/
gimpbezierstroke.c
2373 lines (1944 loc) · 75.7 KB
/
gimpbezierstroke.c
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/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimpbezierstroke.c
* Copyright (C) 2002 Simon Budig <simon@gimp.org>
*
* 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 <glib-object.h>
#include <cairo.h>
#include "libgimpmath/gimpmath.h"
#include "vectors-types.h"
#include "core/gimp-transform-utils.h"
#include "core/gimpbezierdesc.h"
#include "core/gimpcoords.h"
#include "core/gimpcoords-interpolate.h"
#include "gimpanchor.h"
#include "gimpbezierstroke.h"
/* local prototypes */
static gdouble
gimp_bezier_stroke_nearest_point_get (GimpStroke *stroke,
const GimpCoords *coord,
gdouble precision,
GimpCoords *ret_point,
GimpAnchor **ret_segment_start,
GimpAnchor **ret_segment_end,
gdouble *ret_pos);
static gdouble
gimp_bezier_stroke_segment_nearest_point_get
(const GimpCoords *beziercoords,
const GimpCoords *coord,
gdouble precision,
GimpCoords *ret_point,
gdouble *ret_pos,
gint depth);
static gdouble
gimp_bezier_stroke_nearest_tangent_get (GimpStroke *stroke,
const GimpCoords *coord1,
const GimpCoords *coord2,
gdouble precision,
GimpCoords *nearest,
GimpAnchor **ret_segment_start,
GimpAnchor **ret_segment_end,
gdouble *ret_pos);
static gdouble
gimp_bezier_stroke_segment_nearest_tangent_get
(const GimpCoords *beziercoords,
const GimpCoords *coord1,
const GimpCoords *coord2,
gdouble precision,
GimpCoords *ret_point,
gdouble *ret_pos);
static void
gimp_bezier_stroke_anchor_move_relative
(GimpStroke *stroke,
GimpAnchor *anchor,
const GimpCoords *deltacoord,
GimpAnchorFeatureType feature);
static void
gimp_bezier_stroke_anchor_move_absolute
(GimpStroke *stroke,
GimpAnchor *anchor,
const GimpCoords *coord,
GimpAnchorFeatureType feature);
static void
gimp_bezier_stroke_anchor_convert (GimpStroke *stroke,
GimpAnchor *anchor,
GimpAnchorFeatureType feature);
static void
gimp_bezier_stroke_anchor_delete (GimpStroke *stroke,
GimpAnchor *anchor);
static gboolean
gimp_bezier_stroke_point_is_movable (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position);
static void
gimp_bezier_stroke_point_move_relative (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position,
const GimpCoords *deltacoord,
GimpAnchorFeatureType feature);
static void
gimp_bezier_stroke_point_move_absolute (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position,
const GimpCoords *coord,
GimpAnchorFeatureType feature);
static void gimp_bezier_stroke_close (GimpStroke *stroke);
static GimpStroke *
gimp_bezier_stroke_open (GimpStroke *stroke,
GimpAnchor *end_anchor);
static gboolean
gimp_bezier_stroke_anchor_is_insertable
(GimpStroke *stroke,
GimpAnchor *predec,
gdouble position);
static GimpAnchor *
gimp_bezier_stroke_anchor_insert (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position);
static gboolean
gimp_bezier_stroke_is_extendable (GimpStroke *stroke,
GimpAnchor *neighbor);
static gboolean
gimp_bezier_stroke_connect_stroke (GimpStroke *stroke,
GimpAnchor *anchor,
GimpStroke *extension,
GimpAnchor *neighbor);
static gboolean
gimp_bezier_stroke_reverse (GimpStroke *stroke);
static gboolean
gimp_bezier_stroke_shift_start (GimpStroke *stroke,
GimpAnchor *anchor);
static GArray *
gimp_bezier_stroke_interpolate (GimpStroke *stroke,
gdouble precision,
gboolean *closed);
static GimpBezierDesc *
gimp_bezier_stroke_make_bezier (GimpStroke *stroke);
static void gimp_bezier_stroke_transform (GimpStroke *stroke,
const GimpMatrix3 *matrix,
GQueue *ret_strokes);
static void gimp_bezier_stroke_finalize (GObject *object);
static GList * gimp_bezier_stroke_get_anchor_listitem
(GList *list);
G_DEFINE_TYPE (GimpBezierStroke, gimp_bezier_stroke, GIMP_TYPE_STROKE)
#define parent_class gimp_bezier_stroke_parent_class
static void
gimp_bezier_stroke_class_init (GimpBezierStrokeClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GimpStrokeClass *stroke_class = GIMP_STROKE_CLASS (klass);
object_class->finalize = gimp_bezier_stroke_finalize;
stroke_class->nearest_point_get = gimp_bezier_stroke_nearest_point_get;
stroke_class->nearest_tangent_get = gimp_bezier_stroke_nearest_tangent_get;
stroke_class->nearest_intersection_get = NULL;
stroke_class->anchor_move_relative = gimp_bezier_stroke_anchor_move_relative;
stroke_class->anchor_move_absolute = gimp_bezier_stroke_anchor_move_absolute;
stroke_class->anchor_convert = gimp_bezier_stroke_anchor_convert;
stroke_class->anchor_delete = gimp_bezier_stroke_anchor_delete;
stroke_class->point_is_movable = gimp_bezier_stroke_point_is_movable;
stroke_class->point_move_relative = gimp_bezier_stroke_point_move_relative;
stroke_class->point_move_absolute = gimp_bezier_stroke_point_move_absolute;
stroke_class->close = gimp_bezier_stroke_close;
stroke_class->open = gimp_bezier_stroke_open;
stroke_class->anchor_is_insertable = gimp_bezier_stroke_anchor_is_insertable;
stroke_class->anchor_insert = gimp_bezier_stroke_anchor_insert;
stroke_class->is_extendable = gimp_bezier_stroke_is_extendable;
stroke_class->extend = gimp_bezier_stroke_extend;
stroke_class->connect_stroke = gimp_bezier_stroke_connect_stroke;
stroke_class->reverse = gimp_bezier_stroke_reverse;
stroke_class->shift_start = gimp_bezier_stroke_shift_start;
stroke_class->interpolate = gimp_bezier_stroke_interpolate;
stroke_class->make_bezier = gimp_bezier_stroke_make_bezier;
stroke_class->transform = gimp_bezier_stroke_transform;
}
static void
gimp_bezier_stroke_init (GimpBezierStroke *stroke)
{
}
static void
gimp_bezier_stroke_finalize (GObject *object)
{
G_OBJECT_CLASS (parent_class)->finalize (object);
}
/* Bezier specific functions */
GimpStroke *
gimp_bezier_stroke_new (void)
{
return g_object_new (GIMP_TYPE_BEZIER_STROKE, NULL);
}
GimpStroke *
gimp_bezier_stroke_new_from_coords (const GimpCoords *coords,
gint n_coords,
gboolean closed)
{
GimpStroke *stroke;
GimpAnchor *last_anchor;
gint count;
g_return_val_if_fail (coords != NULL, NULL);
g_return_val_if_fail (n_coords >= 3, NULL);
g_return_val_if_fail ((n_coords % 3) == 0, NULL);
stroke = gimp_bezier_stroke_new ();
last_anchor = NULL;
for (count = 0; count < n_coords; count++)
last_anchor = gimp_bezier_stroke_extend (stroke,
&coords[count],
last_anchor,
EXTEND_SIMPLE);
if (closed)
gimp_stroke_close (stroke);
return stroke;
}
static void
gimp_bezier_stroke_anchor_delete (GimpStroke *stroke,
GimpAnchor *anchor)
{
GList *list;
GList *list2;
gint i;
/* Anchors always are surrounded by two handles that have to
* be deleted too
*/
list2 = g_queue_find (stroke->anchors, anchor);
list = g_list_previous (list2);
for (i = 0; i < 3; i++)
{
g_return_if_fail (list != NULL);
list2 = g_list_next (list);
gimp_anchor_free (list->data);
g_queue_delete_link (stroke->anchors, list);
list = list2;
}
}
static GimpStroke *
gimp_bezier_stroke_open (GimpStroke *stroke,
GimpAnchor *end_anchor)
{
GList *list;
GList *list2;
GimpStroke *new_stroke = NULL;
list = g_queue_find (stroke->anchors, end_anchor);
g_return_val_if_fail (list != NULL && list->next != NULL, NULL);
list = g_list_next (list); /* protect the handle... */
list2 = list->next;
list->next = NULL;
if (list2 != NULL)
{
GList *tail = stroke->anchors->tail;
stroke->anchors->tail = list;
stroke->anchors->length -= g_list_length (list2);
list2->prev = NULL;
if (stroke->closed)
{
GList *l;
for (l = tail; l; l = g_list_previous (l))
g_queue_push_head (stroke->anchors, l->data);
g_list_free (list2);
}
else
{
new_stroke = gimp_bezier_stroke_new ();
new_stroke->anchors->head = list2;
new_stroke->anchors->tail = g_list_last (list2);
new_stroke->anchors->length = g_list_length (list2);
}
}
stroke->closed = FALSE;
g_object_notify (G_OBJECT (stroke), "closed");
return new_stroke;
}
static gboolean
gimp_bezier_stroke_anchor_is_insertable (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position)
{
return (g_queue_find (stroke->anchors, predec) != NULL);
}
static GimpAnchor *
gimp_bezier_stroke_anchor_insert (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position)
{
GList *segment_start;
GList *list;
GList *list2;
GimpCoords subdivided[8];
GimpCoords beziercoords[4];
gint i;
segment_start = g_queue_find (stroke->anchors, predec);
if (! segment_start)
return NULL;
list = segment_start;
for (i = 0; i <= 3; i++)
{
beziercoords[i] = GIMP_ANCHOR (list->data)->position;
list = g_list_next (list);
if (! list)
list = stroke->anchors->head;
}
subdivided[0] = beziercoords[0];
subdivided[6] = beziercoords[3];
gimp_coords_mix (1-position, &(beziercoords[0]),
position, &(beziercoords[1]),
&(subdivided[1]));
gimp_coords_mix (1-position, &(beziercoords[1]),
position, &(beziercoords[2]),
&(subdivided[7]));
gimp_coords_mix (1-position, &(beziercoords[2]),
position, &(beziercoords[3]),
&(subdivided[5]));
gimp_coords_mix (1-position, &(subdivided[1]),
position, &(subdivided[7]),
&(subdivided[2]));
gimp_coords_mix (1-position, &(subdivided[7]),
position, &(subdivided[5]),
&(subdivided[4]));
gimp_coords_mix (1-position, &(subdivided[2]),
position, &(subdivided[4]),
&(subdivided[3]));
/* subdivided 0-6 contains the bezier segment subdivided at <position> */
list = segment_start;
for (i = 0; i <= 6; i++)
{
if (i >= 2 && i <= 4)
{
list2 = g_list_append (NULL,
gimp_anchor_new ((i == 3 ?
GIMP_ANCHOR_ANCHOR:
GIMP_ANCHOR_CONTROL),
&(subdivided[i])));
/* insert it *before* list manually. */
list2->next = list;
list2->prev = list->prev;
if (list->prev)
list->prev->next = list2;
list->prev = list2;
list = list2;
if (i == 3)
segment_start = list;
}
else
{
GIMP_ANCHOR (list->data)->position = subdivided[i];
}
list = g_list_next (list);
if (! list)
list = stroke->anchors->head;
}
stroke->anchors->head = g_list_first (list);
stroke->anchors->tail = g_list_last (list);
stroke->anchors->length += 3;
return GIMP_ANCHOR (segment_start->data);
}
static gboolean
gimp_bezier_stroke_point_is_movable (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position)
{
return (g_queue_find (stroke->anchors, predec) != NULL);
}
static void
gimp_bezier_stroke_point_move_relative (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position,
const GimpCoords *deltacoord,
GimpAnchorFeatureType feature)
{
GimpCoords offsetcoords[2];
GList *segment_start;
GList *list;
gint i;
gdouble feel_good;
segment_start = g_queue_find (stroke->anchors, predec);
g_return_if_fail (segment_start != NULL);
/* dragging close to endpoints just moves the handle related to
* the endpoint. Just make sure that feel_good is in the range from
* 0 to 1. The 1.0 / 6.0 and 5.0 / 6.0 are duplicated in
* tools/gimpvectortool.c.
*/
if (position <= 1.0 / 6.0)
feel_good = 0;
else if (position <= 0.5)
feel_good = (pow((6 * position - 1) / 2.0, 3)) / 2;
else if (position <= 5.0 / 6.0)
feel_good = (1 - pow((6 * (1-position) - 1) / 2.0, 3)) / 2 + 0.5;
else
feel_good = 1;
gimp_coords_scale ((1-feel_good)/(3*position*
(1-position)*(1-position)),
deltacoord,
&(offsetcoords[0]));
gimp_coords_scale (feel_good/(3*position*position*(1-position)),
deltacoord,
&(offsetcoords[1]));
list = segment_start;
list = g_list_next (list);
if (! list)
list = stroke->anchors->head;
for (i = 0; i <= 1; i++)
{
gimp_stroke_anchor_move_relative (stroke, GIMP_ANCHOR (list->data),
&(offsetcoords[i]), feature);
list = g_list_next (list);
if (! list)
list = stroke->anchors->head;
}
}
static void
gimp_bezier_stroke_point_move_absolute (GimpStroke *stroke,
GimpAnchor *predec,
gdouble position,
const GimpCoords *coord,
GimpAnchorFeatureType feature)
{
GimpCoords deltacoord;
GimpCoords tmp1, tmp2, abs_pos;
GimpCoords beziercoords[4];
GList *segment_start;
GList *list;
gint i;
segment_start = g_queue_find (stroke->anchors, predec);
g_return_if_fail (segment_start != NULL);
list = segment_start;
for (i = 0; i <= 3; i++)
{
beziercoords[i] = GIMP_ANCHOR (list->data)->position;
list = g_list_next (list);
if (! list)
list = stroke->anchors->head;
}
gimp_coords_mix ((1-position)*(1-position)*(1-position), &(beziercoords[0]),
3*(1-position)*(1-position)*position, &(beziercoords[1]),
&tmp1);
gimp_coords_mix (3*(1-position)*position*position, &(beziercoords[2]),
position*position*position, &(beziercoords[3]),
&tmp2);
gimp_coords_add (&tmp1, &tmp2, &abs_pos);
gimp_coords_difference (coord, &abs_pos, &deltacoord);
gimp_bezier_stroke_point_move_relative (stroke, predec, position,
&deltacoord, feature);
}
static void
gimp_bezier_stroke_close (GimpStroke *stroke)
{
GList *start;
GList *end;
GimpAnchor *anchor;
start = stroke->anchors->head;
end = stroke->anchors->tail;
g_return_if_fail (start->next != NULL && end->prev != NULL);
if (start->next != end->prev)
{
if (gimp_coords_equal (&(GIMP_ANCHOR (start->next->data)->position),
&(GIMP_ANCHOR (start->data)->position)) &&
gimp_coords_equal (&(GIMP_ANCHOR (start->data)->position),
&(GIMP_ANCHOR (end->data)->position)) &&
gimp_coords_equal (&(GIMP_ANCHOR (end->data)->position),
&(GIMP_ANCHOR (end->prev->data)->position)))
{
/* redundant segment */
gimp_anchor_free (stroke->anchors->tail->data);
g_queue_delete_link (stroke->anchors, stroke->anchors->tail);
gimp_anchor_free (stroke->anchors->tail->data);
g_queue_delete_link (stroke->anchors, stroke->anchors->tail);
anchor = stroke->anchors->tail->data;
g_queue_delete_link (stroke->anchors, stroke->anchors->tail);
gimp_anchor_free (stroke->anchors->head->data);
stroke->anchors->head->data = anchor;
}
}
GIMP_STROKE_CLASS (parent_class)->close (stroke);
}
static gdouble
gimp_bezier_stroke_nearest_point_get (GimpStroke *stroke,
const GimpCoords *coord,
gdouble precision,
GimpCoords *ret_point,
GimpAnchor **ret_segment_start,
GimpAnchor **ret_segment_end,
gdouble *ret_pos)
{
gdouble min_dist, dist, pos;
GimpCoords point = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };
GimpCoords segmentcoords[4];
GList *anchorlist;
GimpAnchor *segment_start;
GimpAnchor *segment_end = NULL;
GimpAnchor *anchor;
gint count;
if (g_queue_is_empty (stroke->anchors))
return -1.0;
count = 0;
min_dist = -1;
pos = 0;
for (anchorlist = stroke->anchors->head;
GIMP_ANCHOR (anchorlist->data)->type != GIMP_ANCHOR_ANCHOR;
anchorlist = g_list_next (anchorlist));
segment_start = anchorlist->data;
for ( ; anchorlist; anchorlist = g_list_next (anchorlist))
{
anchor = anchorlist->data;
segmentcoords[count] = anchor->position;
count++;
if (count == 4)
{
segment_end = anchorlist->data;
dist = gimp_bezier_stroke_segment_nearest_point_get (segmentcoords,
coord, precision,
&point, &pos,
10);
if (dist < min_dist || min_dist < 0)
{
min_dist = dist;
if (ret_pos)
*ret_pos = pos;
if (ret_point)
*ret_point = point;
if (ret_segment_start)
*ret_segment_start = segment_start;
if (ret_segment_end)
*ret_segment_end = segment_end;
}
segment_start = anchorlist->data;
segmentcoords[0] = segmentcoords[3];
count = 1;
}
}
if (stroke->closed && stroke->anchors->head)
{
anchorlist = stroke->anchors->head;
while (count < 3)
{
segmentcoords[count] = GIMP_ANCHOR (anchorlist->data)->position;
count++;
}
anchorlist = g_list_next (anchorlist);
if (anchorlist)
{
segment_end = GIMP_ANCHOR (anchorlist->data);
segmentcoords[3] = segment_end->position;
}
dist = gimp_bezier_stroke_segment_nearest_point_get (segmentcoords,
coord, precision,
&point, &pos,
10);
if (dist < min_dist || min_dist < 0)
{
min_dist = dist;
if (ret_pos)
*ret_pos = pos;
if (ret_point)
*ret_point = point;
if (ret_segment_start)
*ret_segment_start = segment_start;
if (ret_segment_end)
*ret_segment_end = segment_end;
}
}
return min_dist;
}
static gdouble
gimp_bezier_stroke_segment_nearest_point_get (const GimpCoords *beziercoords,
const GimpCoords *coord,
gdouble precision,
GimpCoords *ret_point,
gdouble *ret_pos,
gint depth)
{
/*
* beziercoords has to contain four GimpCoords with the four control points
* of the bezier segment. We subdivide it at the parameter 0.5.
*/
GimpCoords subdivided[8];
gdouble dist1, dist2;
GimpCoords point1, point2;
gdouble pos1, pos2;
gimp_coords_difference (&beziercoords[1], &beziercoords[0], &point1);
gimp_coords_difference (&beziercoords[3], &beziercoords[2], &point2);
if (! depth || (gimp_coords_bezier_is_straight (beziercoords, precision) &&
gimp_coords_length_squared (&point1) < precision &&
gimp_coords_length_squared (&point2) < precision))
{
GimpCoords line, dcoord;
gdouble length2, scalar;
gint i;
gimp_coords_difference (&(beziercoords[3]),
&(beziercoords[0]),
&line);
gimp_coords_difference (coord,
&(beziercoords[0]),
&dcoord);
length2 = gimp_coords_scalarprod (&line, &line);
scalar = gimp_coords_scalarprod (&line, &dcoord) / length2;
scalar = CLAMP (scalar, 0.0, 1.0);
/* lines look the same as bezier curves where the handles
* sit on the anchors, however, they are parametrized
* differently. Hence we have to do some weird approximation. */
pos1 = pos2 = 0.5;
for (i = 0; i <= 15; i++)
{
pos2 *= 0.5;
if (3 * pos1 * pos1 * (1-pos1) + pos1 * pos1 * pos1 < scalar)
pos1 += pos2;
else
pos1 -= pos2;
}
*ret_pos = pos1;
gimp_coords_mix (1.0, &(beziercoords[0]),
scalar, &line,
ret_point);
gimp_coords_difference (coord, ret_point, &dcoord);
return gimp_coords_length (&dcoord);
}
/* ok, we have to subdivide */
subdivided[0] = beziercoords[0];
subdivided[6] = beziercoords[3];
/* if (!depth) g_printerr ("Hit recursion depth limit!\n"); */
gimp_coords_average (&(beziercoords[0]), &(beziercoords[1]),
&(subdivided[1]));
gimp_coords_average (&(beziercoords[1]), &(beziercoords[2]),
&(subdivided[7]));
gimp_coords_average (&(beziercoords[2]), &(beziercoords[3]),
&(subdivided[5]));
gimp_coords_average (&(subdivided[1]), &(subdivided[7]),
&(subdivided[2]));
gimp_coords_average (&(subdivided[7]), &(subdivided[5]),
&(subdivided[4]));
gimp_coords_average (&(subdivided[2]), &(subdivided[4]),
&(subdivided[3]));
/*
* We now have the coordinates of the two bezier segments in
* subdivided [0-3] and subdivided [3-6]
*/
dist1 = gimp_bezier_stroke_segment_nearest_point_get (&(subdivided[0]),
coord, precision,
&point1, &pos1,
depth - 1);
dist2 = gimp_bezier_stroke_segment_nearest_point_get (&(subdivided[3]),
coord, precision,
&point2, &pos2,
depth - 1);
if (dist1 <= dist2)
{
*ret_point = point1;
*ret_pos = 0.5 * pos1;
return dist1;
}
else
{
*ret_point = point2;
*ret_pos = 0.5 + 0.5 * pos2;
return dist2;
}
}
static gdouble
gimp_bezier_stroke_nearest_tangent_get (GimpStroke *stroke,
const GimpCoords *coord1,
const GimpCoords *coord2,
gdouble precision,
GimpCoords *nearest,
GimpAnchor **ret_segment_start,
GimpAnchor **ret_segment_end,
gdouble *ret_pos)
{
gdouble min_dist, dist, pos;
GimpCoords point;
GimpCoords segmentcoords[4];
GList *anchorlist;
GimpAnchor *segment_start;
GimpAnchor *segment_end = NULL;
GimpAnchor *anchor;
gint count;
if (g_queue_is_empty (stroke->anchors))
return -1.0;
count = 0;
min_dist = -1;
for (anchorlist = stroke->anchors->head;
GIMP_ANCHOR (anchorlist->data)->type != GIMP_ANCHOR_ANCHOR;
anchorlist = g_list_next (anchorlist));
segment_start = anchorlist->data;
for ( ; anchorlist; anchorlist = g_list_next (anchorlist))
{
anchor = anchorlist->data;
segmentcoords[count] = anchor->position;
count++;
if (count == 4)
{
segment_end = anchorlist->data;
dist = gimp_bezier_stroke_segment_nearest_tangent_get (segmentcoords,
coord1, coord2,
precision,
&point, &pos);
if (dist >= 0 && (dist < min_dist || min_dist < 0))
{
min_dist = dist;
if (ret_pos)
*ret_pos = pos;
if (nearest)
*nearest = point;
if (ret_segment_start)
*ret_segment_start = segment_start;
if (ret_segment_end)
*ret_segment_end = segment_end;
}
segment_start = anchorlist->data;
segmentcoords[0] = segmentcoords[3];
count = 1;
}
}
if (stroke->closed && ! g_queue_is_empty (stroke->anchors))
{
anchorlist = stroke->anchors->head;
while (count < 3)
{
segmentcoords[count] = GIMP_ANCHOR (anchorlist->data)->position;
count++;
}
anchorlist = g_list_next (anchorlist);
if (anchorlist)
{
segment_end = GIMP_ANCHOR (anchorlist->data);
segmentcoords[3] = segment_end->position;
}
dist = gimp_bezier_stroke_segment_nearest_tangent_get (segmentcoords,
coord1, coord2,
precision,
&point, &pos);
if (dist >= 0 && (dist < min_dist || min_dist < 0))
{
min_dist = dist;
if (ret_pos)
*ret_pos = pos;
if (nearest)
*nearest = point;
if (ret_segment_start)
*ret_segment_start = segment_start;
if (ret_segment_end)
*ret_segment_end = segment_end;
}
}
return min_dist;
}
static gdouble
gimp_bezier_stroke_segment_nearest_tangent_get (const GimpCoords *beziercoords,
const GimpCoords *coord1,
const GimpCoords *coord2,
gdouble precision,
GimpCoords *ret_point,
gdouble *ret_pos)
{
GArray *ret_coords;
GArray *ret_params;
GimpCoords dir, line, dcoord, min_point;
gdouble min_dist = -1;
gdouble dist, length2, scalar, ori, ori2;
gint i;
gimp_coords_difference (coord2, coord1, &line);
ret_coords = g_array_new (FALSE, FALSE, sizeof (GimpCoords));
ret_params = g_array_new (FALSE, FALSE, sizeof (gdouble));
g_printerr ("(%.2f, %.2f)-(%.2f,%.2f): ", coord1->x, coord1->y,
coord2->x, coord2->y);
gimp_coords_interpolate_bezier (beziercoords, precision,
ret_coords, ret_params);
g_return_val_if_fail (ret_coords->len == ret_params->len, -1.0);
if (ret_coords->len < 2)
return -1;
gimp_coords_difference (&g_array_index (ret_coords, GimpCoords, 1),
&g_array_index (ret_coords, GimpCoords, 0),
&dir);
ori = dir.x * line.y - dir.y * line.x;
for (i = 2; i < ret_coords->len; i++)
{
gimp_coords_difference (&g_array_index (ret_coords, GimpCoords, i),
&g_array_index (ret_coords, GimpCoords, i-1),
&dir);
ori2 = dir.x * line.y - dir.y * line.x;
if (ori * ori2 <= 0)
{
gimp_coords_difference (&g_array_index (ret_coords, GimpCoords, i),
coord1,
&dcoord);
length2 = gimp_coords_scalarprod (&line, &line);
scalar = gimp_coords_scalarprod (&line, &dcoord) / length2;
if (scalar >= 0 && scalar <= 1)
{
gimp_coords_mix (1.0, coord1,
scalar, &line,
&min_point);
gimp_coords_difference (&min_point,
&g_array_index (ret_coords, GimpCoords, i),
&dcoord);
dist = gimp_coords_length (&dcoord);
if (dist < min_dist || min_dist < 0)
{
min_dist = dist;
*ret_point = g_array_index (ret_coords, GimpCoords, i);
*ret_pos = g_array_index (ret_params, gdouble, i);
}
}
}
ori = ori2;
}
if (min_dist < 0)
g_printerr ("-\n");
else
g_printerr ("%f: (%.2f, %.2f) /%.3f/\n", min_dist,
(*ret_point).x, (*ret_point).y, *ret_pos);
g_array_free (ret_coords, TRUE);
g_array_free (ret_params, TRUE);
return min_dist;
}
static gboolean
gimp_bezier_stroke_is_extendable (GimpStroke *stroke,
GimpAnchor *neighbor)
{
GList *listneighbor;
gint loose_end;
if (stroke->closed)