summaryrefslogtreecommitdiffhomepage
path: root/spline/spline.cpp
blob: 76a6190f0eea5bba17add66215119e193efc6992 (plain)
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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
/* Copyright (c) 2012-2016, Stanislaw Halik <sthalik@misaki.pl>

 * Permission to use, copy, modify, and/or distribute this
 * software for any purpose with or without fee is hereby granted,
 * provided that the above copyright notice and this permission
 * notice appear in all copies.
 */

#include "spline.hpp"

#include <algorithm>
#include <cmath>
#include <memory>

#include <QObject>
#include <QMutexLocker>
#include <QCoreApplication>
#include <QPointF>
#include <QSettings>
#include <QString>

#include <QDebug>

constexpr int spline::value_count;

spline::spline(qreal maxx, qreal maxy, const QString& name) :
    s(nullptr),
    data(value_count, -16),
    _mutex(QMutex::Recursive),
    max_x(maxx),
    max_y(maxy),
    activep(false),
    validp(false)
{
    set_bundle(options::make_bundle(name));
}

spline::~spline()
{
    QMutexLocker l(&_mutex);

    if (connection)
    {
        QObject::disconnect(connection);
        connection = QMetaObject::Connection();
    }
}

spline::spline() : spline(0, 0, "") {}

void spline::set_tracking_active(bool value)
{
    QMutexLocker l(&_mutex);
    activep = value;
}

bundle spline::get_bundle()
{
    return s->b;
}

void spline::clear()
{
    QMutexLocker l(&_mutex);
    s->points = points_t();
    validp = false;
}

void spline::set_max_input(qreal max_input)
{
    QMutexLocker l(&_mutex);
    max_x = max_input;
    validp = false;
}

void spline::set_max_output(qreal max_output)
{
    QMutexLocker l(&_mutex);
    max_y = max_output;
    validp = false;
}

qreal spline::max_input() const
{
    QMutexLocker l(&_mutex);
    return max_x;
}

qreal spline::max_output() const
{
    QMutexLocker l(&_mutex);
    return max_y;
}

float spline::get_value(double x)
{
    QMutexLocker foo(&_mutex);

    const float ret = get_value_no_save(x);
    last_input_value.setX(std::fabs(x));
    last_input_value.setY(double(std::fabs(ret)));
    return ret;
}

float spline::get_value_no_save(double x) const
{
    return const_cast<spline&>(*this).get_value_no_save_internal(x);
}

float spline::get_value_no_save_internal(double x)
{
    QMutexLocker foo(&_mutex);

    if (max_x > 0)
        x = std::fmin(max_x, x);

    float  q  = float(x * bucket_size_coefficient(s->points));
    int    xi = (int)q;
    float  yi = get_value_internal(xi);
    float  yiplus1 = get_value_internal(xi+1);
    float  f = (q-xi);
    float  ret = yiplus1 * f + yi * (1.0f - f); // at least do a linear interpolation.
    return ret;
}

DEFUN_WARN_UNUSED bool spline::get_last_value(QPointF& point)
{
    QMutexLocker foo(&_mutex);
    point = last_input_value;
    return activep;
}

float spline::get_value_internal(int x)
{
    if (!validp)
    {
        recompute();
        update_interp_data();
        validp = true;
    }

    float sign = x < 0 ? -1 : 1;
    x = std::abs(x);
    float ret = data[std::min(unsigned(x), unsigned(value_count)-1u)];
    return ret * sign;
}

void spline::add_lone_point()
{
    points_t points;
    points.push_back(QPointF(max_x, max_y));

    s->points = points;
}

QPointF spline::ensure_in_bounds(const QList<QPointF>& points, double max_x, int i)
{
    const int sz = element_count(points, max_x);

    if (i < 0 || sz == 0)
        return QPointF(0, 0);

    if (i < sz)
        return points[i];

    return points[sz - 1];
}

int spline::element_count(const QList<QPointF>& points, double max_x)
{
    if (!(max_x > 0))
        return points.size();
    else
    {
        const unsigned sz = points.size();
        for (unsigned i = 0; i < sz; i++)
        {
            if (!(points[i].x() <= max_x))
                return i;
        }
        return points.size();
    }
}

bool spline::sort_fn(const QPointF& one, const QPointF& two)
{
    return one.x() < two.x();
}

void spline::update_interp_data()
{
    points_t points = s->points;

    int sz = element_count(points, max_x);

    if (sz == 0)
        points.prepend(QPointF(max_x, max_y));

    std::stable_sort(points.begin(), points.begin() + sz, sort_fn);

    const double c = bucket_size_coefficient(points);
    const double c_interp = c * 30;

    for (unsigned i = 0; i < value_count; i++)
        data[i] = -16;

    if (sz < 2)
    {
        if (points[0].x() - 1e-2 <= max_x)
        {
            const double x = points[0].x();
            const double y = points[0].y();
            const int max = clamp(iround(x * c), 1, value_count-1);
            for (int k = 0; k <= max; k++)
            {
                if (k < value_count)
                    data[unsigned(k)] = float(y * k / max);
            }
        }
    }
    else
    {
        if (points[0].x() > 1e-2 && points[0].x() <= max_x)
            points.push_front(QPointF(0, 0));

        for (int i = 0; i < sz; i++)
        {
            const QPointF p0 = ensure_in_bounds(points, max_x, i - 1);
            const QPointF p1 = ensure_in_bounds(points, max_x, i + 0);
            const QPointF p2 = ensure_in_bounds(points, max_x, i + 1);
            const QPointF p3 = ensure_in_bounds(points, max_x, i + 2);
            const double p0_x = p0.x(), p1_x = p1.x(), p2_x = p2.x(), p3_x = p3.x();
            const double p0_y = p0.y(), p1_y = p1.y(), p2_y = p2.y(), p3_y = p3.y();

            const double cx[4] = {
                2 * p1_x, // 1
                -p0_x + p2_x, // t
                2 * p0_x - 5 * p1_x + 4 * p2_x - p3_x, // t^2
                -p0_x + 3 * p1_x - 3 * p2_x + p3_x, // t3
            };

            const double cy[4] =
            {
                2 * p1_y, // 1
                -p0_y + p2_y, // t
                2 * p0_y - 5 * p1_y + 4 * p2_y - p3_y, // t^2
                -p0_y + 3 * p1_y - 3 * p2_y + p3_y, // t3
            };

            // multiplier helps fill in all the x's needed
            const unsigned end = int(c_interp * (p2_x - p1_x)) + 1;

            for (unsigned k = 0; k <= end; k++)
            {
                const double t = k / double(end);
                const double t2 = t*t;
                const double t3 = t*t*t;

                const int x = int(.5 * c * (cx[0] + cx[1] * t + cx[2] * t2 + cx[3] * t3));
                const float y = float(.5 * (cy[0] + cy[1] * t + cy[2] * t2 + cy[3] * t3));

                if (x >= 0 && x < value_count)
                {
                    data[x] = y;
                }
            }
        }
    }

    float last = 0;
    for (unsigned i = 0; i < unsigned(value_count); i++)
    {
        if (data[i] == -16)
            data[i] = last;
        last = data[i];
    }
}

void spline::remove_point(int i)
{
    QMutexLocker foo(&_mutex);

    points_t points = s->points;
    const int sz = element_count(points, max_x);

    if (i >= 0 && i < sz)
    {
        points.erase(points.begin() + i);
        s->points = points;
        validp = false;
    }
}

void spline::add_point(QPointF pt)
{
    QMutexLocker foo(&_mutex);

    points_t points = s->points;
    points.push_back(pt);
    std::stable_sort(points.begin(), points.end(), sort_fn);
    s->points = points;
    validp = false;
}

void spline::add_point(double x, double y)
{
    add_point(QPointF(x, y));
}

void spline::move_point(int idx, QPointF pt)
{
    QMutexLocker foo(&_mutex);

    points_t points = s->points;

    const int sz = element_count(points, max_x);

    if (idx >= 0 && idx < sz)
    {
        points[idx] = pt;
        // we don't allow points to be reordered, but sort due to possible caller logic error
        std::stable_sort(points.begin(), points.end(), sort_fn);
        s->points = points;
        validp = false;
    }
}

QList<QPointF> spline::get_points() const
{
    QMutexLocker foo(&_mutex);
    return s->points;
}

int spline::get_point_count() const
{
    QMutexLocker foo(&_mutex);
    return element_count(s->points, max_x);
}

void spline::reload()
{
    QMutexLocker foo(&_mutex);
    s->b->reload();
}

void spline::save()
{
    QMutexLocker foo(&_mutex);
    s->b->save();
}

void spline::set_bundle(bundle b)
{
    QMutexLocker l(&_mutex);

    // gets called from ctor hence the need for nullptr checks
    // the sentinel settings/bundle objects don't need any further branching once created
    if (!s || s->b != b)
    {
        s = std::make_shared<settings>(b);

        if (connection)
            QObject::disconnect(connection);

        if (b)
        {
            connection = QObject::connect(b.get(), &bundle_::changed,
            s.get(), [&]()
            {
                    // we're holding the mutex to allow signal disconnection in spline dtor
                    // before this slot gets called for the next time

                    // spline isn't a QObject and the connection context is incorrect

                    QMutexLocker l(&_mutex);
                    validp = false;

                    emit s->recomputed();
                },
            Qt::QueuedConnection);
        }

        validp = false;
    }
}

void spline::recompute()
{
    QMutexLocker foo(&_mutex);

    QList<QPointF> list = s->points;

    // storing to s->points fires bundle::changed and that leads to an infinite loop
    // thus, only store if we can't help it
    std::stable_sort(list.begin(), list.end(), sort_fn);

    const int sz = list.size();

    QList<QPointF> ret_list;
    ret_list.reserve(sz);

    for (int i = 0; i < sz; i++)
    {
        QPointF& pt(list[i]);

        const bool overlap = progn(
            for (int j = 0; j < i; j++)
            {
                const QPointF& pt2(list[j]);
                const QPointF tmp(pt - pt2);
                const double dist_sq = QPointF::dotProduct(tmp, tmp);
                const double overlap = max_x / 500.;
                if (dist_sq < overlap * overlap)
                    return true;
            }
            return false;
        );
        if (!overlap)
            ret_list.push_back(pt);
    }

    if (ret_list != s->points)
        s->points = ret_list;

    last_input_value = QPointF(0, 0);
    activep = false;
}

// the return value is only safe to use with no spline::set_bundle calls
std::shared_ptr<spline::settings> spline::get_settings()
{
    QMutexLocker foo(&_mutex);
    return s;
}

std::shared_ptr<const spline::settings> spline::get_settings() const
{
    QMutexLocker foo(&_mutex);
    return s;
}

double spline::bucket_size_coefficient(const QList<QPointF>& points) const
{
    static constexpr double eps = 1e-4;

    if (unlikely(max_x < eps))
        return 0;

    const int sz = element_count(points, max_x);
    const double last_x = sz ? points[sz - 1].x() : max_x;

    return clamp((value_count-1) / clamp(last_x, eps, max_x), 0., (value_count-1));
}

namespace spline_detail {

settings::settings(bundle b):
    b(b ? b : make_bundle("")),
    points(b, "points", QList<QPointF>())
{}

settings::~settings()
{
}

}