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1.1 root 1: /*
1.1.1.5 root 2: Hatari - sound.c
3:
4: This file is distributed under the GNU Public License, version 2 or at
5: your option any later version. Read the file gpl.txt for details.
1.1 root 6:
7: This is where we emulate the YM2149. To obtain cycle-accurate timing we store the current cycle
8: time and this is incremented during each instruction. When a write occurs in the PSG registers
9: we take the difference in time and generate this many samples using the previous register data.
10: Now we begin again from this point. To make sure we always have 1/50th of samples we update
11: the buffer generation every 1/50th second, just in case no write took place on the PSG.
12: As with most 'sample' emulation it appears very quiet. We detect for any sample playback on a channel
13: by a decay timer on the channel amplitude - this will remain high if the PSG register is constantly
14: written to. We use this decay timer to boost the output of a sampled channel so the final sound is more
15: even through-out.
1.1.1.2 root 16: NOTE: If the emulator runs slower than 50fps it cannot update the buffers, but the sound thread still
1.1 root 17: needs some data to play to prevent a 'pop'. The ONLY feasible solution is to play the same buffer again.
18: I have tried all kinds of methods to play the sound 'slower', but this produces un-even timing in the
19: sound and it simply doesn't work. If the emulator cannot keep the speed, users will have to turn off
20: the sound - that's it.
21: */
1.1.1.9 ! root 22: char Sound_rcsid[] = "Hatari $Id: sound.c,v 1.21 2005/09/27 08:53:50 thothy Exp $";
1.1.1.5 root 23:
24: #include <SDL_types.h>
1.1 root 25:
26: #include "main.h"
27: #include "audio.h"
1.1.1.9 ! root 28: #include "dmaSnd.h"
1.1 root 29: #include "file.h"
30: #include "int.h"
1.1.1.8 root 31: #include "log.h"
1.1 root 32: #include "memorySnapShot.h"
33: #include "misc.h"
34: #include "psg.h"
35: #include "sound.h"
36: #include "video.h"
37: #include "wavFormat.h"
38: #include "ymFormat.h"
39:
1.1.1.5 root 40: #define LONGLONG Uint64
1.1 root 41:
1.1.1.8 root 42: #define ENVELOPE_PERIOD(Fine,Coarse) ((((Uint32)Coarse)<<8) + (Uint32)Fine)
43: #define NOISE_PERIOD(Freq) (((((Uint32)Freq)&0x1f)<<11))
44: #define TONE_PERIOD(Fine,Coarse) (((((Uint32)Coarse)&0x0f)<<8) + (Uint32)Fine)
1.1.1.5 root 45: #define MIXTABLE_SIZE (256*8) /* Large table, so don't overflow */
46: #define TONEFREQ_SHIFT 28 /* 4.28 fixed point */
47: #define NOISEFREQ_SHIFT 28 /* 4.28 fixed point */
48: #define ENVFREQ_SHIFT 16 /* 16.16 fixed */
1.1 root 49:
1.1.1.6 root 50: #define SAMPLES_BUFFER_SIZE 1024
51: /* Number of generated samples per frame (eg. 44Khz=882) : */
52: #define SAMPLES_PER_FRAME ((SoundPlayBackFrequencies[OutputAudioFreqIndex]+35)/nScreenRefreshRate)
53: /* Frequency of generated samples: */
54: #define SAMPLES_FREQ (SoundPlayBackFrequencies[OutputAudioFreqIndex])
55: #define YM_FREQ (2000000/SAMPLES_FREQ) /* YM Frequency 2Mhz */
56:
57:
1.1 root 58: /* Original wave samples */
1.1.1.7 root 59: static int EnvelopeShapeValues[16*1024]; /* Shape x Length(repeat 3rd/4th entries) */
1.1 root 60: /* Frequency and time period samples */
1.1.1.8 root 61: static Uint32 ChannelFreq[3], EnvelopeFreq, NoiseFreq; /* Current frequency of each channel A,B,C,Envelope and Noise */
1.1.1.7 root 62: static int ChannelAmpDecayTime[3]; /* Store counter to show if amplitude is changed to generate 'samples' */
63: static int Envelope[SAMPLES_BUFFER_SIZE],Noise[SAMPLES_BUFFER_SIZE]; /* Current sample for this time period */
1.1 root 64: /* Output channel data */
1.1.1.7 root 65: static int Channel_A_Buffer[SAMPLES_BUFFER_SIZE],Channel_B_Buffer[SAMPLES_BUFFER_SIZE],Channel_C_Buffer[SAMPLES_BUFFER_SIZE];
1.1.1.9 ! root 66: /* Use table to convert from (A+B+C) to clipped 8-bit for sound buffer */
! 67: static Sint8 MixTable[MIXTABLE_SIZE]; /* -ve and +ve range */
! 68: static Sint8 *pMixTable = &MixTable[MIXTABLE_SIZE/2]; /* Signed index into above */
1.1.1.7 root 69: static int ActiveSndBufIdx; /* Current working index into above mix buffer */
70: static int nSamplesToGenerate; /* How many samples are needed for this time-frame */
71:
72: /* global values */
1.1 root 73: BOOL bWriteEnvelopeFreq; /* Did write to register '13' - causes frequency reset */
1.1.1.5 root 74: BOOL bWriteChannelAAmp, bWriteChannelBAmp, bWriteChannelCAmp; /* Did write to amplitude registers? */
1.1 root 75: BOOL bEnvelopeFreqFlag; /* As above, but cleared each frame for YM saving */
1.1.1.2 root 76: /* Buffer to store circular samples */
1.1.1.9 ! root 77: Sint8 MixBuffer[MIXBUFFER_SIZE];
1.1.1.5 root 78: int nGeneratedSamples; /* Generated samples since audio buffer update */
1.1.1.7 root 79: int SoundCycles;
1.1.1.3 root 80:
1.1 root 81:
1.1.1.2 root 82: /*-----------------------------------------------------------------------*/
1.1.1.7 root 83: /* Envelope shape table */
84: typedef struct
85: {
86: int WaveStart[4], WaveDelta[4];
87: } ENVSHAPE;
88:
1.1.1.2 root 89: /* Envelope shapes */
1.1.1.7 root 90: static ENVSHAPE EnvShapes[16] =
1.1.1.5 root 91: {
1.1.1.4 root 92: { {127,-128,-128,-128}, {-1, 0, 0, 0} }, /* \_____ 00xx */
93: { {127,-128,-128,-128}, {-1, 0, 0, 0} }, /* \_____ 00xx */
94: { {127,-128,-128,-128}, {-1, 0, 0, 0} }, /* \_____ 00xx */
95: { {127,-128,-128,-128}, {-1, 0, 0, 0} }, /* \_____ 00xx */
96: { {-128,-128,-128,-128}, {1, 0, 0, 0} }, /* /_____ 01xx */
97: { {-128,-128,-128,-128}, {1, 0, 0, 0} }, /* /_____ 01xx */
98: { {-128,-128,-128,-128}, {1, 0, 0, 0} }, /* /_____ 01xx */
99: { {-128,-128,-128,-128}, {1, 0, 0, 0} }, /* /_____ 01xx */
100: { {127,127,127,127}, {-1,-1,-1,-1} }, /* \\\\\\ 1000 */
101: { {127,-128,-128,-128}, {-1, 0, 0, 0} }, /* \_____ 1001 */
102: { {127,-128,127,-128}, {-1, 1,-1, 1} }, /* \/\/\/ 1010 */
103: { {127,127,127,127}, {-1, 0, 0, 0} }, /* \~~~~~ 1011 */
104: { {-128,-128,-128,-128}, {1, 1, 1, 1} }, /* ////// 1100 */
105: { {-128,127,127,127}, {1, 0, 0, 0} }, /* /~~~~~ 1101 */
106: { {-128,127,-128,127}, {1,-1, 1,-1} }, /* /\/\/\ 1110 */
107: { {-128,-128,-128,-128}, {1, 0, 0, 0} } /* /_____ 1111 */
1.1 root 108: };
109:
110: /* Square wave look up table */
1.1.1.7 root 111: static int SquareWave[16] = { 127,127,127,127,127,127,127,127, -128,-128,-128,-128,-128,-128,-128,-128 };
1.1 root 112: /* LogTable */
1.1.1.7 root 113: static int LogTable[256];
114: static int LogTable16[16];
115: static int *pEnvelopeLogTable = &LogTable[128];
1.1 root 116:
1.1.1.5 root 117:
1.1.1.2 root 118: /*-----------------------------------------------------------------------*/
1.1 root 119: /*
120: Create Log tables
121: */
1.1.1.7 root 122: static void Sound_CreateLogTables(void)
1.1 root 123: {
124: float a;
125: int i;
126:
127: /* Generate 'log' table for envelope output. It isn't quite a 'log' but it mimicks the ST */
1.1.1.2 root 128: /* output very well */
1.1 root 129: a = 1.0f;
1.1.1.5 root 130: for(i=0; i<256; i++)
131: {
1.1 root 132: LogTable[255-i] = (int)(255*a);
133: a /= 1.02f;
134: }
135: LogTable[0] = 0;
136:
137: /* And a 16 entry version(thanks to Nick for the '/= 1.5' bit) */
138: /* This is VERY important for clear sample playback */
139: a = 1.0f;
1.1.1.5 root 140: for(i=0; i<15; i++)
141: {
1.1 root 142: LogTable16[15-i] = (int)(255*a);
143: a /= 1.5f;
144: }
145: LogTable16[0] = 0;
146: }
147:
1.1.1.5 root 148:
1.1.1.2 root 149: /*-----------------------------------------------------------------------*/
1.1 root 150: /*
151: Create envelope shape, store to table
152: ( Wave is stored as 4 cycles, where cycles 1,2 are start and 3,4 are looped )
153: */
1.1.1.7 root 154: static void Sound_CreateEnvelopeShape(ENVSHAPE *pEnvShape,int *pEnvelopeValues)
1.1 root 155: {
156: int i,j,Value;
157:
1.1.1.2 root 158: /* Create shape */
1.1.1.5 root 159: for(i=0; i<4; i++)
160: {
1.1.1.2 root 161: Value = pEnvShape->WaveStart[i]; /* Set starting value for gradient */
1.1 root 162: for(j=0; j<256; j++,Value+=pEnvShape->WaveDelta[i])
163: *pEnvelopeValues++ = Misc_LimitInt(Value,-128,127);
164: }
165: }
166:
1.1.1.5 root 167:
1.1.1.2 root 168: /*-----------------------------------------------------------------------*/
1.1 root 169: /*
170: Create YM2149 envelope shapes(x16)
171: */
1.1.1.7 root 172: static void Sound_CreateEnvelopeShapes(void)
1.1 root 173: {
174: int i;
175:
1.1.1.2 root 176: /* Create 'envelopes' for YM table */
1.1 root 177: for(i=0; i<16; i++)
178: Sound_CreateEnvelopeShape(&EnvShapes[i],&EnvelopeShapeValues[i*1024]);
179: }
180:
1.1.1.5 root 181:
1.1.1.2 root 182: /*-----------------------------------------------------------------------*/
1.1 root 183: /*
184: Create table to clip samples top 8-bit range
1.1.1.7 root 185: This keeps then 'signed', although many sound cards want 'unsigned' values,
1.1.1.5 root 186: but we keep them signed so we can vary the volume easily.
1.1 root 187: */
1.1.1.7 root 188: static void Sound_CreateSoundMixClipTable(void)
1.1 root 189: {
190: int i,v;
191:
1.1.1.2 root 192: /* Create table to 'clip' values to -128...127 */
1.1.1.5 root 193: for(i=0; i<MIXTABLE_SIZE; i++)
194: {
1.1.1.2 root 195: v = (float)(i-(MIXTABLE_SIZE/2)) * 0.3f; /* Scale, to prevent clipping */
196: if (v<-128) v = -128; /* Limit -128..128 */
1.1 root 197: if (v>127) v = 127;
198: MixTable[i] = v;
199: }
200: }
201:
202:
1.1.1.2 root 203: /*-----------------------------------------------------------------------*/
1.1 root 204: /*
1.1.1.7 root 205: Init sound tables and envelopes
206: */
207: void Sound_Init(void)
208: {
209: Sound_CreateLogTables();
210: Sound_CreateEnvelopeShapes();
211: Sound_CreateSoundMixClipTable();
212:
213: Sound_Reset();
214: }
215:
216:
217: /*-----------------------------------------------------------------------*/
218: /*
219: Reset the sound emulation
220: */
221: void Sound_Reset(void)
222: {
223: int i;
224:
1.1.1.9 ! root 225: /* Lock audio system before accessing variables which are used by the
! 226: * callback function, too! */
! 227: Audio_Lock();
! 228:
! 229: /* Clear sound mixing buffer: */
! 230: memset(MixBuffer, 0, MIXBUFFER_SIZE);
1.1.1.7 root 231:
232: /* Clear cycle counts, buffer index and register '13' flags */
233: SoundCycles = 0;
234: bEnvelopeFreqFlag = FALSE;
235: bWriteEnvelopeFreq = FALSE;
236: bWriteChannelAAmp = bWriteChannelBAmp = bWriteChannelCAmp = FALSE;
237:
238: CompleteSndBufIdx = 0;
239: ActiveSndBufIdx = (SoundBufferSize + SAMPLES_PER_FRAME) % MIXBUFFER_SIZE;
240: nGeneratedSamples = 0;
241:
242: /* Clear frequency counter */
243: for(i=0; i<3; i++)
244: {
245: ChannelFreq[i] =
246: ChannelAmpDecayTime[i] = 0;
247: }
248: EnvelopeFreq = NoiseFreq = 0;
1.1.1.9 ! root 249:
! 250: Audio_Unlock();
1.1.1.7 root 251: }
252:
253:
254: /*-----------------------------------------------------------------------*/
255: /*
1.1.1.9 ! root 256: Reset the sound buffer index variables.
1.1.1.7 root 257: */
1.1.1.9 ! root 258: void Sound_ResetBufferIndex(void)
1.1.1.7 root 259: {
260: Audio_Lock();
1.1.1.9 ! root 261: ActiveSndBufIdx = (CompleteSndBufIdx + SoundBufferSize + SAMPLES_PER_FRAME)
! 262: % MIXBUFFER_SIZE;
1.1.1.7 root 263: Audio_Unlock();
264: }
265:
266:
267: /*-----------------------------------------------------------------------*/
268: /*
269: Save/Restore snapshot of local variables('MemorySnapShot_Store' handles type)
270: */
271: void Sound_MemorySnapShot_Capture(BOOL bSave)
272: {
273: /* Save/Restore details */
274: MemorySnapShot_Store(ChannelFreq,sizeof(ChannelFreq));
275: MemorySnapShot_Store(&EnvelopeFreq,sizeof(EnvelopeFreq));
276: MemorySnapShot_Store(&NoiseFreq,sizeof(NoiseFreq));
277: }
278:
279:
280: /*-----------------------------------------------------------------------*/
281: /*
1.1 root 282: Find how many samples to generate and store in 'nSamplesToGenerate'
1.1.1.9 ! root 283: Also update 'SoundCycles' to store how many we actually did so generates set
! 284: amount each frame.
1.1 root 285: */
1.1.1.7 root 286: static void Sound_SetSamplesPassed(void)
1.1 root 287: {
288: int nSampleCycles;
1.1.1.7 root 289: int nSamplesPerFrame;
1.1 root 290: int Dec=1;
291:
1.1.1.2 root 292: /* Check how many cycles have passed, as we use this to help find out if we are playing sample data */
1.1 root 293:
1.1.1.2 root 294: /* First, add decay to channel amplitude variables */
1.1 root 295: if (SoundCycles>(CYCLES_PER_FRAME/4))
1.1.1.2 root 296: Dec = 16; /* Been long time between sound writes, must be normal tone sound */
1.1 root 297:
1.1.1.5 root 298: if (!bWriteChannelAAmp) /* Not written to amplitude, decay value */
299: {
1.1 root 300: ChannelAmpDecayTime[0]-=Dec;
301: if (ChannelAmpDecayTime[0]<0) ChannelAmpDecayTime[0] = 0;
302: }
1.1.1.5 root 303: if (!bWriteChannelBAmp)
304: {
1.1 root 305: ChannelAmpDecayTime[1]-=Dec;
306: if (ChannelAmpDecayTime[1]<0) ChannelAmpDecayTime[1] = 0;
307: }
1.1.1.5 root 308: if (!bWriteChannelCAmp)
309: {
1.1 root 310: ChannelAmpDecayTime[2]-=Dec;
311: if (ChannelAmpDecayTime[2]<0) ChannelAmpDecayTime[2] = 0;
312: }
313:
1.1.1.2 root 314: /* 160256 cycles per VBL, 44Khz = 882 samples per VBL */
315: /* 882/160256 samples per clock cycle */
1.1.1.7 root 316: nSamplesPerFrame = SAMPLES_PER_FRAME;
317: #if 0 /* Use floats for calculation */
318: nSamplesToGenerate = (int)( (float)SoundCycles * ((float)nSamplesPerFrame/(float)CYCLES_PER_FRAME) );
319: if (nSamplesToGenerate > nSamplesPerFrame)
320: nSamplesToGenerate = nSamplesPerFrame;
1.1 root 321:
1.1.1.7 root 322: nSampleCycles = (int)( (float)nSamplesToGenerate / ((float)nSamplesPerFrame/(float)CYCLES_PER_FRAME) );
1.1 root 323: SoundCycles -= nSampleCycles;
1.1.1.7 root 324: #else /* Use integers for calculation - both of these calculations should fit into 32-bit int */
325: nSamplesToGenerate = SoundCycles * nSamplesPerFrame / CYCLES_PER_FRAME;
326: if (nSamplesToGenerate > nSamplesPerFrame)
327: nSamplesToGenerate = nSamplesPerFrame;
328:
329: nSampleCycles = nSamplesToGenerate * CYCLES_PER_FRAME / nSamplesPerFrame;
330: SoundCycles -= nSampleCycles;
331: #endif
1.1 root 332: }
333:
1.1.1.5 root 334:
1.1.1.2 root 335: /*-----------------------------------------------------------------------*/
1.1 root 336: /*
337: Generate envelope wave for this time-frame
338: */
1.1.1.7 root 339: static void Sound_GenerateEnvelope(unsigned char EnvShape, unsigned char Fine, unsigned char Coarse)
1.1 root 340: {
341: int *pEnvelopeValues;
1.1.1.8 root 342: Uint32 EnvelopePeriod, EnvelopeFreqDelta;
1.1 root 343: int i;
344:
1.1.1.2 root 345: /* Find envelope details */
1.1 root 346: if (bWriteEnvelopeFreq)
347: EnvelopeFreq = 0;
1.1.1.2 root 348: pEnvelopeValues = &EnvelopeShapeValues[ (EnvShape&0x0f)*1024 ]; /* Envelope shape values */
1.1.1.8 root 349: EnvelopePeriod = ENVELOPE_PERIOD((Uint32)Fine, (Uint32)Coarse);
1.1 root 350:
1.1.1.2 root 351: if (EnvelopePeriod==0) /* Handle div by zero */
1.1 root 352: EnvelopeFreqDelta = 0;
353: else
1.1.1.2 root 354: EnvelopeFreqDelta = ((LONGLONG)YM_FREQ<<ENVFREQ_SHIFT) / (EnvelopePeriod); /* 16.16 fixed point */
1.1 root 355:
1.1.1.2 root 356: /* Create envelope from current shape and frequency */
1.1.1.5 root 357: for(i=0; i<nSamplesToGenerate; i++)
358: {
1.1.1.2 root 359: Envelope[i] = pEnvelopeValues[EnvelopeFreq>>ENVFREQ_SHIFT]; /* Store envelope wave, already applied 'log' function */
1.1 root 360: EnvelopeFreq += EnvelopeFreqDelta;
361: if (EnvelopeFreq&0xfe000000)
1.1.1.2 root 362: EnvelopeFreq = 0x02000000 | (EnvelopeFreq&0x01ffffff); /* Keep in range 512-1024 once past 511! */
1.1 root 363: }
364: }
365:
1.1.1.5 root 366:
1.1.1.2 root 367: /*-----------------------------------------------------------------------*/
1.1 root 368: /*
369: Generate nosie for this time-frame
370: */
1.1.1.7 root 371: static void Sound_GenerateNoise(unsigned char MixerControl, unsigned char NoiseGen)
1.1 root 372: {
373: int NoiseValue;
1.1.1.8 root 374: Uint32 NoisePeriod, NoiseFreqDelta;
1.1 root 375: int i;
376:
1.1.1.8 root 377: NoisePeriod = NOISE_PERIOD((Uint32)NoiseGen);
1.1 root 378:
1.1.1.2 root 379: if (NoisePeriod==0) /* Handle div by zero */
1.1 root 380: NoiseFreqDelta = 0;
381: else
1.1.1.2 root 382: NoiseFreqDelta = (((LONGLONG)YM_FREQ)<<NOISEFREQ_SHIFT) / NoisePeriod; /* 4.28 fixed point */
1.1 root 383:
1.1.1.2 root 384: /* Generate noise samples */
1.1.1.5 root 385: for(i=0; i<nSamplesToGenerate; i++)
386: {
1.1.1.2 root 387: NoiseValue = (unsigned int)Misc_GetRandom()%96; /* Get random value */
388: if (SquareWave[NoiseFreq>>NOISEFREQ_SHIFT]<=0) /* Add to square wave at given frequency */
1.1 root 389: NoiseValue = -NoiseValue;
390:
391: Noise[i] = NoiseValue;
392: NoiseFreq += NoiseFreqDelta;
393: }
394: }
395:
1.1.1.5 root 396:
1.1.1.2 root 397: /*-----------------------------------------------------------------------*/
1.1 root 398: /*
399: Generate channel of samples for this time-frame
400: */
1.1.1.8 root 401: static void Sound_GenerateChannel(int *pBuffer, unsigned char ToneFine, unsigned char ToneCoarse, unsigned char Amplitude, unsigned char MixerControl, Uint32 *pChannelFreq, int MixMask)
1.1 root 402: {
403: int *pNoise = Noise, *pEnvelope = Envelope;
1.1.1.8 root 404: Uint32 ToneFreq = *pChannelFreq;
405: Uint32 TonePeriod;
406: Uint32 ToneFreqDelta;
1.1 root 407: int i,Amp,Mix;
408: int ToneOutput,NoiseOutput,MixerOutput,EnvelopeOutput,AmplitudeOutput;
409:
1.1.1.8 root 410: TonePeriod = TONE_PERIOD((Uint32)ToneFine, (Uint32)ToneCoarse);
1.1.1.2 root 411: /* Find frequency of channel */
1.1 root 412: if (TonePeriod==0)
1.1.1.2 root 413: ToneFreqDelta = 0; /* Handle div by zero */
1.1 root 414: else
1.1.1.2 root 415: ToneFreqDelta = (((LONGLONG)YM_FREQ)<<TONEFREQ_SHIFT) / TonePeriod; /* 4.28 fixed point */
1.1 root 416: Amp = LogTable16[(Amplitude&0x0f)];
1.1.1.2 root 417: Mix = (MixerControl>>MixMask)&9; /* Read I/O Mixer */
1.1 root 418:
1.1.1.2 root 419: /* Check if we are trying to play a 'sample' - we need to up the volume on these as they tend to be rather quiet */
1.1.1.5 root 420: if ((Amplitude&0x10)==0) /* Fixed level amplitude? */
421: {
1.1.1.2 root 422: ChannelAmpDecayTime[MixMask]++; /* Increment counter to find out if we are playing samples... */
1.1 root 423: if (ChannelAmpDecayTime[MixMask]>16)
1.1.1.2 root 424: ChannelAmpDecayTime[MixMask] = 16; /* And limit */
1.1 root 425: }
426:
1.1.1.5 root 427: for(i=0; i<nSamplesToGenerate; i++)
428: {
1.1.1.2 root 429: /* Output from Tone Generator(0-255) */
1.1 root 430: ToneOutput = SquareWave[ToneFreq>>TONEFREQ_SHIFT];
431:
1.1.1.2 root 432: /* Output from Noise Generator(0-255) */
1.1 root 433: NoiseOutput = *pNoise++;
1.1.1.2 root 434: /* Output from Mixer(combines Tone+Noise) */
1.1 root 435: switch (Mix) {
1.1.1.2 root 436: case 0: /* Has Noise and Tone */
1.1 root 437: MixerOutput = NoiseOutput+ToneOutput;
438: break;
1.1.1.2 root 439: case 1: /* Has Noise */
1.1 root 440: MixerOutput = NoiseOutput;
441: break;
1.1.1.2 root 442: case 8: /* Has Tone */
1.1 root 443: MixerOutput = ToneOutput;
444: break;
445:
1.1.1.2 root 446: default: /* This is used to emulate samples - should give no output, but ST gives set tone!!?? */
447: /* MixerControl gets set to give a continuous tone and then then Amplitude */
448: /* of channels A,B and C get changed with all other registers in the PSG */
449: /* staying as zero's. This produces the sounds from Quartet, Speech, NoiseTracker etc...! */
1.1 root 450: MixerOutput = 127;
451: }
452:
453: EnvelopeOutput = pEnvelopeLogTable[*pEnvelope++];
454:
1.1.1.5 root 455: if ((Amplitude&0x10)==0)
456: {
1.1.1.2 root 457: AmplitudeOutput = Amp; /* Fixed level amplitude */
1.1 root 458:
1.1.1.2 root 459: /* As with most emulators, sample playback is always 'quiet'. We check to see if */
460: /* the amplitude of a channel is repeatedly changing and when this is detected we */
461: /* scale the volume accordingly */
1.1 root 462: if (ChannelAmpDecayTime[MixMask]>8)
1.1.1.2 root 463: AmplitudeOutput <<= 1; /* Scale up by a factor of 2 */
1.1 root 464: }
465: else
466: AmplitudeOutput = EnvelopeOutput;
467:
468: *pBuffer++ = (MixerOutput*AmplitudeOutput)>>8;
469:
470: ToneFreq+=ToneFreqDelta;
471: }
472:
1.1.1.2 root 473: /* Store back incremented frequency, for next call */
1.1 root 474: *pChannelFreq = ToneFreq;
475: }
476:
1.1.1.5 root 477:
1.1.1.2 root 478: /*-----------------------------------------------------------------------*/
1.1 root 479: /*
480: Generate samples for all channels during this time-frame
481: */
1.1.1.5 root 482: static void Sound_GenerateSamples(void)
1.1 root 483: {
484: int *pChannelA=Channel_A_Buffer, *pChannelB=Channel_B_Buffer, *pChannelC=Channel_C_Buffer;
485: int i;
486:
1.1.1.2 root 487: /* Anything to do? */
1.1.1.5 root 488: if (nSamplesToGenerate>0)
489: {
1.1.1.2 root 490: /* Generate envelope/noise samples for this time */
1.1 root 491: Sound_GenerateEnvelope(PSGRegisters[PSG_REG_ENV_SHAPE],PSGRegisters[PSG_REG_ENV_FINE],PSGRegisters[PSG_REG_ENV_COARSE]);
492: Sound_GenerateNoise(PSGRegisters[PSG_REG_MIXER_CONTROL],PSGRegisters[PSG_REG_NOISE_GENERATOR]);
493:
1.1.1.2 root 494: /* Generate 3 channels, store to separate buffer so can mix/clip */
1.1 root 495: Sound_GenerateChannel(pChannelA,PSGRegisters[PSG_REG_CHANNEL_A_FINE],PSGRegisters[PSG_REG_CHANNEL_A_COARSE],PSGRegisters[PSG_REG_CHANNEL_A_AMP],PSGRegisters[PSG_REG_MIXER_CONTROL],&ChannelFreq[0],0);
496: Sound_GenerateChannel(pChannelB,PSGRegisters[PSG_REG_CHANNEL_B_FINE],PSGRegisters[PSG_REG_CHANNEL_B_COARSE],PSGRegisters[PSG_REG_CHANNEL_B_AMP],PSGRegisters[PSG_REG_MIXER_CONTROL],&ChannelFreq[1],1);
497: Sound_GenerateChannel(pChannelC,PSGRegisters[PSG_REG_CHANNEL_C_FINE],PSGRegisters[PSG_REG_CHANNEL_C_COARSE],PSGRegisters[PSG_REG_CHANNEL_C_AMP],PSGRegisters[PSG_REG_MIXER_CONTROL],&ChannelFreq[2],2);
498:
1.1.1.9 ! root 499: /* Mix channels together, using table to clip and convert to proper 8-bit type */
1.1 root 500: for(i=0; i<nSamplesToGenerate; i++)
1.1.1.5 root 501: MixBuffer[(i+ActiveSndBufIdx)%MIXBUFFER_SIZE] = pMixTable[(*pChannelA++) + (*pChannelB++) + (*pChannelC++)];
502:
1.1.1.9 ! root 503: DmaSnd_GenerateSamples(ActiveSndBufIdx, nSamplesToGenerate);
! 504:
1.1.1.5 root 505: ActiveSndBufIdx = (ActiveSndBufIdx + nSamplesToGenerate) % MIXBUFFER_SIZE;
506: nGeneratedSamples += nSamplesToGenerate;
507:
1.1.1.2 root 508: /* Reset the write to register '13' flag */
1.1 root 509: bWriteEnvelopeFreq = FALSE;
1.1.1.2 root 510: /* And amplitude write flags */
1.1 root 511: bWriteChannelAAmp = bWriteChannelBAmp = bWriteChannelCAmp = FALSE;
512: }
513: }
514:
1.1.1.5 root 515:
1.1.1.2 root 516: /*-----------------------------------------------------------------------*/
1.1 root 517: /*
1.1.1.5 root 518: This is called to built samples up until this clock cycle
1.1 root 519: */
1.1.1.5 root 520: void Sound_Update(void)
1.1 root 521: {
1.1.1.5 root 522: int OldSndBufIdx = ActiveSndBufIdx;
523:
1.1.1.6 root 524: /* Make sure that we don't interfere with the audio callback function */
525: Audio_Lock();
526:
1.1.1.5 root 527: /* Find how many to generate */
1.1 root 528: Sound_SetSamplesPassed();
1.1.1.2 root 529: /* And generate */
1.1 root 530: Sound_GenerateSamples();
531:
1.1.1.6 root 532: /* Allow audio callback function to occur again */
533: Audio_Unlock();
534:
1.1.1.2 root 535: /* Save to WAV file, if open */
1.1.1.5 root 536: WAVFormat_Update(MixBuffer, OldSndBufIdx, nSamplesToGenerate);
1.1 root 537: }
538:
1.1.1.5 root 539:
1.1.1.2 root 540: /*-----------------------------------------------------------------------*/
1.1 root 541: /*
1.1.1.5 root 542: On each VBL (50fps) complete samples.
1.1 root 543: */
1.1.1.5 root 544: void Sound_Update_VBL(void)
1.1 root 545: {
1.1.1.5 root 546: Sound_Update();
547:
548: /* Clear write to register '13', used for YM file saving */
549: bEnvelopeFreqFlag = FALSE;
1.1 root 550: }
551:
552:
1.1.1.2 root 553: /*-----------------------------------------------------------------------*/
1.1 root 554: /*
1.1.1.6 root 555: This is called from the audio callback function to create enough samples
556: to fill the current sound buffer.
557: */
558: void Sound_UpdateFromAudioCallBack(void)
559: {
560: /* If there are already enough samples or if we are recording, we should
561: * not generate more samples here! */
562: if(nGeneratedSamples >= SoundBufferSize || Sound_AreWeRecording())
563: return;
564:
565: nSamplesToGenerate = SoundBufferSize - nGeneratedSamples;
566:
567: Sound_GenerateSamples();
568: }
569:
570:
571: /*-----------------------------------------------------------------------*/
572: /*
1.1 root 573: Start recording sound, as .YM or .WAV output
574: */
575: BOOL Sound_BeginRecording(char *pszCaptureFileName)
576: {
577: BOOL bRet;
578:
1.1.1.7 root 579: if (!pszCaptureFileName || strlen(pszCaptureFileName) <= 3)
580: {
1.1.1.8 root 581: Log_Printf(LOG_ERROR, "Illegal sound recording file name!\n");
1.1.1.7 root 582: return FALSE;
583: }
584:
1.1.1.2 root 585: /* Did specify .YM or .WAV? If neither report error */
1.1.1.7 root 586: if (File_DoesFileExtensionMatch(pszCaptureFileName,".ym"))
1.1.1.4 root 587: bRet = YMFormat_BeginRecording(pszCaptureFileName);
1.1 root 588: else if (File_DoesFileExtensionMatch(pszCaptureFileName,".wav"))
1.1.1.4 root 589: bRet = WAVFormat_OpenFile(pszCaptureFileName);
1.1.1.5 root 590: else
591: {
1.1.1.8 root 592: Log_AlertDlg(LOG_ERROR, "Unknown Sound Recording format.\n"
593: "Please specify a .YM or .WAV output file.");
1.1 root 594: bRet = FALSE;
595: }
596:
1.1.1.8 root 597: return bRet;
1.1 root 598: }
599:
1.1.1.5 root 600:
1.1.1.2 root 601: /*-----------------------------------------------------------------------*/
1.1 root 602: /*
603: End sound recording
604: */
1.1.1.7 root 605: void Sound_EndRecording(void)
1.1 root 606: {
1.1.1.2 root 607: /* Stop sound recording and close files */
1.1 root 608: if (bRecordingYM)
1.1.1.4 root 609: YMFormat_EndRecording();
1.1 root 610: if (bRecordingWav)
1.1.1.4 root 611: WAVFormat_CloseFile();
1.1 root 612: }
613:
1.1.1.6 root 614:
1.1.1.2 root 615: /*-----------------------------------------------------------------------*/
1.1 root 616: /*
617: Are we recording sound data?
618: */
619: BOOL Sound_AreWeRecording(void)
620: {
621: return(bRecordingYM || bRecordingWav);
622: }
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