1 |
/*************************************************************************** |
2 |
* * |
3 |
* LinuxSampler - modular, streaming capable sampler * |
4 |
* * |
5 |
* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck * |
6 |
* Copyright (C) 2005 Christian Schoenebeck * |
7 |
* Copyright (C) 2006-2017 Christian Schoenebeck and Andreas Persson * |
8 |
* * |
9 |
* This program is free software; you can redistribute it and/or modify * |
10 |
* it under the terms of the GNU General Public License as published by * |
11 |
* the Free Software Foundation; either version 2 of the License, or * |
12 |
* (at your option) any later version. * |
13 |
* * |
14 |
* This program is distributed in the hope that it will be useful, * |
15 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
16 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
17 |
* GNU General Public License for more details. * |
18 |
* * |
19 |
* You should have received a copy of the GNU General Public License * |
20 |
* along with this program; if not, write to the Free Software * |
21 |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
22 |
* MA 02111-1307 USA * |
23 |
***************************************************************************/ |
24 |
|
25 |
#ifndef __LS_GIG_FILTER_H__ |
26 |
#define __LS_GIG_FILTER_H__ |
27 |
|
28 |
#include "../../common/global.h" |
29 |
|
30 |
#if AC_APPLE_UNIVERSAL_BUILD |
31 |
# include <libgig/gig.h> |
32 |
#else |
33 |
# include <gig.h> |
34 |
#endif |
35 |
|
36 |
#include <cmath> |
37 |
|
38 |
/* TODO: This file contains both generic filters (used by the sfz |
39 |
engine) and gig specific filters. It should probably be split up, |
40 |
and the generic parts should be moved out of the gig directory. */ |
41 |
|
42 |
/* |
43 |
* The formulas for the biquad coefficients come from Robert |
44 |
* Bristow-Johnson's Audio EQ Cookbook. The one pole filter formulas |
45 |
* come from a post on musicdsp.org. The one poles, biquads and |
46 |
* cascaded biquads are modeled after output from Dimension LE and SFZ |
47 |
* Player. The gig filters are modeled after output from GigaStudio. |
48 |
*/ |
49 |
namespace LinuxSampler { |
50 |
|
51 |
/** |
52 |
* Filter state and parameters for a biquad filter. |
53 |
*/ |
54 |
class BiquadFilterData { |
55 |
public: |
56 |
float b0, b1, b2; |
57 |
float a1, a2; |
58 |
|
59 |
float x1, x2; |
60 |
float y1, y2; |
61 |
}; |
62 |
|
63 |
/** |
64 |
* Filter state and parameters for cascaded biquad filters and gig |
65 |
* engine filters. |
66 |
*/ |
67 |
class FilterData : public BiquadFilterData |
68 |
{ |
69 |
public: |
70 |
union { |
71 |
// gig filter parameters |
72 |
struct { |
73 |
float a3; |
74 |
float x3; |
75 |
float y3; |
76 |
|
77 |
float scale; |
78 |
float b20; |
79 |
float y21, y22, y23; |
80 |
}; |
81 |
// cascaded biquad parameters |
82 |
struct { |
83 |
BiquadFilterData d2; |
84 |
BiquadFilterData d3; |
85 |
}; |
86 |
}; |
87 |
}; |
88 |
|
89 |
/** |
90 |
* Abstract base class for all filter implementations. |
91 |
*/ |
92 |
class FilterBase { |
93 |
public: |
94 |
virtual float Apply(FilterData& d, float x) const = 0; |
95 |
virtual void SetParameters(FilterData& d, float fc, float r, |
96 |
float fs) const = 0; |
97 |
virtual void Reset(FilterData& d) const = 0; |
98 |
protected: |
99 |
void KillDenormal(float& f) const { |
100 |
f += 1e-18f; |
101 |
f -= 1e-18f; |
102 |
} |
103 |
}; |
104 |
|
105 |
/** |
106 |
* One-pole lowpass filter. |
107 |
*/ |
108 |
class LowpassFilter1p : public FilterBase { |
109 |
public: |
110 |
LowpassFilter1p() { } |
111 |
|
112 |
float Apply(FilterData& d, float x) const { |
113 |
float y = x + d.a1 * (x - d.y1); // d.b0 * x - d.a1 * d.y1; |
114 |
KillDenormal(y); |
115 |
d.y1 = y; |
116 |
return y; |
117 |
} |
118 |
|
119 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
120 |
float omega = 2.0 * M_PI * fc / fs; |
121 |
float c = 2 - cos(omega); |
122 |
d.a1 = -(c - sqrt(c * c - 1)); |
123 |
// d.b0 = 1 + d.a1; |
124 |
} |
125 |
|
126 |
void Reset(FilterData& d) const { |
127 |
d.y1 = 0; |
128 |
} |
129 |
}; |
130 |
|
131 |
/** |
132 |
* One pole highpass filter. |
133 |
*/ |
134 |
class HighpassFilter1p : public FilterBase { |
135 |
public: |
136 |
HighpassFilter1p() { } |
137 |
|
138 |
float Apply(FilterData& d, float x) const { |
139 |
// d.b0 * x + d.b1 * d.x1 - d.a1 * d.y1; |
140 |
float y = d.a1 * (-x + d.x1 - d.y1); |
141 |
KillDenormal(y); |
142 |
d.x1 = x; |
143 |
d.y1 = y; |
144 |
return y; |
145 |
} |
146 |
|
147 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
148 |
float omega = 2.0 * M_PI * fc / fs; |
149 |
float c = 2 - cos(omega); |
150 |
d.a1 = -(c - sqrt(c * c - 1)); |
151 |
// d.b0 = -d.a1 |
152 |
// d.b1 = d.a1 |
153 |
} |
154 |
|
155 |
void Reset(FilterData& d) const { |
156 |
d.x1 = 0; |
157 |
d.y1 = 0; |
158 |
} |
159 |
}; |
160 |
|
161 |
/** |
162 |
* Base class for biquad filter implementations. |
163 |
*/ |
164 |
class BiquadFilter : public FilterBase { |
165 |
protected: |
166 |
float ApplyBQ(BiquadFilterData& d, float x) const { |
167 |
float y = d.b0 * x + d.b1 * d.x1 + d.b2 * d.x2 + |
168 |
d.a1 * d.y1 + d.a2 * d.y2; |
169 |
KillDenormal(y); |
170 |
d.x2 = d.x1; |
171 |
d.x1 = x; |
172 |
d.y2 = d.y1; |
173 |
d.y1 = y; |
174 |
return y; |
175 |
} |
176 |
|
177 |
public: |
178 |
float Apply(FilterData& d, float x) const { |
179 |
return ApplyBQ(d, x); |
180 |
} |
181 |
|
182 |
void Reset(FilterData& d) const { |
183 |
d.x1 = d.x2 = 0; |
184 |
d.y1 = d.y2 = 0; |
185 |
} |
186 |
}; |
187 |
|
188 |
/** |
189 |
* Base class for cascaded double biquad filter (four poles). |
190 |
*/ |
191 |
class DoubleBiquadFilter : public BiquadFilter { |
192 |
public: |
193 |
float Apply(FilterData& d, float x) const { |
194 |
return ApplyBQ(d.d2, BiquadFilter::Apply(d, x)); |
195 |
} |
196 |
|
197 |
void Reset(FilterData& d) const { |
198 |
BiquadFilter::Reset(d); |
199 |
d.d2.x1 = d.d2.x2 = 0; |
200 |
d.d2.y1 = d.d2.y2 = 0; |
201 |
} |
202 |
}; |
203 |
|
204 |
/** |
205 |
* Base class for cascaded triple biquad filter (six poles). |
206 |
*/ |
207 |
class TripleBiquadFilter : public DoubleBiquadFilter { |
208 |
public: |
209 |
float Apply(FilterData& d, float x) const { |
210 |
return ApplyBQ(d.d3, DoubleBiquadFilter::Apply(d, x)); |
211 |
} |
212 |
|
213 |
void Reset(FilterData& d) const { |
214 |
DoubleBiquadFilter::Reset(d); |
215 |
d.d3.x1 = d.d3.x2 = 0; |
216 |
d.d3.y1 = d.d3.y2 = 0; |
217 |
} |
218 |
}; |
219 |
|
220 |
|
221 |
/** @brief Lowpass Filter |
222 |
* |
223 |
* Lowpass filter based on biquad filter implementation. |
224 |
*/ |
225 |
class LowpassFilter : public BiquadFilter { |
226 |
public: |
227 |
LowpassFilter() { } |
228 |
|
229 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
230 |
float omega = 2.0 * M_PI * fc / fs; |
231 |
float sn = sin(omega); |
232 |
float cs = cos(omega); |
233 |
float alpha = sn * M_SQRT1_2 * exp(-M_LN10 / 20 * r); |
234 |
float a0r = 1.0 / (1.0 + alpha); |
235 |
|
236 |
d.b0 = a0r * (1.0 - cs) * 0.5; |
237 |
d.b1 = a0r * (1.0 - cs); |
238 |
d.b2 = a0r * (1.0 - cs) * 0.5; |
239 |
d.a1 = a0r * (2.0 * cs); |
240 |
d.a2 = a0r * (alpha - 1.0); |
241 |
} |
242 |
}; |
243 |
|
244 |
/** @brief Four pole lowpass filter |
245 |
* |
246 |
* Lowpass filter based on two cascaded biquad filters. |
247 |
*/ |
248 |
class LowpassFilter4p : public DoubleBiquadFilter { |
249 |
public: |
250 |
LowpassFilter4p() { } |
251 |
|
252 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
253 |
float omega = 2.0 * M_PI * fc / fs; |
254 |
float sn = sin(omega); |
255 |
float cs = cos(omega); |
256 |
float alpha = sn * M_SQRT1_2; |
257 |
float a0r = 1.0 / (1.0 + alpha); |
258 |
|
259 |
d.b0 = a0r * (1.0 - cs) * 0.5; |
260 |
d.b1 = a0r * (1.0 - cs); |
261 |
d.b2 = a0r * (1.0 - cs) * 0.5; |
262 |
d.a1 = a0r * (2.0 * cs); |
263 |
d.a2 = a0r * (alpha - 1.0); |
264 |
|
265 |
alpha *= exp(-M_LN10 / 20 * r); |
266 |
a0r = 1.0 / (1.0 + alpha); |
267 |
|
268 |
d.d2.b0 = a0r * (1.0 - cs) * 0.5; |
269 |
d.d2.b1 = a0r * (1.0 - cs); |
270 |
d.d2.b2 = a0r * (1.0 - cs) * 0.5; |
271 |
d.d2.a1 = a0r * (2.0 * cs); |
272 |
d.d2.a2 = a0r * (alpha - 1.0); |
273 |
} |
274 |
}; |
275 |
|
276 |
/** @brief Six pole lowpass filter |
277 |
* |
278 |
* Lowpass filter based on three cascaded biquad filters. |
279 |
*/ |
280 |
class LowpassFilter6p : public TripleBiquadFilter { |
281 |
public: |
282 |
LowpassFilter6p() { } |
283 |
|
284 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
285 |
float omega = 2.0 * M_PI * fc / fs; |
286 |
float sn = sin(omega); |
287 |
float cs = cos(omega); |
288 |
float alpha = sn * M_SQRT1_2; |
289 |
float a0r = 1.0 / (1.0 + alpha); |
290 |
|
291 |
d.b0 = d.d2.b0 = a0r * (1.0 - cs) * 0.5; |
292 |
d.b1 = d.d2.b1 = a0r * (1.0 - cs); |
293 |
d.b2 = d.d2.b2 = a0r * (1.0 - cs) * 0.5; |
294 |
d.a1 = d.d2.a1 = a0r * (2.0 * cs); |
295 |
d.a2 = d.d2.a2 = a0r * (alpha - 1.0); |
296 |
|
297 |
alpha *= exp(-M_LN10 / 20 * r); |
298 |
a0r = 1.0 / (1.0 + alpha); |
299 |
|
300 |
d.d3.b0 = a0r * (1.0 - cs) * 0.5; |
301 |
d.d3.b1 = a0r * (1.0 - cs); |
302 |
d.d3.b2 = a0r * (1.0 - cs) * 0.5; |
303 |
d.d3.a1 = a0r * (2.0 * cs); |
304 |
d.d3.a2 = a0r * (alpha - 1.0); |
305 |
} |
306 |
}; |
307 |
|
308 |
/** @brief Bandpass filter |
309 |
* |
310 |
* Bandpass filter based on biquad filter implementation. |
311 |
*/ |
312 |
class BandpassFilter : public BiquadFilter { |
313 |
public: |
314 |
BandpassFilter() { } |
315 |
|
316 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
317 |
float omega = 2.0 * M_PI * fc / fs; |
318 |
float sn = sin(omega); |
319 |
float cs = cos(omega); |
320 |
float alpha = sn * M_SQRT1_2 * exp(-M_LN10 / 20 * r); |
321 |
|
322 |
float a0r = 1.0 / (1.0 + alpha); |
323 |
d.b0 = a0r * alpha; |
324 |
d.b1 = 0.0; |
325 |
d.b2 = a0r * -alpha; |
326 |
d.a1 = a0r * (2.0 * cs); |
327 |
d.a2 = a0r * (alpha - 1.0); |
328 |
} |
329 |
}; |
330 |
|
331 |
/** @brief Bandreject filter |
332 |
* |
333 |
* Bandreject filter based on biquad filter implementation. |
334 |
*/ |
335 |
class BandrejectFilter : public BiquadFilter { |
336 |
public: |
337 |
BandrejectFilter() { } |
338 |
|
339 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
340 |
float omega = 2.0 * M_PI * fc / fs; |
341 |
float sn = sin(omega); |
342 |
float cs = cos(omega); |
343 |
float alpha = sn * M_SQRT1_2 * exp(-M_LN10 / 20 * r); |
344 |
|
345 |
float a0r = 1.0 / (1.0 + alpha); |
346 |
d.b0 = a0r; |
347 |
d.b1 = a0r * (-2.0 * cs); |
348 |
d.b2 = a0r; |
349 |
d.a1 = a0r * (2.0 * cs); |
350 |
d.a2 = a0r * (alpha - 1.0); |
351 |
} |
352 |
}; |
353 |
|
354 |
/** @brief Highpass filter |
355 |
* |
356 |
* Highpass filter based on biquad filter implementation. |
357 |
*/ |
358 |
class HighpassFilter : public BiquadFilter { |
359 |
public: |
360 |
HighpassFilter() { } |
361 |
|
362 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
363 |
float omega = 2.0 * M_PI * fc / fs; |
364 |
float sn = sin(omega); |
365 |
float cs = cos(omega); |
366 |
float alpha = sn * M_SQRT1_2 * exp(-M_LN10 / 20 * r); |
367 |
|
368 |
float a0r = 1.0 / (1.0 + alpha); |
369 |
d.b0 = a0r * (1.0 + cs) * 0.5; |
370 |
d.b1 = a0r * -(1.0 + cs); |
371 |
d.b2 = a0r * (1.0 + cs) * 0.5; |
372 |
d.a1 = a0r * (2.0 * cs); |
373 |
d.a2 = a0r * (alpha - 1.0); |
374 |
} |
375 |
}; |
376 |
|
377 |
/** @brief Four pole highpass filter |
378 |
* |
379 |
* Highpass filter based on three cascaded biquad filters. |
380 |
*/ |
381 |
class HighpassFilter4p : public DoubleBiquadFilter { |
382 |
public: |
383 |
HighpassFilter4p() { } |
384 |
|
385 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
386 |
float omega = 2.0 * M_PI * fc / fs; |
387 |
float sn = sin(omega); |
388 |
float cs = cos(omega); |
389 |
float alpha = sn * M_SQRT1_2; |
390 |
|
391 |
float a0r = 1.0 / (1.0 + alpha); |
392 |
d.b0 = a0r * (1.0 + cs) * 0.5; |
393 |
d.b1 = a0r * -(1.0 + cs); |
394 |
d.b2 = a0r * (1.0 + cs) * 0.5; |
395 |
d.a1 = a0r * (2.0 * cs); |
396 |
d.a2 = a0r * (alpha - 1.0); |
397 |
|
398 |
alpha *= exp(-M_LN10 / 20 * r); |
399 |
a0r = 1.0 / (1.0 + alpha); |
400 |
|
401 |
d.d2.b0 = a0r * (1.0 + cs) * 0.5; |
402 |
d.d2.b1 = a0r * -(1.0 + cs); |
403 |
d.d2.b2 = a0r * (1.0 + cs) * 0.5; |
404 |
d.d2.a1 = a0r * (2.0 * cs); |
405 |
d.d2.a2 = a0r * (alpha - 1.0); |
406 |
} |
407 |
}; |
408 |
|
409 |
/** @brief Six pole highpass filter |
410 |
* |
411 |
* Highpass filter based on three cascaded biquad filters. |
412 |
*/ |
413 |
class HighpassFilter6p : public TripleBiquadFilter { |
414 |
public: |
415 |
HighpassFilter6p() { } |
416 |
|
417 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
418 |
float omega = 2.0 * M_PI * fc / fs; |
419 |
float sn = sin(omega); |
420 |
float cs = cos(omega); |
421 |
float alpha = sn * M_SQRT1_2; |
422 |
|
423 |
float a0r = 1.0 / (1.0 + alpha); |
424 |
d.b0 = d.d2.b0 = a0r * (1.0 + cs) * 0.5; |
425 |
d.b1 = d.d2.b1 = a0r * -(1.0 + cs); |
426 |
d.b2 = d.d2.b2 = a0r * (1.0 + cs) * 0.5; |
427 |
d.a1 = d.d2.a1 = a0r * (2.0 * cs); |
428 |
d.a2 = d.d2.a2 = a0r * (alpha - 1.0); |
429 |
|
430 |
alpha *= exp(-M_LN10 / 20 * r); |
431 |
a0r = 1.0 / (1.0 + alpha); |
432 |
|
433 |
d.d3.b0 = a0r * (1.0 + cs) * 0.5; |
434 |
d.d3.b1 = a0r * -(1.0 + cs); |
435 |
d.d3.b2 = a0r * (1.0 + cs) * 0.5; |
436 |
d.d3.a1 = a0r * (2.0 * cs); |
437 |
d.d3.a2 = a0r * (alpha - 1.0); |
438 |
} |
439 |
}; |
440 |
|
441 |
namespace gig { |
442 |
|
443 |
/** |
444 |
* Base class for the gig engine filters. |
445 |
*/ |
446 |
class GigFilter : public FilterBase { |
447 |
public: |
448 |
void Reset(FilterData& d) const { |
449 |
d.x1 = d.x2 = d.x3 = 0; |
450 |
d.y1 = d.y2 = d.y3 = 0; |
451 |
} |
452 |
protected: |
453 |
float ApplyA(FilterData& d, float x) const { |
454 |
float y = x - d.a1 * d.y1 - d.a2 * d.y2 - d.a3 * d.y3; |
455 |
KillDenormal(y); |
456 |
d.y3 = d.y2; |
457 |
d.y2 = d.y1; |
458 |
d.y1 = y; |
459 |
return y; |
460 |
} |
461 |
}; |
462 |
|
463 |
#define GIG_PARAM_INIT \ |
464 |
float f1 = fc * 0.0075279; \ |
465 |
float f2 = f1 - 1 + r * fc * (-5.5389e-5 + 1.1982e-7 * fc); \ |
466 |
float scale = r < 51 ? 1.0f : 1.3762f - 0.0075073f * r |
467 |
|
468 |
class LowpassFilter : public GigFilter { |
469 |
public: |
470 |
LowpassFilter() { } |
471 |
|
472 |
float Apply(FilterData& d, float x) const { |
473 |
return ApplyA(d, d.b0 * x); |
474 |
} |
475 |
|
476 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
477 |
GIG_PARAM_INIT; |
478 |
|
479 |
float f1_2 = f1 * f1; |
480 |
d.b0 = f1_2 * scale; |
481 |
d.a1 = f2; |
482 |
d.a2 = f1_2 - 1; |
483 |
d.a3 = -f2; |
484 |
} |
485 |
}; |
486 |
|
487 |
class BandpassFilter : public GigFilter { |
488 |
public: |
489 |
BandpassFilter() { } |
490 |
|
491 |
float Apply(FilterData& d, float x) const { |
492 |
float y = ApplyA(d, d.b0 * x + d.b2 * d.x2); |
493 |
d.x2 = d.x1; |
494 |
d.x1 = x; |
495 |
return y; |
496 |
} |
497 |
|
498 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
499 |
GIG_PARAM_INIT; |
500 |
|
501 |
d.b0 = f1 * scale; |
502 |
d.b2 = -d.b0; |
503 |
d.a1 = f2; |
504 |
d.a2 = f1 * f1 - 1; |
505 |
d.a3 = -f2; |
506 |
} |
507 |
}; |
508 |
|
509 |
class HighpassFilter : public GigFilter { |
510 |
public: |
511 |
HighpassFilter() { } |
512 |
|
513 |
float Apply(FilterData& d, float x) const { |
514 |
float y = ApplyA(d, -x + d.x1 + d.x2 - d.x3); |
515 |
d.x3 = d.x2; |
516 |
d.x2 = d.x1; |
517 |
d.x1 = x; |
518 |
return y * d.scale; |
519 |
} |
520 |
|
521 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
522 |
GIG_PARAM_INIT; |
523 |
|
524 |
d.a1 = f2; |
525 |
d.a2 = f1 * f1 - 1; |
526 |
d.a3 = -f2; |
527 |
d.scale = scale; |
528 |
} |
529 |
}; |
530 |
|
531 |
class BandrejectFilter : public GigFilter { |
532 |
public: |
533 |
BandrejectFilter() { } |
534 |
|
535 |
float Apply(FilterData& d, float x) const { |
536 |
float y = ApplyA(d, x - d.x1 + d.b2 * d.x2 + d.x3); |
537 |
d.x3 = d.x2; |
538 |
d.x2 = d.x1; |
539 |
d.x1 = x; |
540 |
return y * d.scale; |
541 |
} |
542 |
|
543 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
544 |
GIG_PARAM_INIT; |
545 |
|
546 |
d.b2 = f1 * f1 - 1; |
547 |
d.a1 = f2; |
548 |
d.a2 = d.b2; |
549 |
d.a3 = -f2; |
550 |
d.scale = scale; |
551 |
} |
552 |
}; |
553 |
|
554 |
class LowpassTurboFilter : public LowpassFilter { |
555 |
public: |
556 |
LowpassTurboFilter() { } |
557 |
|
558 |
float Apply(FilterData& d, float x) const { |
559 |
float y = d.b20 * LowpassFilter::Apply(d, x) |
560 |
- d.a1 * d.y21 - d.a2 * d.y22 - d.a3 * d.y23; |
561 |
KillDenormal(y); |
562 |
d.y23 = d.y22; |
563 |
d.y22 = d.y21; |
564 |
d.y21 = y; |
565 |
return y; |
566 |
} |
567 |
|
568 |
void SetParameters(FilterData& d, float fc, float r, float fs) const { |
569 |
if (fc < 1.f) fc = 1.f; // this lowpass turbo filter cannot cope with cutoff being zero (would cause click sounds) |
570 |
LowpassFilter::SetParameters(d, fc, r, fs); |
571 |
d.b20 = d.b0 * 0.5; |
572 |
} |
573 |
}; |
574 |
} //namespace gig |
575 |
|
576 |
|
577 |
/** |
578 |
* Main filter class. |
579 |
*/ |
580 |
class Filter { |
581 |
protected: |
582 |
static const LowpassFilter1p lp1p; |
583 |
static const LowpassFilter lp2p; |
584 |
static const LowpassFilter4p lp4p; |
585 |
static const LowpassFilter6p lp6p; |
586 |
static const BandpassFilter bp2p; |
587 |
static const BandrejectFilter br2p; |
588 |
static const HighpassFilter1p hp1p; |
589 |
static const HighpassFilter hp2p; |
590 |
static const HighpassFilter4p hp4p; |
591 |
static const HighpassFilter6p hp6p; |
592 |
/** |
593 |
* These are filters similar to the ones from Gigasampler. |
594 |
*/ |
595 |
static const gig::HighpassFilter HPFilter; |
596 |
static const gig::BandpassFilter BPFilter; |
597 |
static const gig::LowpassFilter LPFilter; |
598 |
static const gig::BandrejectFilter BRFilter; |
599 |
static const gig::LowpassTurboFilter LPTFilter; |
600 |
|
601 |
FilterData d; |
602 |
const FilterBase* pFilter; |
603 |
|
604 |
public: |
605 |
Filter() { |
606 |
// set filter type to 'lowpass' by default |
607 |
pFilter = &LPFilter; |
608 |
pFilter->Reset(d); |
609 |
} |
610 |
|
611 |
enum vcf_type_t { |
612 |
// GigaStudio original filter types |
613 |
vcf_type_gig_lowpass = ::gig::vcf_type_lowpass, |
614 |
vcf_type_gig_lowpassturbo = ::gig::vcf_type_lowpassturbo, |
615 |
vcf_type_gig_bandpass = ::gig::vcf_type_bandpass, |
616 |
vcf_type_gig_highpass = ::gig::vcf_type_highpass, |
617 |
vcf_type_gig_bandreject = ::gig::vcf_type_bandreject, |
618 |
// own filter types |
619 |
vcf_type_1p_lowpass = ::gig::vcf_type_lowpass_1p, |
620 |
vcf_type_1p_highpass = ::gig::vcf_type_highpass_1p, |
621 |
vcf_type_2p_lowpass = ::gig::vcf_type_lowpass_2p, |
622 |
vcf_type_2p_highpass = ::gig::vcf_type_highpass_2p, |
623 |
vcf_type_2p_bandpass = ::gig::vcf_type_bandpass_2p, |
624 |
vcf_type_2p_bandreject = ::gig::vcf_type_bandreject_2p, |
625 |
vcf_type_4p_lowpass = ::gig::vcf_type_lowpass_4p, |
626 |
vcf_type_4p_highpass = ::gig::vcf_type_highpass_4p, |
627 |
vcf_type_6p_lowpass = ::gig::vcf_type_lowpass_6p, |
628 |
vcf_type_6p_highpass = ::gig::vcf_type_highpass_6p, |
629 |
}; |
630 |
|
631 |
void SetType(vcf_type_t FilterType) { |
632 |
switch (FilterType) { |
633 |
case vcf_type_gig_highpass: |
634 |
pFilter = &HPFilter; |
635 |
break; |
636 |
case vcf_type_gig_bandreject: |
637 |
pFilter = &BRFilter; |
638 |
break; |
639 |
case vcf_type_gig_bandpass: |
640 |
pFilter = &BPFilter; |
641 |
break; |
642 |
case vcf_type_gig_lowpassturbo: |
643 |
pFilter = &LPTFilter; |
644 |
break; |
645 |
case vcf_type_1p_lowpass: |
646 |
pFilter = &lp1p; |
647 |
break; |
648 |
case vcf_type_1p_highpass: |
649 |
pFilter = &hp1p; |
650 |
break; |
651 |
case vcf_type_2p_lowpass: |
652 |
pFilter = &lp2p; |
653 |
break; |
654 |
case vcf_type_2p_highpass: |
655 |
pFilter = &hp2p; |
656 |
break; |
657 |
case vcf_type_2p_bandpass: |
658 |
pFilter = &bp2p; |
659 |
break; |
660 |
case vcf_type_2p_bandreject: |
661 |
pFilter = &br2p; |
662 |
break; |
663 |
case vcf_type_4p_lowpass: |
664 |
pFilter = &lp4p; |
665 |
break; |
666 |
case vcf_type_4p_highpass: |
667 |
pFilter = &hp4p; |
668 |
break; |
669 |
case vcf_type_6p_lowpass: |
670 |
pFilter = &lp6p; |
671 |
break; |
672 |
case vcf_type_6p_highpass: |
673 |
pFilter = &hp6p; |
674 |
break; |
675 |
default: |
676 |
pFilter = &LPFilter; |
677 |
} |
678 |
pFilter->Reset(d); |
679 |
} |
680 |
|
681 |
void SetParameters(float cutoff, float resonance, float fs) { |
682 |
pFilter->SetParameters(d, cutoff, resonance, fs); |
683 |
} |
684 |
|
685 |
void Reset() { |
686 |
return pFilter->Reset(d); |
687 |
} |
688 |
|
689 |
float Apply(float in) { |
690 |
return pFilter->Apply(d, in); |
691 |
} |
692 |
}; |
693 |
|
694 |
} //namespace LinuxSampler |
695 |
|
696 |
#endif // __LS_GIG_FILTER_H__ |