abe0ea43 |
1 | #include "../PicoInt.h" |
2 | #include "pcm.h" |
3 | |
4 | static unsigned int g_rate = 0; // 18.14 fixed point |
5 | |
6 | void pcm_write(unsigned int a, unsigned int d) |
7 | { |
8 | //printf("pcm_write(%i, %02x)\n", a, d); |
9 | |
10 | if (a < 7) |
11 | { |
12 | Pico_mcd->pcm.ch[Pico_mcd->pcm.cur_ch].regs[a] = d; |
13 | } |
14 | else if (a == 7) // control register |
15 | { |
16 | if (d & 0x40) Pico_mcd->pcm.cur_ch = d & 7; |
17 | else Pico_mcd->pcm.bank = d & 0xf; |
18 | Pico_mcd->pcm.control = d; |
19 | // dprintf("pcm control=%02x", Pico_mcd->pcm.control); |
20 | } |
21 | else if (a == 8) // sound on/off |
22 | { |
23 | if (!(Pico_mcd->pcm.enabled & 0x01)) Pico_mcd->pcm.ch[0].addr = |
24 | Pico_mcd->pcm.ch[0].regs[6] << (PCM_STEP_SHIFT + 8); |
25 | if (!(Pico_mcd->pcm.enabled & 0x02)) Pico_mcd->pcm.ch[1].addr = |
26 | Pico_mcd->pcm.ch[1].regs[6] << (PCM_STEP_SHIFT + 8); |
27 | if (!(Pico_mcd->pcm.enabled & 0x04)) Pico_mcd->pcm.ch[2].addr = |
28 | Pico_mcd->pcm.ch[2].regs[6] << (PCM_STEP_SHIFT + 8); |
29 | if (!(Pico_mcd->pcm.enabled & 0x08)) Pico_mcd->pcm.ch[3].addr = |
30 | Pico_mcd->pcm.ch[3].regs[6] << (PCM_STEP_SHIFT + 8); |
31 | if (!(Pico_mcd->pcm.enabled & 0x10)) Pico_mcd->pcm.ch[4].addr = |
32 | Pico_mcd->pcm.ch[4].regs[6] << (PCM_STEP_SHIFT + 8); |
33 | if (!(Pico_mcd->pcm.enabled & 0x20)) Pico_mcd->pcm.ch[5].addr = |
34 | Pico_mcd->pcm.ch[5].regs[6] << (PCM_STEP_SHIFT + 8); |
35 | if (!(Pico_mcd->pcm.enabled & 0x40)) Pico_mcd->pcm.ch[6].addr = |
36 | Pico_mcd->pcm.ch[6].regs[6] << (PCM_STEP_SHIFT + 8); |
37 | if (!(Pico_mcd->pcm.enabled & 0x80)) Pico_mcd->pcm.ch[7].addr = |
38 | Pico_mcd->pcm.ch[7].regs[6] << (PCM_STEP_SHIFT + 8); |
39 | // printf("addr %x %x %x %x %x %x %x %x\n", Pico_mcd->pcm.ch[0].addr, Pico_mcd->pcm.ch[1].addr |
40 | // , Pico_mcd->pcm.ch[2].addr, Pico_mcd->pcm.ch[3].addr, Pico_mcd->pcm.ch[4].addr, Pico_mcd->pcm.ch[5].addr |
41 | // , Pico_mcd->pcm.ch[6].addr, Pico_mcd->pcm.ch[7].addr); |
42 | |
43 | Pico_mcd->pcm.enabled = ~d; |
44 | //printf("enabled=%02x\n", Pico_mcd->pcm.enabled); |
45 | } |
46 | } |
47 | |
48 | |
49 | void pcm_set_rate(int rate) |
50 | { |
51 | double step = 31.8 * 1024.0 / (double) rate; // max <4 @ 8000Hz |
52 | step *= 256*256/4; |
53 | g_rate = (unsigned int) step; |
54 | printf("g_rate: %08x\n", g_rate); |
55 | } |
56 | |
57 | |
58 | // TODO: make use of the fact that max_length == 3 |
59 | |
60 | void pcm_update(int *buffer, int length, int stereo) |
61 | { |
62 | struct pcm_chan *ch; |
63 | unsigned int step, addr; |
64 | int mul_l, mul_r, smp; |
65 | int i, j, k; |
66 | int *out; |
67 | |
68 | |
69 | // PCM disabled or all channels off (to be checked by caller) |
70 | //if (!(Pico_mcd->pcm.control & 0x80) || !Pico_mcd->pcm.enabled) return; |
71 | |
72 | //printf("-- upd %i\n", length); |
73 | |
74 | for (i = 0; i < 8; i++) |
75 | { |
76 | if (!(Pico_mcd->pcm.enabled & (1 << i))) continue; // channel disabled |
77 | |
78 | out = buffer; |
79 | ch = &Pico_mcd->pcm.ch[i]; |
80 | |
81 | addr = ch->addr; // >> PCM_STEP_SHIFT; |
82 | mul_l = ((int)ch->regs[0] * (ch->regs[1] & 0xf)) >> (5+1); // (env * pan) >> 5 |
83 | mul_r = ((int)ch->regs[0] * (ch->regs[1] >> 4)) >> (5+1); |
84 | step = ((unsigned int)(*(unsigned short *)&ch->regs[2]) * g_rate) >> 14; // freq step |
85 | // printf("step=%i, cstep=%i, mul_l=%i, mul_r=%i, ch=%i, addr=%x, en=%02x\n", |
86 | // *(unsigned short *)&ch->regs[2], step, mul_l, mul_r, i, addr, Pico_mcd->pcm.enabled); |
87 | |
88 | if (!stereo && mul_l < mul_r) mul_l = mul_r; |
89 | |
90 | for (j = 0; j < length; j++) |
91 | { |
92 | // printf("addr=%08x\n", addr); |
93 | smp = Pico_mcd->pcm_ram[addr >> PCM_STEP_SHIFT]; |
94 | |
95 | // test for loop signal |
96 | if (smp == 0xff) |
97 | { |
98 | addr = *(unsigned short *)&ch->regs[4]; // loop_addr |
99 | smp = Pico_mcd->pcm_ram[addr]; |
100 | addr <<= PCM_STEP_SHIFT; |
101 | if (smp == 0xff) break; |
102 | } |
103 | |
104 | if (smp & 0x80) smp = -(smp & 0x7f); |
105 | |
106 | *out++ += smp * mul_l; // max 128 * 119 = 15232 |
107 | if(stereo) |
108 | *out++ += smp * mul_r; |
109 | |
110 | // update address register |
111 | k = (addr >> PCM_STEP_SHIFT) + 1; |
112 | addr = (addr + step) & 0x7FFFFFF; |
113 | |
114 | for(; k < (addr >> PCM_STEP_SHIFT); k++) |
115 | { |
116 | if (Pico_mcd->pcm_ram[k] == 0xff) |
117 | { |
118 | addr = (unsigned int)(*(unsigned short *)&ch->regs[4]) << PCM_STEP_SHIFT; // loop_addr |
119 | break; |
120 | } |
121 | } |
122 | } |
123 | |
124 | if (Pico_mcd->pcm_ram[addr >> PCM_STEP_SHIFT] == 0xff) |
125 | addr = (unsigned int)(*(unsigned short *)&ch->regs[4]) << PCM_STEP_SHIFT; // loop_addr |
126 | |
127 | ch->addr = addr; |
128 | } |
129 | } |
130 | |