[wrap]
MAME source file: / src / mame / audio / gridlee.c [download] (view on mamedev.org)
/*************************************************************************

    Basic Gridlee sound driver

*************************************************************************/

#include "driver.h"
#include "streams.h"
#include "gridlee.h"
#include "sound/custom.h"
#include "sound/samples.h"


/*************************************
 *
 *  Constants
 *
 *************************************/



/*************************************
 *
 *  Local variables
 *
 *************************************/

/* tone variables */
static UINT32 tone_step;
static UINT32 tone_fraction;
static UINT8 tone_volume;

/* sound streaming variables */
static sound_stream *gridlee_stream;
static double freq_to_step;



/*************************************
 *
 *  Core sound generation
 *
 *************************************/

static STREAM_UPDATE( gridlee_stream_update )
{
	stream_sample_t *buffer = outputs[0];

	/* loop over samples */
	while (samples--)
	{
		/* tone channel */
		tone_fraction += tone_step;
		*buffer++ = (tone_fraction & 0x0800000) ? (tone_volume << 6) : 0;
	}
}



/*************************************
 *
 *  Sound startup routines
 *
 *************************************/

CUSTOM_START( gridlee_sh_start )
{
	running_machine *machine = device->machine;

	/* allocate the stream */
	gridlee_stream = stream_create(device, 0, 1, machine->sample_rate, NULL, gridlee_stream_update);

	freq_to_step = (double)(1 << 24) / (double)machine->sample_rate;

	return auto_malloc(1);
}



WRITE8_HANDLER( gridlee_sound_w )
{
static UINT8 sound_data[24];

	stream_update(gridlee_stream);

	switch (offset)
	{
		case 0x04:
			if (data == 0xef && sound_data[offset] != 0xef)
				sample_start(4, 1, 0);
			else if (data != 0xef && sound_data[offset] == 0xef)
				sample_stop(4);
//          if (!(data & 0x01) && (sound_data[offset] & 0x01))
//              sample_start(5, 1, 0);
//          else if ((data & 0x01) && !(sound_data[offset] & 0x01))
//              sample_stop(5);
			break;

		case 0x0c:
		case 0x0d:
		case 0x0e:
		case 0x0f:
			if ((data & 1) && !(sound_data[offset] & 1))
				sample_start(offset - 0x0c, 1 - sound_data[offset - 4], 0);
			else if (!(data & 1) && (sound_data[offset] & 1))
				sample_stop(offset - 0x0c);
			break;

		case 0x08+0x08:
			if (data)
				tone_step = freq_to_step * (double)(data * 5);
			else
				tone_step = 0;
			break;

		case 0x09+0x08:
			tone_volume = data;
			break;

		case 0x0b+0x08:
//          tone_volume = (data | sound_data[0x0c+0x08]) ? 0xff : 0x00;
			break;

		case 0x0c+0x08:
//          tone_volume = (data | sound_data[0x0b+0x08]) ? 0xff : 0x00;
			break;

		case 0x0d+0x08:
//          if (data)
//              tone_step = freq_to_step * (double)(data * 11);
//          else
//              tone_step = 0;
			break;
	}
	sound_data[offset] = data;



#if 0
{
static int first = 1;
FILE *f;
f = fopen("sound.log", first ? "w" : "a");
first = 0;
fprintf(f, "[%02x=%02x] %02x %02x %02x %02x %02x %02x %02x %02x - %02x %02x %02x %02x %02x %02x %02x %02x - %02x %02x %02x %02x %02x %02x %02x %02x\n",
	offset,data,
	sound_data[0],
	sound_data[1],
	sound_data[2],
	sound_data[3],
	sound_data[4],
	sound_data[5],
	sound_data[6],
	sound_data[7],
	sound_data[8],
	sound_data[9],
	sound_data[10],
	sound_data[11],
	sound_data[12],
	sound_data[13],
	sound_data[14],
	sound_data[15],
	sound_data[16],
	sound_data[17],
	sound_data[18],
	sound_data[19],
	sound_data[20],
	sound_data[21],
	sound_data[22],
	sound_data[23]);
fclose(f);
}
#endif
}
  
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