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Diffstat (limited to 'app/vectors/gimpvectors-warp.c')
| -rw-r--r-- | app/vectors/gimpvectors-warp.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/app/vectors/gimpvectors-warp.c b/app/vectors/gimpvectors-warp.c new file mode 100644 index 0000000..aeb8dec --- /dev/null +++ b/app/vectors/gimpvectors-warp.c @@ -0,0 +1,210 @@ +/* GIMP - The GNU Image Manipulation Program + * Copyright (C) 1995 Spencer Kimball and Peter Mattis + * + * gimpvectors-warp.c + * Copyright (C) 2005 Bill Skaggs <weskaggs@primate.ucdavis.edu> + * + * 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 <gdk-pixbuf/gdk-pixbuf.h> +#include <gegl.h> + +#include "vectors-types.h" + +#include "libgimpmath/gimpmath.h" + +#include "core/gimp-utils.h" +#include "core/gimpcoords.h" + +#include "gimpanchor.h" +#include "gimpstroke.h" +#include "gimpvectors.h" +#include "gimpvectors-warp.h" + + +#define EPSILON 0.2 +#define DX 2.0 + + +static void gimp_stroke_warp_point (GimpStroke *stroke, + gdouble x, + gdouble y, + GimpCoords *point_warped, + gdouble y_offset, + gdouble x_len); + +static void gimp_vectors_warp_stroke (GimpVectors *vectors, + GimpStroke *stroke, + gdouble y_offset); + + +void +gimp_vectors_warp_point (GimpVectors *vectors, + GimpCoords *point, + GimpCoords *point_warped, + gdouble y_offset) +{ + gdouble x = point->x; + gdouble y = point->y; + gdouble len; + GList *list; + GimpStroke *stroke; + + for (list = vectors->strokes->head; + list; + list = g_list_next (list)) + { + stroke = list->data; + + len = gimp_vectors_stroke_get_length (vectors, stroke); + + if (x < len || ! list->next) + break; + + x -= len; + } + + if (! list) + { + point_warped->x = 0; + point_warped->y = 0; + return; + } + + gimp_stroke_warp_point (stroke, x, y, point_warped, y_offset, len); +} + +static void +gimp_stroke_warp_point (GimpStroke *stroke, + gdouble x, + gdouble y, + GimpCoords *point_warped, + gdouble y_offset, + gdouble x_len) +{ + GimpCoords point_zero = { 0, }; + GimpCoords point_minus = { 0, }; + GimpCoords point_plus = { 0, }; + gdouble slope; + gdouble dx, dy, nx, ny, len; + + if (x + DX >= x_len) + { + gdouble tx, ty; + + if (! gimp_stroke_get_point_at_dist (stroke, x_len, EPSILON, + &point_zero, &slope)) + { + point_warped->x = 0; + point_warped->y = 0; + return; + } + + point_warped->x = point_zero.x; + point_warped->y = point_zero.y; + + if (! gimp_stroke_get_point_at_dist (stroke, x_len - DX, EPSILON, + &point_minus, &slope)) + return; + + dx = point_zero.x - point_minus.x; + dy = point_zero.y - point_minus.y; + + len = hypot (dx, dy); + + if (len < 0.01) + return; + + tx = dx / len; + ty = dy / len; + + nx = - dy / len; + ny = dx / len; + + point_warped->x += tx * (x - x_len) + nx * (y - y_offset); + point_warped->y += ty * (x - x_len) + ny * (y - y_offset); + + return; + } + + if (! gimp_stroke_get_point_at_dist (stroke, x, EPSILON, + &point_zero, &slope)) + { + point_warped->x = 0; + point_warped->y = 0; + return; + } + + point_warped->x = point_zero.x; + point_warped->y = point_zero.y; + + if (! gimp_stroke_get_point_at_dist (stroke, x - DX, EPSILON, + &point_minus, &slope)) + return; + + if (! gimp_stroke_get_point_at_dist (stroke, x + DX, EPSILON, + &point_plus, &slope)) + return; + + dx = point_plus.x - point_minus.x; + dy = point_plus.y - point_minus.y; + + len = hypot (dx, dy); + + if (len < 0.01) + return; + + nx = - dy / len; + ny = dx / len; + + point_warped->x = point_zero.x + nx * (y - y_offset); + point_warped->y = point_zero.y + ny * (y - y_offset); +} + +static void +gimp_vectors_warp_stroke (GimpVectors *vectors, + GimpStroke *stroke, + gdouble y_offset) +{ + GList *list; + + for (list = stroke->anchors->head; list; list = g_list_next (list)) + { + GimpAnchor *anchor = list->data; + + gimp_vectors_warp_point (vectors, + &anchor->position, &anchor->position, + y_offset); + } +} + +void +gimp_vectors_warp_vectors (GimpVectors *vectors, + GimpVectors *vectors_in, + gdouble y_offset) +{ + GList *list; + + for (list = vectors_in->strokes->head; + list; + list = g_list_next (list)) + { + GimpStroke *stroke = list->data; + + gimp_vectors_warp_stroke (vectors, stroke, y_offset); + } +} |