main.c

#include <stdlib.h>
#include <stdio.h>

#include <gme.h>
#include <emscripten/webaudio.h>

//#include <math.h> //for sin

Music_Emu* emu;
void* nsfdata;
long nsfdataSize=0;
int track;
//int limitlogs=0;
int buf_size;

short* buf;

void handle_error( const char* str );

//static void play_siren( long count, short* out )
//	{
//		static double a, a2;
//		while ( count-- )
//			*out++ = 0x2000 * sin( a += .1 + .05*sin( a2+=.00005 ) );
//	}

//EMSCRIPTEN_KEEPALIVE
//int setupNSF(void* inputdata, long inputdataSize, int inputBufSize, int tracknum)
//{
//	printf("setupNSF\n");
//	
//	nsfdata = inputdata;
//	
//	nsfdataSize = inputdataSize;
//			
//	buf_size = inputBufSize;
//	
//	int sample_rate = 44100;
//	
//	/* Open music file in new emulator */
//	handle_error( gme_open_data( nsfdata, nsfdataSize, &emu, sample_rate ) );
//	
//	printf("nsfdataSize: %li \n", nsfdataSize);
//	
//	/* Start track */
//	handle_error( gme_start_track( emu, tracknum ) );
//	
//	
//	buf = malloc(sizeof(*buf) * buf_size); // https://stackoverflow.com/questions/4240331/c-initializing-a-global-array-in-a-function
//	//printf("array buf entry number 3: %d\n", buf[3]);
//	
//	printf("voice count: %d\n", gme_voice_count( emu ));
//	
//	for (int i=0;i<10;++i){
//		gme_play( emu, buf_size*2, buf ); // I think doing this decreases the frequency of it crackling on startup
//	}
//	handle_error( gme_start_track( emu, tracknum ) );
//	
//	printf("setupNSF done\n");
//	return 0;
//}

EMSCRIPTEN_KEEPALIVE
short* playNSF() { // run in script processor node's on audio process event
	/* Sample buffer */
	gme_play( emu, buf_size*2, buf ); // I don't know why buf_size is multiplied by 2 here, but it only works when it's multiplied by 2. I figured this out from studying Chip Player JS.
	//if (limitlogs<1) {
	//	short tempbuf [buf_size];
	//	size_t n = sizeof(tempbuf)/sizeof(tempbuf[0]);
	//	printf("total size of buf: %zu\n", sizeof(tempbuf));
	//	printf("number of elements in buf: %zu\n", n);
	//	printf("size of buf_size: %d\n", buf_size);
	//	printf("size of buf_size times 2: %d\n", buf_size*2);
	//	printf("size of one element in buf: %lu\n", sizeof(buf[1]));
	//	++limitlogs;
	//}
	//play_siren(buf_size, buf);
	/*if (limitlogs < 50) {
		handle_error( gme_play( emu, buf_size, buf ) );
		printf("array buf entry number 0: %d\n", buf[0]);
		printf("array buf entry number 1: %d\n", buf[1]);
		printf("array buf entry number 2: %d\n", buf[2]);
		printf("array buf entry number 3: %d\n", buf[3]);
		printf("array buf entry number 4: %d\n", buf[4]);
		printf("array buf entry number 5: %d\n", buf[5]);
		++limitlogs;
	} else {
		gme_play( emu, buf_size, buf );
	}*/
	
	// the c code cannot return an array to javascript, use runtime method getValue to access the buf array.
	return buf; //buf is a pointer, c arrays are pointers.
}

EMSCRIPTEN_KEEPALIVE
int getTime() {
	return gme_tell(emu);
}

EMSCRIPTEN_KEEPALIVE
int getIfTrackEnded() {
	return gme_track_ended(emu);
}


EMSCRIPTEN_KEEPALIVE
int setupNSFstereo(void* inputdata, long inputdataSize, int inputBufSize, int tracknum)
{
	printf("setupNSF\n");
	
	nsfdata = inputdata;
	
	nsfdataSize = inputdataSize;
			
	buf_size = inputBufSize;
	
	track = tracknum;
	
	int sample_rate = 44100;
	
	/* Open music file in new emulator */
	handle_error( gme_open_data( nsfdata, nsfdataSize, &emu, sample_rate ) );
	
	//gme_mute_voices( emu, -1 ); // mute all voices
	
	gme_ignore_silence( emu, 1 ); // very important for recording separate tracks. 1 is true
	
	printf("nsfdataSize: %li \n", nsfdataSize);
	
	/* Start track */
	handle_error( gme_start_track( emu, tracknum ) );
	
	
	buf = malloc(sizeof(*buf) * buf_size); // https://stackoverflow.com/questions/4240331/c-initializing-a-global-array-in-a-function
	//printf("array buf entry number 3: %d\n", buf[3]);
	
	int totalvoices=gme_voice_count( emu );
	
	printf("voice count: %d\n", totalvoices);
	
	for (int i=0;i<totalvoices;++i) {
		printf("voice name %d: %s\n", i, gme_voice_name( emu, i ));
	}
	
	gme_info_t* info;
	
	gme_track_info( emu, &info, tracknum );
	
	printf("info: song: %s, length: %d, intro_length: %d, loop_length: %d, play_length: %d, fade_length: %d\n", info->song, info->length, info->intro_length, info->loop_length, info->play_length, info->fade_length);
	
	handle_error( gme_start_track( emu, tracknum ) );
	
	printf("setupNSF done\n");
	return info->length;
}

EMSCRIPTEN_KEEPALIVE
int getTotalVoices() {
	return gme_voice_count( emu ); // making a tiny function like this is easier than figuring out how to return length and total voices in the setupNSFstereo function.
}

EMSCRIPTEN_KEEPALIVE
const char* getVoiceName(int voicenum) {
	return gme_voice_name(emu, voicenum);
}

//EMSCRIPTEN_KEEPALIVE
//int setIgnoreSilence(intbool) {
//	gme_ignore_silence( emu, intbool );
//	return 0;
//}

EMSCRIPTEN_KEEPALIVE
int setVoiceForRecording(int voicenum)
{
	printf("setVoiceForRecording with voicenum: %d, name: %s\n", voicenum, gme_voice_name( emu, voicenum ));
	
	if (gme_tell(emu)>0) {
		//gme_start_track(emu, track); // restart track from beginning. doesn't work
		printf("Time is greater than 0. Seeking to start...\n");
		gme_seek( emu, 0 );
		printf("Seek to start finished, new time: %d\n", gme_tell(emu));
	}
	
	gme_mute_voices( emu, -1 ); // mute all voices
	
	gme_mute_voice( emu, voicenum, 0 ); // unmute
	
	printf("setVoiceForRecording done\n");
	return 0;
}

EMSCRIPTEN_KEEPALIVE
int unmuteVoice(int voicenum)
{
	printf("unmuteVoice with voicenum: %d, name: %s\n", voicenum, gme_voice_name( emu, voicenum ));
	
	gme_mute_voice( emu, voicenum, 0 ); // unmute
	
	printf("unmuteVoice done\n");
	return 0;
}

void handle_error( const char* str )
{
	if ( str )
	{
		printf( "Error: %s\n", str ); //getchar();
		//exit( EXIT_FAILURE );
	}
}