mirror of https://github.com/GNOME/gimp.git
329 lines
9.0 KiB
C
329 lines
9.0 KiB
C
/* The GIMP -- an image manipulation program
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*
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* This file Copyright (C) 1999 Simon Budig
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <math.h>
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#include "path_curves.h"
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#include "path_bezier.h"
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/* only here temporarily */
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PathSegment * path_split_segment (PathSegment *, gdouble);
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/* Here the different curves register their functions */
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static CurveDescription CurveTypes[] =
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{
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/* SEGMENT_LINE */
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{
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NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
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},
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/* SEGMENT_BEZIER */
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{
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NULL, /* path_bezier_get_points, */
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path_bezier_get_point,
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path_bezier_draw_handles,
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NULL, /* path_bezier_draw_segment, */
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NULL, /* path_bezier_on_segment, */
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path_bezier_drag_segment,
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path_bezier_on_handles,
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path_bezier_drag_handles,
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NULL, /* path_bezier_insert_anchor, */
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NULL, /* path_bezier_update_segment, */
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path_bezier_flip_segment,
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path_bezier_init_segment,
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NULL /* path_bezier_cleanup_segment */
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}
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};
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/*
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* these functions implement the dispatching for the different
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* curve-types. It implements default actions, which happen
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* to work with straight lines.
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*/
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guint
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path_curve_get_points (PathTool *path_tool,
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PathSegment *segment,
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GdkPoint *points,
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guint npoints,
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gdouble start,
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gdouble end)
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{
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gdouble pos, x, y;
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gint index=0;
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if (segment && segment->next) {
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if (CurveTypes[segment->type].get_points)
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return (* CurveTypes[segment->type].get_points) (path_tool, segment, points, npoints, start, end);
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else {
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if (npoints > 1 && segment && segment->next) {
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for (pos = start; pos <= end; pos += (end - start) / (npoints -1)) {
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path_curve_get_point (path_tool, segment, pos, &x, &y);
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points[index].x = (guint) (x + 0.5);
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points[index].y = (guint) (y + 0.5);
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index++;
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}
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return index;
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} else
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return 0;
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}
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}
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#ifdef PATH_TOOL_DEBUG
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else
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fprintf (stderr, "path_curve_get_point called without valid curve");
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#endif
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return 0;
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}
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void
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path_curve_get_point (PathTool *path_tool,
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PathSegment *segment,
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gdouble position,
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gdouble *x,
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gdouble *y)
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{
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if (segment && segment->next) {
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if (CurveTypes[segment->type].get_point)
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(* CurveTypes[segment->type].get_point) (path_tool, segment, position, x, y);
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else {
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#if 0
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*x = segment->x + (segment->next->x - segment->x) * position;
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*y = segment->y + (segment->next->y - segment->y) * position;
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#else
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/* Only here for debugging purposes: A bezier curve fith fixed tangents */
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*x = (1-position)*(1-position)*(1-position) * segment->x +
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3 * position *(1-position)*(1-position) * (segment->x - 60) +
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3 * position * position *(1-position) * (segment->next->x + 60) +
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position * position * position * (segment->next->x);
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*y = (1-position)*(1-position)*(1-position) * segment->y +
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3 * position *(1-position)*(1-position) * (segment->y + 60) +
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3 * position * position *(1-position) * (segment->next->y + 60) +
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position * position * position * (segment->next->y);
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#endif
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}
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}
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#ifdef PATH_TOOL_DEBUG
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else
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fprintf (stderr, "path_curve_get_point called without valid curve");
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#endif
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return;
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}
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void
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path_curve_draw_handles (Tool *tool,
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PathSegment *segment)
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{
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if (segment && CurveTypes[segment->type].draw_handles)
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(* CurveTypes[segment->type].draw_handles) (tool, segment);
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/* straight lines do not have handles... */
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return;
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}
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void
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path_curve_draw_segment (Tool *tool,
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PathSegment *segment)
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{
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gint x, y, numpts, index;
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if (segment && segment->next) {
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if (CurveTypes[segment->type].draw_segment) {
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(* CurveTypes[segment->type].draw_segment) (tool, segment);
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return;
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} else {
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GdkPoint *coordinates = g_new (GdkPoint, 100);
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numpts = path_curve_get_points (((PathTool *) tool->private), segment,
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coordinates, 100, 0, 1);
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for (index=0; index < numpts; index++) {
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gdisplay_transform_coords (tool->gdisp,
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coordinates[index].x,
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coordinates[index].y,
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&x, &y, FALSE);
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coordinates[index].x = x;
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coordinates[index].y = y;
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}
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gdk_draw_lines (((PathTool *) tool->private)->core->win,
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((PathTool *) tool->private)->core->gc,
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coordinates, numpts);
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g_free (coordinates);
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}
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#ifdef PATH_TOOL_DEBUG
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} else {
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fprintf (stderr, "Fatal Error: path_curve_draw_segment called without valid segment *\n");
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#endif
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}
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return;
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}
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gdouble
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path_curve_on_segment (Tool *tool,
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PathSegment *segment,
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gint x,
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gint y,
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gint halfwidth,
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gint *distance)
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{
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if (segment && CurveTypes[segment->type].on_segment)
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return (* CurveTypes[segment->type].on_segment) (tool, segment, x, y, halfwidth, distance);
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else {
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if (segment && segment->next) {
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#if 1
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gint x1, y1, numpts, index;
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GdkPoint *coordinates = g_new (GdkPoint, 100);
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gint bestindex = -1;
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*distance = halfwidth * halfwidth + 1;
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numpts = path_curve_get_points (((PathTool *) tool->private), segment,
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coordinates, 100, 0, 1);
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for (index=0; index < numpts; index++) {
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x1 = coordinates[index].x;
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y1 = coordinates[index].y;
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if (((x - x1) * (x - x1) + (y - y1) * (y - y1)) < *distance) {
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*distance = (x - x1) * (x - x1) + (y - y1) * (y - y1);
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bestindex = index;
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}
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}
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g_free (coordinates);
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if (numpts == 1) {
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*distance = (gint) sqrt ((gdouble) *distance);
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return bestindex;
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}
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if (bestindex >= 0 && (*distance <= halfwidth * halfwidth)) {
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*distance = (gint) sqrt ((gdouble) *distance);
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return bestindex == 0 ? 0 : ((gdouble) bestindex) / (numpts - 1);
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}
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#else
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/* Special case for lines */
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gdouble Ax, Ay, Bx, By, r, d;
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Ax = segment->x;
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Ay = segment->y;
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Bx = segment->next->x;
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By = segment->next->y;
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r = (( x - Ax)*(Bx - Ax) + ( y - Ay)* (By - Ay)) /
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((Bx - Ax)*(Bx - Ax) + (By - Ay)* (By - Ay)) ;
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if (r >= 0 && r <= 1) {
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d = (((Ax + (Bx - Ax) * r) - x) * ((Ax + (Bx - Ax) * r) - x) +
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((Ay + (By - Ay) * r) - y) * ((Ay + (By - Ay) * r) - y));
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if (d <= halfwidth * halfwidth) {
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*distance = (gint) (d + 0.5);
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return r;
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}
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}
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#endif
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}
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}
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return -1;
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}
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void
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path_curve_drag_segment (PathTool *path_tool,
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PathSegment *segment,
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gdouble position,
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gdouble dx,
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gdouble dy)
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{
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if (segment && CurveTypes[segment->type].drag_segment)
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(* CurveTypes[segment->type].drag_segment) (path_tool, segment, position, dx, dy);
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return;
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}
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gint
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path_curve_on_handle (PathTool *path_tool,
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PathSegment *segment,
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gdouble x,
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gdouble y,
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gdouble halfwidth)
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{
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if (segment && CurveTypes[segment->type].on_handles)
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return (* CurveTypes[segment->type].on_handles) (path_tool, segment, x, y, halfwidth);
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return FALSE;
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}
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void
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path_curve_drag_handle (PathTool *path_tool,
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PathSegment *segment,
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gdouble dx,
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gdouble dy,
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gint handle_id)
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{
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if (segment && CurveTypes[segment->type].drag_handle)
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(* CurveTypes[segment->type].drag_handle) (path_tool, segment, dx, dy, handle_id);
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}
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PathSegment *
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path_curve_insert_anchor (PathTool *path_tool,
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PathSegment *segment,
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gdouble position)
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{
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if (segment && CurveTypes[segment->type].insert_anchor)
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return (* CurveTypes[segment->type].insert_anchor) (path_tool, segment, position);
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else {
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return path_split_segment (segment, position);
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}
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}
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void
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path_curve_flip_segment (PathSegment *segment)
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{
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if (segment && CurveTypes[segment->type].flip_segment)
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(* CurveTypes[segment->type].flip_segment) (segment);
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return;
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}
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void
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path_curve_update_segment (PathTool *path_tool,
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PathSegment *segment)
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{
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if (segment && CurveTypes[segment->type].update_segment)
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(* CurveTypes[segment->type].update_segment) (path_tool, segment);
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return;
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}
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void
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path_curve_init_segment (PathSegment *segment)
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{
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if (segment && CurveTypes[segment->type].init_segment)
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(* CurveTypes[segment->type].init_segment) (segment);
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return;
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}
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void
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path_curve_cleanup_segment (PathSegment *segment)
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{
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if (segment && CurveTypes[segment->type].cleanup_segment)
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(* CurveTypes[segment->type].cleanup_segment) (segment);
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return;
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}
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