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#include "render.h"
#include "ym2612.h"
#include "psg.h"
#include <stdint.h>
#include <stdio.h>
#define MCLKS_NTSC 53693175
#define MCLKS_PAL 53203395
#define MCLKS_PER_68K 7
#define MCLKS_PER_YM MCLKS_PER_68K
#define MCLKS_PER_Z80 15
#define MCLKS_PER_PSG (MCLKS_PER_Z80*16)
#pragma pack(push, 1)
typedef struct {
char ident[4];
uint32_t eof_offset;
uint32_t version;
uint32_t sn76489_clk;
uint32_t ym2413_clk;
uint32_t gd3_offset;
uint32_t num_samples;
uint32_t loop_offset;
uint32_t loop_count;
uint32_t rate;
uint16_t sn76489_fb;
uint8_t sn76489_shift;
uint8_t sn76489_flags;
uint32_t ym2612_clk;
uint32_t ym2151_clk;
uint32_t data_offset;
uint32_t sega_pcm_clk;
uint32_t sega_pcm_reg;
} vgm_header;
enum {
CMD_PSG_STEREO = 0x4F,
CMD_PSG,
CMD_YM2413,
CMD_YM2612_0,
CMD_YM2612_1,
CMD_YM2151,
CMD_YM2203,
CMD_YM2608_0,
CMD_YM2608_1,
CMD_YM2610_0,
CMD_YM2610_1,
CMD_YM3812,
CMD_YM3526,
CMD_Y8950,
CMD_YMZ280B,
CMD_YMF262_0,
CMD_YMF262_1,
CMD_WAIT = 0x61,
CMD_WAIT_60,
CMD_WAIT_50,
CMD_END = 0x66,
CMD_DATA,
CMD_PCM_WRITE,
CMD_WAIT_SHORT = 0x70,
CMD_YM2612_DAC = 0x80
};
#pragma pack(pop)
void handle_keydown(int keycode)
{
}
void handle_keyup(int keycode)
{
}
void wait(ym2612_context * y_context, psg_context * p_context, uint32_t * current_cycle, uint32_t cycles)
{
*current_cycle += cycles;
psg_run(p_context, *current_cycle);
ym_run(y_context, *current_cycle);
if (*current_cycle > 0x1FFFFFFF) {
*current_cycle -= 0x1FFFFFFF;
p_context->cycles -= 0x1FFFFFFF;
y_context->current_cycle -= 0x1FFFFFFF;
}
}
int main(int argc, char ** argv)
{
uint32_t fps = 60;
render_init(320, 240, "vgm play", 60);
ym2612_context y_context;
ym_init(&y_context, render_sample_rate(), MCLKS_NTSC, MCLKS_PER_YM, render_audio_buffer(), 0);
psg_context p_context;
psg_init(&p_context, render_sample_rate(), MCLKS_NTSC, MCLKS_PER_PSG, render_audio_buffer());
FILE * f = fopen(argv[1], "rb");
vgm_header header;
fread(&header, sizeof(header), 1, f);
if (header.version < 0x150 || !header.data_offset) {
header.data_offset = 0xC;
}
fseek(f, header.data_offset + 0x34, SEEK_SET);
uint32_t data_size = header.eof_offset + 4 - (header.data_offset + 0x34);
uint8_t * data = malloc(data_size);
fread(data, 1, data_size, f);
fclose(f);
uint32_t mclks_sample = MCLKS_NTSC / 44100;
uint8_t * end = data + data_size;
uint8_t * cur = data;
uint32_t current_cycle = 0;
while (cur < end) {
uint8_t cmd = *(cur++);
switch(cmd)
{
case CMD_PSG_STEREO:
//ignore for now
cur++;
break;
case CMD_PSG:
psg_write(&p_context, *(cur++));
break;
case CMD_YM2612_0:
ym_address_write_part1(&y_context, *(cur++));
ym_data_write(&y_context, *(cur++));
break;
case CMD_YM2612_1:
ym_address_write_part2(&y_context, *(cur++));
ym_data_write(&y_context, *(cur++));
break;
case CMD_WAIT: {
uint32_t wait_time = *(cur++);
wait_time |= *(cur++) << 8;
wait_time *= mclks_sample;
wait(&y_context, &p_context, ¤t_cycle, wait_time);
break;
}
case CMD_WAIT_60:
wait(&y_context, &p_context, ¤t_cycle, 735 * mclks_sample);
break;
case CMD_WAIT_50:
wait(&y_context, &p_context, ¤t_cycle, 882 * mclks_sample);
break;
case CMD_END:
return 0;
default:
if (cmd >= CMD_WAIT_SHORT && cmd < (CMD_WAIT_SHORT + 0x10)) {
uint32_t wait_time = (cmd & 0xF) + 1;
wait_time *= mclks_sample;
wait(&y_context, &p_context, ¤t_cycle, wait_time);
} else {
printf("unimplemented command: %X at offset %X\n", cmd, cur - data - 1);
exit(1);
}
}
}
return 0;
}
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