 731ba0cec2
			
		
	
	
		731ba0cec2
		
	
	
	
	
		
			
			git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4696 c046a42c-6fe2-441c-8c8c-71466251a162
		
			
				
	
	
		
			241 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			241 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * GUSEMU32 - mixing engine (similar to Interwave GF1 compatibility)
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|  *
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|  * Copyright (C) 2000-2007 Tibor "TS" Schütz
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|  *
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|  * Permission is hereby granted, free of charge, to any person obtaining a copy
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|  * of this software and associated documentation files (the "Software"), to deal
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|  * in the Software without restriction, including without limitation the rights
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|  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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|  * copies of the Software, and to permit persons to whom the Software is
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|  * furnished to do so, subject to the following conditions:
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|  *
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|  * The above copyright notice and this permission notice shall be included in
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|  * all copies or substantial portions of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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|  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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|  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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|  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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|  * THE SOFTWARE.
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|  */
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| 
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| #include "gusemu.h"
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| #include "gustate.h"
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| 
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| #define GUSregb(position)  (*            (gusptr+(position)))
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| #define GUSregw(position)  (*(GUSword *) (gusptr+(position)))
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| #define GUSregd(position)  (*(GUSdword *)(gusptr+(position)))
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| 
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| #define GUSvoice(position) (*(GUSword *)(voiceptr+(position)))
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| 
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| /* samples are always 16bit stereo (4 bytes each, first right then left interleaved) */
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| void gus_mixvoices(GUSEmuState * state, unsigned int playback_freq, unsigned int numsamples,
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|                    GUSsample *bufferpos)
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| {
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|     /* note that byte registers are stored in the upper half of each voice register! */
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|     GUSbyte        *gusptr;
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|     int             Voice;
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|     GUSword        *voiceptr;
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| 
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|     unsigned int    count;
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|     for (count = 0; count < numsamples * 2; count++)
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|         *(bufferpos + count) = 0;       /* clear */
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| 
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|     gusptr = state->gusdatapos;
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|     voiceptr = (GUSword *) gusptr;
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|     if (!(GUSregb(GUS4cReset) & 0x01))  /* reset flag active? */
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|         return;
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| 
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|     for (Voice = 0; Voice <= (GUSregb(NumVoices) & 31); Voice++)
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|     {
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|         if (GUSvoice(wVSRControl)        &  0x200)
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|             GUSvoice(wVSRControl)        |= 0x100; /* voice stop request */
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|         if (GUSvoice(wVSRVolRampControl) &  0x200)
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|             GUSvoice(wVSRVolRampControl) |= 0x100; /* Volume ramp stop request */
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|         if (!(GUSvoice(wVSRControl) & GUSvoice(wVSRVolRampControl) & 0x100)) /* neither voice nor volume calculation active - save some time here ;) */
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|         {
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|             unsigned int    sample;
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| 
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|             unsigned int    LoopStart = (GUSvoice(wVSRLoopStartHi) << 16) | GUSvoice(wVSRLoopStartLo); /* 23.9 format */
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|             unsigned int    LoopEnd   = (GUSvoice(wVSRLoopEndHi)   << 16) | GUSvoice(wVSRLoopEndLo);   /* 23.9 format */
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|             unsigned int    CurrPos   = (GUSvoice(wVSRCurrPosHi)   << 16) | GUSvoice(wVSRCurrPosLo);   /* 23.9 format */
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|             int             VoiceIncrement = ((((unsigned long) GUSvoice(wVSRFreq) * 44100) / playback_freq) * (14 >> 1)) /
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|                                              ((GUSregb(NumVoices) & 31) + 1); /* 6.10 increment/frame to 23.9 increment/sample */
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| 
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|             int             PanningPos = (GUSvoice(wVSRPanning) >> 8) & 0xf;
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| 
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|             unsigned int    Volume32   = 32 * GUSvoice(wVSRCurrVol); /* 32 times larger than original gus for maintaining precision while ramping */
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|             unsigned int    StartVol32 = (GUSvoice(wVSRVolRampStartVol) & 0xff00) * 32;
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|             unsigned int    EndVol32   = (GUSvoice(wVSRVolRampEndVol)   & 0xff00) * 32;
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|             int             VolumeIncrement32 = (32 * 16 * (GUSvoice(wVSRVolRampRate) & 0x3f00) >> 8) >> ((((GUSvoice(wVSRVolRampRate) & 0xc000) >> 8) >> 6) * 3); /* including 1/8/64/512 volume speed divisor */
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|             VolumeIncrement32 = (((VolumeIncrement32 * 44100 / 2) / playback_freq) * 14) / ((GUSregb(NumVoices) & 31) + 1); /* adjust ramping speed to playback speed */
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| 
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|             if (GUSvoice(wVSRControl) & 0x4000)
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|                 VoiceIncrement    = -VoiceIncrement;    /* reverse playback */
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|             if (GUSvoice(wVSRVolRampControl) & 0x4000)
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|                 VolumeIncrement32 = -VolumeIncrement32; /* reverse ramping */
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| 
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|             for (sample = 0; sample < numsamples; sample++)
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|             {
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|                 int             sample1, sample2, Volume;
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|                 if (GUSvoice(wVSRControl) & 0x400)      /* 16bit */
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|                 {
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|                     int offset = ((CurrPos >> 9) & 0xc0000) + (((CurrPos >> 9) & 0x1ffff) << 1);
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|                     GUSchar *adr;
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|                     adr = (GUSchar *) state->himemaddr + offset;
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|                     sample1 = (*adr & 0xff) + (*(adr + 1) * 256);
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|                     sample2 = (*(adr + 2) & 0xff) + (*(adr + 2 + 1) * 256);
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|                 }
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|                 else            /* 8bit */
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|                 {
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|                     int offset = (CurrPos >> 9) & 0xfffff;
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|                     GUSchar *adr;
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|                     adr = (GUSchar *) state->himemaddr + offset;
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|                     sample1 = (*adr) * 256;
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|                     sample2 = (*(adr + 1)) * 256;
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|                 }
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| 
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|                 Volume = ((((Volume32 >> (4 + 5)) & 0xff) + 256) << (Volume32 >> ((4 + 8) + 5))) / 512; /* semi-logarithmic volume, +5 due to additional precision */
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|                 sample1 = (((sample1 * Volume) >> 16) * (512 - (CurrPos % 512))) / 512;
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|                 sample2 = (((sample2 * Volume) >> 16) * (CurrPos % 512)) / 512;
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|                 sample1 += sample2;
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| 
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|                 if (!(GUSvoice(wVSRVolRampControl) & 0x100))
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|                 {
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|                     Volume32 += VolumeIncrement32;
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|                     if ((GUSvoice(wVSRVolRampControl) & 0x4000) ? (Volume32 <= StartVol32) : (Volume32 >= EndVol32)) /* ramp up boundary cross */
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|                     {
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|                         if (GUSvoice(wVSRVolRampControl) & 0x2000)
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|                             GUSvoice(wVSRVolRampControl) |= 0x8000;     /* volramp IRQ enabled? -> IRQ wait flag */
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|                         if (GUSvoice(wVSRVolRampControl) & 0x800)       /* loop enabled */
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|                         {
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|                             if (GUSvoice(wVSRVolRampControl) & 0x1000)  /* bidir. loop */
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|                             {
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|                                 GUSvoice(wVSRVolRampControl) ^= 0x4000; /* toggle dir */
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|                                 VolumeIncrement32 = -VolumeIncrement32;
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|                             }
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|                             else
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|                                 Volume32 = (GUSvoice(wVSRVolRampControl) & 0x4000) ? EndVol32 : StartVol32; /* unidir. loop ramp */
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|                         }
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|                         else
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|                         {
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|                             GUSvoice(wVSRVolRampControl) |= 0x100;
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|                             Volume32 =
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|                                 (GUSvoice(wVSRVolRampControl) & 0x4000) ? StartVol32 : EndVol32;
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|                         }
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|                     }
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|                 }
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|                 if ((GUSvoice(wVSRVolRampControl) & 0xa000) == 0xa000)  /* volramp IRQ set and enabled? */
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|                 {
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|                     GUSregd(voicevolrampirq) |= 1 << Voice;             /* set irq slot */
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|                 }
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|                 else
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|                 {
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|                     GUSregd(voicevolrampirq) &= (~(1 << Voice));        /* clear irq slot */
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|                     GUSvoice(wVSRVolRampControl) &= 0x7f00;
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|                 }
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| 
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|                 if (!(GUSvoice(wVSRControl) & 0x100))
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|                 {
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|                     CurrPos += VoiceIncrement;
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|                     if ((GUSvoice(wVSRControl) & 0x4000) ? (CurrPos <= LoopStart) : (CurrPos >= LoopEnd)) /* playback boundary cross */
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|                     {
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|                         if (GUSvoice(wVSRControl) & 0x2000)
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|                             GUSvoice(wVSRControl) |= 0x8000;       /* voice IRQ enabled -> IRQ wait flag */
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|                         if (GUSvoice(wVSRControl) & 0x800)         /* loop enabled */
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|                         {
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|                             if (GUSvoice(wVSRControl) & 0x1000)    /* pingpong loop */
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|                             {
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|                                 GUSvoice(wVSRControl) ^= 0x4000;   /* toggle dir */
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|                                 VoiceIncrement = -VoiceIncrement;
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|                             }
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|                             else
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|                                 CurrPos = (GUSvoice(wVSRControl) & 0x4000) ? LoopEnd : LoopStart; /* unidir. loop */
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|                         }
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|                         else if (!(GUSvoice(wVSRVolRampControl) & 0x400))
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|                             GUSvoice(wVSRControl) |= 0x100;        /* loop disabled, rollover check */
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|                     }
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|                 }
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|                 if ((GUSvoice(wVSRControl) & 0xa000) == 0xa000)    /* wavetable IRQ set and enabled? */
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|                 {
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|                     GUSregd(voicewavetableirq) |= 1 << Voice;      /* set irq slot */
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|                 }
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|                 else
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|                 {
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|                     GUSregd(voicewavetableirq) &= (~(1 << Voice)); /* clear irq slot */
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|                     GUSvoice(wVSRControl) &= 0x7f00;
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|                 }
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| 
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|                 /* mix samples into buffer */
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|                 *(bufferpos + 2 * sample)     += (GUSsample) ((sample1 * PanningPos) >> 4);        /* right */
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|                 *(bufferpos + 2 * sample + 1) += (GUSsample) ((sample1 * (15 - PanningPos)) >> 4); /* left */
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|             }
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|             /* write back voice and volume */
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|             GUSvoice(wVSRCurrVol)   = Volume32 / 32;
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|             GUSvoice(wVSRCurrPosHi) = CurrPos >> 16;
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|             GUSvoice(wVSRCurrPosLo) = CurrPos & 0xffff;
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|         }
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|         voiceptr += 16; /* next voice */
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|     }
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| }
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| 
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| void gus_irqgen(GUSEmuState * state, unsigned int elapsed_time)
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| /* time given in microseconds */
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| {
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|     int             requestedIRQs = 0;
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|     GUSbyte        *gusptr;
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|     gusptr = state->gusdatapos;
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|     if (GUSregb(TimerDataReg2x9) & 1) /* start timer 1 (80us decrement rate) */
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|     {
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|         unsigned int    timer1fraction = state->timer1fraction;
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|         int             newtimerirqs;
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|         newtimerirqs          = (elapsed_time + timer1fraction) / (80 * (256 - GUSregb(GUS46Counter1)));
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|         state->timer1fraction = (elapsed_time + timer1fraction) % (80 * (256 - GUSregb(GUS46Counter1)));
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|         if (newtimerirqs)
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|         {
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|             if (!(GUSregb(TimerDataReg2x9) & 0x40))
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|                 GUSregb(TimerStatus2x8) |= 0xc0; /* maskable bits */
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|             if (GUSregb(GUS45TimerCtrl) & 4)     /* timer1 irq enable */
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|             {
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|                 GUSregb(TimerStatus2x8) |= 4;    /* nonmaskable bit */
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|                 GUSregb(IRQStatReg2x6)  |= 4;    /* timer 1 irq pending */
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|                 GUSregw(TimerIRQs) += newtimerirqs;
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|                 requestedIRQs += newtimerirqs;
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|             }
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|         }
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|     }
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|     if (GUSregb(TimerDataReg2x9) & 2) /* start timer 2 (320us decrement rate) */
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|     {
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|         unsigned int timer2fraction = state->timer2fraction;
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|         int             newtimerirqs;
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|         newtimerirqs          = (elapsed_time + timer2fraction) / (320 * (256 - GUSregb(GUS47Counter2)));
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|         state->timer2fraction = (elapsed_time + timer2fraction) % (320 * (256 - GUSregb(GUS47Counter2)));
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|         if (newtimerirqs)
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|         {
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|             if (!(GUSregb(TimerDataReg2x9) & 0x20))
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|                 GUSregb(TimerStatus2x8) |= 0xa0; /* maskable bits */
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|             if (GUSregb(GUS45TimerCtrl) & 8)     /* timer2 irq enable */
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|             {
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|                 GUSregb(TimerStatus2x8) |= 2;    /* nonmaskable bit */
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|                 GUSregb(IRQStatReg2x6)  |= 8;    /* timer 2 irq pending */
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|                 GUSregw(TimerIRQs) += newtimerirqs;
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|                 requestedIRQs += newtimerirqs;
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|             }
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|         }
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|     }
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|     if (GUSregb(GUS4cReset) & 0x4) /* synth IRQ enable */
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|     {
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|         if (GUSregd(voicewavetableirq))
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|             GUSregb(IRQStatReg2x6) |= 0x20;
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|         if (GUSregd(voicevolrampirq))
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|             GUSregb(IRQStatReg2x6) |= 0x40;
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|     }
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|     if ((!requestedIRQs) && GUSregb(IRQStatReg2x6))
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|         requestedIRQs++;
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|     if (GUSregb(IRQStatReg2x6))
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|         GUSregw(BusyTimerIRQs) = GUS_irqrequest(state, state->gusirq, requestedIRQs);
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| }
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