void BLI_jitter_init(float (*jitarr)[2], int num)
{
float (*jit2)[2];
float num_fl, num_fl_sqrt;
float x, rad1, rad2, rad3;
RNG *rng;
int i;
if (num == 0) {
return;
}
num_fl = (float)num;
num_fl_sqrt = sqrtf(num_fl);
jit2 = MEM_mallocN(12 + (unsigned int)num * sizeof(float[2]), "initjit");
rad1 = 1.0f / num_fl_sqrt;
rad2 = 1.0f / num_fl;
rad3 = num_fl_sqrt / num_fl;
rng = BLI_rng_new(31415926 + (unsigned int)num);
x = 0;
for (i = 0; i < num; i++) {
jitarr[i][0] = x + rad1 * (float)(0.5 - BLI_rng_get_double(rng));
jitarr[i][1] = (float)i / num_fl + rad1 * (float)(0.5 - BLI_rng_get_double(rng));
x += rad3;
x -= floorf(x);
}
BLI_rng_free(rng);
for (i = 0; i < 24; i++) {
BLI_jitterate1(jitarr, jit2, num, rad1);
BLI_jitterate1(jitarr, jit2, num, rad1);
BLI_jitterate2(jitarr, jit2, num, rad2);
}
MEM_freeN(jit2);
/* finally, move jittertab to be centered around (0, 0) */
for (i = 0; i < num; i++) {
jitarr[i][0] -= 0.5f;
jitarr[i][1] -= 0.5f;
}
}
/* almost exact copy of BLI_jitter_init */
static void init_mv_jit(float *jit, int num, int seed2, float amount)
{
RNG *rng;
float *jit2, x, rad1, rad2, rad3;
int i, num2;
if (num==0) return;
rad1= (float)(1.0f/sqrtf((float)num));
rad2= (float)(1.0f/((float)num));
rad3= (float)sqrtf((float)num)/((float)num);
rng = BLI_rng_new(31415926 + num + seed2);
x= 0;
num2 = 2 * num;
for (i=0; i<num2; i+=2) {
jit[i] = x + amount*rad1*(0.5f - BLI_rng_get_float(rng));
jit[i+1] = i/(2.0f*num) + amount*rad1*(0.5f - BLI_rng_get_float(rng));
jit[i]-= (float)floor(jit[i]);
jit[i+1]-= (float)floor(jit[i+1]);
x+= rad3;
x -= (float)floor(x);
}
jit2= MEM_mallocN(12 + 2*sizeof(float)*num, "initjit");
for (i=0 ; i<4 ; i++) {
BLI_jitterate1((float (*)[2])jit, (float (*)[2])jit2, num, rad1);
BLI_jitterate1((float (*)[2])jit, (float (*)[2])jit2, num, rad1);
BLI_jitterate2((float (*)[2])jit, (float (*)[2])jit2, num, rad2);
}
MEM_freeN(jit2);
BLI_rng_free(rng);
}
void BLI_jitter_init(float *jitarr, int num)
{
float *jit2, x, rad1, rad2, rad3;
int i;
if (num == 0) return;
jit2 = MEM_mallocN(12 + 2 * sizeof(float) * num, "initjit");
rad1 = 1.0f / sqrtf((float)num);
rad2 = 1.0f / ((float)num);
rad3 = sqrtf((float)num) / ((float)num);
BLI_srand(31415926 + num);
x = 0;
for (i = 0; i < 2 * num; i += 2) {
jitarr[i] = x + rad1 * (float)(0.5 - BLI_drand());
jitarr[i + 1] = ((float)i / 2) / num + rad1 * (float)(0.5 - BLI_drand());
x += rad3;
x -= floorf(x);
}
for (i = 0; i < 24; i++) {
BLI_jitterate1(jitarr, jit2, num, rad1);
BLI_jitterate1(jitarr, jit2, num, rad1);
BLI_jitterate2(jitarr, jit2, num, rad2);
}
MEM_freeN(jit2);
/* finally, move jittertab to be centered around (0,0) */
for (i = 0; i < 2 * num; i += 2) {
jitarr[i] -= 0.5f;
jitarr[i + 1] -= 0.5f;
}
}