static void
ycbcr709_to_rgba (const Babl *conversion,
char *src,
char *dst,
long n)
{
while (n--)
{
double luminance = ((double *) src)[0];
double cb = ((double *) src)[1];
double cr = ((double *) src)[2];
double red, green, blue;
red = 1.0 * luminance + 0.0 * cb + 1.5748 * cr;
green = 1.0 * luminance - 0.1873 * cb - 0.4681 * cr;
blue = 1.0 * luminance + 1.8556 * cb + 0.0 * cr;
red = gamma_2_2_to_linear (red);
green = gamma_2_2_to_linear (green);
blue = gamma_2_2_to_linear (blue);
((double *) dst)[0] = red;
((double *) dst)[1] = green;
((double *) dst)[2] = blue;
((double *) dst)[3] = 1.0;
src += sizeof (double) * 3;
dst += sizeof (double) * 4;
}
}
static void
hsv_to_rgba_step (char *src,
char *dst)
{
double hue = ((double *) src)[0];
double saturation = ((double *) src)[1];
double value = ((double *) src)[2];
double red = 0, green = 0, blue = 0;
double chroma, h_tmp, x, min;
chroma = saturation * value;
h_tmp = hue * 6.0;
x = chroma * (1.0 - fabs (fmod (h_tmp, 2.0) - 1.0));
if (h_tmp < 1.0)
{
red = chroma;
green = x;
}
else if (h_tmp < 2.0)
{
red = x;
green = chroma;
}
else if (h_tmp < 3.0)
{
green = chroma;
blue = x;
}
else if (h_tmp < 4.0)
{
green = x;
blue = chroma;
}
else if (h_tmp < 5.0)
{
red = x;
blue = chroma;
}
else if (h_tmp < 6.0)
{
red = chroma;
blue = x;
}
min = value - chroma;
red += min;
green += min;
blue += min;
((double *) dst)[0] = gamma_2_2_to_linear (red);
((double *) dst)[1] = gamma_2_2_to_linear (green);
((double *) dst)[2] = gamma_2_2_to_linear (blue);
}
static void
table_init (void)
{
if (table_inited)
return;
table_inited = 1;
/* fill tables for conversion from integer to float */
{
int i;
for (i = 0; i < 1 << 8; i++)
{
float direct = i / 255.0;
table_8_F[i] = direct;
table_8g_F[i] = gamma_2_2_to_linear (direct);
}
}
/* fill tables for conversion from float to integer */
{
union
{
float f;
uint32_t s;
} u;
u.f = 0.0;
//u.s[0] = 0;
for (u.s = 0; u.s < 4294900000U; u.s += 32768)
{
int c;
int cg;
if (u.f <= 0.0)
{
c = 0;
cg = 0;
}
else
{
c = (u.f * 255.1619) + 0.5;
cg = (linear_to_gamma_2_2 (u.f) * 255.1619) + 0.5;
if (cg > 255) cg = 255;
if (c > 255) c = 255;
}
table_F_8[(u.s >> 15) & ((1 << 17)-1)] = c;
table_F_8g[(u.s >> 15) & ((1 << 17)-1)] = cg;
}
}
#if 0
/* fix tables to ensure 1:1 conversions back and forth */
if (0)
{
int i;
for (i = 0; i < 256; i++)
{
float f;
unsigned short *hi = ((unsigned short *) (void *) &f);
unsigned short *lo = ((unsigned short *) (void *) &f);
f = table_8_F[i];
*lo = 0;
table_F_8[*hi] = i;
f = table_8g_F[i];
*lo = 0;
table_F_8g[*hi] = i;
}
}
#endif
}
