void
gegl_sampler_nearest_get ( GeglSampler* restrict self,
const gdouble absolute_x,
const gdouble absolute_y,
GeglMatrix2 *scale,
void* restrict output,
GeglAbyssPolicy repeat_mode)
{
/*
* The reason why floor of the absolute position gives the nearest
* pixel (with ties resolved toward -infinity) is that the absolute
* position is corner-based (origin at the top left corner of the
* pixel labeled (0,0)) so that the center of the top left pixel is
* located at (.5,.5) (instead of (0,0) as it would be if absolute
* positions were center-based).
*/
const gint channels = 4;
gfloat newval[channels];
const gfloat* restrict in_bptr =
gegl_sampler_get_ptr (self,
(gint) floor ((double) absolute_x),
(gint) floor ((double) absolute_y),
repeat_mode);
newval[0] = *in_bptr++;
newval[1] = *in_bptr++;
newval[2] = *in_bptr++;
newval[3] = *in_bptr;
babl_process (self->fish, newval, output, 1);
}
void
gegl_sampler_cubic_get (GeglSampler *self,
gdouble x,
gdouble y,
void *output)
{
GeglSamplerCubic *cubic = (GeglSamplerCubic*)(self);
GeglRectangle context_rect;
const gint offsets[16]={-4-64*4, 4, 4, 4,
(64-3)*4, 4, 4, 4,
(64-3)*4, 4, 4, 4,
(64-3)*4, 4, 4, 4};
gfloat *sampler_bptr;
gfloat factor;
#ifdef HAS_G4FLOAT
g4float newval4 = g4float_zero;
gfloat *newval = &newval4;
#else
gfloat newval[4] = {0.0, 0.0, 0.0, 0.0};
#endif
gint u,v;
gint dx,dy;
gint i;
context_rect = self->context_rect;
dx = (gint) x;
dy = (gint) y;
sampler_bptr = gegl_sampler_get_ptr (self, dx, dy);
#ifdef HAS_G4FLOAT
if (G_LIKELY (gegl_cpu_accel_get_support () & (GEGL_CPU_ACCEL_X86_SSE|
GEGL_CPU_ACCEL_X8&_MMX)))
{
for (v=dy+context_rect.y, i=0; v < dy+context_rect.y+context_rect.height ; v++)
for (u=dx+context_rect.x ; u < dx+context_rect.x+context_rect.width ; u++, i++)
{
sampler_bptr += offsets[i];
factor = cubicKernel (y - v, cubic->b, cubic->c) *
cubicKernel (x - u, cubic->b, cubic->c);
newval4 += g4float_mul(&sampler_bptr[0], factor);
}
}
else
#endif
{
for (v=dy+context_rect.y, i=0; v < dy+context_rect.y+context_rect.height ; v++)
for (u=dx+context_rect.x ; u < dx+context_rect.x+context_rect.width ; u++, i++)
{
/*sampler_bptr = gegl_sampler_get_from_buffer (self, u, v);*/
sampler_bptr += offsets[i];
factor = cubicKernel (y - v, cubic->b, cubic->c) *
cubicKernel (x - u, cubic->b, cubic->c);
newval[0] += factor * sampler_bptr[0];
newval[1] += factor * sampler_bptr[1];
newval[2] += factor * sampler_bptr[2];
newval[3] += factor * sampler_bptr[3];
}
}
babl_process (self->fish, newval, output, 1);
}
const gint ix = FAST_PSEUDO_FLOOR (absolute_x); const gint iy = FAST_PSEUDO_FLOOR (absolute_y); /* * x is the x-coordinate of the sampling point relative to the * position of the top left pixel center. Similarly for y. Range of * values: [0,1]. */ const gfloat x = absolute_x - ix; const gfloat y = absolute_y - iy; /* * Point the data tile pointer to the first channel of the top_left * pixel value: */ const gfloat* restrict in_bptr = gegl_sampler_get_ptr (self, ix, iy); /* * First bilinear weight: */ const gfloat x_times_y = x * y; /* * Load top row: */ const gfloat top_left_0 = *in_bptr++; const gfloat top_left_1 = *in_bptr++; const gfloat top_left_2 = *in_bptr++; const gfloat top_left_3 = *in_bptr++; const gfloat top_rite_0 = *in_bptr++; const gfloat top_rite_1 = *in_bptr++;
