gimp/plug-ins/selection-to-path/pxl-outline.h

70 lines
2.1 KiB
C

/* pxl-outline.h: find a list of outlines which make up one character.
*
* 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 2, 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef PXL_OUTLINE_H
#define PXL_OUTLINE_H
#include "types.h"
/* This is a list of contiguous points on the bitmap. */
typedef struct
{
coordinate_type *data;
unsigned length;
boolean clockwise;
} pixel_outline_type;
/* The Nth coordinate in the list. */
#define O_COORDINATE(p_o, n) ((p_o).data[n])
/* The length of the list. */
#define O_LENGTH(p_o) ((p_o).length)
/* Whether the outline moves clockwise or counterclockwise. */
#define O_CLOCKWISE(p_o) ((p_o).clockwise)
/* Since a pixel outline is cyclic, the index of thenext coordinate
after the last is the first, and the previous coordinate before the
first is the last. */
#define O_NEXT(p_o, n) (((n) + 1) % O_LENGTH (p_o))
#define O_PREV(p_o, n) ((n) == 0 ? O_LENGTH (p_o) - 1 : (n) - 1)
/* And the character turns into a list of such lists. */
typedef struct
{
pixel_outline_type *data;
unsigned length;
} pixel_outline_list_type;
/* The Nth list in the list of lists. */
#define O_LIST_OUTLINE(p_o_l, n) ((p_o_l).data[n])
/* The length of the list of lists. */
#define O_LIST_LENGTH(p_o_l) ((p_o_l).length)
/* Find all pixels on the outline in the character C. */
extern pixel_outline_list_type find_outline_pixels (void);
/* Free the memory in the list. */
extern void free_pixel_outline_list (pixel_outline_list_type *);
#endif /* not PXL_OUTLINE_H */