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-rw-r--r--trunk/src/emu/sound/beep.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/trunk/src/emu/sound/beep.c b/trunk/src/emu/sound/beep.c
new file mode 100644
index 00000000000..fc5f9d5e124
--- /dev/null
+++ b/trunk/src/emu/sound/beep.c
@@ -0,0 +1,192 @@
+/***************************************************************************
+
+ beep.c
+
+ This is used for computers/systems which can only output a constant tone.
+ This tone can be turned on and off.
+ e.g. PCW and PCW16 computer systems
+ KT - 25-Jun-2000
+
+ Sound handler
+
+****************************************************************************/
+
+#include "emu.h"
+#include "sound/beep.h"
+
+
+#define BEEP_RATE 48000
+
+typedef struct _beep_state beep_state;
+struct _beep_state
+{
+ sound_stream *stream; /* stream number */
+ int enable; /* enable beep */
+ int frequency; /* set frequency - this can be changed using the appropiate function */
+ int incr; /* initial wave state */
+ INT16 signal; /* current signal */
+};
+
+
+INLINE beep_state *get_safe_token(device_t *device)
+{
+ assert(device != NULL);
+ assert(device->type() == BEEP);
+ return (beep_state *)downcast<legacy_device_base *>(device)->token();
+}
+
+
+
+/*************************************
+ *
+ * Stream updater
+ *
+ *************************************/
+
+static STREAM_UPDATE( beep_sound_update )
+{
+ beep_state *bs = (beep_state *) param;
+ stream_sample_t *buffer = outputs[0];
+ INT16 signal = bs->signal;
+ int clock = 0, rate = BEEP_RATE / 2;
+
+ /* get progress through wave */
+ int incr = bs->incr;
+
+ if (bs->frequency > 0)
+ clock = bs->frequency;
+
+ /* if we're not enabled, just fill with 0 */
+ if ( !bs->enable || clock == 0 )
+ {
+ memset( buffer, 0, samples * sizeof(*buffer) );
+ return;
+ }
+
+ /* fill in the sample */
+ while( samples-- > 0 )
+ {
+ *buffer++ = signal;
+ incr -= clock;
+ while( incr < 0 )
+ {
+ incr += rate;
+ signal = -signal;
+ }
+ }
+
+ /* store progress through wave */
+ bs->incr = incr;
+ bs->signal = signal;
+}
+
+
+
+/*************************************
+ *
+ * Sound handler start
+ *
+ *************************************/
+
+static DEVICE_START( beep )
+{
+ beep_state *pBeep = get_safe_token(device);
+
+ pBeep->stream = device->machine().sound().stream_alloc(*device, 0, 1, BEEP_RATE, pBeep, beep_sound_update );
+ pBeep->enable = 0;
+ pBeep->frequency = 3250;
+ pBeep->incr = 0;
+ pBeep->signal = 0x07fff;
+}
+
+
+
+/*************************************
+ *
+ * changing state to on from off will restart tone
+ *
+ *************************************/
+
+void beep_set_state(device_t *device, int on)
+{
+ beep_state *info = get_safe_token(device);
+
+ /* only update if new state is not the same as old state */
+ if (info->enable == on)
+ return;
+
+ info->stream->update();
+
+ info->enable = on;
+ /* restart wave from beginning */
+ info->incr = 0;
+ info->signal = 0x07fff;
+}
+
+
+
+/*************************************
+ *
+ * setting new frequency starts from beginning
+ *
+ *************************************/
+
+void beep_set_frequency(device_t *device,int frequency)
+{
+ beep_state *info = get_safe_token(device);
+
+ if (info->frequency == frequency)
+ return;
+
+ info->stream->update();
+ info->frequency = frequency;
+ info->signal = 0x07fff;
+ info->incr = 0;
+}
+
+
+
+/*************************************
+ *
+ * change a channel volume
+ *
+ *************************************/
+
+void beep_set_volume(device_t *device, int volume)
+{
+ beep_state *info = get_safe_token(device);
+
+ info->stream->update();
+
+ volume = 100 * volume / 7;
+
+ downcast<beep_device *>(device)->set_output_gain(0, volume);
+}
+
+
+
+/**************************************************************************
+ * Generic get_info
+ **************************************************************************/
+
+DEVICE_GET_INFO( beep )
+{
+ switch (state)
+ {
+ /* --- the following bits of info are returned as 64-bit signed integers --- */
+ case DEVINFO_INT_TOKEN_BYTES: info->i = sizeof(beep_state); break;
+
+ /* --- the following bits of info are returned as pointers to data or functions --- */
+ case DEVINFO_FCT_START: info->start = DEVICE_START_NAME( beep ); break;
+
+ /* --- the following bits of info are returned as NULL-terminated strings --- */
+ case DEVINFO_STR_NAME: strcpy(info->s, "Beep"); break;
+ case DEVINFO_STR_FAMILY: strcpy(info->s, "Beep"); break;
+ case DEVINFO_STR_VERSION: strcpy(info->s, "1.0"); break;
+ case DEVINFO_STR_SOURCE_FILE: strcpy(info->s, __FILE__); break;
+ case DEVINFO_STR_CREDITS: strcpy(info->s, "Copyright The MESS Team"); break;
+ }
+}
+
+
+DEFINE_LEGACY_SOUND_DEVICE(BEEP, beep);