From 5c1676dfe6d2f3c837a5e074117b45613fd29a72 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:30:19 +0200 Subject: Adding upstream version 2.10.34. Signed-off-by: Daniel Baumann --- plug-ins/selection-to-path/edge.h | 59 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 plug-ins/selection-to-path/edge.h (limited to 'plug-ins/selection-to-path/edge.h') diff --git a/plug-ins/selection-to-path/edge.h b/plug-ins/selection-to-path/edge.h new file mode 100644 index 0000000..1d9d347 --- /dev/null +++ b/plug-ins/selection-to-path/edge.h @@ -0,0 +1,59 @@ +/* edge.h: declarations for edge traversing. + * + * 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 . + */ + +#ifndef EDGE_H +#define EDGE_H + +#include "bitmap.h" + +/* We consider each pixel to consist of four edges, and we travel along + edges, instead of through pixel centers. This is necessary for those + unfortunate times when a single pixel is on both an inside and an + outside outline. + + The numbers chosen here are not arbitrary; the code that figures out + which edge to move to depends on particular values. See the + `TRY_PIXEL' macro in `edge.c'. To emphasize this, I've written in the + numbers we need for each edge value. */ + +typedef enum +{ + top = 1, left = 2, bottom = 3, right = 0, no_edge = 4 +} edge_type; + +/* This choice is also not arbitrary: starting at the top edge makes the + code find outside outlines before inside ones, which is certainly + what we want. */ +#define START_EDGE top + + +/* Return the next outline edge on B in EDGE, ROW, and COL. */ +extern void next_outline_edge (edge_type *edge, + unsigned *row, unsigned *col); + +/* Return the next edge after START on the pixel ROW/COL in B that is + unmarked, according to the MARKED array. */ +extern edge_type next_unmarked_outline_edge (unsigned row, unsigned col, + edge_type start, + bitmap_type marked); + +/* Mark the edge E at the pixel ROW/COL in MARKED. */ +extern void mark_edge (edge_type e, unsigned row, unsigned col, + bitmap_type *marked); + +#endif /* not EDGE_H */ -- cgit v1.2.3