Branch data Line data Source code
1 : : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : : /*
3 : : * This file is part of the LibreOffice project.
4 : : *
5 : : * This Source Code Form is subject to the terms of the Mozilla Public
6 : : * License, v. 2.0. If a copy of the MPL was not distributed with this
7 : : * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8 : : *
9 : : * This file incorporates work covered by the following license notice:
10 : : *
11 : : * Licensed to the Apache Software Foundation (ASF) under one or more
12 : : * contributor license agreements. See the NOTICE file distributed
13 : : * with this work for additional information regarding copyright
14 : : * ownership. The ASF licenses this file to you under the Apache
15 : : * License, Version 2.0 (the "License"); you may not use this file
16 : : * except in compliance with the License. You may obtain a copy of
17 : : * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 : : */
19 : :
20 : : #include "basegfx/tools/tools.hxx"
21 : : #include "basegfx/range/b2drange.hxx"
22 : :
23 : : #include <algorithm>
24 : :
25 : :
26 : : namespace basegfx
27 : : {
28 : : namespace tools
29 : : {
30 : : namespace
31 : : {
32 : 0 : inline double distance( const double& nX,
33 : : const double& nY,
34 : : const ::basegfx::B2DVector& rNormal,
35 : : const double& nC )
36 : : {
37 : 0 : return nX*rNormal.getX() + nY*rNormal.getY() - nC;
38 : : }
39 : :
40 : 0 : void moveLineOutsideRect( ::basegfx::B2DPoint& io_rStart,
41 : : ::basegfx::B2DPoint& io_rEnd,
42 : : const ::basegfx::B2DVector& rMoveDirection,
43 : : const ::basegfx::B2DRange& rFitTarget )
44 : : {
45 : : // calc c for normal line form equation n x - c = 0
46 [ # # ]: 0 : const double nC( rMoveDirection.scalar( io_rStart ) );
47 : :
48 : : // calc maximum orthogonal distance for all four bound
49 : : // rect corners to the line
50 : : const double nMaxDistance( ::std::max(
51 : : 0.0,
52 : : ::std::max(
53 [ # # ]: 0 : distance(rFitTarget.getMinX(),
54 [ # # ]: 0 : rFitTarget.getMinY(),
55 : : rMoveDirection,
56 : 0 : nC),
57 : : ::std::max(
58 [ # # ]: 0 : distance(rFitTarget.getMinX(),
59 [ # # ]: 0 : rFitTarget.getMaxY(),
60 : : rMoveDirection,
61 : 0 : nC),
62 : : ::std::max(
63 [ # # ]: 0 : distance(rFitTarget.getMaxX(),
64 [ # # ]: 0 : rFitTarget.getMinY(),
65 : : rMoveDirection,
66 : 0 : nC),
67 [ # # ]: 0 : distance(rFitTarget.getMaxX(),
68 [ # # ]: 0 : rFitTarget.getMaxY(),
69 : : rMoveDirection,
70 [ # # # # : 0 : nC) ) ) ) ) );
# # ][ # # ]
71 : :
72 : : // now move line points, such that the bound rect
73 : : // points are all either 'on' or on the negative side
74 : : // of the half-plane
75 : 0 : io_rStart += nMaxDistance*rMoveDirection;
76 : 0 : io_rEnd += nMaxDistance*rMoveDirection;
77 : 0 : }
78 : : }
79 : :
80 : 0 : void infiniteLineFromParallelogram( ::basegfx::B2DPoint& io_rLeftTop,
81 : : ::basegfx::B2DPoint& io_rLeftBottom,
82 : : ::basegfx::B2DPoint& io_rRightTop,
83 : : ::basegfx::B2DPoint& io_rRightBottom,
84 : : const ::basegfx::B2DRange& rFitTarget )
85 : : {
86 : : // For the top and bottom border line of the
87 : : // parallelogram, we determine the distance to all four
88 : : // corner points of the bound rect (tl, tr, bl, br). When
89 : : // using the unit normal form for lines (n x - c = 0), and
90 : : // choosing n to point 'outwards' the parallelogram, then
91 : : // all bound rect corner points having positive distance
92 : : // to the line lie outside the extended gradient rect, and
93 : : // thus, the corresponding border line must be moved the
94 : : // maximum distance outwards.
95 : :
96 : : // don't use the top and bottom border line direction, and
97 : : // calculate the normal from them. Instead, use the
98 : : // vertical lines (lt - lb or rt - rb), as they more
99 : : // faithfully represent the direction of the
100 : : // to-be-generated infinite line
101 : 0 : ::basegfx::B2DVector aDirectionVertical( io_rLeftTop - io_rLeftBottom );
102 [ # # ]: 0 : aDirectionVertical.normalize();
103 : :
104 : 0 : const ::basegfx::B2DVector aNormalTop( aDirectionVertical );
105 : 0 : const ::basegfx::B2DVector aNormalBottom( -aDirectionVertical );
106 : :
107 : : // now extend parallelogram, such that the bound rect
108 : : // point are included
109 [ # # ]: 0 : moveLineOutsideRect( io_rLeftTop, io_rRightTop, aNormalTop, rFitTarget );
110 [ # # ]: 0 : moveLineOutsideRect( io_rLeftBottom, io_rRightBottom, aNormalBottom, rFitTarget );
111 : 0 : }
112 : : }
113 : : }
114 : :
115 : : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|