gimp/plug-ins/sel2path/pxl-outline.h

71 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., 675 Mass Ave, Cambridge, MA 02139, 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 ();
/* Free the memory in the list. */
extern void free_pixel_outline_list (pixel_outline_list_type *);
#endif /* not PXL_OUTLINE_H */