gimp/plug-ins/selection-to-path/curve.c

185 lines
4.4 KiB
C

/* curve.c: operations on the lists of pixels and lists of curves.
*
* Copyright (C) 1992 Free Software Foundation, Inc.
*
* 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, 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 <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <glib.h>
#include "global.h"
#include "curve.h"
/* Return an entirely empty curve. */
curve_type
new_curve (void)
{
curve_type curve = g_new (struct curve, 1);
curve->point_list = NULL;
CURVE_LENGTH (curve) = 0;
CURVE_CYCLIC (curve) = false;
CURVE_START_TANGENT (curve) = CURVE_END_TANGENT (curve) = NULL;
PREVIOUS_CURVE (curve) = NEXT_CURVE (curve) = NULL;
return curve;
}
/* Start the returned curve off with COORD as the first point. */
curve_type
init_curve (coordinate_type coord)
{
curve_type curve = new_curve ();
curve->point_list = g_new (point_type, 1);
CURVE_LENGTH (curve) = 1;
CURVE_POINT (curve, 0) = int_to_real_coord (coord);
return curve;
}
/* Don't copy the points or tangents, but copy everything else. */
curve_type
copy_most_of_curve (curve_type old_curve)
{
curve_type curve = new_curve ();
CURVE_CYCLIC (curve) = CURVE_CYCLIC (old_curve);
PREVIOUS_CURVE (curve) = PREVIOUS_CURVE (old_curve);
NEXT_CURVE (curve) = NEXT_CURVE (old_curve);
return curve;
}
/* The length of CURVE will be zero if we ended up not being able to fit
it (which in turn implies a problem elsewhere in the program, but at
any rate, we shouldn't try here to free the nonexistent curve). */
void
free_curve (curve_type curve)
{
if (CURVE_LENGTH (curve) > 0)
safe_free ((address *) &(curve->point_list));
}
void
append_pixel (curve_type curve, coordinate_type coord)
{
append_point (curve, int_to_real_coord (coord));
}
void
append_point (curve_type curve, real_coordinate_type coord)
{
CURVE_LENGTH (curve)++;
curve->point_list = g_realloc (curve->point_list,CURVE_LENGTH (curve) * sizeof(point_type));
LAST_CURVE_POINT (curve) = coord;
/* The t value does not need to be set. */
}
/* Return an initialized but empty curve list. */
curve_list_type
new_curve_list (void)
{
curve_list_type curve_list;
curve_list.length = 0;
curve_list.data = NULL;
curve_list.clockwise = FALSE;
return curve_list;
}
/* Free a curve list and all the curves it contains. */
void
free_curve_list (curve_list_type *curve_list)
{
unsigned this_curve;
for (this_curve = 0; this_curve < curve_list->length; this_curve++)
free_curve (curve_list->data[this_curve]);
/* If the character was empty, it won't have any curves. */
if (curve_list->data != NULL)
safe_free ((address *) &(curve_list->data));
}
/* Add an element to a curve list. */
void
append_curve (curve_list_type *curve_list, curve_type curve)
{
curve_list->length++;
curve_list->data = g_realloc (curve_list->data,curve_list->length*sizeof(curve_type));
curve_list->data[curve_list->length - 1] = curve;
}
/* Return an initialized but empty curve list array. */
curve_list_array_type
new_curve_list_array (void)
{
curve_list_array_type curve_list_array;
CURVE_LIST_ARRAY_LENGTH (curve_list_array) = 0;
curve_list_array.data = NULL;
return curve_list_array;
}
/* Free a curve list array and all the curve lists it contains. */
void
free_curve_list_array (curve_list_array_type *curve_list_array)
{
unsigned this_list;
for (this_list = 0; this_list < CURVE_LIST_ARRAY_LENGTH (*curve_list_array);
this_list++)
free_curve_list (&CURVE_LIST_ARRAY_ELT (*curve_list_array, this_list));
/* If the character was empty, it won't have any curves. */
if (curve_list_array->data != NULL)
safe_free ((address *) &(curve_list_array->data));
}
/* Add an element to a curve list array. */
void
append_curve_list (curve_list_array_type *l, curve_list_type curve_list)
{
CURVE_LIST_ARRAY_LENGTH (*l)++;
l->data = g_realloc (l->data,( CURVE_LIST_ARRAY_LENGTH (*l))*sizeof(curve_list_type));
LAST_CURVE_LIST_ARRAY_ELT (*l) = curve_list;
}