devkitPro

Code: Select all

//-----------------------------------------------------------------
	// create our custom sample
	//-----------------------------------------------------------------
	
	// allocate memory for sample
	// the sample header and data must be in mainram (for ARM7 side)
	my_very_own_sample = malloc( sizeof( mm_ds_sample ) );
	
	// disable loop
	my_very_own_sample->loop_start = 0;
	
	// set length = 1000 words (4000 samples @ 8bit)
	my_very_own_sample->length = 1000;
	
	// format: 0 = 8bit, 1 = 16bit, 2 = adpcm
	my_very_own_sample->format = 0;
	
	// repeat, 1 = looping sample, 2 = one-shot sample
	my_very_own_sample->repeat_mode = 2;
	
	// base rate, 0x400/2 = 16KHz, (KHz = (base_rate * 32) / 0x400)
	my_very_own_sample->base_rate = 0x400/2;
	
	// allocate sample data
	my_very_own_sample->data = malloc( my_very_own_sample->length * 4 );
	
	{
		//-------------------------------------------
		// generate fading square wave as sample data
		//-------------------------------------------
		
		int t;
		s8* sample = my_very_own_sample->data;
		int a;
		int volume = 1000*4;
		for( t = 0; t < my_very_own_sample->length * 4; t++ )
		{
			if( (t & 63) > 20 )
				a = 127;
			else
				a = -128;
			*sample++ = (a * volume) / (1000*4);
			volume--;
		}
	}

Code: Select all

mm_sound_effect sound;
	
	// sample = sample address of our sample
	// the 'id' parameter is not used
	sound.sample = my_very_own_sample;
	
	// rate = 0x400 which is 1.0 which is original playback rate
	sound.rate = 0x400;
	
	// handle = 0 means allocate a new handle
	sound.handle = 0;
	
	// volume = 200/256 = ~78%
	sound.volume = 200;
	
	// panning = 128/256 = centered
	sound.panning = 128;
	
	// play sound
	mmEffectEx( &sound );