mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-12-25 00:31:04 +00:00
126 lines
2.8 KiB
C
126 lines
2.8 KiB
C
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/*
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Generates random sounds in the APU, printing the parameters
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to the screen. Also shows an asterisk while each channel is
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playing, i.e. while its length counter is active.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include "neslib.h"
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#include "apu.h"
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//#link "apu.c"
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#include "vrambuf.h"
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//#link "vrambuf.c"
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// link the pattern table into CHR ROM
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//#link "chr_generic.s"
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typedef struct APUParam {
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byte chmask;
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const char* name;
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word valmask;
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} APUParam;
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#define APU_DEFCOUNT 20
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const APUParam APU_DEFS[APU_DEFCOUNT] = {
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{0x01, "Pulse1 Period", 0x7ff },
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{0x01, "Pulse1 Duty", 0xc0 },
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{0x01, "Pulse1 Decay", 0x0f },
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{0x01, "Pulse1 Length", 0x0f },
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{0x01, "Pulse1 Sweep Period", 0x07 },
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{0x01, "Pulse1 Sweep Rate", 0x07 },
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{0x01, "Pulse1 Sweep Up?", 0x01 },
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{0x02, "Pulse2 Period", 0x7ff },
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{0x02, "Pulse2 Duty", 0xc0 },
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{0x02, "Pulse2 Decay", 0x0f },
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{0x02, "Pulse2 Length", 0x0f },
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{0x02, "Pulse2 Sweep Period", 0x07 },
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{0x02, "Pulse2 Sweep Rate", 0x07 },
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{0x02, "Pulse2 Sweep Up?", 0x01 },
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{0x04, "Triangle Period", 0x7ff },
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{0x04, "Triangle Length", 0x0f },
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{0x08, "Noise Period", 0x0f },
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{0x08, "Noise Decay", 0x0f },
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{0x08, "Noise Length", 0x0f },
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{0x08, "Noise Buzz", NOISE_PERIOD_BUZZ },
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};
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word enmask;
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word vals[APU_DEFCOUNT];
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void random_sound() {
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byte i;
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do {
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enmask = rand() & 15; // all except DMC
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} while (enmask == 0);
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for (i=0; i<APU_DEFCOUNT; i++) {
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vals[i] = rand() & APU_DEFS[i].valmask;
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}
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}
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void print_sound() {
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byte i;
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char buf[32];
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for (i=0; i<APU_DEFCOUNT; i++) {
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memset(buf, 0, sizeof(buf));
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if (enmask & APU_DEFS[i].chmask) {
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sprintf(buf, "%2d %19s %5d", i, APU_DEFS[i].name, vals[i]);
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}
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vram_adr(NTADR_A(1,i+1));
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vram_write(buf, 32);
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}
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}
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void play_sound() {
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APU_ENABLE(enmask);
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APU_PULSE_DECAY(0, vals[0], vals[1], vals[2], vals[3]);
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APU_PULSE_SWEEP(0, vals[4], vals[5], vals[6]);
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APU_PULSE_DECAY(1, vals[7], vals[8], vals[9], vals[10]);
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APU_PULSE_SWEEP(1, vals[11], vals[12], vals[13]);
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APU_TRIANGLE_LENGTH(vals[14], vals[15]);
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APU_NOISE_DECAY(vals[16]|vals[19], vals[17], vals[18]);
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}
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void print_status() {
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byte i;
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vrambuf_clear();
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for (i=0; i<APU_DEFCOUNT; i++) {
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char ch = APU.status & APU_DEFS[i].chmask ? '*' : ' ';
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vrambuf_put(NTADR_A(29,i+1), &ch, 1);
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}
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}
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void main(void)
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{
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pal_col(1,0x04);
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pal_col(2,0x20);
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pal_col(3,0x30);
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vram_adr(NTADR_A(0,26));
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vram_write(" Space=New Sound, Enter=Replay ", 32);
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apu_init();
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while(1) {
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ppu_off();
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if (!(pad_state(0) & PAD_START)) {
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random_sound();
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}
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print_sound();
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play_sound();
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vrambuf_clear();
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set_vram_update(updbuf);
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ppu_on_all();
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// wait for key
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while (!pad_trigger(0)) {
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ppu_wait_nmi();
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print_status();
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}
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}
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}
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