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1 /*----------------------------------------------------------------------------
2  *
3  * File:
4  * eas_wtsynth.c
5  *
6  * Contents and purpose:
7  * Implements the synthesizer functions.
8  *
9  * Copyright Sonic Network Inc. 2004
10 
11  * Licensed under the Apache License, Version 2.0 (the "License");
12  * you may not use this file except in compliance with the License.
13  * You may obtain a copy of the License at
14  *
15  *      http://www.apache.org/licenses/LICENSE-2.0
16  *
17  * Unless required by applicable law or agreed to in writing, software
18  * distributed under the License is distributed on an "AS IS" BASIS,
19  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20  * See the License for the specific language governing permissions and
21  * limitations under the License.
22  *
23  *----------------------------------------------------------------------------
24  * Revision Control:
25  *   $Revision: 795 $
26  *   $Date: 2007-08-01 00:14:45 -0700 (Wed, 01 Aug 2007) $
27  *----------------------------------------------------------------------------
28 */
29 
30 // includes
31 #include "eas_data.h"
32 #include "eas_report.h"
33 #include "eas_host.h"
34 #include "eas_math.h"
35 #include "eas_synth_protos.h"
36 #include "eas_wtsynth.h"
37 #include "eas_pan.h"
38 
39 #ifdef DLS_SYNTHESIZER
40 #include "eas_dlssynth.h"
41 #endif
42 
43 #ifdef _METRICS_ENABLED
44 #include "eas_perf.h"
45 #endif
46 
47 /* local prototypes */
48 static EAS_RESULT WT_Initialize(S_VOICE_MGR *pVoiceMgr);
49 static void WT_ReleaseVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum);
50 static void WT_MuteVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum);
51 static void WT_SustainPedal (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, S_SYNTH_CHANNEL *pChannel, EAS_I32 voiceNum);
52 static EAS_RESULT WT_StartVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum, EAS_U16 regionIndex);
53 static EAS_BOOL WT_UpdateVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum, EAS_I32 *pMixBuffer, EAS_I32 numSamples);
54 static void WT_UpdateChannel (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, EAS_U8 channel);
55 static EAS_I32 WT_UpdatePhaseInc (S_WT_VOICE *pWTVoice, const S_ARTICULATION *pArt, S_SYNTH_CHANNEL *pChannel, EAS_I32 pitchCents);
56 static EAS_I32 WT_UpdateGain (S_SYNTH_VOICE *pVoice, S_WT_VOICE *pWTVoice, const S_ARTICULATION *pArt, S_SYNTH_CHANNEL *pChannel, EAS_I32 gain);
57 static void WT_UpdateEG1 (S_WT_VOICE *pWTVoice, const S_ENVELOPE *pEnv);
58 static void WT_UpdateEG2 (S_WT_VOICE *pWTVoice, const S_ENVELOPE *pEnv);
59 
60 #ifdef EAS_SPLIT_WT_SYNTH
61 extern EAS_BOOL WTE_StartFrame (EAS_FRAME_BUFFER_HANDLE pFrameBuffer);
62 extern EAS_BOOL WTE_EndFrame (EAS_FRAME_BUFFER_HANDLE pFrameBuffer, EAS_I32 *pMixBuffer, EAS_I16 masterGain);
63 #endif
64 
65 #ifdef _FILTER_ENABLED
66 static void WT_UpdateFilter (S_WT_VOICE *pWTVoice, S_WT_INT_FRAME *pIntFrame, const S_ARTICULATION *pArt);
67 #endif
68 
69 #ifdef _STATS
70 extern double statsPhaseIncrement;
71 extern double statsMaxPhaseIncrement;
72 extern long statsPhaseSampleCount;
73 extern double statsSampleSize;
74 extern long statsSampleCount;
75 #endif
76 
77 /*----------------------------------------------------------------------------
78  * Synthesizer interface
79  *----------------------------------------------------------------------------
80 */
81 
82 const S_SYNTH_INTERFACE wtSynth =
83 {
84     WT_Initialize,
85     WT_StartVoice,
86     WT_UpdateVoice,
87     WT_ReleaseVoice,
88     WT_MuteVoice,
89     WT_SustainPedal,
90     WT_UpdateChannel
91 };
92 
93 #ifdef EAS_SPLIT_WT_SYNTH
94 const S_FRAME_INTERFACE wtFrameInterface =
95 {
96     WTE_StartFrame,
97     WTE_EndFrame
98 };
99 #endif
100 
101 /*----------------------------------------------------------------------------
102  * WT_Initialize()
103  *----------------------------------------------------------------------------
104  * Purpose:
105  *
106  * Inputs:
107  * pVoice - pointer to voice to initialize
108  *
109  * Outputs:
110  *
111  *----------------------------------------------------------------------------
112 */
WT_Initialize(S_VOICE_MGR * pVoiceMgr)113 static EAS_RESULT WT_Initialize (S_VOICE_MGR *pVoiceMgr)
114 {
115     EAS_INT i;
116 
117     for (i = 0; i < NUM_WT_VOICES; i++)
118     {
119 
120         pVoiceMgr->wtVoices[i].artIndex = DEFAULT_ARTICULATION_INDEX;
121 
122         pVoiceMgr->wtVoices[i].eg1State = DEFAULT_EG1_STATE;
123         pVoiceMgr->wtVoices[i].eg1Value = DEFAULT_EG1_VALUE;
124         pVoiceMgr->wtVoices[i].eg1Increment = DEFAULT_EG1_INCREMENT;
125 
126         pVoiceMgr->wtVoices[i].eg2State = DEFAULT_EG2_STATE;
127         pVoiceMgr->wtVoices[i].eg2Value = DEFAULT_EG2_VALUE;
128         pVoiceMgr->wtVoices[i].eg2Increment = DEFAULT_EG2_INCREMENT;
129 
130         /* left and right gain values are needed only if stereo output */
131 #if (NUM_OUTPUT_CHANNELS == 2)
132         pVoiceMgr->wtVoices[i].gainLeft = DEFAULT_VOICE_GAIN;
133         pVoiceMgr->wtVoices[i].gainRight = DEFAULT_VOICE_GAIN;
134 #endif
135 
136         pVoiceMgr->wtVoices[i].phaseFrac = DEFAULT_PHASE_FRAC;
137         pVoiceMgr->wtVoices[i].phaseAccum = DEFAULT_PHASE_INT;
138 
139 #ifdef _FILTER_ENABLED
140         pVoiceMgr->wtVoices[i].filter.z1 = DEFAULT_FILTER_ZERO;
141         pVoiceMgr->wtVoices[i].filter.z2 = DEFAULT_FILTER_ZERO;
142 #endif
143     }
144 
145     return EAS_TRUE;
146 }
147 
148 /*----------------------------------------------------------------------------
149  * WT_ReleaseVoice()
150  *----------------------------------------------------------------------------
151  * Purpose:
152  * The selected voice is being released.
153  *
154  * Inputs:
155  * pEASData - pointer to S_EAS_DATA
156  * pVoice - pointer to voice to release
157  *
158  * Outputs:
159  * None
160  *----------------------------------------------------------------------------
161 */
162 /*lint -esym(715, pVoice) used in some implementations */
WT_ReleaseVoice(S_VOICE_MGR * pVoiceMgr,S_SYNTH * pSynth,S_SYNTH_VOICE * pVoice,EAS_I32 voiceNum)163 static void WT_ReleaseVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum)
164 {
165     S_WT_VOICE *pWTVoice;
166     const S_ARTICULATION *pArticulation;
167 
168 #ifdef DLS_SYNTHESIZER
169     if (pVoice->regionIndex & FLAG_RGN_IDX_DLS_SYNTH)
170     {
171         DLS_ReleaseVoice(pVoiceMgr, pSynth, pVoice, voiceNum);
172         return;
173     }
174 #endif
175 
176     pWTVoice = &pVoiceMgr->wtVoices[voiceNum];
177     pArticulation = &pSynth->pEAS->pArticulations[pWTVoice->artIndex];
178 
179     /* release EG1 */
180     pWTVoice->eg1State = eEnvelopeStateRelease;
181     pWTVoice->eg1Increment = pArticulation->eg1.releaseTime;
182 
183     /*
184     The spec says we should release EG2, but doing so with the current
185     voicing is causing clicks. This fix will need to be coordinated with
186     a new sound library release
187     */
188 
189     /* release EG2 */
190     pWTVoice->eg2State = eEnvelopeStateRelease;
191     pWTVoice->eg2Increment = pArticulation->eg2.releaseTime;
192 }
193 
194 /*----------------------------------------------------------------------------
195  * WT_MuteVoice()
196  *----------------------------------------------------------------------------
197  * Purpose:
198  * The selected voice is being muted.
199  *
200  * Inputs:
201  * pVoice - pointer to voice to release
202  *
203  * Outputs:
204  * None
205  *----------------------------------------------------------------------------
206 */
207 /*lint -esym(715, pSynth) used in some implementations */
WT_MuteVoice(S_VOICE_MGR * pVoiceMgr,S_SYNTH * pSynth,S_SYNTH_VOICE * pVoice,EAS_I32 voiceNum)208 static void WT_MuteVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum)
209 {
210 
211 #ifdef DLS_SYNTHESIZER
212     if (pVoice->regionIndex & FLAG_RGN_IDX_DLS_SYNTH)
213     {
214         DLS_MuteVoice(pVoiceMgr, pSynth, pVoice, voiceNum);
215         return;
216     }
217 #endif
218 
219     /* clear deferred action flags */
220     pVoice->voiceFlags &=
221         ~(VOICE_FLAG_DEFER_MIDI_NOTE_OFF |
222         VOICE_FLAG_SUSTAIN_PEDAL_DEFER_NOTE_OFF |
223         VOICE_FLAG_DEFER_MUTE);
224 
225     /* set the envelope state */
226     pVoiceMgr->wtVoices[voiceNum].eg1State = eEnvelopeStateMuted;
227     pVoiceMgr->wtVoices[voiceNum].eg2State = eEnvelopeStateMuted;
228 }
229 
230 /*----------------------------------------------------------------------------
231  * WT_SustainPedal()
232  *----------------------------------------------------------------------------
233  * Purpose:
234  * The selected voice is held due to sustain pedal
235  *
236  * Inputs:
237  * pVoice - pointer to voice to sustain
238  *
239  * Outputs:
240  * None
241  *----------------------------------------------------------------------------
242 */
243 /*lint -esym(715, pChannel) used in some implementations */
WT_SustainPedal(S_VOICE_MGR * pVoiceMgr,S_SYNTH * pSynth,S_SYNTH_VOICE * pVoice,S_SYNTH_CHANNEL * pChannel,EAS_I32 voiceNum)244 static void WT_SustainPedal (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, S_SYNTH_CHANNEL *pChannel, EAS_I32 voiceNum)
245 {
246     S_WT_VOICE *pWTVoice;
247 
248 #ifdef DLS_SYNTHESIZER
249     if (pVoice->regionIndex & FLAG_RGN_IDX_DLS_SYNTH)
250     {
251         DLS_SustainPedal(pVoiceMgr, pSynth, pVoice, pChannel, voiceNum);
252         return;
253     }
254 #endif
255 
256     /* don't catch the voice if below the sustain level */
257     pWTVoice = &pVoiceMgr->wtVoices[voiceNum];
258     if (pWTVoice->eg1Value < pSynth->pEAS->pArticulations[pWTVoice->artIndex].eg1.sustainLevel)
259         return;
260 
261     /* sustain flag is set, damper pedal is on */
262     /* defer releasing this note until the damper pedal is off */
263     pWTVoice->eg1State = eEnvelopeStateDecay;
264     pVoice->voiceState = eVoiceStatePlay;
265 
266     /*
267     because sustain pedal is on, this voice
268     should defer releasing its note
269     */
270     pVoice->voiceFlags |= VOICE_FLAG_SUSTAIN_PEDAL_DEFER_NOTE_OFF;
271 
272 #ifdef _DEBUG_SYNTH
273     { /* dpp: EAS_ReportEx(_EAS_SEVERITY_INFO, "WT_SustainPedal: defer note off because sustain pedal is on\n"); */ }
274 #endif
275 }
276 
277 /*----------------------------------------------------------------------------
278  * WT_StartVoice()
279  *----------------------------------------------------------------------------
280  * Purpose:
281  * Assign the region for the given instrument using the midi key number
282  * and the RPN2 (coarse tuning) value. By using RPN2 as part of the
283  * region selection process, we reduce the amount a given sample has
284  * to be transposed by selecting the closest recorded root instead.
285  *
286  * This routine is the second half of SynthAssignRegion().
287  * If the region was successfully found by SynthFindRegionIndex(),
288  * then assign the region's parameters to the voice.
289  *
290  * Setup and initialize the following voice parameters:
291  * m_nRegionIndex
292  *
293  * Inputs:
294  * pVoice - ptr to the voice we have assigned for this channel
295  * nRegionIndex - index of the region
296  * pEASData - pointer to overall EAS data structure
297  *
298  * Outputs:
299  * success - could find and assign the region for this voice's note otherwise
300  * failure - could not find nor assign the region for this voice's note
301  *
302  * Side Effects:
303  * psSynthObject->m_sVoice[].m_nRegionIndex is assigned
304  * psSynthObject->m_sVoice[] parameters are assigned
305  *----------------------------------------------------------------------------
306 */
WT_StartVoice(S_VOICE_MGR * pVoiceMgr,S_SYNTH * pSynth,S_SYNTH_VOICE * pVoice,EAS_I32 voiceNum,EAS_U16 regionIndex)307 static EAS_RESULT WT_StartVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum, EAS_U16 regionIndex)
308 {
309     S_WT_VOICE *pWTVoice;
310     const S_WT_REGION *pRegion;
311     const S_ARTICULATION *pArt;
312     S_SYNTH_CHANNEL *pChannel;
313 
314 #if (NUM_OUTPUT_CHANNELS == 2)
315     EAS_INT pan;
316 #endif
317 
318 #ifdef EAS_SPLIT_WT_SYNTH
319     S_WT_CONFIG wtConfig;
320 #endif
321 
322     /* no samples have been synthesized for this note yet */
323     pVoice->regionIndex = regionIndex;
324     pVoice->voiceFlags = VOICE_FLAG_NO_SAMPLES_SYNTHESIZED_YET;
325 
326     /* get the articulation index for this region */
327     pWTVoice = &pVoiceMgr->wtVoices[voiceNum];
328     pChannel = &pSynth->channels[pVoice->channel & 15];
329 
330     /* update static channel parameters */
331     if (pChannel->channelFlags & CHANNEL_FLAG_UPDATE_CHANNEL_PARAMETERS)
332         WT_UpdateChannel(pVoiceMgr, pSynth, pVoice->channel & 15);
333 
334 #ifdef DLS_SYNTHESIZER
335     if (pVoice->regionIndex & FLAG_RGN_IDX_DLS_SYNTH)
336         return DLS_StartVoice(pVoiceMgr, pSynth, pVoice, voiceNum, regionIndex);
337 #endif
338 
339     pRegion = &(pSynth->pEAS->pWTRegions[regionIndex]);
340     pWTVoice->artIndex = pRegion->artIndex;
341 
342 #ifdef _DEBUG_SYNTH
343     { /* dpp: EAS_ReportEx(_EAS_SEVERITY_INFO, "WT_StartVoice: Voice %ld; Region %d\n", (EAS_I32) (pVoice - pVoiceMgr->voices), regionIndex); */ }
344 #endif
345 
346     pArt = &pSynth->pEAS->pArticulations[pWTVoice->artIndex];
347 
348     /* MIDI note on puts this voice into attack state */
349     pWTVoice->eg1State = eEnvelopeStateAttack;
350     pWTVoice->eg1Value = 0;
351     pWTVoice->eg1Increment = pArt->eg1.attackTime;
352     pWTVoice->eg2State = eEnvelopeStateAttack;
353     pWTVoice->eg2Value = 0;
354     pWTVoice->eg2Increment = pArt->eg2.attackTime;
355 
356     /* init the LFO */
357     pWTVoice->modLFO.lfoValue = 0;
358     pWTVoice->modLFO.lfoPhase = -pArt->lfoDelay;
359 
360     pVoice->gain = 0;
361 
362 #if (NUM_OUTPUT_CHANNELS == 2)
363     /*
364     Get the Midi CC10 pan value for this voice's channel
365     convert the pan value to an "angle" representation suitable for
366     our sin, cos calculator. This representation is NOT necessarily the same
367     as the transform in the GM manuals because of our sin, cos calculator.
368     "angle" = (CC10 - 64)/128
369     */
370     pan = (EAS_INT) pSynth->channels[pVoice->channel & 15].pan - 64;
371     pan += pArt->pan;
372     EAS_CalcPanControl(pan, &pWTVoice->gainLeft, &pWTVoice->gainRight);
373 #endif
374 
375 #ifdef _FILTER_ENABLED
376     /* clear out the filter states */
377     pWTVoice->filter.z1 = 0;
378     pWTVoice->filter.z2 = 0;
379 #endif
380 
381     /* if this wave is to be generated using noise generator */
382     if (pRegion->region.keyGroupAndFlags & REGION_FLAG_USE_WAVE_GENERATOR)
383     {
384         pWTVoice->phaseAccum = 4574296;
385         pWTVoice->loopStart = WT_NOISE_GENERATOR;
386         pWTVoice->loopEnd = 4574295;
387     }
388 
389     /* normal sample */
390     else
391     {
392 
393 #ifdef EAS_SPLIT_WT_SYNTH
394         if (voiceNum < NUM_PRIMARY_VOICES)
395             pWTVoice->phaseAccum = (EAS_U32) pSynth->pEAS->pSamples + pSynth->pEAS->pSampleOffsets[pRegion->waveIndex];
396         else
397             pWTVoice->phaseAccum = pSynth->pEAS->pSampleOffsets[pRegion->waveIndex];
398 #else
399         pWTVoice->phaseAccum = (EAS_U32) pSynth->pEAS->pSamples + pSynth->pEAS->pSampleOffsets[pRegion->waveIndex];
400 #endif
401 
402         if (pRegion->region.keyGroupAndFlags & REGION_FLAG_IS_LOOPED)
403         {
404             pWTVoice->loopStart = pWTVoice->phaseAccum + pRegion->loopStart;
405             pWTVoice->loopEnd = pWTVoice->phaseAccum + pRegion->loopEnd - 1;
406         }
407         else
408             pWTVoice->loopStart = pWTVoice->loopEnd = pWTVoice->phaseAccum + pSynth->pEAS->pSampleLen[pRegion->waveIndex] - 1;
409     }
410 
411 #ifdef EAS_SPLIT_WT_SYNTH
412     /* configure off-chip voices */
413     if (voiceNum >= NUM_PRIMARY_VOICES)
414     {
415         wtConfig.phaseAccum = pWTVoice->phaseAccum;
416         wtConfig.loopStart = pWTVoice->loopStart;
417         wtConfig.loopEnd = pWTVoice->loopEnd;
418         wtConfig.gain = pVoice->gain;
419 
420 #if (NUM_OUTPUT_CHANNELS == 2)
421         wtConfig.gainLeft = pWTVoice->gainLeft;
422         wtConfig.gainRight = pWTVoice->gainRight;
423 #endif
424 
425         WTE_ConfigVoice(voiceNum - NUM_PRIMARY_VOICES, &wtConfig, pVoiceMgr->pFrameBuffer);
426     }
427 #endif
428 
429     return EAS_SUCCESS;
430 }
431 
432 /*----------------------------------------------------------------------------
433  * WT_CheckSampleEnd
434  *----------------------------------------------------------------------------
435  * Purpose:
436  * Check for end of sample and calculate number of samples to synthesize
437  *
438  * Inputs:
439  *
440  * Outputs:
441  *
442  * Notes:
443  *
444  *----------------------------------------------------------------------------
445 */
WT_CheckSampleEnd(S_WT_VOICE * pWTVoice,S_WT_INT_FRAME * pWTIntFrame,EAS_BOOL update)446 EAS_BOOL WT_CheckSampleEnd (S_WT_VOICE *pWTVoice, S_WT_INT_FRAME *pWTIntFrame, EAS_BOOL update)
447 {
448     EAS_U32 endPhaseAccum;
449     EAS_U32 endPhaseFrac;
450     EAS_I32 numSamples;
451     EAS_BOOL done = EAS_FALSE;
452 
453     /* check to see if we hit the end of the waveform this time */
454     /*lint -e{703} use shift for performance */
455     endPhaseFrac = pWTVoice->phaseFrac + (pWTIntFrame->frame.phaseIncrement << SYNTH_UPDATE_PERIOD_IN_BITS);
456     endPhaseAccum = pWTVoice->phaseAccum + GET_PHASE_INT_PART(endPhaseFrac);
457     if (endPhaseAccum >= pWTVoice->loopEnd)
458     {
459         /* calculate how far current ptr is from end */
460         numSamples = (EAS_I32) (pWTVoice->loopEnd - pWTVoice->phaseAccum);
461 
462         /* now account for the fractional portion */
463         /*lint -e{703} use shift for performance */
464         numSamples = (EAS_I32) ((numSamples << NUM_PHASE_FRAC_BITS) - pWTVoice->phaseFrac);
465         pWTIntFrame->numSamples = 1 + (numSamples / pWTIntFrame->frame.phaseIncrement);
466 
467         /* sound will be done this frame */
468         done = EAS_TRUE;
469     }
470 
471     /* update data for off-chip synth */
472     if (update)
473     {
474         pWTVoice->phaseFrac = endPhaseFrac;
475         pWTVoice->phaseAccum = endPhaseAccum;
476     }
477 
478     return done;
479 }
480 
481 /*----------------------------------------------------------------------------
482  * WT_UpdateVoice()
483  *----------------------------------------------------------------------------
484  * Purpose:
485  * Synthesize a block of samples for the given voice.
486  * Use linear interpolation.
487  *
488  * Inputs:
489  * pEASData - pointer to overall EAS data structure
490  *
491  * Outputs:
492  * number of samples actually written to buffer
493  *
494  * Side Effects:
495  * - samples are added to the presently free buffer
496  *
497  *----------------------------------------------------------------------------
498 */
WT_UpdateVoice(S_VOICE_MGR * pVoiceMgr,S_SYNTH * pSynth,S_SYNTH_VOICE * pVoice,EAS_I32 voiceNum,EAS_I32 * pMixBuffer,EAS_I32 numSamples)499 static EAS_BOOL WT_UpdateVoice (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, S_SYNTH_VOICE *pVoice, EAS_I32 voiceNum, EAS_I32 *pMixBuffer, EAS_I32  numSamples)
500 {
501     S_WT_VOICE *pWTVoice;
502     S_WT_INT_FRAME intFrame;
503     S_SYNTH_CHANNEL *pChannel;
504     const S_WT_REGION *pWTRegion;
505     const S_ARTICULATION *pArt;
506     EAS_I32 temp;
507     EAS_BOOL done;
508 
509 #ifdef DLS_SYNTHESIZER
510     if (pVoice->regionIndex & FLAG_RGN_IDX_DLS_SYNTH)
511         return DLS_UpdateVoice(pVoiceMgr, pSynth, pVoice, voiceNum, pMixBuffer, numSamples);
512 #endif
513 
514     /* establish pointers to critical data */
515     pWTVoice = &pVoiceMgr->wtVoices[voiceNum];
516     pWTRegion = &pSynth->pEAS->pWTRegions[pVoice->regionIndex & REGION_INDEX_MASK];
517     pArt = &pSynth->pEAS->pArticulations[pWTVoice->artIndex];
518     pChannel = &pSynth->channels[pVoice->channel & 15];
519     intFrame.prevGain = pVoice->gain;
520 
521     /* update the envelopes */
522     WT_UpdateEG1(pWTVoice, &pArt->eg1);
523     WT_UpdateEG2(pWTVoice, &pArt->eg2);
524 
525     /* update the LFO */
526     WT_UpdateLFO(&pWTVoice->modLFO, pArt->lfoFreq);
527 
528 #ifdef _FILTER_ENABLED
529     /* calculate filter if library uses filter */
530     if (pSynth->pEAS->libAttr & LIB_FORMAT_FILTER_ENABLED)
531         WT_UpdateFilter(pWTVoice, &intFrame, pArt);
532     else
533         intFrame.frame.k = 0;
534 #endif
535 
536     /* update the gain */
537     intFrame.frame.gainTarget = WT_UpdateGain(pVoice, pWTVoice, pArt, pChannel, pWTRegion->gain);
538 
539     /* calculate base pitch*/
540     temp = pChannel->staticPitch + pWTRegion->tuning;
541 
542     /* include global transpose */
543     if (pChannel->channelFlags & CHANNEL_FLAG_RHYTHM_CHANNEL)
544         temp += pVoice->note * 100;
545     else
546         temp += (pVoice->note + pSynth->globalTranspose) * 100;
547     intFrame.frame.phaseIncrement = WT_UpdatePhaseInc(pWTVoice, pArt, pChannel, temp);
548 
549     /* call into engine to generate samples */
550     intFrame.pAudioBuffer = pVoiceMgr->voiceBuffer;
551     intFrame.pMixBuffer = pMixBuffer;
552     intFrame.numSamples = numSamples;
553 
554     /* check for end of sample */
555     if ((pWTVoice->loopStart != WT_NOISE_GENERATOR) && (pWTVoice->loopStart == pWTVoice->loopEnd))
556         done = WT_CheckSampleEnd(pWTVoice, &intFrame, (EAS_BOOL) (voiceNum >= NUM_PRIMARY_VOICES));
557     else
558         done = EAS_FALSE;
559 
560 #ifdef EAS_SPLIT_WT_SYNTH
561     if (voiceNum < NUM_PRIMARY_VOICES)
562     {
563 #ifndef _SPLIT_WT_TEST_HARNESS
564         WT_ProcessVoice(pWTVoice, &intFrame);
565 #endif
566     }
567     else
568         WTE_ProcessVoice(voiceNum - NUM_PRIMARY_VOICES, &intFrame.frame, pVoiceMgr->pFrameBuffer);
569 #else
570     WT_ProcessVoice(pWTVoice, &intFrame);
571 #endif
572 
573     /* clear flag */
574     pVoice->voiceFlags &= ~VOICE_FLAG_NO_SAMPLES_SYNTHESIZED_YET;
575 
576     /* if voice has finished, set flag for voice manager */
577     if ((pVoice->voiceState != eVoiceStateStolen) && (pWTVoice->eg1State == eEnvelopeStateMuted))
578         done = EAS_TRUE;
579 
580     /* if the update interval has elapsed, then force the current gain to the next
581      * gain since we never actually reach the next gain when ramping -- we just get
582      * very close to the target gain.
583      */
584     pVoice->gain = (EAS_I16) intFrame.frame.gainTarget;
585 
586     return done;
587 }
588 
589 /*----------------------------------------------------------------------------
590  * WT_UpdatePhaseInc()
591  *----------------------------------------------------------------------------
592  * Purpose:
593  * Calculate the phase increment
594  *
595  * Inputs:
596  * pVoice - pointer to the voice being updated
597  * psRegion - pointer to the region
598  * psArticulation - pointer to the articulation
599  * nChannelPitchForThisVoice - the portion of the pitch that is fixed for this
600  *                  voice during the duration of this synthesis
601  * pEASData - pointer to overall EAS data structure
602  *
603  * Outputs:
604  *
605  * Side Effects:
606  * set the phase increment for this voice
607  *----------------------------------------------------------------------------
608 */
WT_UpdatePhaseInc(S_WT_VOICE * pWTVoice,const S_ARTICULATION * pArt,S_SYNTH_CHANNEL * pChannel,EAS_I32 pitchCents)609 static EAS_I32 WT_UpdatePhaseInc (S_WT_VOICE *pWTVoice, const S_ARTICULATION *pArt, S_SYNTH_CHANNEL *pChannel, EAS_I32 pitchCents)
610 {
611     EAS_I32 temp;
612 
613     /*pitchCents due to CC1 = LFO * (CC1 / 128) * DEFAULT_LFO_MOD_WHEEL_TO_PITCH_CENTS */
614     temp = MULT_EG1_EG1(DEFAULT_LFO_MOD_WHEEL_TO_PITCH_CENTS,
615         ((pChannel->modWheel) << (NUM_EG1_FRAC_BITS -7)));
616 
617     /* pitchCents due to channel pressure = LFO * (channel pressure / 128) * DEFAULT_LFO_CHANNEL_PRESSURE_TO_PITCH_CENTS */
618     temp += MULT_EG1_EG1(DEFAULT_LFO_CHANNEL_PRESSURE_TO_PITCH_CENTS,
619          ((pChannel->channelPressure) << (NUM_EG1_FRAC_BITS -7)));
620 
621     /* now multiply the (channel pressure + CC1) pitch values by the LFO value */
622     temp = MULT_EG1_EG1(pWTVoice->modLFO.lfoValue, temp);
623 
624     /*
625     add in the LFO pitch due to
626     channel pressure and CC1 along with
627     the LFO pitch, the EG2 pitch, and the
628     "static" pitch for this voice on this channel
629     */
630     temp += pitchCents +
631         (MULT_EG1_EG1(pWTVoice->eg2Value, pArt->eg2ToPitch)) +
632         (MULT_EG1_EG1(pWTVoice->modLFO.lfoValue, pArt->lfoToPitch));
633 
634     /* convert from cents to linear phase increment */
635     return EAS_Calculate2toX(temp);
636 }
637 
638 /*----------------------------------------------------------------------------
639  * WT_UpdateChannel()
640  *----------------------------------------------------------------------------
641  * Purpose:
642  * Calculate and assign static channel parameters
643  * These values only need to be updated if one of the controller values
644  * for this channel changes
645  *
646  * Inputs:
647  * nChannel - channel to update
648  * pEASData - pointer to overall EAS data structure
649  *
650  * Outputs:
651  *
652  * Side Effects:
653  * - the given channel's static gain and static pitch are updated
654  *----------------------------------------------------------------------------
655 */
656 /*lint -esym(715, pVoiceMgr) reserved for future use */
WT_UpdateChannel(S_VOICE_MGR * pVoiceMgr,S_SYNTH * pSynth,EAS_U8 channel)657 static void WT_UpdateChannel (S_VOICE_MGR *pVoiceMgr, S_SYNTH *pSynth, EAS_U8 channel)
658 {
659     EAS_I32 staticGain;
660     EAS_I32 pitchBend;
661     S_SYNTH_CHANNEL *pChannel;
662 
663     pChannel = &pSynth->channels[channel];
664 
665     /*
666     nChannelGain = (CC7 * CC11)^2  * master volume
667     where CC7 == 100 by default, CC11 == 127, master volume == 32767
668     */
669     staticGain = MULT_EG1_EG1((pChannel->volume) << (NUM_EG1_FRAC_BITS - 7),
670         (pChannel->expression) << (NUM_EG1_FRAC_BITS - 7));
671 
672     /* staticGain has to be squared */
673     staticGain = MULT_EG1_EG1(staticGain, staticGain);
674 
675     pChannel->staticGain = (EAS_I16) MULT_EG1_EG1(staticGain, pSynth->masterVolume);
676 
677     /*
678     calculate pitch bend: RPN0 * ((2*pitch wheel)/16384  -1)
679     However, if we use the EG1 macros, remember that EG1 has a full
680     scale value of 32768 (instead of 16384). So instead of multiplying
681     by 2, multiply by 4 (left shift by 2), and subtract by 32768 instead
682     of 16384. This utilizes the fact that the EG1 macro places a binary
683     point 15 places to the left instead of 14 places.
684     */
685     /*lint -e{703} <avoid multiply for performance>*/
686     pitchBend =
687         (((EAS_I32)(pChannel->pitchBend) << 2)
688         - 32768);
689 
690     pChannel->staticPitch =
691         MULT_EG1_EG1(pitchBend, pChannel->pitchBendSensitivity);
692 
693     /* if this is not a drum channel, then add in the per-channel tuning */
694     if (!(pChannel->channelFlags & CHANNEL_FLAG_RHYTHM_CHANNEL))
695         pChannel->staticPitch += pChannel->finePitch + (pChannel->coarsePitch * 100);
696 
697     /* clear update flag */
698     pChannel->channelFlags &= ~CHANNEL_FLAG_UPDATE_CHANNEL_PARAMETERS;
699     return;
700 }
701 
702 /*----------------------------------------------------------------------------
703  * WT_UpdateGain()
704  *----------------------------------------------------------------------------
705  * Purpose:
706  * Calculate and assign static voice parameters as part of WT_UpdateVoice()
707  *
708  * Inputs:
709  * pVoice - ptr to the synth voice that we want to synthesize
710  * pEASData - pointer to overall EAS data structure
711  *
712  * Outputs:
713  *
714  * Side Effects:
715  * - various voice parameters are calculated and assigned
716  *
717  *----------------------------------------------------------------------------
718 */
WT_UpdateGain(S_SYNTH_VOICE * pVoice,S_WT_VOICE * pWTVoice,const S_ARTICULATION * pArt,S_SYNTH_CHANNEL * pChannel,EAS_I32 gain)719 static EAS_I32 WT_UpdateGain (S_SYNTH_VOICE *pVoice, S_WT_VOICE *pWTVoice, const S_ARTICULATION *pArt, S_SYNTH_CHANNEL *pChannel, EAS_I32 gain)
720 {
721     EAS_I32 lfoGain;
722     EAS_I32 temp;
723 
724     /*
725     If this voice was stolen, then the velocity is actually
726     for the new note, not the note that we are currently ramping down.
727     So we really shouldn't use this velocity. However, that would require
728     more memory to store the velocity value, and the improvement may
729     not be sufficient to warrant the added memory.
730     */
731     /* velocity is fixed at note start for a given voice and must be squared */
732     temp = (pVoice->velocity) << (NUM_EG1_FRAC_BITS - 7);
733     temp = MULT_EG1_EG1(temp, temp);
734 
735     /* region gain is fixed as part of the articulation */
736     temp = MULT_EG1_EG1(temp, gain);
737 
738     /* include the channel gain */
739     temp = MULT_EG1_EG1(temp, pChannel->staticGain);
740 
741     /* calculate LFO gain using an approximation for 10^x */
742     lfoGain = MULT_EG1_EG1(pWTVoice->modLFO.lfoValue, pArt->lfoToGain);
743     lfoGain = MULT_EG1_EG1(lfoGain, LFO_GAIN_TO_CENTS);
744 
745     /* convert from a dB-like value to linear gain */
746     lfoGain = EAS_Calculate2toX(lfoGain);
747     temp = MULT_EG1_EG1(temp, lfoGain);
748 
749     /* calculate the voice's gain */
750     temp = (EAS_I16)MULT_EG1_EG1(temp, pWTVoice->eg1Value);
751 
752     return temp;
753 }
754 
755 /*----------------------------------------------------------------------------
756  * WT_UpdateEG1()
757  *----------------------------------------------------------------------------
758  * Purpose:
759  * Calculate the EG1 envelope for the given voice (but do not update any
760  * state)
761  *
762  * Inputs:
763  * pVoice - ptr to the voice whose envelope we want to update
764  * nVoice - this voice's number - used only for debug
765  * pEASData - pointer to overall EAS data structure
766  *
767  * Outputs:
768  * nValue - the envelope value
769  *
770  * Side Effects:
771  * - updates EG1 state value for the given voice
772  *----------------------------------------------------------------------------
773 */
WT_UpdateEG1(S_WT_VOICE * pWTVoice,const S_ENVELOPE * pEnv)774 static void WT_UpdateEG1 (S_WT_VOICE *pWTVoice, const S_ENVELOPE *pEnv)
775 {
776     EAS_I32 temp;
777 
778     switch (pWTVoice->eg1State)
779     {
780         case eEnvelopeStateAttack:
781             temp = pWTVoice->eg1Value + pWTVoice->eg1Increment;
782 
783             /* check if we have reached peak amplitude */
784             if (temp >= SYNTH_FULL_SCALE_EG1_GAIN)
785             {
786                 /* limit the volume */
787                 temp = SYNTH_FULL_SCALE_EG1_GAIN;
788 
789                 /* prepare to move to decay state */
790                 pWTVoice->eg1State = eEnvelopeStateDecay;
791                 pWTVoice->eg1Increment = pEnv->decayTime;
792             }
793 
794             break;
795 
796         /* exponential decay */
797         case eEnvelopeStateDecay:
798             temp = MULT_EG1_EG1(pWTVoice->eg1Value, pWTVoice->eg1Increment);
799 
800             /* check if we have reached sustain level */
801             if (temp <= pEnv->sustainLevel)
802             {
803                 /* enforce the sustain level */
804                 temp = pEnv->sustainLevel;
805 
806                 /* if sustain level is zero, skip sustain & release the voice */
807                 if (temp > 0)
808                     pWTVoice->eg1State = eEnvelopeStateSustain;
809 
810                 /* move to sustain state */
811                 else
812                     pWTVoice->eg1State = eEnvelopeStateMuted;
813             }
814 
815             break;
816 
817         case eEnvelopeStateSustain:
818             return;
819 
820         case eEnvelopeStateRelease:
821             temp = MULT_EG1_EG1(pWTVoice->eg1Value, pWTVoice->eg1Increment);
822 
823             /* if we hit zero, this voice isn't contributing any audio */
824             if (temp <= 0)
825             {
826                 temp = 0;
827                 pWTVoice->eg1State = eEnvelopeStateMuted;
828             }
829             break;
830 
831         /* voice is muted, set target to zero */
832         case eEnvelopeStateMuted:
833             temp = 0;
834             break;
835 
836         case eEnvelopeStateInvalid:
837         default:
838             temp = 0;
839 #ifdef  _DEBUG_SYNTH
840             { /* dpp: EAS_ReportEx(_EAS_SEVERITY_INFO, "WT_UpdateEG1: error, %d is an unrecognized state\n",
841                 pWTVoice->eg1State); */ }
842 #endif
843             break;
844 
845     }
846 
847     pWTVoice->eg1Value = (EAS_I16) temp;
848 }
849 
850 /*----------------------------------------------------------------------------
851  * WT_UpdateEG2()
852  *----------------------------------------------------------------------------
853  * Purpose:
854  * Update the EG2 envelope for the given voice
855  *
856  * Inputs:
857  * pVoice - ptr to the voice whose envelope we want to update
858  * pEASData - pointer to overall EAS data structure
859  *
860  * Outputs:
861  *
862  * Side Effects:
863  * - updates EG2 values for the given voice
864  *----------------------------------------------------------------------------
865 */
866 
WT_UpdateEG2(S_WT_VOICE * pWTVoice,const S_ENVELOPE * pEnv)867 static void WT_UpdateEG2 (S_WT_VOICE *pWTVoice, const S_ENVELOPE *pEnv)
868 {
869     EAS_I32 temp;
870 
871     switch (pWTVoice->eg2State)
872     {
873         case eEnvelopeStateAttack:
874             temp = pWTVoice->eg2Value + pWTVoice->eg2Increment;
875 
876             /* check if we have reached peak amplitude */
877             if (temp >= SYNTH_FULL_SCALE_EG1_GAIN)
878             {
879                 /* limit the volume */
880                 temp = SYNTH_FULL_SCALE_EG1_GAIN;
881 
882                 /* prepare to move to decay state */
883                 pWTVoice->eg2State = eEnvelopeStateDecay;
884 
885                 pWTVoice->eg2Increment = pEnv->decayTime;
886             }
887 
888             break;
889 
890             /* implement linear pitch decay in cents */
891         case eEnvelopeStateDecay:
892             temp = pWTVoice->eg2Value -pWTVoice->eg2Increment;
893 
894             /* check if we have reached sustain level */
895             if (temp <= pEnv->sustainLevel)
896             {
897                 /* enforce the sustain level */
898                 temp = pEnv->sustainLevel;
899 
900                 /* prepare to move to sustain state */
901                 pWTVoice->eg2State = eEnvelopeStateSustain;
902             }
903             break;
904 
905         case eEnvelopeStateSustain:
906             return;
907 
908         case eEnvelopeStateRelease:
909             temp = pWTVoice->eg2Value - pWTVoice->eg2Increment;
910 
911             if (temp <= 0)
912             {
913                 temp = 0;
914                 pWTVoice->eg2State = eEnvelopeStateMuted;
915             }
916 
917             break;
918 
919         /* voice is muted, set target to zero */
920         case eEnvelopeStateMuted:
921             temp = 0;
922             break;
923 
924         case eEnvelopeStateInvalid:
925         default:
926             temp = 0;
927 #ifdef  _DEBUG_SYNTH
928             { /* dpp: EAS_ReportEx(_EAS_SEVERITY_INFO, "WT_UpdateEG2: error, %d is an unrecognized state\n",
929                 pWTVoice->eg2State); */ }
930 #endif
931             break;
932     }
933 
934     pWTVoice->eg2Value = (EAS_I16) temp;
935 }
936 
937 /*----------------------------------------------------------------------------
938  * WT_UpdateLFO ()
939  *----------------------------------------------------------------------------
940  * Purpose:
941  * Calculate the LFO for the given voice
942  *
943  * Inputs:
944  * pLFO         - ptr to the LFO data
945  * phaseInc     - phase increment
946  *
947  * Outputs:
948  *
949  * Side Effects:
950  * - updates LFO values for the given voice
951  *----------------------------------------------------------------------------
952 */
WT_UpdateLFO(S_LFO_CONTROL * pLFO,EAS_I16 phaseInc)953 void WT_UpdateLFO (S_LFO_CONTROL *pLFO, EAS_I16 phaseInc)
954 {
955 
956     /* To save memory, if m_nPhaseValue is negative, we are in the
957      * delay phase, and m_nPhaseValue represents the time left
958      * in the delay.
959      */
960      if (pLFO->lfoPhase < 0)
961      {
962         pLFO->lfoPhase++;
963         return;
964      }
965 
966     /* calculate LFO output from phase value */
967     /*lint -e{701} Use shift for performance */
968     pLFO->lfoValue = (EAS_I16) (pLFO->lfoPhase << 2);
969     /*lint -e{502} <shortcut to turn sawtooth into triangle wave> */
970     if ((pLFO->lfoPhase > 0x1fff) && (pLFO->lfoPhase < 0x6000))
971         pLFO->lfoValue = ~pLFO->lfoValue;
972 
973     /* update LFO phase */
974     pLFO->lfoPhase = (pLFO->lfoPhase + phaseInc) & 0x7fff;
975 }
976 
977 #ifdef _FILTER_ENABLED
978 /*----------------------------------------------------------------------------
979  * WT_UpdateFilter()
980  *----------------------------------------------------------------------------
981  * Purpose:
982  * Update the Filter parameters
983  *
984  * Inputs:
985  * pVoice - ptr to the voice whose filter we want to update
986  * pEASData - pointer to overall EAS data structure
987  *
988  * Outputs:
989  *
990  * Side Effects:
991  * - updates Filter values for the given voice
992  *----------------------------------------------------------------------------
993 */
WT_UpdateFilter(S_WT_VOICE * pWTVoice,S_WT_INT_FRAME * pIntFrame,const S_ARTICULATION * pArt)994 static void WT_UpdateFilter (S_WT_VOICE *pWTVoice, S_WT_INT_FRAME *pIntFrame, const S_ARTICULATION *pArt)
995 {
996     EAS_I32 cutoff;
997 
998     /* no need to calculate filter coefficients if it is bypassed */
999     if (pArt->filterCutoff == DEFAULT_EAS_FILTER_CUTOFF_FREQUENCY)
1000     {
1001         pIntFrame->frame.k = 0;
1002         return;
1003     }
1004 
1005     /* determine the dynamic cutoff frequency */
1006     cutoff = MULT_EG1_EG1(pWTVoice->eg2Value, pArt->eg2ToFc);
1007     cutoff += pArt->filterCutoff;
1008 
1009     /* subtract the A5 offset and the sampling frequency */
1010     cutoff -= FILTER_CUTOFF_FREQ_ADJUST + A5_PITCH_OFFSET_IN_CENTS;
1011 
1012     /* limit the cutoff frequency */
1013     if (cutoff > FILTER_CUTOFF_MAX_PITCH_CENTS)
1014         cutoff = FILTER_CUTOFF_MAX_PITCH_CENTS;
1015     else if (cutoff < FILTER_CUTOFF_MIN_PITCH_CENTS)
1016         cutoff = FILTER_CUTOFF_MIN_PITCH_CENTS;
1017 
1018     WT_SetFilterCoeffs(pIntFrame, cutoff, pArt->filterQ);
1019 }
1020 #endif
1021 
1022 #if defined(_FILTER_ENABLED) || defined(DLS_SYNTHESIZER)
1023 /*----------------------------------------------------------------------------
1024  * coef
1025  *----------------------------------------------------------------------------
1026  * Table of filter coefficients for low-pass filter
1027  *----------------------------------------------------------------------------
1028  *
1029  * polynomial coefficients are based on 8kHz sampling frequency
1030  * filter coef b2 = k2 = k2g0*k^0 + k2g1*k^1*(2^x) + k2g2*k^2*(2^x)
1031  *
1032  *where k2g0, k2g1, k2g2 are from the truncated power series expansion on theta
1033  *(k*2^x = theta, but we incorporate the k along with the k2g0, k2g1, k2g2)
1034  *note: this is a power series in 2^x, not k*2^x
1035  *where k = (2*pi*440)/8kHz == convert octaves to radians
1036  *
1037  *  so actually, the following coefs listed as k2g0, k2g1, k2g2 are really
1038  *  k2g0*k^0 = k2g0
1039  *  k2g1*k^1
1040  *  k2g2*k^2
1041  *
1042  *
1043  * filter coef n1 = numerator = n1g0*k^0 + n1g1*k^1*(2^x) + n1g2*k^2*(2^x) + n1g3*k^3*(2^x)
1044  *
1045  *where n1g0, n1g1, n1g2, n1g3 are from the truncated power series expansion on theta
1046  *(k*2^x = theta, but we incorporate the k along with the n1g0, n1g1, n1g2, n2g3)
1047  *note: this is a power series in 2^x, not k*2^x
1048  *where k = (2*pi*440)/8kHz == convert octaves to radians
1049  *we also include the optimization factor of 0.81
1050  *
1051  *  so actually, the following coefs listed as n1g0, n1g1, n1g2, n2g3 are really
1052  *  n1g0*k^0 = n1g0
1053  *  n1g1*k^1
1054  *  n1g2*k^2
1055  *  n1g3*k^3
1056  *
1057  *  NOTE that n1g0 == n1g1 == 0, always, so we only need to store n1g2 and n1g3
1058  *----------------------------------------------------------------------------
1059 */
1060 
1061 static const EAS_I16 nk1g0 = -32768;
1062 static const EAS_I16 nk1g2 = 1580;
1063 static const EAS_I16 k2g0 = 32767;
1064 
1065 static const EAS_I16 k2g1[] =
1066 {
1067         -11324, /* k2g1[0] = -0.3455751918948761 */
1068         -10387, /* k2g1[1] = -0.3169878073928751 */
1069         -9528,  /* k2g1[2] = -0.29076528753345476 */
1070         -8740,  /* k2g1[3] = -0.2667120011011279 */
1071         -8017,  /* k2g1[4] = -0.24464850028971705 */
1072         -7353,  /* k2g1[5] = -0.22441018194495696 */
1073         -6745,  /* k2g1[6] = -0.20584605955455101 */
1074         -6187,  /* k2g1[7] = -0.18881763682420102 */
1075         -5675,  /* k2g1[8] = -0.1731978744360067 */
1076         -5206,  /* k2g1[9] = -0.15887024228080968 */
1077         -4775,  /* k2g1[10] = -0.14572785009373057 */
1078         -4380,  /* k2g1[11] = -0.13367265000706827 */
1079         -4018,  /* k2g1[12] = -0.1226147050712642 */
1080         -3685,  /* k2g1[13] = -0.11247151828678581 */
1081         -3381,  /* k2g1[14] = -0.10316741714122014 */
1082         -3101,  /* k2g1[15] = -0.0946329890599603 */
1083         -2844,  /* k2g1[16] = -0.08680456355870586 */
1084         -2609,  /* k2g1[17] = -0.07962373723441349 */
1085         -2393,  /* k2g1[18] = -0.07303693805092666 */
1086         -2195,  /* k2g1[19] = -0.06699502566866912 */
1087         -2014,  /* k2g1[20] = -0.06145292483669077 */
1088         -1847,  /* k2g1[21] = -0.056369289112013346 */
1089         -1694,  /* k2g1[22] = -0.05170619239747895 */
1090         -1554,  /* k2g1[23] = -0.04742884599684141 */
1091         -1426,  /* k2g1[24] = -0.043505339076210514 */
1092         -1308,  /* k2g1[25] = -0.03990640059558053 */
1093         -1199,  /* k2g1[26] = -0.03660518093435039 */
1094         -1100,  /* k2g1[27] = -0.03357705158166837 */
1095         -1009,  /* k2g1[28] = -0.030799421397205727 */
1096         -926,   /* k2g1[29] = -0.028251568071585884 */
1097         -849    /* k2g1[30] = -0.025914483529091967 */
1098 };
1099 
1100 static const EAS_I16 k2g2[] =
1101 {
1102         1957,   /* k2g2[0] = 0.059711106626580836 */
1103         1646,   /* k2g2[1] = 0.05024063501786333 */
1104         1385,   /* k2g2[2] = 0.042272226217199664 */
1105         1165,   /* k2g2[3] = 0.03556764576567844 */
1106         981,    /* k2g2[4] = 0.029926444346999134 */
1107         825,    /* k2g2[5] = 0.025179964880280382 */
1108         694,    /* k2g2[6] = 0.02118630011706455 */
1109         584,    /* k2g2[7] = 0.01782604998793514 */
1110         491,    /* k2g2[8] = 0.014998751854573014 */
1111         414,    /* k2g2[9] = 0.012619876941179595 */
1112         348,    /* k2g2[10] = 0.010618303146468736 */
1113         293,    /* k2g2[11] = 0.008934188679954682 */
1114         246,    /* k2g2[12] = 0.007517182949855368 */
1115         207,    /* k2g2[13] = 0.006324921212866403 */
1116         174,    /* k2g2[14] = 0.005321757979794424 */
1117         147,    /* k2g2[15] = 0.004477701309210577 */
1118         123,    /* k2g2[16] = 0.00376751612730811 */
1119         104,    /* k2g2[17] = 0.0031699697655869644 */
1120         87,     /* k2g2[18] = 0.00266719715992703 */
1121         74,     /* k2g2[19] = 0.0022441667321724647 */
1122         62,     /* k2g2[20] = 0.0018882309854916855 */
1123         52,     /* k2g2[21] = 0.0015887483774966232 */
1124         44,     /* k2g2[22] = 0.0013367651661223448 */
1125         37,     /* k2g2[23] = 0.0011247477162958733 */
1126         31,     /* k2g2[24] = 0.0009463572640678758 */
1127         26,     /* k2g2[25] = 0.0007962604042473498 */
1128         22,     /* k2g2[26] = 0.0006699696356181593 */
1129         18,     /* k2g2[27] = 0.0005637091964589207 */
1130         16,     /* k2g2[28] = 0.00047430217920125243 */
1131         13,     /* k2g2[29] = 0.00039907554925166274 */
1132         11      /* k2g2[30] = 0.00033578022828973666 */
1133 };
1134 
1135 static const EAS_I16 n1g2[] =
1136 {
1137         3170,   /* n1g2[0] = 0.0967319927350769 */
1138         3036,   /* n1g2[1] = 0.0926446051254155 */
1139         2908,   /* n1g2[2] = 0.08872992911818503 */
1140         2785,   /* n1g2[3] = 0.08498066682523227 */
1141         2667,   /* n1g2[4] = 0.08138982872895201 */
1142         2554,   /* n1g2[5] = 0.07795072065216213 */
1143         2446,   /* n1g2[6] = 0.0746569312785634 */
1144         2343,   /* n1g2[7] = 0.07150232020051943 */
1145         2244,   /* n1g2[8] = 0.06848100647187474 */
1146         2149,   /* n1g2[9] = 0.06558735764447099 */
1147         2058,   /* n1g2[10] = 0.06281597926792246 */
1148         1971,   /* n1g2[11] = 0.06016170483307614 */
1149         1888,   /* n1g2[12] = 0.05761958614040857 */
1150         1808,   /* n1g2[13] = 0.05518488407540374 */
1151         1732,   /* n1g2[14] = 0.052853059773715245 */
1152         1659,   /* n1g2[15] = 0.05061976615964251 */
1153         1589,   /* n1g2[16] = 0.04848083984214659 */
1154         1521,   /* n1g2[17] = 0.046432293353298 */
1155         1457,   /* n1g2[18] = 0.04447030771468711 */
1156         1396,   /* n1g2[19] = 0.04259122531793907 */
1157         1337,   /* n1g2[20] = 0.040791543106060944 */
1158         1280,   /* n1g2[21] = 0.03906790604290942 */
1159         1226,   /* n1g2[22] = 0.037417100858604564 */
1160         1174,   /* n1g2[23] = 0.035836050059229754 */
1161         1125,   /* n1g2[24] = 0.03432180618965023 */
1162         1077,   /* n1g2[25] = 0.03287154633875494 */
1163         1032,   /* n1g2[26] = 0.03148256687687814 */
1164         988,    /* n1g2[27] = 0.030152278415589925 */
1165         946,    /* n1g2[28] = 0.028878200980459685 */
1166         906,    /* n1g2[29] = 0.02765795938779331 */
1167         868     /* n1g2[30] = 0.02648927881672521 */
1168 };
1169 
1170 static const EAS_I16 n1g3[] =
1171 {
1172         -548,   /* n1g3[0] = -0.016714088475899017 */
1173         -481,   /* n1g3[1] = -0.014683605122742116 */
1174         -423,   /* n1g3[2] = -0.012899791676436092 */
1175         -371,   /* n1g3[3] = -0.01133268185193299 */
1176         -326,   /* n1g3[4] = -0.00995594976868754 */
1177         -287,   /* n1g3[5] = -0.008746467702146129 */
1178         -252,   /* n1g3[6] = -0.00768391756106361 */
1179         -221,   /* n1g3[7] = -0.006750449563854721 */
1180         -194,   /* n1g3[8] = -0.005930382380083576 */
1181         -171,   /* n1g3[9] = -0.005209939699767622 */
1182         -150,   /* n1g3[10] = -0.004577018805123356 */
1183         -132,   /* n1g3[11] = -0.004020987256990177 */
1184         -116,   /* n1g3[12] = -0.003532504280467257 */
1185         -102,   /* n1g3[13] = -0.00310336384922047 */
1186         -89,    /* n1g3[14] = -0.002726356832432369 */
1187         -78,    /* n1g3[15] = -0.002395149888601605 */
1188         -69,    /* n1g3[16] = -0.0021041790717285314 */
1189         -61,    /* n1g3[17] = -0.0018485563625771063 */
1190         -53,    /* n1g3[18] = -0.001623987554831628 */
1191         -47,    /* n1g3[19] = -0.0014267001167177025 */
1192         -41,    /* n1g3[20] = -0.0012533798162347005 */
1193         -36,    /* n1g3[21] = -0.0011011150453668693 */
1194         -32,    /* n1g3[22] = -0.0009673479079754438 */
1195         -28,    /* n1g3[23] = -0.0008498312496971563 */
1196         -24,    /* n1g3[24] = -0.0007465909079943587 */
1197         -21,    /* n1g3[25] = -0.0006558925481952733 */
1198         -19,    /* n1g3[26] = -0.0005762125284029567 */
1199         -17,    /* n1g3[27] = -0.0005062123038325457 */
1200         -15,    /* n1g3[28] = -0.0004447159405951901 */
1201         -13,    /* n1g3[29] = -0.00039069036118270117 */
1202         -11     /* n1g3[30] = -0.00034322798979677605 */
1203 };
1204 
1205 /*----------------------------------------------------------------------------
1206  * WT_SetFilterCoeffs()
1207  *----------------------------------------------------------------------------
1208  * Purpose:
1209  * Update the Filter parameters
1210  *
1211  * Inputs:
1212  * pVoice - ptr to the voice whose filter we want to update
1213  * pEASData - pointer to overall EAS data structure
1214  *
1215  * Outputs:
1216  *
1217  * Side Effects:
1218  * - updates Filter values for the given voice
1219  *----------------------------------------------------------------------------
1220 */
WT_SetFilterCoeffs(S_WT_INT_FRAME * pIntFrame,EAS_I32 cutoff,EAS_I32 resonance)1221 void WT_SetFilterCoeffs (S_WT_INT_FRAME *pIntFrame, EAS_I32 cutoff, EAS_I32 resonance)
1222 {
1223     EAS_I32 temp;
1224 
1225     /*
1226     Convert the cutoff, which has had A5 subtracted, using the 2^x approx
1227     Note, this cutoff is related to theta cutoff by
1228     theta = k * 2^x
1229     We use 2^x and incorporate k in the power series coefs instead
1230     */
1231     cutoff = EAS_Calculate2toX(cutoff);
1232 
1233     /* calculate b2 coef */
1234     temp = k2g1[resonance] + MULT_AUDIO_COEF(cutoff, k2g2[resonance]);
1235     temp = k2g0 + MULT_AUDIO_COEF(cutoff, temp);
1236     pIntFrame->frame.b2 = temp;
1237 
1238     /* calculate b1 coef */
1239     temp = MULT_AUDIO_COEF(cutoff, nk1g2);
1240     temp = nk1g0 + MULT_AUDIO_COEF(cutoff, temp);
1241     temp += MULT_AUDIO_COEF(temp, pIntFrame->frame.b2);
1242     pIntFrame->frame.b1 = temp >> 1;
1243 
1244     /* calculate K coef */
1245     temp = n1g2[resonance] + MULT_AUDIO_COEF(cutoff, n1g3[resonance]);
1246     temp = MULT_AUDIO_COEF(cutoff, temp);
1247     temp = MULT_AUDIO_COEF(cutoff, temp);
1248     pIntFrame->frame.k = temp;
1249 }
1250 #endif
1251 
1252