## -*- mode: tcl ; fill-column: 90 -*-
# # ## ### ##### ######## ############# #####################
## Generators -- Virtual Image - Gaussian noise
operator image::noise::gauss {
section generator virtual
# fixed seed to keep the examples identical across runs
example {width 256 height 256 depth 1 seed 703011174}
example {width 256 height 256 depth 3 seed 703011174}
note Returns image where pixels are set to random values \
drawn from a gaussian distribution with mean and \
sigma over +/-sigma. The defaults are 0 and 1.
uint width Width of the returned image
uint height Height of the returned image
uint depth Depth of the returned image
double? 0 mean Mean of the desired gauss distribution.
double? 1 sigma Sigma of the desired gauss distribution.
uint? {[expr {int(4294967296*rand())}]} seed \
Randomizer seed. Needed only to force fixed results.
state -fields {
aktive_uint seed;
} -setup {
aktive_geometry_set (domain, 0, 0, param->width, param->height, param->depth);
state->seed = param->seed;
// Merge w, h, d into seed ? No. Does not make things more random.
}
blit gausssampling {
{AH {y AY 1 up} {y SY 1 up}}
{AW {x AX 1 up} {x SX 1 up}}
{DD {z 0 1 up} {z 0 1 up}}
} {point {
mean + (sigma * GAUSS (MERGE3 (istate->seed, x, y, z)))
}}
pixels {
double mean = param->mean;
double sigma = param->sigma;
#define GAUSS aktive_fnv_gauss
#define MERGE aktive_fnv_merge_uint32
#define MERGE3(s,a,b,c) MERGE (MERGE (MERGE (s, a), b), c)
#define SD (idomain->depth)
#define SH (idomain->height)
#define SW (idomain->width)
#define SX (request->x)
#define SY (request->y)
@@gausssampling@@
#undef STEP
#undef MERGE3
#undef MERGE
}
}
##
# # ## ### ##### ######## ############# #####################
::return