opencsg-sys 1.1.0

FFI bindings to OpenCSG (image-based CSG rendering for OpenGL)
Documentation 
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

// OpenCSG - library for image-based CSG rendering for OpenGL
// Copyright (C) 2025-2026, Florian Kirsch
//
// This library 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 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110 - 1301 USA.

//
// sequencer.h
//
// algorithms to create short permutation embedding sequences.
// c.f. https://oeis.org/A062714. Such sequences are used in the
// SCS algorithm.
//

#ifndef __OpenCSG__sequencer_h__
#define __OpenCSG__sequencer_h__

#include "opencsgConfig.h"

#include <algorithm>

namespace OpenCSG {

    class Sequencer
    {
    public:
        virtual ~Sequencer()
        {
        }

        virtual size_t index(size_t position) const = 0;
        virtual size_t size() const = 0;
        virtual size_t sizeForDepthComplexity(size_t dc) const = 0;

    protected:
        Sequencer(size_t numElems)
            : n(numElems)
        {
        }
        size_t n;
    };

    class SimpleSequencer : public Sequencer
    {
    public:
        SimpleSequencer(size_t numElems)
          : Sequencer(numElems)
        {
        }
        virtual size_t index(size_t position) const
        {
            return position % n;
        }
        virtual size_t size() const
        {
            return n * (n - 1) + 1;
        }
        virtual size_t sizeForDepthComplexity(size_t dc) const
        {
            return n * dc;
        }

    };

    class BouncingSequencer : public Sequencer
    {
    public:
        BouncingSequencer(size_t numElems)
            : Sequencer(numElems)
        {
        }
        virtual size_t index(size_t position) const
        {
            if (n == 1)
                return 0;
            size_t wave = position % (n + n - 2);
            if (wave < n)
                return wave;
            else
                return (n + n - 2) - wave;
        }
        virtual size_t size() const
        {
            return n * (n - 1) + 1;
        }
        virtual size_t sizeForDepthComplexity(size_t dc) const
        {
            return (dc & 1) == 1
                ?  (dc - 1) * (n - 1) + n
                :     dc    * (n - 1) + 1;
        }
    };

    class SchoenfieldSequencer : public Sequencer
    {
    public:
        SchoenfieldSequencer(size_t numElems)
            : Sequencer(numElems)
        {
        }
        virtual size_t index(size_t position) const
        {
            if (n == 1)
                return 0;
            if (n == 2)
                return position & 1;
            if (position < n)
                return position;
            else if ((position - 1) % (n - 1) == 0)
                return 0;
            else
                return (position * (n - 2) / (n - 1)) % (n - 1) + 1;
        }
        virtual size_t size() const
        {
            if (n == 1)
                return 1;
            if (n == 2)
                return 3;
            return n * n - 2 * n + 4;
        }
        virtual size_t sizeForDepthComplexity(size_t dc) const
        {
            return std::min(size(), n * dc);
        }
    };

} // namespace OpenCSG

#endif // __OpenCSG__sequencer_h__