sound.c

#include "sound.h"

#include <AgbDefine.h>
#include <AgbMemoryMap.h>

extern u16 *sound_tbl[];

SND_STATIC sndStatic;

static void snd_stop(void);

void snd_init(void)
{
	*(vu16 *)REG_SOUNDCNT_X=SOUND_DMG_ON;
	*(vu16 *)REG_SOUNDCNT_L=SOUND_DMG_ALL_SO_ON<<8
		| 7<<SOUND_SO1_LEVEL_SHIFT
		| 7<<SOUND_SO2_LEVEL_SHIFT;
	*(vu16 *)REG_SOUNDCNT_H=SOUND_DMG_MIX_FULL;
	*(vu16 *)REG_SOUNDBIAS=3<<14 | 0x200;
	snd_stop();
}

void snd_syncVBlank(void)
{
	u8 i;
	vu16 *soundCnt;
	
	if(sndStatic.time==(u8)-1)
		return;
	
	if(sndStatic.time==0) {
		for(;;) {
			sndStatic.time=*sndStatic.playPtr>>8;
			soundCnt=(vu16 *)REG_SOUND1CNT;
			if(sndStatic.time==(u8)-2) {
				sndStatic.playPtr=sndStatic.basePtr;
				continue;
			}
			if(sndStatic.time==(u8)-1) {
				for(i=0;i<3;i++)
					*soundCnt++=0;
				return;
			}
			
			*(vu16 *)REG_SOUND1CNT_X=0;
			for(i=0;i<3;i++) {
				*soundCnt=*sndStatic.playPtr;
				if(i<2) {
					soundCnt++;
					sndStatic.playPtr++;
				}
			}
			*soundCnt=*sndStatic.playPtr++;
			break;
		}
	}
	
	sndStatic.time--;
}

void snd_play(u8 num)
{
	if(sndStatic.sfxNum>num&&sndStatic.time!=(u8)-1)
		return;
	sndStatic.playPtr=sound_tbl[num];
	sndStatic.basePtr=sndStatic.playPtr;
	sndStatic.time=0;
	sndStatic.sfxNum=num;
}

static void snd_stop(void)
{
	sndStatic.sfxNum=0;
	sndStatic.time=-1;
}