1 | /* |
2 | * GUSEMU32 - mixing engine (similar to Interwave GF1 compatibility) |
3 | * |
4 | * Copyright (C) 2000-2007 Tibor "TS" Schütz |
5 | * |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
7 | * of this software and associated documentation files (the "Software"), to deal |
8 | * in the Software without restriction, including without limitation the rights |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
10 | * copies of the Software, and to permit persons to whom the Software is |
11 | * furnished to do so, subject to the following conditions: |
12 | * |
13 | * The above copyright notice and this permission notice shall be included in |
14 | * all copies or substantial portions of the Software. |
15 | * |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
22 | * THE SOFTWARE. |
23 | */ |
24 | |
25 | #include "qemu/osdep.h" |
26 | #include "gusemu.h" |
27 | #include "gustate.h" |
28 | |
29 | #define GUSregb(position) (* (gusptr+(position))) |
30 | #define GUSregw(position) (*(uint16_t *) (gusptr+(position))) |
31 | #define GUSregd(position) (*(uint16_t *)(gusptr+(position))) |
32 | |
33 | #define GUSvoice(position) (*(uint16_t *)(voiceptr+(position))) |
34 | |
35 | /* samples are always 16bit stereo (4 bytes each, first right then left interleaved) */ |
36 | void gus_mixvoices(GUSEmuState * state, unsigned int playback_freq, unsigned int numsamples, |
37 | int16_t *bufferpos) |
38 | { |
39 | /* note that byte registers are stored in the upper half of each voice register! */ |
40 | uint8_t *gusptr; |
41 | int Voice; |
42 | uint16_t *voiceptr; |
43 | |
44 | unsigned int count; |
45 | for (count = 0; count < numsamples * 2; count++) |
46 | *(bufferpos + count) = 0; /* clear */ |
47 | |
48 | gusptr = state->gusdatapos; |
49 | voiceptr = (uint16_t *) gusptr; |
50 | if (!(GUSregb(GUS4cReset) & 0x01)) /* reset flag active? */ |
51 | return; |
52 | |
53 | for (Voice = 0; Voice <= (GUSregb(NumVoices) & 31); Voice++) |
54 | { |
55 | if (GUSvoice(wVSRControl) & 0x200) |
56 | GUSvoice(wVSRControl) |= 0x100; /* voice stop request */ |
57 | if (GUSvoice(wVSRVolRampControl) & 0x200) |
58 | GUSvoice(wVSRVolRampControl) |= 0x100; /* Volume ramp stop request */ |
59 | if (!(GUSvoice(wVSRControl) & GUSvoice(wVSRVolRampControl) & 0x100)) /* neither voice nor volume calculation active - save some time here ;) */ |
60 | { |
61 | unsigned int sample; |
62 | |
63 | unsigned int LoopStart = (GUSvoice(wVSRLoopStartHi) << 16) | GUSvoice(wVSRLoopStartLo); /* 23.9 format */ |
64 | unsigned int LoopEnd = (GUSvoice(wVSRLoopEndHi) << 16) | GUSvoice(wVSRLoopEndLo); /* 23.9 format */ |
65 | unsigned int CurrPos = (GUSvoice(wVSRCurrPosHi) << 16) | GUSvoice(wVSRCurrPosLo); /* 23.9 format */ |
66 | int VoiceIncrement = ((((unsigned long) GUSvoice(wVSRFreq) * 44100) / playback_freq) * (14 >> 1)) / |
67 | ((GUSregb(NumVoices) & 31) + 1); /* 6.10 increment/frame to 23.9 increment/sample */ |
68 | |
69 | int PanningPos = (GUSvoice(wVSRPanning) >> 8) & 0xf; |
70 | |
71 | unsigned int Volume32 = 32 * GUSvoice(wVSRCurrVol); /* 32 times larger than original gus for maintaining precision while ramping */ |
72 | unsigned int StartVol32 = (GUSvoice(wVSRVolRampStartVol) & 0xff00) * 32; |
73 | unsigned int EndVol32 = (GUSvoice(wVSRVolRampEndVol) & 0xff00) * 32; |
74 | int VolumeIncrement32 = (32 * 16 * (GUSvoice(wVSRVolRampRate) & 0x3f00) >> 8) >> ((((GUSvoice(wVSRVolRampRate) & 0xc000) >> 8) >> 6) * 3); /* including 1/8/64/512 volume speed divisor */ |
75 | VolumeIncrement32 = (((VolumeIncrement32 * 44100 / 2) / playback_freq) * 14) / ((GUSregb(NumVoices) & 31) + 1); /* adjust ramping speed to playback speed */ |
76 | |
77 | if (GUSvoice(wVSRControl) & 0x4000) |
78 | VoiceIncrement = -VoiceIncrement; /* reverse playback */ |
79 | if (GUSvoice(wVSRVolRampControl) & 0x4000) |
80 | VolumeIncrement32 = -VolumeIncrement32; /* reverse ramping */ |
81 | |
82 | for (sample = 0; sample < numsamples; sample++) |
83 | { |
84 | int sample1, sample2, Volume; |
85 | if (GUSvoice(wVSRControl) & 0x400) /* 16bit */ |
86 | { |
87 | int offset = ((CurrPos >> 9) & 0xc0000) + (((CurrPos >> 9) & 0x1ffff) << 1); |
88 | int8_t *adr; |
89 | adr = (int8_t *) state->himemaddr + offset; |
90 | sample1 = (*adr & 0xff) + (*(adr + 1) * 256); |
91 | sample2 = (*(adr + 2) & 0xff) + (*(adr + 2 + 1) * 256); |
92 | } |
93 | else /* 8bit */ |
94 | { |
95 | int offset = (CurrPos >> 9) & 0xfffff; |
96 | int8_t *adr; |
97 | adr = (int8_t *) state->himemaddr + offset; |
98 | sample1 = (*adr) * 256; |
99 | sample2 = (*(adr + 1)) * 256; |
100 | } |
101 | |
102 | Volume = ((((Volume32 >> (4 + 5)) & 0xff) + 256) << (Volume32 >> ((4 + 8) + 5))) / 512; /* semi-logarithmic volume, +5 due to additional precision */ |
103 | sample1 = (((sample1 * Volume) >> 16) * (512 - (CurrPos % 512))) / 512; |
104 | sample2 = (((sample2 * Volume) >> 16) * (CurrPos % 512)) / 512; |
105 | sample1 += sample2; |
106 | |
107 | if (!(GUSvoice(wVSRVolRampControl) & 0x100)) |
108 | { |
109 | Volume32 += VolumeIncrement32; |
110 | if ((GUSvoice(wVSRVolRampControl) & 0x4000) ? (Volume32 <= StartVol32) : (Volume32 >= EndVol32)) /* ramp up boundary cross */ |
111 | { |
112 | if (GUSvoice(wVSRVolRampControl) & 0x2000) |
113 | GUSvoice(wVSRVolRampControl) |= 0x8000; /* volramp IRQ enabled? -> IRQ wait flag */ |
114 | if (GUSvoice(wVSRVolRampControl) & 0x800) /* loop enabled */ |
115 | { |
116 | if (GUSvoice(wVSRVolRampControl) & 0x1000) /* bidir. loop */ |
117 | { |
118 | GUSvoice(wVSRVolRampControl) ^= 0x4000; /* toggle dir */ |
119 | VolumeIncrement32 = -VolumeIncrement32; |
120 | } |
121 | else |
122 | Volume32 = (GUSvoice(wVSRVolRampControl) & 0x4000) ? EndVol32 : StartVol32; /* unidir. loop ramp */ |
123 | } |
124 | else |
125 | { |
126 | GUSvoice(wVSRVolRampControl) |= 0x100; |
127 | Volume32 = |
128 | (GUSvoice(wVSRVolRampControl) & 0x4000) ? StartVol32 : EndVol32; |
129 | } |
130 | } |
131 | } |
132 | if ((GUSvoice(wVSRVolRampControl) & 0xa000) == 0xa000) /* volramp IRQ set and enabled? */ |
133 | { |
134 | GUSregd(voicevolrampirq) |= 1 << Voice; /* set irq slot */ |
135 | } |
136 | else |
137 | { |
138 | GUSregd(voicevolrampirq) &= (~(1 << Voice)); /* clear irq slot */ |
139 | GUSvoice(wVSRVolRampControl) &= 0x7f00; |
140 | } |
141 | |
142 | if (!(GUSvoice(wVSRControl) & 0x100)) |
143 | { |
144 | CurrPos += VoiceIncrement; |
145 | if ((GUSvoice(wVSRControl) & 0x4000) ? (CurrPos <= LoopStart) : (CurrPos >= LoopEnd)) /* playback boundary cross */ |
146 | { |
147 | if (GUSvoice(wVSRControl) & 0x2000) |
148 | GUSvoice(wVSRControl) |= 0x8000; /* voice IRQ enabled -> IRQ wait flag */ |
149 | if (GUSvoice(wVSRControl) & 0x800) /* loop enabled */ |
150 | { |
151 | if (GUSvoice(wVSRControl) & 0x1000) /* pingpong loop */ |
152 | { |
153 | GUSvoice(wVSRControl) ^= 0x4000; /* toggle dir */ |
154 | VoiceIncrement = -VoiceIncrement; |
155 | } |
156 | else |
157 | CurrPos = (GUSvoice(wVSRControl) & 0x4000) ? LoopEnd : LoopStart; /* unidir. loop */ |
158 | } |
159 | else if (!(GUSvoice(wVSRVolRampControl) & 0x400)) |
160 | GUSvoice(wVSRControl) |= 0x100; /* loop disabled, rollover check */ |
161 | } |
162 | } |
163 | if ((GUSvoice(wVSRControl) & 0xa000) == 0xa000) /* wavetable IRQ set and enabled? */ |
164 | { |
165 | GUSregd(voicewavetableirq) |= 1 << Voice; /* set irq slot */ |
166 | } |
167 | else |
168 | { |
169 | GUSregd(voicewavetableirq) &= (~(1 << Voice)); /* clear irq slot */ |
170 | GUSvoice(wVSRControl) &= 0x7f00; |
171 | } |
172 | |
173 | /* mix samples into buffer */ |
174 | *(bufferpos + 2 * sample) += (int16_t) ((sample1 * PanningPos) >> 4); /* right */ |
175 | *(bufferpos + 2 * sample + 1) += (int16_t) ((sample1 * (15 - PanningPos)) >> 4); /* left */ |
176 | } |
177 | /* write back voice and volume */ |
178 | GUSvoice(wVSRCurrVol) = Volume32 / 32; |
179 | GUSvoice(wVSRCurrPosHi) = CurrPos >> 16; |
180 | GUSvoice(wVSRCurrPosLo) = CurrPos & 0xffff; |
181 | } |
182 | voiceptr += 16; /* next voice */ |
183 | } |
184 | } |
185 | |
186 | void gus_irqgen(GUSEmuState * state, unsigned int elapsed_time) |
187 | /* time given in microseconds */ |
188 | { |
189 | int requestedIRQs = 0; |
190 | uint8_t *gusptr; |
191 | gusptr = state->gusdatapos; |
192 | if (GUSregb(TimerDataReg2x9) & 1) /* start timer 1 (80us decrement rate) */ |
193 | { |
194 | unsigned int timer1fraction = state->timer1fraction; |
195 | int newtimerirqs; |
196 | newtimerirqs = (elapsed_time + timer1fraction) / (80 * (256 - GUSregb(GUS46Counter1))); |
197 | state->timer1fraction = (elapsed_time + timer1fraction) % (80 * (256 - GUSregb(GUS46Counter1))); |
198 | if (newtimerirqs) |
199 | { |
200 | if (!(GUSregb(TimerDataReg2x9) & 0x40)) |
201 | GUSregb(TimerStatus2x8) |= 0xc0; /* maskable bits */ |
202 | if (GUSregb(GUS45TimerCtrl) & 4) /* timer1 irq enable */ |
203 | { |
204 | GUSregb(TimerStatus2x8) |= 4; /* nonmaskable bit */ |
205 | GUSregb(IRQStatReg2x6) |= 4; /* timer 1 irq pending */ |
206 | GUSregw(TimerIRQs) += newtimerirqs; |
207 | requestedIRQs += newtimerirqs; |
208 | } |
209 | } |
210 | } |
211 | if (GUSregb(TimerDataReg2x9) & 2) /* start timer 2 (320us decrement rate) */ |
212 | { |
213 | unsigned int timer2fraction = state->timer2fraction; |
214 | int newtimerirqs; |
215 | newtimerirqs = (elapsed_time + timer2fraction) / (320 * (256 - GUSregb(GUS47Counter2))); |
216 | state->timer2fraction = (elapsed_time + timer2fraction) % (320 * (256 - GUSregb(GUS47Counter2))); |
217 | if (newtimerirqs) |
218 | { |
219 | if (!(GUSregb(TimerDataReg2x9) & 0x20)) |
220 | GUSregb(TimerStatus2x8) |= 0xa0; /* maskable bits */ |
221 | if (GUSregb(GUS45TimerCtrl) & 8) /* timer2 irq enable */ |
222 | { |
223 | GUSregb(TimerStatus2x8) |= 2; /* nonmaskable bit */ |
224 | GUSregb(IRQStatReg2x6) |= 8; /* timer 2 irq pending */ |
225 | GUSregw(TimerIRQs) += newtimerirqs; |
226 | requestedIRQs += newtimerirqs; |
227 | } |
228 | } |
229 | } |
230 | if (GUSregb(GUS4cReset) & 0x4) /* synth IRQ enable */ |
231 | { |
232 | if (GUSregd(voicewavetableirq)) |
233 | GUSregb(IRQStatReg2x6) |= 0x20; |
234 | if (GUSregd(voicevolrampirq)) |
235 | GUSregb(IRQStatReg2x6) |= 0x40; |
236 | } |
237 | if ((!requestedIRQs) && GUSregb(IRQStatReg2x6)) |
238 | requestedIRQs++; |
239 | if (GUSregb(IRQStatReg2x6)) |
240 | GUSregw(BusyTimerIRQs) = GUS_irqrequest(state, state->gusirq, requestedIRQs); |
241 | } |
242 | |