diff options
Diffstat (limited to 'trunk/src/mame/audio/wiping.c')
-rw-r--r-- | trunk/src/mame/audio/wiping.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/trunk/src/mame/audio/wiping.c b/trunk/src/mame/audio/wiping.c new file mode 100644 index 00000000000..eb148a95440 --- /dev/null +++ b/trunk/src/mame/audio/wiping.c @@ -0,0 +1,281 @@ +/*************************************************************************** + + Wiping sound driver (quick hack of the Namco sound driver) + + used by wiping.c and clshroad.c + +***************************************************************************/ + +#include "emu.h" +#include "audio/wiping.h" + + +/* 8 voices max */ +#define MAX_VOICES 8 + + +static const int samplerate = 48000; +static const int defgain = 48; + + +/* this structure defines the parameters for a channel */ +typedef struct +{ + int frequency; + int counter; + int volume; + const UINT8 *wave; + int oneshot; + int oneshotplaying; +} sound_channel; + + + + +typedef struct _wiping_sound_state wiping_sound_state; +struct _wiping_sound_state +{ + /* data about the sound system */ + sound_channel m_channel_list[MAX_VOICES]; + sound_channel *m_last_channel; + + /* global sound parameters */ + const UINT8 *m_sound_prom; + const UINT8 *m_sound_rom; + int m_num_voices; + int m_sound_enable; + sound_stream *m_stream; + + /* mixer tables and internal buffers */ + INT16 *m_mixer_table; + INT16 *m_mixer_lookup; + short *m_mixer_buffer; + short *m_mixer_buffer_2; + + UINT8 m_soundregs[0x4000]; +}; + + +INLINE wiping_sound_state *get_safe_token( device_t *device ) +{ + assert(device != NULL); + assert(device->type() == WIPING); + + return (wiping_sound_state *)downcast<legacy_device_base *>(device)->token(); +} + +/* build a table to divide by the number of voices; gain is specified as gain*16 */ +static void make_mixer_table(device_t *device, int voices, int gain) +{ + wiping_sound_state *state = get_safe_token(device); + int count = voices * 128; + int i; + + /* allocate memory */ + state->m_mixer_table = auto_alloc_array(device->machine(), INT16, 256 * voices); + + /* find the middle of the table */ + state->m_mixer_lookup = state->m_mixer_table + (128 * voices); + + /* fill in the table - 16 bit case */ + for (i = 0; i < count; i++) + { + int val = i * gain * 16 / voices; + if (val > 32767) val = 32767; + state->m_mixer_lookup[ i] = val; + state->m_mixer_lookup[-i] = -val; + } +} + + +/* generate sound to the mix buffer in mono */ +static STREAM_UPDATE( wiping_update_mono ) +{ + wiping_sound_state *state = get_safe_token(device); + stream_sample_t *buffer = outputs[0]; + sound_channel *voice; + short *mix; + int i; + + /* if no sound, we're done */ + if (state->m_sound_enable == 0) + { + memset(buffer, 0, samples * sizeof(*buffer)); + return; + } + + /* zap the contents of the mixer buffer */ + memset(state->m_mixer_buffer, 0, samples * sizeof(short)); + + /* loop over each voice and add its contribution */ + for (voice = state->m_channel_list; voice < state->m_last_channel; voice++) + { + int f = 16*voice->frequency; + int v = voice->volume; + + /* only update if we have non-zero volume and frequency */ + if (v && f) + { + const UINT8 *w = voice->wave; + int c = voice->counter; + + mix = state->m_mixer_buffer; + + /* add our contribution */ + for (i = 0; i < samples; i++) + { + int offs; + + c += f; + + if (voice->oneshot) + { + if (voice->oneshotplaying) + { + offs = (c >> 15); + if (w[offs>>1] == 0xff) + { + voice->oneshotplaying = 0; + } + + else + { + /* use full byte, first the high 4 bits, then the low 4 bits */ + if (offs & 1) + *mix++ += ((w[offs>>1] & 0x0f) - 8) * v; + else + *mix++ += (((w[offs>>1]>>4) & 0x0f) - 8) * v; + } + } + } + else + { + offs = (c >> 15) & 0x1f; + + /* use full byte, first the high 4 bits, then the low 4 bits */ + if (offs & 1) + *mix++ += ((w[offs>>1] & 0x0f) - 8) * v; + else + *mix++ += (((w[offs>>1]>>4) & 0x0f) - 8) * v; + } + } + + /* update the counter for this voice */ + voice->counter = c; + } + } + + /* mix it down */ + mix = state->m_mixer_buffer; + for (i = 0; i < samples; i++) + *buffer++ = state->m_mixer_lookup[*mix++]; +} + + + +static DEVICE_START( wiping_sound ) +{ + wiping_sound_state *state = get_safe_token(device); + running_machine &machine = device->machine(); + sound_channel *voice; + + /* get stream channels */ + state->m_stream = device->machine().sound().stream_alloc(*device, 0, 1, samplerate, NULL, wiping_update_mono); + + /* allocate a pair of buffers to mix into - 1 second's worth should be more than enough */ + state->m_mixer_buffer = auto_alloc_array(machine, short, 2 * samplerate); + state->m_mixer_buffer_2 = state->m_mixer_buffer + samplerate; + + /* build the mixer table */ + make_mixer_table(device, 8, defgain); + + /* extract globals from the interface */ + state->m_num_voices = 8; + state->m_last_channel = state->m_channel_list + state->m_num_voices; + + state->m_sound_rom = machine.region("samples")->base(); + state->m_sound_prom = machine.region("soundproms")->base(); + + /* start with sound enabled, many games don't have a sound enable register */ + state->m_sound_enable = 1; + + /* reset all the voices */ + for (voice = state->m_channel_list; voice < state->m_last_channel; voice++) + { + voice->frequency = 0; + voice->volume = 0; + voice->wave = &state->m_sound_prom[0]; + voice->counter = 0; + } +} + + +DEVICE_GET_INFO( wiping_sound ) +{ + switch (state) + { + /* --- the following bits of info are returned as 64-bit signed integers --- */ + case DEVINFO_INT_TOKEN_BYTES: info->i = sizeof(wiping_sound_state); break; + + /* --- the following bits of info are returned as pointers to data or functions --- */ + case DEVINFO_FCT_START: info->start = DEVICE_START_NAME(wiping_sound); break; + + /* --- the following bits of info are returned as NULL-terminated strings --- */ + case DEVINFO_STR_NAME: strcpy(info->s, "Wiping Custom"); break; + case DEVINFO_STR_SOURCE_FILE: strcpy(info->s, __FILE__); break; + } +} + + + +/********************************************************************************/ + +WRITE8_DEVICE_HANDLER( wiping_sound_w ) +{ + wiping_sound_state *state = get_safe_token(device); + sound_channel *voice; + int base; + + /* update the streams */ + state->m_stream->update(); + + /* set the register */ + state->m_soundregs[offset] = data; + + /* recompute all the voice parameters */ + if (offset <= 0x3f) + { + for (base = 0, voice = state->m_channel_list; voice < state->m_last_channel; voice++, base += 8) + { + voice->frequency = state->m_soundregs[0x02 + base] & 0x0f; + voice->frequency = voice->frequency * 16 + ((state->m_soundregs[0x01 + base]) & 0x0f); + voice->frequency = voice->frequency * 16 + ((state->m_soundregs[0x00 + base]) & 0x0f); + + voice->volume = state->m_soundregs[0x07 + base] & 0x0f; + if (state->m_soundregs[0x5 + base] & 0x0f) + { + voice->wave = &state->m_sound_rom[128 * (16 * (state->m_soundregs[0x5 + base] & 0x0f) + + (state->m_soundregs[0x2005 + base] & 0x0f))]; + voice->oneshot = 1; + } + else + { + voice->wave = &state->m_sound_rom[16 * (state->m_soundregs[0x3 + base] & 0x0f)]; + voice->oneshot = 0; + voice->oneshotplaying = 0; + } + } + } + else if (offset >= 0x2000) + { + voice = &state->m_channel_list[(offset & 0x3f)/8]; + if (voice->oneshot) + { + voice->counter = 0; + voice->oneshotplaying = 1; + } + } +} + + +DEFINE_LEGACY_SOUND_DEVICE(WIPING, wiping_sound); |