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/*
* Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
* All rights reserved.
*
* This file is part of the Gnome Library.
*
* The Gnome Library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* The Gnome Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with the Gnome Library; see the file COPYING.LIB. If not,
* write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
@NOTATION@
*/
/* Miscellaneous utility functions for the EelCanvas widget
*
* EelCanvas is basically a port of the Tk toolkit's most excellent canvas widget. Tk is
* copyrighted by the Regents of the University of California, Sun Microsystems, and other parties.
*
* Author: Federico Mena <federico@nuclecu.unam.mx>
*/
#ifndef EEL_CANVAS_UTIL_H
#define EEL_CANVAS_UTIL_H
G_BEGIN_DECLS
/* This structure defines an array of points. X coordinates are stored in the even-numbered
* indices, and Y coordinates are stored in the odd-numbered indices. num_points indicates the
* number of points, so the array is 2*num_points elements big.
*/
typedef struct {
double *coords;
int num_points;
int ref_count;
} EelCanvasPoints;
/* Allocate a new EelCanvasPoints structure with enough space for the specified number of points */
EelCanvasPoints *eel_canvas_points_new (int num_points);
/* Increate ref count */
EelCanvasPoints *eel_canvas_points_ref (EelCanvasPoints *points);
#define eel_canvas_points_unref eel_canvas_points_free
/* Decrease ref count and free structure if it has reached zero */
void eel_canvas_points_free (EelCanvasPoints *points);
/* Given three points forming an angle, compute the coordinates of the inside and outside points of
* the mitered corner formed by a line of a given width at that angle.
*
* If the angle is less than 11 degrees, then FALSE is returned and the return points are not
* modified. Otherwise, TRUE is returned.
*/
int eel_canvas_get_miter_points (double x1, double y1, double x2, double y2, double x3, double y3,
double width,
double *mx1, double *my1, double *mx2, double *my2);
/* Compute the butt points of a line segment. If project is FALSE, then the results are as follows:
*
* -------------------* (bx1, by1)
* |
* (x1, y1) *------------------* (x2, y2)
* |
* -------------------* (bx2, by2)
*
* that is, the line is not projected beyond (x2, y2). If project is TRUE, then the results are as
* follows:
*
* -------------------* (bx1, by1)
* (x2, y2) |
* (x1, y1) *-------------* |
* |
* -------------------* (bx2, by2)
*/
void eel_canvas_get_butt_points (double x1, double y1, double x2, double y2,
double width, int project,
double *bx1, double *by1, double *bx2, double *by2);
/* Calculate the distance from a polygon to a point. The polygon's X coordinates are in the even
* indices of the poly array, and the Y coordinates are in the odd indices.
*/
double eel_canvas_polygon_to_point (double *poly, int num_points, double x, double y);
void eel_canvas_item_reset_bounds (EelCanvasItem *item);
/* Sets the bbox to the new value, requesting full repaint. */
void eel_canvas_update_bbox (EelCanvasItem *item, int x1, int y1, int x2, int y2);
G_END_DECLS
#endif
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