diff options
Diffstat (limited to 'source/blender/blenlib/intern/jitter_2d.c')
| -rw-r--r-- | source/blender/blenlib/intern/jitter_2d.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/source/blender/blenlib/intern/jitter_2d.c b/source/blender/blenlib/intern/jitter_2d.c new file mode 100644 index 00000000000..6c51eeb36d9 --- /dev/null +++ b/source/blender/blenlib/intern/jitter_2d.c @@ -0,0 +1,186 @@ +/* + * ***** 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 ***** + */ + +/** \file blender/blenlib/intern/jitter.c + * \ingroup bli + * \brief Jitter offset table + */ + +#include <math.h> +#include <string.h> +#include "MEM_guardedalloc.h" + +#include "BLI_rand.h" +#include "BLI_jitter_2d.h" + +#include "BLI_strict_flags.h" + + +void BLI_jitterate1(float (*jit1)[2], float (*jit2)[2], int num, float rad1) +{ + int i, j, k; + float vecx, vecy, dvecx, dvecy, x, y, len; + + for (i = num - 1; i >= 0; i--) { + dvecx = dvecy = 0.0; + x = jit1[i][0]; + y = jit1[i][1]; + for (j = num - 1; j >= 0; j--) { + if (i != j) { + vecx = jit1[j][0] - x - 1.0f; + vecy = jit1[j][1] - y - 1.0f; + for (k = 3; k > 0; k--) { + if (fabsf(vecx) < rad1 && fabsf(vecy) < rad1) { + len = sqrtf(vecx * vecx + vecy * vecy); + if (len > 0 && len < rad1) { + len = len / rad1; + dvecx += vecx / len; + dvecy += vecy / len; + } + } + vecx += 1.0f; + + if (fabsf(vecx) < rad1 && fabsf(vecy) < rad1) { + len = sqrtf(vecx * vecx + vecy * vecy); + if (len > 0 && len < rad1) { + len = len / rad1; + dvecx += vecx / len; + dvecy += vecy / len; + } + } + vecx += 1.0f; + + if (fabsf(vecx) < rad1 && fabsf(vecy) < rad1) { + len = sqrtf(vecx * vecx + vecy * vecy); + if (len > 0 && len < rad1) { + len = len / rad1; + dvecx += vecx / len; + dvecy += vecy / len; + } + } + vecx -= 2.0f; + vecy += 1.0f; + } + } + } + + x -= dvecx / 18.0f; + y -= dvecy / 18.0f; + x -= floorf(x); + y -= floorf(y); + jit2[i][0] = x; + jit2[i][1] = y; + } + memcpy(jit1, jit2, 2 * (unsigned int)num * sizeof(float)); +} + +void BLI_jitterate2(float (*jit1)[2], float (*jit2)[2], int num, float rad2) +{ + int i, j; + float vecx, vecy, dvecx, dvecy, x, y; + + for (i = num - 1; i >= 0; i--) { + dvecx = dvecy = 0.0; + x = jit1[i][0]; + y = jit1[i][1]; + for (j = num - 1; j >= 0; j--) { + if (i != j) { + vecx = jit1[j][0] - x - 1.0f; + vecy = jit1[j][1] - y - 1.0f; + + if (fabsf(vecx) < rad2) dvecx += vecx * rad2; + vecx += 1.0f; + if (fabsf(vecx) < rad2) dvecx += vecx * rad2; + vecx += 1.0f; + if (fabsf(vecx) < rad2) dvecx += vecx * rad2; + + if (fabsf(vecy) < rad2) dvecy += vecy * rad2; + vecy += 1.0f; + if (fabsf(vecy) < rad2) dvecy += vecy * rad2; + vecy += 1.0f; + if (fabsf(vecy) < rad2) dvecy += vecy * rad2; + + } + } + + x -= dvecx / 2.0f; + y -= dvecy / 2.0f; + x -= floorf(x); + y -= floorf(y); + jit2[i][0] = x; + jit2[i][1] = y; + } + memcpy(jit1, jit2, (unsigned int)num * sizeof(float[2])); +} + + +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; + } +} |