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Diffstat (limited to 'source/blender/blenlib/intern/jitter.c')
-rw-r--r-- | source/blender/blenlib/intern/jitter.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/source/blender/blenlib/intern/jitter.c b/source/blender/blenlib/intern/jitter.c new file mode 100644 index 00000000000..fd658765802 --- /dev/null +++ b/source/blender/blenlib/intern/jitter.c @@ -0,0 +1,178 @@ +/** + * Jitter offset table + * + * $Id$ + * + * ***** BEGIN GPL LICENSE BLOCK ***** + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV. + * All rights reserved. + * + * The Original Code is: all of this file. + * + * Contributor(s): none yet. + * + * ***** END GPL LICENSE BLOCK ***** + */ + +#include <math.h> +#include <stdlib.h> +#include <string.h> +#include "MEM_guardedalloc.h" + +#include "BLI_arithb.h" +#include "BLI_rand.h" +#include "BLI_jitter.h" + + +void BLI_jitterate1(float *jit1, float *jit2, int num, float rad1) +{ + int i , j , k; + float vecx, vecy, dvecx, dvecy, x, y, len; + + for (i = 2*num-2; i>=0 ; i-=2) { + dvecx = dvecy = 0.0; + x = jit1[i]; + y = jit1[i+1]; + for (j = 2*num-2; j>=0 ; j-=2) { + if (i != j){ + vecx = jit1[j] - x - 1.0; + vecy = jit1[j+1] - y - 1.0; + for (k = 3; k>0 ; k--){ + if( fabs(vecx)<rad1 && fabs(vecy)<rad1) { + len= sqrt(vecx*vecx + vecy*vecy); + if(len>0 && len<rad1) { + len= len/rad1; + dvecx += vecx/len; + dvecy += vecy/len; + } + } + vecx += 1.0; + + if( fabs(vecx)<rad1 && fabs(vecy)<rad1) { + len= sqrt(vecx*vecx + vecy*vecy); + if(len>0 && len<rad1) { + len= len/rad1; + dvecx += vecx/len; + dvecy += vecy/len; + } + } + vecx += 1.0; + + if( fabs(vecx)<rad1 && fabs(vecy)<rad1) { + len= sqrt(vecx*vecx + vecy*vecy); + if(len>0 && len<rad1) { + len= len/rad1; + dvecx += vecx/len; + dvecy += vecy/len; + } + } + vecx -= 2.0; + vecy += 1.0; + } + } + } + + x -= dvecx/18.0 ; + y -= dvecy/18.0; + x -= floor(x) ; + y -= floor(y); + jit2[i] = x; + jit2[i+1] = y; + } + memcpy(jit1,jit2,2 * num * sizeof(float)); +} + +void BLI_jitterate2(float *jit1, float *jit2, int num, float rad2) +{ + int i, j; + float vecx, vecy, dvecx, dvecy, x, y; + + for (i=2*num -2; i>= 0 ; i-=2){ + dvecx = dvecy = 0.0; + x = jit1[i]; + y = jit1[i+1]; + for (j =2*num -2; j>= 0 ; j-=2){ + if (i != j){ + vecx = jit1[j] - x - 1.0; + vecy = jit1[j+1] - y - 1.0; + + if( fabs(vecx)<rad2) dvecx+= vecx*rad2; + vecx += 1.0; + if( fabs(vecx)<rad2) dvecx+= vecx*rad2; + vecx += 1.0; + if( fabs(vecx)<rad2) dvecx+= vecx*rad2; + + if( fabs(vecy)<rad2) dvecy+= vecy*rad2; + vecy += 1.0; + if( fabs(vecy)<rad2) dvecy+= vecy*rad2; + vecy += 1.0; + if( fabs(vecy)<rad2) dvecy+= vecy*rad2; + + } + } + + x -= dvecx/2 ; + y -= dvecy/2; + x -= floor(x) ; + y -= floor(y); + jit2[i] = x; + jit2[i+1] = y; + } + memcpy(jit1,jit2,2 * num * sizeof(float)); +} + + +void BLI_initjit(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= 1.0/sqrt((float)num); + rad2= 1.0/((float)num); + rad3= sqrt((float)num)/((float)num); + + BLI_srand(31415926 + num); + x= 0; + for(i=0; i<2*num; i+=2) { + jitarr[i]= x+ rad1*(0.5-BLI_drand()); + jitarr[i+1]= ((float)i/2)/num +rad1*(0.5-BLI_drand()); + x+= rad3; + x -= floor(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] -= 0.5; + jitarr[i+1] -= 0.5; + } + +} + + +/* eof */ |