File size: 7,661 Bytes
985c397
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
// SPDX-License-Identifier: LGPL-2.1-or-later

/***************************************************************************

 *   Copyright (c) 2005 Werner Mayer <wmayer[at]users.sourceforge.net>     *

 *                                                                         *

 *   This file is part of the FreeCAD CAx development system.              *

 *                                                                         *

 *   This 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.      *

 *                                                                         *

 *   This 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 this 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                                *

 *                                                                         *

 ***************************************************************************/

#include <algorithm>
#include <cmath>
#include <limits>
#include <map>


#include "Grid.h"
#include "Iterator.h"
#include "MeshKernel.h"
#include "Projection.h"


using namespace MeshCore;

// ------------------------------------------------------------------------

MeshProjection::MeshProjection(const MeshKernel& mesh)
    : kernel(mesh)
{}

bool MeshProjection::bboxInsideRectangle(

    const Base::BoundBox3f& bbox,

    const Base::Vector3f& p1,

    const Base::Vector3f& p2,

    const Base::Vector3f& view

) const

{
    Base::Vector3f dir(p2 - p1);
    Base::Vector3f base(p1), normal(view % dir);
    normal.Normalize();

    if (bbox.IsCutPlane(base, normal)) {
        dir.Normalize();
        Base::Vector3f cnt(bbox.GetCenter());

        return (fabs(cnt.DistanceToPlane(p1, dir)) + fabs(cnt.DistanceToPlane(p2, dir)))
            <= (bbox.CalcDiagonalLength() + (p2 - p1).Length());
    }

    return false;
}

bool MeshProjection::isPointInsideDistance(

    const Base::Vector3f& p1,

    const Base::Vector3f& p2,

    const Base::Vector3f& pt

) const

{
    // project point on line
    Base::Vector3f proj, dir(p2 - p1);
    Base::Vector3f move(pt - p1);
    proj.ProjectToLine(move, dir);
    proj = pt + proj;
    return (((p1 - proj) * (p2 - proj)) < 0.0F);
}

bool MeshProjection::connectLines(

    std::list<std::pair<Base::Vector3f, Base::Vector3f>>& cutLines,

    const Base::Vector3f& startPoint,

    const Base::Vector3f& endPoint,

    std::vector<Base::Vector3f>& polyline

) const

{
    const float fMaxDist = std::sqrt(std::numeric_limits<float>::max());  // max. length of a gap
    const float fMinEps = 1.0e-4F;

    polyline.clear();
    polyline.push_back(startPoint);

    Base::Vector3f curr(startPoint);
    while ((curr != endPoint) && (!cutLines.empty())) {
        std::list<std::pair<Base::Vector3f, Base::Vector3f>>::iterator it, pCurr = cutLines.end();

        // get nearest line
        float fMin = fMaxDist * fMaxDist;

        bool bPos = false;
        for (it = cutLines.begin(); it != cutLines.end(); ++it) {
            float fD1 = Base::DistanceP2(curr, it->first);
            float fD2 = Base::DistanceP2(curr, it->second);
            if (std::min<float>(fD1, fD2) < fMin) {
                pCurr = it;
                bPos = fD1 < fD2;
                fMin = std::min<float>(fD1, fD2);
                if (fMin < fMinEps) {  // abort because next line already found
                    break;
                }
            }
        }

        if (pCurr != cutLines.end()) {
            if (bPos) {
                if (fMin > fMinEps) {  // gap, insert point
                    polyline.push_back(pCurr->first);
                }
                polyline.push_back(pCurr->second);
                curr = pCurr->second;
            }
            else {
                if (fMin > fMinEps) {  // gap, insert point
                    polyline.push_back(pCurr->second);
                }
                polyline.push_back(pCurr->first);
                curr = pCurr->first;
            }
        }
        else {
            return false;  // abort because no line was found
        }

        cutLines.erase(pCurr);
    }

    return true;
}

bool MeshProjection::projectLineOnMesh(

    const MeshFacetGrid& grid,

    const Base::Vector3f& v1,

    FacetIndex f1,

    const Base::Vector3f& v2,

    FacetIndex f2,

    const Base::Vector3f& vd,

    std::vector<Base::Vector3f>& polyline

)

{
    Base::Vector3f dir(v2 - v1);
    Base::Vector3f base(v1), normal(vd % dir);
    normal.Normalize();
    dir.Normalize();


    std::vector<FacetIndex> facets;

    // special case: start and endpoint inside same facet
    if (f1 == f2) {
        polyline.push_back(v1);
        polyline.push_back(v2);
        return true;
    }

    // cut all facets between the two endpoints
    MeshGridIterator gridIter(grid);
    for (gridIter.Init(); gridIter.More(); gridIter.Next()) {
        // bbox cuts plane
        if (bboxInsideRectangle(gridIter.GetBoundBox(), v1, v2, vd)) {
            gridIter.GetElements(facets);
        }
    }

    std::sort(facets.begin(), facets.end());
    facets.erase(std::unique(facets.begin(), facets.end()), facets.end());

    // cut all facets with plane
    std::list<std::pair<Base::Vector3f, Base::Vector3f>> cutLine;
    for (FacetIndex facet : facets) {
        Base::Vector3f e1, e2;
        MeshGeomFacet tria = kernel.GetFacet(facet);
        if (bboxInsideRectangle(tria.GetBoundBox(), v1, v2, vd)) {
            if (tria.IntersectWithPlane(base, normal, e1, e2)) {
                if ((facet != f1) && (facet != f2)) {
                    // inside cut line
                    if (!isPointInsideDistance(v1, v2, e1) || !isPointInsideDistance(v1, v2, e2)) {
                        continue;
                    }

                    cutLine.emplace_back(e1, e2);
                }
                else {
                    if (facet == f1) {  // start facet
                        if (((e2 - v1) * dir) > 0.0F) {
                            cutLine.emplace_back(v1, e2);
                        }
                        else {
                            cutLine.emplace_back(v1, e1);
                        }

                        // start = it - facets.begin();
                    }

                    if (facet == f2) {  // end facet
                        if (((e2 - v2) * -dir) > 0.0F) {
                            cutLine.emplace_back(v2, e2);
                        }
                        else {
                            cutLine.emplace_back(v2, e1);
                        }

                        // end = it - facets.begin();
                    }
                }
            }
        }
    }

    return connectLines(cutLine, v1, v2, polyline);
}