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Diffstat (limited to '')
| -rw-r--r-- | plug-ins/gimpressionist/plasma.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/plug-ins/gimpressionist/plasma.c b/plug-ins/gimpressionist/plasma.c new file mode 100644 index 0000000..82f9212 --- /dev/null +++ b/plug-ins/gimpressionist/plasma.c @@ -0,0 +1,122 @@ +/* GIMP - The GNU Image Manipulation Program + * Copyright (C) 1995 Spencer Kimball and Peter Mattis + * + * 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 3 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, see <https://www.gnu.org/licenses/>. + */ + +#include "config.h" + +#include <stdlib.h> + +#include <gtk/gtk.h> + +#include <libgimpmath/gimpmath.h> +#include <libgimp/gimp.h> + +#include "gimpressionist.h" +#include "ppmtool.h" +#include "random.h" + +static int +pfix (int n) +{ + if (n < 1) return 1; + if (n > 255) return 255; + return n; +} + +#define PIXEL(y,x,z) p->col[(y) * rowstride + (x) * 3 + z] + +static void +mkplasma_sub (ppm_t *p, int x1, int x2, int y1, int y2, float turb) +{ + int rowstride = p->width * 3; + int r=0; + int xr, yr, nx, ny; + + xr = abs (x1 - x2); + yr = abs (y1 - y2); + + if ((xr == 0) && (yr == 0)) + return; + + nx = (x1 + x2)/2; + ny = (y1 + y2)/2; + if (!PIXEL (y1,nx,r)) + PIXEL (y1, nx, r) = pfix ((PIXEL (y1, x1, r) + PIXEL (y1, x2, r)) / 2.0 + + turb * g_rand_double_range (random_generator, + -xr / 2.0, + xr / 2.0)); + if (!PIXEL (y2, nx, r)) + PIXEL (y2, nx, r) = pfix ((PIXEL (y2, x1, r) + PIXEL (y2, x2, r)) / 2.0 + + turb * g_rand_double_range (random_generator, + -xr / 2.0, + xr / 2.0)); + if (!PIXEL (ny, x1, r)) + PIXEL (ny, x1, r) = pfix ((PIXEL (y1, x1, r)+PIXEL (y2, x1, r)) / 2.0 + + turb * g_rand_double_range (random_generator, + -yr / 2.0, + yr / 2.0)); + if (!PIXEL (ny, x2, r)) + PIXEL (ny, x2, r) = pfix ((PIXEL (y1, x2, r) + PIXEL (y2, x2, r)) / 2.0 + + turb * g_rand_double_range (random_generator, + -yr / 2.0, + yr / 2.0)); + if (!PIXEL (ny, nx, r)) + PIXEL (ny, nx, r) = + pfix ((PIXEL (y1, x1, r) + PIXEL (y1, x2, r) + + PIXEL (y2, x1, r) + PIXEL( y2, x2, r)) / 4.0 + + turb * g_rand_double_range (random_generator, + -(xr + yr)/4.0, + (xr + yr)/4.0)); + + if (xr>1) + { + mkplasma_sub (p, x1, nx, y1, ny, turb); + mkplasma_sub (p, nx, x2, y1, ny, turb); + } + if (yr>1) + { + mkplasma_sub (p, x1, nx, ny, y2, turb); + mkplasma_sub (p, nx, x2, ny, y2, turb); + } +} + +static void +mkplasma_red (ppm_t *p, float turb) +{ + int x = 0, y = 0; + int rowstride = p->width * 3; + + for (x = 0; x < p->width; x++) + for (y = 0; y < p->height; y++) + PIXEL (y, x, 0) = 0; + x--; y--; + PIXEL (0, 0, 0) = g_rand_int_range (random_generator, 1, 256); + PIXEL (y, 0, 0) = g_rand_int_range (random_generator, 1, 256); + PIXEL (0, x, 0) = g_rand_int_range (random_generator, 1, 256); + PIXEL (y, x, 0) = g_rand_int_range (random_generator, 1, 256); + mkplasma_sub (p, 0, x, 0, y, turb); +} + +void +mkgrayplasma (ppm_t *p, float turb) +{ + int y, l; + + mkplasma_red (p, turb); + l = p->width * 3 * p->height; + for (y = 0; y < l; y += 3) + p->col[y+1] = p->col[y+2] = p->col[y]; +} |