/* * 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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