#include "fitz.h"
/* Unpack image samples and optionally pad pixels with opaque alpha */
#define get1(buf,x) ((buf[x >> 3] >> ( 7 - (x & 7) ) ) & 1 )
#define get2(buf,x) ((buf[x >> 2] >> ( ( 3 - (x & 3) ) << 1 ) ) & 3 )
#define get4(buf,x) ((buf[x >> 1] >> ( ( 1 - (x & 1) ) << 2 ) ) & 15 )
#define get8(buf,x) (buf[x])
#define get16(buf,x) (buf[x << 1])
static unsigned char get1_tab_1[256][8];
static unsigned char get1_tab_1p[256][16];
static unsigned char get1_tab_255[256][8];
static unsigned char get1_tab_255p[256][16];
static void
init_get1_tables(void)
{
static int once = 0;
unsigned char bits[1];
int i, k, x;
/* TODO: mutex lock here */
if (once)
return;
for (i = 0; i < 256; i++)
{
bits[0] = i;
for (k = 0; k < 8; k++)
{
x = get1(bits, k);
get1_tab_1[i][k] = x;
get1_tab_1p[i][k * 2] = x;
get1_tab_1p[i][k * 2 + 1] = 255;
get1_tab_255[i][k] = x * 255;
get1_tab_255p[i][k * 2] = x * 255;
get1_tab_255p[i][k * 2 + 1] = 255;
}
}
once = 1;
}
void
fz_unpack_tile(fz_pixmap *dst, unsigned char * restrict src, int n, int depth, int stride, int scale)
{
int pad, x, y, k;
int w = dst->w;
pad = 0;
if (dst->n > n)
pad = 255;
if (depth == 1)
init_get1_tables();
if (scale == 0)
{
switch (depth)
{
case 1: scale = 255; break;
case 2: scale = 85; break;
case 4: scale = 17; break;
}
}
for (y = 0; y < dst->h; y++)
{
unsigned char *sp = src + y * stride;
unsigned char *dp = dst->samples + y * (dst->w * dst->n);
/* Specialized loops */
if (n == 1 && depth == 1 && scale == 1 && !pad)
{
int w3 = w >> 3;
for (x = 0; x < w3; x++)
{
memcpy(dp
, get1_tab_1
[*sp
++], 8); dp += 8;
}
x = x << 3;
if (x < w)
memcpy(dp
, get1_tab_1
[*sp
], w
- x
); }
else if (n == 1 && depth == 1 && scale == 255 && !pad)
{
int w3 = w >> 3;
for (x = 0; x < w3; x++)
{
memcpy(dp
, get1_tab_255
[*sp
++], 8); dp += 8;
}
x = x << 3;
if (x < w)
memcpy(dp
, get1_tab_255
[*sp
], w
- x
); }
else if (n == 1 && depth == 1 && scale == 1 && pad)
{
int w3 = w >> 3;
for (x = 0; x < w3; x++)
{
memcpy(dp
, get1_tab_1p
[*sp
++], 16); dp += 16;
}
x = x << 3;
if (x < w)
memcpy(dp
, get1_tab_1p
[*sp
], (w
- x
) << 1); }
else if (n == 1 && depth == 1 && scale == 255 && pad)
{
int w3 = w >> 3;
for (x = 0; x < w3; x++)
{
memcpy(dp
, get1_tab_255p
[*sp
++], 16); dp += 16;
}
x = x << 3;
if (x < w)
memcpy(dp
, get1_tab_255p
[*sp
], (w
- x
) << 1); }
else if (depth == 8 && !pad)
{
int len = w * n;
while (len--)
*dp++ = *sp++;
}
else if (depth == 8 && pad)
{
for (x = 0; x < w; x++)
{
for (k = 0; k < n; k++)
*dp++ = *sp++;
*dp++ = 255;
}
}
else
{
int b = 0;
for (x = 0; x < w; x++)
{
for (k = 0; k < n; k++)
{
switch (depth)
{
case 1: *dp++ = get1(sp, b) * scale; break;
case 2: *dp++ = get2(sp, b) * scale; break;
case 4: *dp++ = get4(sp, b) * scale; break;
case 8: *dp++ = get8(sp, b); break;
case 16: *dp++ = get16(sp, b); break;
}
b++;
}
if (pad)
*dp++ = 255;
}
}
}
}
/* Apply decode array */
void
fz_decode_indexed_tile(fz_pixmap *pix, float *decode, int maxval)
{
int add[FZ_MAX_COLORS];
int mul[FZ_MAX_COLORS];
unsigned char *p = pix->samples;
int len = pix->w * pix->h;
int n = pix->n - 1;
int needed;
int k;
needed = 0;
for (k = 0; k < n; k++)
{
int min = decode[k * 2] * 256;
int max = decode[k * 2 + 1] * 256;
add[k] = min;
mul[k] = (max - min) / maxval;
needed |= min != 0 || max != maxval * 256;
}
if (!needed)
return;
while (len--)
{
for (k = 0; k < n; k++)
p[k] = (add[k] + (((p[k] << 8) * mul[k]) >> 8)) >> 8;
p += n + 1;
}
}
void
fz_decode_tile(fz_pixmap *pix, float *decode)
{
int add[FZ_MAX_COLORS];
int mul[FZ_MAX_COLORS];
unsigned char *p = pix->samples;
int len = pix->w * pix->h;
int n = MAX(1, pix->n - 1);
int needed;
int k;
needed = 0;
for (k = 0; k < n; k++)
{
int min = decode[k * 2] * 255;
int max = decode[k * 2 + 1] * 255;
add[k] = min;
mul[k] = max - min;
needed |= min != 0 || max != 255;
}
if (!needed)
return;
while (len--)
{
for (k = 0; k < n; k++)
p[k] = add[k] + fz_mul255(p[k], mul[k]);
p += pix->n;
}
}