, 35, 36, 37, 165, 175, 177, 176, 48, 49, 50, 51, 52,
|
|
53, 112, 113, 114, 115, 64, 65, 66, 67, 68, 69, 160, 161, 162, 163, 80, 81,
|
|
82, 83, 84, 85, 128, 129, 130, 131, 96, 97, 98, 99, 100, 101, 144, 145,
|
|
146, 147, 148, 149},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 32,
|
|
33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
|
|
64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 80, 81, 82, 83, 84, 85, 86, 87, 88,
|
|
89},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 32,
|
|
33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 56, 10,
|
|
64, 65, 66, 67, 68, 69, 70, 71, 72, 26, 80, 81, 82, 83, 84, 85, 86, 87, 88,
|
|
42},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 32,
|
|
33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 11, 10,
|
|
64, 65, 66, 67, 68, 69, 70, 71, 27, 26, 80, 81, 82, 83, 84, 85, 86, 87, 43,
|
|
42},
|
|
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 32,
|
|
33, 34, 35, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 15, 14, 13, 12, 11, 10,
|
|
64, 65, 66, 67, 31, 30, 29, 28, 27, 26, 80, 81, 82, 83, 47, 46, 45, 44, 43,
|
|
42}};
|
|
|
|
static void bc6_sign_extend(UINT16 *v, int prec) {
|
|
int x = *v;
|
|
if (x & (1 << (prec - 1))) {
|
|
x |= -1 << prec;
|
|
}
|
|
*v = (UINT16)x;
|
|
}
|
|
|
|
static int bc6_unquantize(UINT16 v, int prec, int sign) {
|
|
int s = 0;
|
|
int x;
|
|
if (!sign) {
|
|
x = v;
|
|
if (prec >= 15) return x;
|
|
if (x == 0) return 0;
|
|
if (x == ((1 << prec) - 1)) {
|
|
return 0xffff;
|
|
}
|
|
return ((x << 15) + 0x4000) >> (prec - 1);
|
|
} else {
|
|
x = (INT16)v;
|
|
if (prec >= 16) return x;
|
|
if (x < 0) {
|
|
s = 1;
|
|
x = -x;
|
|
}
|
|
|
|
if (x != 0) {
|
|
if (x >= ((1 << (prec - 1)) - 1)) {
|
|
x = 0x7fff;
|
|
} else {
|
|
x = ((x << 15) + 0x4000) >> (prec - 1);
|
|
}
|
|
}
|
|
|
|
if (s) {
|
|
return -x;
|
|
}
|
|
return x;
|
|
}
|
|
}
|
|
|
|
static float half_to_float(UINT16 h) {
|
|
/* https://gist.github.com/rygorous/2144712 */
|
|
union {
|
|
UINT32 u;
|
|
float f;
|
|
} o, m;
|
|
m.u = 0x77800000;
|
|
o.u = (h & 0x7fff) << 13;
|
|
o.f *= m.f;
|
|
m.u = 0x47800000;
|
|
if (o.f >= m.f) {
|
|
o.u |= 255 << 23;
|
|
}
|
|
o.u |= (h & 0x8000) << 16;
|
|
return o.f;
|
|
}
|
|
|
|
static float bc6_finalize(int v, int sign) {
|
|
if (sign) {
|
|
if (v < 0) {
|
|
v = ((-v) * 31) / 32;
|
|
return half_to_float((UINT16)(0x8000 | v));
|
|
} else {
|
|
return half_to_float((UINT16)((v * 31) / 32));
|
|
}
|
|
} else {
|
|
return half_to_float((UINT16)((v * 31) / 64));
|
|
}
|
|
}
|
|
|
|
static void bc6_lerp(rgb32f *col, int *e0, int *e1, int s, int sign) {
|
|
int r, g, b;
|
|
int t = 64 - s;
|
|
r = (e0[0] * t + e1[0] * s) >> 6;
|
|
g = (e0[1] * t + e1[1] * s) >> 6;
|
|
b = (e0[2] * t + e1[2] * s) >> 6;
|
|
col->r = bc6_finalize(r, sign);
|
|
col->g = bc6_finalize(g, sign);
|
|
col->b = bc6_finalize(b, sign);
|
|
}
|
|
|
|
static void decode_bc6_block(rgb32f *col, const UINT8* src, int sign) {
|
|
UINT16 endpoints[12]; /* storage for r0, g0, b0, r1, ... */
|
|
int ueps[12];
|
|
int i, i0, ib2, di, dw, mask, numep, s;
|
|
UINT8 partition;
|
|
const bc6_mode_info *info;
|
|
const char *cw;
|
|
int bit = 5;
|
|
int epbits = 75;
|
|
int ib = 3;
|
|
int mode = src[0] & 0x1f;
|
|
if ((mode & 3) == 0 || (mode & 3) == 1) {
|
|
mode &= 3;
|
|
bit = 2;
|
|
} else if ((mode & 3) == 2) {
|
|
mode = 2 + (mode >> 2);
|
|
epbits = 72;
|
|
} else {
|
|
mode = 10 + (mode >> 2);
|
|
epbits = 60;
|
|
ib = 4;
|
|
}
|
|
if (mode >= 14) {
|
|
/* invalid block */
|
|
memset(col, 0, 16 * sizeof(col[0]));
|
|
return;
|
|
}
|
|
info = &bc6_modes[mode];
|
|
cw = bc7_get_weights(ib);
|
|
numep = info->ns == 2 ? 12 : 6;
|
|
for (i = 0; i < 12; i++) {
|
|
endpoints[i] = 0;
|
|
}
|
|
for (i = 0; i < epbits; i++) {
|
|
di = bc6_bit_packings[mode][i];
|
|
dw = di >> 4;
|
|
di &= 15;
|
|
endpoints[dw] |= (UINT16)get_bit(src, bit + i) << di;
|
|
}
|
|
bit += epbits;
|
|
partition = get_bits(src, bit, info->pb);
|
|
bit += info->pb;
|
|
mask = (1 << info->epb) - 1;
|
|
if (sign) { /* sign-extend e0 if signed */
|
|
bc6_sign_extend(&endpoints[0], info->epb);
|
|
bc6_sign_extend(&endpoints[1], info->epb);
|
|
bc6_sign_extend(&endpoints[2], info->epb);
|
|
}
|
|
if (sign || info->tr) { /* sign-extend e1,2,3 if signed or deltas */
|
|
for (i = 3; i < numep; i += 3) {
|
|
bc6_sign_extend(&endpoints[i+0], info->rb);
|
|
bc6_sign_extend(&endpoints[i+1], info->gb);
|
|
bc6_sign_extend(&endpoints[i+2], info->bb);
|
|
}
|
|
}
|
|
if (info->tr) { /* apply deltas */
|
|
for (i = 3; i < numep; i++) {
|
|
endpoints[i] = (endpoints[i] + endpoints[0]) & mask;
|
|
}
|
|
if (sign) {
|
|
for (i = 3; i < numep; i += 3) {
|
|
bc6_sign_extend(&endpoints[i+0], info->rb);
|
|
bc6_sign_extend(&endpoints[i+1], info->gb);
|
|
bc6_sign_extend(&endpoints[i+2], info->bb);
|
|
}
|
|
}
|
|
}
|
|
for (i = 0; i < numep; i++) {
|
|
ueps[i] = bc6_unquantize(endpoints[i], info->epb, sign);
|
|
}
|
|
for (i = 0; i < 16; i++) {
|
|
s = bc7_get_subset(info->ns, partition, i) * 6;
|
|
ib2 = ib;
|
|
if (i == 0) {
|
|
ib2--;
|
|
} else if (info->ns == 2) {
|
|
if (i == bc7_ai0[partition]) {
|
|
ib2--;
|
|
}
|
|
}
|
|
i0 = get_bits(src, bit, ib2);
|
|
bit += ib2;
|
|
|
|
bc6_lerp(&col[i], &ueps[s], &ueps[s+3], cw[i0], sign);
|
|
}
|
|
}
|
|
|
|
static void put_block(Imaging im, ImagingCodecState state, const char *col, int sz, int C) {
|
|
int width = state->xsize;
|
|
int height = state->ysize;
|
|
int xmax = width + state->xoff;
|
|
int ymax = height + state->yoff;
|
|
int j, i, y, x;
|
|
char *dst;
|
|
for (j = 0; j < 4; j++) {
|
|
y = state->y + j;
|
|
if (C) {
|
|
if (y >= height) {
|
|
continue;
|
|
}
|
|
if (state->ystep < 0) {
|
|
y = state->yoff + ymax - y - 1;
|
|
}
|
|
dst = im->image[y];
|
|
for (i = 0; i < 4; i++) {
|
|
x = state->x + i;
|
|
if (x >= width) {
|
|
continue;
|
|
}
|
|
memcpy(dst + sz*x, col + sz*(j*4 + i), sz);
|
|
}
|
|
} else {
|
|
if (state->ystep < 0) {
|
|
y = state->yoff + ymax - y - 1;
|
|
}
|
|
x = state->x;
|
|
dst = im->image[y] + sz*x;
|
|
memcpy(dst, col + sz*(j*4), 4 * sz);
|
|
}
|
|
}
|
|
state->x += 4;
|
|
if (state->x >= xmax) {
|
|
state->y += 4;
|
|
state->x = state->xoff;
|
|
}
|
|
}
|
|
|
|
static int decode_bcn(Imaging im, ImagingCodecState state, const UINT8* src, int bytes, int N, int C) {
|
|
int ymax = state->ysize + state->yoff;
|
|
const UINT8 *ptr = src;
|
|
switch (N) {
|
|
#define DECODE_LOOP(NN, SZ, TY, ...) \
|
|
case NN: \
|
|
while (bytes >= SZ) { \
|
|
TY col[16]; \
|
|
memset(col, 0, 16 * sizeof(col[0])); \
|
|
decode_bc##NN##_block(col, ptr); \
|
|
put_block(im, state, (const char *)col, sizeof(col[0]), C); \
|
|
ptr += SZ; \
|
|
bytes -= SZ; \
|
|
if (state->y >= ymax) return -1; \
|
|
} \
|
|
break
|
|
DECODE_LOOP(1, 8, rgba);
|
|
DECODE_LOOP(2, 16, rgba);
|
|
DECODE_LOOP(3, 16, rgba);
|
|
DECODE_LOOP(4, 8, lum);
|
|
DECODE_LOOP(5, 16, rgba);
|
|
case 6:
|
|
while (bytes >= 16) {
|
|
rgb32f col[16];
|
|
decode_bc6_block(col, ptr, (state->state >> 4) & 1);
|
|
put_block(im, state, (const char *)col, sizeof(col[0]), C);
|
|
ptr += 16;
|
|
bytes -= 16;
|
|
if (state->y >= ymax) return -1; \
|
|
}
|
|
break;
|
|
DECODE_LOOP(7, 16, rgba);
|
|
#undef DECODE_LOOP
|
|
}
|
|
return (int)(ptr - src);
|
|
}
|
|
|
|
int ImagingBcnDecode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes) {
|
|
int N = state->state & 0xf;
|
|
int width = state->xsize;
|
|
int height = state->ysize;
|
|
if ((width & 3) | (height & 3)) {
|
|
return decode_bcn(im, state, buf, bytes, N, 1);
|
|
} else {
|
|
return decode_bcn(im, state, buf, bytes, N, 0);
|
|
}
|
|
}
|