root / hw / gusemu_mixer.c @ 5703c174
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1 | 423d65f4 | balrog | /*
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2 | 423d65f4 | balrog | * GUSEMU32 - mixing engine (similar to Interwave GF1 compatibility)
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3 | 423d65f4 | balrog | *
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4 | 423d65f4 | balrog | * Copyright (C) 2000-2007 Tibor "TS" Schütz
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5 | 423d65f4 | balrog | *
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6 | 423d65f4 | balrog | * Permission is hereby granted, free of charge, to any person obtaining a copy
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7 | 423d65f4 | balrog | * of this software and associated documentation files (the "Software"), to deal
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8 | 423d65f4 | balrog | * in the Software without restriction, including without limitation the rights
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9 | 423d65f4 | balrog | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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10 | 423d65f4 | balrog | * copies of the Software, and to permit persons to whom the Software is
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11 | 423d65f4 | balrog | * furnished to do so, subject to the following conditions:
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12 | 423d65f4 | balrog | *
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13 | 423d65f4 | balrog | * The above copyright notice and this permission notice shall be included in
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14 | 423d65f4 | balrog | * all copies or substantial portions of the Software.
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15 | 423d65f4 | balrog | *
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16 | 423d65f4 | balrog | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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17 | 423d65f4 | balrog | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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18 | 423d65f4 | balrog | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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19 | 423d65f4 | balrog | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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20 | 423d65f4 | balrog | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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21 | 423d65f4 | balrog | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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22 | 423d65f4 | balrog | * THE SOFTWARE.
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23 | 423d65f4 | balrog | */
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24 | 423d65f4 | balrog | |
25 | 423d65f4 | balrog | #include "gusemu.h" |
26 | 423d65f4 | balrog | #include "gustate.h" |
27 | 423d65f4 | balrog | |
28 | 423d65f4 | balrog | #define GUSregb(position) (* (gusptr+(position)))
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29 | 423d65f4 | balrog | #define GUSregw(position) (*(GUSword *) (gusptr+(position)))
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30 | 423d65f4 | balrog | #define GUSregd(position) (*(GUSdword *)(gusptr+(position)))
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31 | 423d65f4 | balrog | |
32 | 423d65f4 | balrog | #define GUSvoice(position) (*(GUSword *)(voiceptr+(position)))
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33 | 423d65f4 | balrog | |
34 | 423d65f4 | balrog | /* samples are always 16bit stereo (4 bytes each, first right then left interleaved) */
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35 | 423d65f4 | balrog | void gus_mixvoices(GUSEmuState * state, unsigned int playback_freq, unsigned int numsamples, |
36 | 731ba0ce | malc | GUSsample *bufferpos) |
37 | 423d65f4 | balrog | { |
38 | 423d65f4 | balrog | /* note that byte registers are stored in the upper half of each voice register! */
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39 | 423d65f4 | balrog | GUSbyte *gusptr; |
40 | 423d65f4 | balrog | int Voice;
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41 | 423d65f4 | balrog | GUSword *voiceptr; |
42 | 423d65f4 | balrog | |
43 | 423d65f4 | balrog | unsigned int count; |
44 | 423d65f4 | balrog | for (count = 0; count < numsamples * 2; count++) |
45 | 423d65f4 | balrog | *(bufferpos + count) = 0; /* clear */ |
46 | 423d65f4 | balrog | |
47 | 423d65f4 | balrog | gusptr = state->gusdatapos; |
48 | 423d65f4 | balrog | voiceptr = (GUSword *) gusptr; |
49 | 423d65f4 | balrog | if (!(GUSregb(GUS4cReset) & 0x01)) /* reset flag active? */ |
50 | 423d65f4 | balrog | return;
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51 | 423d65f4 | balrog | |
52 | 423d65f4 | balrog | for (Voice = 0; Voice <= (GUSregb(NumVoices) & 31); Voice++) |
53 | 423d65f4 | balrog | { |
54 | 423d65f4 | balrog | if (GUSvoice(wVSRControl) & 0x200) |
55 | 423d65f4 | balrog | GUSvoice(wVSRControl) |= 0x100; /* voice stop request */ |
56 | 423d65f4 | balrog | if (GUSvoice(wVSRVolRampControl) & 0x200) |
57 | 423d65f4 | balrog | GUSvoice(wVSRVolRampControl) |= 0x100; /* Volume ramp stop request */ |
58 | 423d65f4 | balrog | if (!(GUSvoice(wVSRControl) & GUSvoice(wVSRVolRampControl) & 0x100)) /* neither voice nor volume calculation active - save some time here ;) */ |
59 | 423d65f4 | balrog | { |
60 | 423d65f4 | balrog | unsigned int sample; |
61 | 423d65f4 | balrog | |
62 | 423d65f4 | balrog | unsigned int LoopStart = (GUSvoice(wVSRLoopStartHi) << 16) | GUSvoice(wVSRLoopStartLo); /* 23.9 format */ |
63 | 423d65f4 | balrog | unsigned int LoopEnd = (GUSvoice(wVSRLoopEndHi) << 16) | GUSvoice(wVSRLoopEndLo); /* 23.9 format */ |
64 | 423d65f4 | balrog | unsigned int CurrPos = (GUSvoice(wVSRCurrPosHi) << 16) | GUSvoice(wVSRCurrPosLo); /* 23.9 format */ |
65 | 423d65f4 | balrog | int VoiceIncrement = ((((unsigned long) GUSvoice(wVSRFreq) * 44100) / playback_freq) * (14 >> 1)) / |
66 | 423d65f4 | balrog | ((GUSregb(NumVoices) & 31) + 1); /* 6.10 increment/frame to 23.9 increment/sample */ |
67 | 423d65f4 | balrog | |
68 | 423d65f4 | balrog | int PanningPos = (GUSvoice(wVSRPanning) >> 8) & 0xf; |
69 | 423d65f4 | balrog | |
70 | 423d65f4 | balrog | unsigned int Volume32 = 32 * GUSvoice(wVSRCurrVol); /* 32 times larger than original gus for maintaining precision while ramping */ |
71 | 423d65f4 | balrog | unsigned int StartVol32 = (GUSvoice(wVSRVolRampStartVol) & 0xff00) * 32; |
72 | 423d65f4 | balrog | unsigned int EndVol32 = (GUSvoice(wVSRVolRampEndVol) & 0xff00) * 32; |
73 | 423d65f4 | balrog | int VolumeIncrement32 = (32 * 16 * (GUSvoice(wVSRVolRampRate) & 0x3f00) >> 8) >> ((((GUSvoice(wVSRVolRampRate) & 0xc000) >> 8) >> 6) * 3); /* including 1/8/64/512 volume speed divisor */ |
74 | 423d65f4 | balrog | VolumeIncrement32 = (((VolumeIncrement32 * 44100 / 2) / playback_freq) * 14) / ((GUSregb(NumVoices) & 31) + 1); /* adjust ramping speed to playback speed */ |
75 | 423d65f4 | balrog | |
76 | 423d65f4 | balrog | if (GUSvoice(wVSRControl) & 0x4000) |
77 | 423d65f4 | balrog | VoiceIncrement = -VoiceIncrement; /* reverse playback */
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78 | 423d65f4 | balrog | if (GUSvoice(wVSRVolRampControl) & 0x4000) |
79 | 423d65f4 | balrog | VolumeIncrement32 = -VolumeIncrement32; /* reverse ramping */
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80 | 423d65f4 | balrog | |
81 | 423d65f4 | balrog | for (sample = 0; sample < numsamples; sample++) |
82 | 423d65f4 | balrog | { |
83 | 423d65f4 | balrog | int sample1, sample2, Volume;
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84 | 423d65f4 | balrog | if (GUSvoice(wVSRControl) & 0x400) /* 16bit */ |
85 | 423d65f4 | balrog | { |
86 | 423d65f4 | balrog | int offset = ((CurrPos >> 9) & 0xc0000) + (((CurrPos >> 9) & 0x1ffff) << 1); |
87 | 423d65f4 | balrog | GUSchar *adr; |
88 | 423d65f4 | balrog | adr = (GUSchar *) state->himemaddr + offset; |
89 | 423d65f4 | balrog | sample1 = (*adr & 0xff) + (*(adr + 1) * 256); |
90 | 423d65f4 | balrog | sample2 = (*(adr + 2) & 0xff) + (*(adr + 2 + 1) * 256); |
91 | 423d65f4 | balrog | } |
92 | 423d65f4 | balrog | else /* 8bit */ |
93 | 423d65f4 | balrog | { |
94 | 423d65f4 | balrog | int offset = (CurrPos >> 9) & 0xfffff; |
95 | 423d65f4 | balrog | GUSchar *adr; |
96 | 423d65f4 | balrog | adr = (GUSchar *) state->himemaddr + offset; |
97 | 423d65f4 | balrog | sample1 = (*adr) * 256;
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98 | 423d65f4 | balrog | sample2 = (*(adr + 1)) * 256; |
99 | 423d65f4 | balrog | } |
100 | 423d65f4 | balrog | |
101 | 423d65f4 | balrog | Volume = ((((Volume32 >> (4 + 5)) & 0xff) + 256) << (Volume32 >> ((4 + 8) + 5))) / 512; /* semi-logarithmic volume, +5 due to additional precision */ |
102 | 423d65f4 | balrog | sample1 = (((sample1 * Volume) >> 16) * (512 - (CurrPos % 512))) / 512; |
103 | 423d65f4 | balrog | sample2 = (((sample2 * Volume) >> 16) * (CurrPos % 512)) / 512; |
104 | 423d65f4 | balrog | sample1 += sample2; |
105 | 423d65f4 | balrog | |
106 | 423d65f4 | balrog | if (!(GUSvoice(wVSRVolRampControl) & 0x100)) |
107 | 423d65f4 | balrog | { |
108 | 423d65f4 | balrog | Volume32 += VolumeIncrement32; |
109 | 423d65f4 | balrog | if ((GUSvoice(wVSRVolRampControl) & 0x4000) ? (Volume32 <= StartVol32) : (Volume32 >= EndVol32)) /* ramp up boundary cross */ |
110 | 423d65f4 | balrog | { |
111 | 423d65f4 | balrog | if (GUSvoice(wVSRVolRampControl) & 0x2000) |
112 | 423d65f4 | balrog | GUSvoice(wVSRVolRampControl) |= 0x8000; /* volramp IRQ enabled? -> IRQ wait flag */ |
113 | 423d65f4 | balrog | if (GUSvoice(wVSRVolRampControl) & 0x800) /* loop enabled */ |
114 | 423d65f4 | balrog | { |
115 | 423d65f4 | balrog | if (GUSvoice(wVSRVolRampControl) & 0x1000) /* bidir. loop */ |
116 | 423d65f4 | balrog | { |
117 | 423d65f4 | balrog | GUSvoice(wVSRVolRampControl) ^= 0x4000; /* toggle dir */ |
118 | 423d65f4 | balrog | VolumeIncrement32 = -VolumeIncrement32; |
119 | 423d65f4 | balrog | } |
120 | 423d65f4 | balrog | else
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121 | 423d65f4 | balrog | Volume32 = (GUSvoice(wVSRVolRampControl) & 0x4000) ? EndVol32 : StartVol32; /* unidir. loop ramp */ |
122 | 423d65f4 | balrog | } |
123 | 423d65f4 | balrog | else
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124 | 423d65f4 | balrog | { |
125 | 423d65f4 | balrog | GUSvoice(wVSRVolRampControl) |= 0x100;
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126 | 423d65f4 | balrog | Volume32 = |
127 | 423d65f4 | balrog | (GUSvoice(wVSRVolRampControl) & 0x4000) ? StartVol32 : EndVol32;
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128 | 423d65f4 | balrog | } |
129 | 423d65f4 | balrog | } |
130 | 423d65f4 | balrog | } |
131 | 423d65f4 | balrog | if ((GUSvoice(wVSRVolRampControl) & 0xa000) == 0xa000) /* volramp IRQ set and enabled? */ |
132 | 423d65f4 | balrog | { |
133 | 423d65f4 | balrog | GUSregd(voicevolrampirq) |= 1 << Voice; /* set irq slot */ |
134 | 423d65f4 | balrog | } |
135 | 423d65f4 | balrog | else
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136 | 423d65f4 | balrog | { |
137 | 423d65f4 | balrog | GUSregd(voicevolrampirq) &= (~(1 << Voice)); /* clear irq slot */ |
138 | 423d65f4 | balrog | GUSvoice(wVSRVolRampControl) &= 0x7f00;
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139 | 423d65f4 | balrog | } |
140 | 423d65f4 | balrog | |
141 | 423d65f4 | balrog | if (!(GUSvoice(wVSRControl) & 0x100)) |
142 | 423d65f4 | balrog | { |
143 | 423d65f4 | balrog | CurrPos += VoiceIncrement; |
144 | 423d65f4 | balrog | if ((GUSvoice(wVSRControl) & 0x4000) ? (CurrPos <= LoopStart) : (CurrPos >= LoopEnd)) /* playback boundary cross */ |
145 | 423d65f4 | balrog | { |
146 | 423d65f4 | balrog | if (GUSvoice(wVSRControl) & 0x2000) |
147 | 423d65f4 | balrog | GUSvoice(wVSRControl) |= 0x8000; /* voice IRQ enabled -> IRQ wait flag */ |
148 | 423d65f4 | balrog | if (GUSvoice(wVSRControl) & 0x800) /* loop enabled */ |
149 | 423d65f4 | balrog | { |
150 | 423d65f4 | balrog | if (GUSvoice(wVSRControl) & 0x1000) /* pingpong loop */ |
151 | 423d65f4 | balrog | { |
152 | 423d65f4 | balrog | GUSvoice(wVSRControl) ^= 0x4000; /* toggle dir */ |
153 | 423d65f4 | balrog | VoiceIncrement = -VoiceIncrement; |
154 | 423d65f4 | balrog | } |
155 | 423d65f4 | balrog | else
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156 | 423d65f4 | balrog | CurrPos = (GUSvoice(wVSRControl) & 0x4000) ? LoopEnd : LoopStart; /* unidir. loop */ |
157 | 423d65f4 | balrog | } |
158 | 423d65f4 | balrog | else if (!(GUSvoice(wVSRVolRampControl) & 0x400)) |
159 | 423d65f4 | balrog | GUSvoice(wVSRControl) |= 0x100; /* loop disabled, rollover check */ |
160 | 423d65f4 | balrog | } |
161 | 423d65f4 | balrog | } |
162 | 423d65f4 | balrog | if ((GUSvoice(wVSRControl) & 0xa000) == 0xa000) /* wavetable IRQ set and enabled? */ |
163 | 423d65f4 | balrog | { |
164 | 423d65f4 | balrog | GUSregd(voicewavetableirq) |= 1 << Voice; /* set irq slot */ |
165 | 423d65f4 | balrog | } |
166 | 423d65f4 | balrog | else
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167 | 423d65f4 | balrog | { |
168 | 423d65f4 | balrog | GUSregd(voicewavetableirq) &= (~(1 << Voice)); /* clear irq slot */ |
169 | 423d65f4 | balrog | GUSvoice(wVSRControl) &= 0x7f00;
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170 | 423d65f4 | balrog | } |
171 | 423d65f4 | balrog | |
172 | 423d65f4 | balrog | /* mix samples into buffer */
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173 | 731ba0ce | malc | *(bufferpos + 2 * sample) += (GUSsample) ((sample1 * PanningPos) >> 4); /* right */ |
174 | 731ba0ce | malc | *(bufferpos + 2 * sample + 1) += (GUSsample) ((sample1 * (15 - PanningPos)) >> 4); /* left */ |
175 | 423d65f4 | balrog | } |
176 | 423d65f4 | balrog | /* write back voice and volume */
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177 | 423d65f4 | balrog | GUSvoice(wVSRCurrVol) = Volume32 / 32;
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178 | 423d65f4 | balrog | GUSvoice(wVSRCurrPosHi) = CurrPos >> 16;
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179 | 423d65f4 | balrog | GUSvoice(wVSRCurrPosLo) = CurrPos & 0xffff;
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180 | 423d65f4 | balrog | } |
181 | 423d65f4 | balrog | voiceptr += 16; /* next voice */ |
182 | 423d65f4 | balrog | } |
183 | 423d65f4 | balrog | } |
184 | 423d65f4 | balrog | |
185 | 423d65f4 | balrog | void gus_irqgen(GUSEmuState * state, unsigned int elapsed_time) |
186 | 423d65f4 | balrog | /* time given in microseconds */
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187 | 423d65f4 | balrog | { |
188 | 423d65f4 | balrog | int requestedIRQs = 0; |
189 | 423d65f4 | balrog | GUSbyte *gusptr; |
190 | 423d65f4 | balrog | gusptr = state->gusdatapos; |
191 | 423d65f4 | balrog | if (GUSregb(TimerDataReg2x9) & 1) /* start timer 1 (80us decrement rate) */ |
192 | 423d65f4 | balrog | { |
193 | 423d65f4 | balrog | unsigned int timer1fraction = state->timer1fraction; |
194 | 423d65f4 | balrog | int newtimerirqs;
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195 | 423d65f4 | balrog | newtimerirqs = (elapsed_time + timer1fraction) / (80 * (256 - GUSregb(GUS46Counter1))); |
196 | 423d65f4 | balrog | state->timer1fraction = (elapsed_time + timer1fraction) % (80 * (256 - GUSregb(GUS46Counter1))); |
197 | 423d65f4 | balrog | if (newtimerirqs)
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198 | 423d65f4 | balrog | { |
199 | 423d65f4 | balrog | if (!(GUSregb(TimerDataReg2x9) & 0x40)) |
200 | 423d65f4 | balrog | GUSregb(TimerStatus2x8) |= 0xc0; /* maskable bits */ |
201 | 423d65f4 | balrog | if (GUSregb(GUS45TimerCtrl) & 4) /* timer1 irq enable */ |
202 | 423d65f4 | balrog | { |
203 | 423d65f4 | balrog | GUSregb(TimerStatus2x8) |= 4; /* nonmaskable bit */ |
204 | 423d65f4 | balrog | GUSregb(IRQStatReg2x6) |= 4; /* timer 1 irq pending */ |
205 | 423d65f4 | balrog | GUSregw(TimerIRQs) += newtimerirqs; |
206 | 423d65f4 | balrog | requestedIRQs += newtimerirqs; |
207 | 423d65f4 | balrog | } |
208 | 423d65f4 | balrog | } |
209 | 423d65f4 | balrog | } |
210 | 423d65f4 | balrog | if (GUSregb(TimerDataReg2x9) & 2) /* start timer 2 (320us decrement rate) */ |
211 | 423d65f4 | balrog | { |
212 | 423d65f4 | balrog | unsigned int timer2fraction = state->timer2fraction; |
213 | 423d65f4 | balrog | int newtimerirqs;
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214 | 423d65f4 | balrog | newtimerirqs = (elapsed_time + timer2fraction) / (320 * (256 - GUSregb(GUS47Counter2))); |
215 | 423d65f4 | balrog | state->timer2fraction = (elapsed_time + timer2fraction) % (320 * (256 - GUSregb(GUS47Counter2))); |
216 | 423d65f4 | balrog | if (newtimerirqs)
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217 | 423d65f4 | balrog | { |
218 | 423d65f4 | balrog | if (!(GUSregb(TimerDataReg2x9) & 0x20)) |
219 | 423d65f4 | balrog | GUSregb(TimerStatus2x8) |= 0xa0; /* maskable bits */ |
220 | 423d65f4 | balrog | if (GUSregb(GUS45TimerCtrl) & 8) /* timer2 irq enable */ |
221 | 423d65f4 | balrog | { |
222 | 423d65f4 | balrog | GUSregb(TimerStatus2x8) |= 2; /* nonmaskable bit */ |
223 | 423d65f4 | balrog | GUSregb(IRQStatReg2x6) |= 8; /* timer 2 irq pending */ |
224 | 423d65f4 | balrog | GUSregw(TimerIRQs) += newtimerirqs; |
225 | 423d65f4 | balrog | requestedIRQs += newtimerirqs; |
226 | 423d65f4 | balrog | } |
227 | 423d65f4 | balrog | } |
228 | 423d65f4 | balrog | } |
229 | 423d65f4 | balrog | if (GUSregb(GUS4cReset) & 0x4) /* synth IRQ enable */ |
230 | 423d65f4 | balrog | { |
231 | 423d65f4 | balrog | if (GUSregd(voicewavetableirq))
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232 | 423d65f4 | balrog | GUSregb(IRQStatReg2x6) |= 0x20;
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233 | 423d65f4 | balrog | if (GUSregd(voicevolrampirq))
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234 | 423d65f4 | balrog | GUSregb(IRQStatReg2x6) |= 0x40;
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235 | 423d65f4 | balrog | } |
236 | 423d65f4 | balrog | if ((!requestedIRQs) && GUSregb(IRQStatReg2x6))
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237 | 423d65f4 | balrog | requestedIRQs++; |
238 | 423d65f4 | balrog | if (GUSregb(IRQStatReg2x6))
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239 | 423d65f4 | balrog | GUSregw(BusyTimerIRQs) = GUS_irqrequest(state, state->gusirq, requestedIRQs); |
240 | 423d65f4 | balrog | } |