/************************************************************************************** * Gameboy sound emulation (c) Anthony Kruize (trandor@labyrinth.net.au) * * Anyways, sound on the gameboy consists of 4 separate 'channels' * Sound1 = Quadrangular waves with SWEEP and ENVELOPE functions (NR10,11,12,13,14) * Sound2 = Quadrangular waves with ENVELOPE functions (NR21,22,23,24) * Sound3 = Wave patterns from WaveRAM (NR30,31,32,33,34) * Sound4 = White noise with an envelope (NR41,42,43,44) * * Each sound channel has 2 modes, namely ON and OFF... whoa * * These tend to be the two most important equations in * converting between Hertz and GB frequency registers: * (Sounds will have a 2.4% higher frequency on Super GB.) * gb = 2048 - (131072 / Hz) * Hz = 131072 / (2048 - gb) * * Changes: * * 10/2/2002 AK - Preliminary sound code. * 13/2/2002 AK - Added a hack for mode 4, other fixes. * 23/2/2002 AK - Use lookup tables, added sweep to mode 1. Re-wrote the square * wave generation. * 13/3/2002 AK - Added mode 3, better lookup tables, other adjustments. * 15/3/2002 AK - Mode 4 can now change frequencies. * 31/3/2002 AK - Accidently forgot to handle counter/consecutive for mode 1. * 3/4/2002 AK - Mode 1 sweep can still occur if shift is 0. Don't let frequency * go past the maximum allowed value. Fixed Mode 3 length table. * Slight adjustment to Mode 4's period table generation. * 5/4/2002 AK - Mode 4 is done correctly, using a polynomial counter instead * of being a total hack. * 6/4/2002 AK - Slight tweak to mode 3's frequency calculation. * 13/4/2002 AK - Reset envelope value when sound is initialized. * 21/4/2002 AK - Backed out the mode 3 frequency calculation change. * Merged init functions into gameboy_sound_w(). * 14/5/2002 AK - Removed magic numbers in the fixed point math. * 12/6/2002 AK - Merged SOUNDx structs into one SOUND struct. * 26/10/2002 AK - Finally fixed channel 3! * ***************************************************************************************/ #include "driver.h" #include "includes/gb.h" #include "streams.h" #define NR10 0x00 #define NR11 0x01 #define NR12 0x02 #define NR13 0x03 #define NR14 0x04 #define NR21 0x06 #define NR22 0x07 #define NR23 0x08 #define NR24 0x09 #define NR30 0x0A #define NR31 0x0B #define NR32 0x0C #define NR33 0x0D #define NR34 0x0E #define NR41 0x10 #define NR42 0x11 #define NR43 0x12 #define NR44 0x13 #define NR50 0x14 #define NR51 0x15 #define NR52 0x16 #define AUD3W0 0x20 #define AUD3W1 0x21 #define AUD3W2 0x22 #define AUD3W3 0x23 #define AUD3W4 0x24 #define AUD3W5 0x25 #define AUD3W6 0x26 #define AUD3W7 0x27 #define AUD3W8 0x28 #define AUD3W9 0x29 #define AUD3WA 0x2A #define AUD3WB 0x2B #define AUD3WC 0x2C #define AUD3WD 0x2D #define AUD3WE 0x2E #define AUD3WF 0x2F #define LEFT 1 #define RIGHT 2 #define MAX_FREQUENCIES 2048 #define FIXED_POINT 16 static sound_stream *channel; static int rate; /* Represents wave duties of 12.5%, 25%, 50% and 75% */ static float wave_duty_table[4] = { 8, 4, 2, 1.33 }; static INT32 env_length_table[8]; static INT32 swp_time_table[8]; static UINT32 period_table[MAX_FREQUENCIES]; static UINT32 period_mode3_table[MAX_FREQUENCIES]; static UINT32 period_mode4_table[8][16]; static UINT32 length_table[64]; static UINT32 length_mode3_table[256]; struct SOUND { /* Common */ UINT8 on; UINT8 channel; INT32 length; INT32 pos; UINT32 period; INT32 count; INT8 mode; /* Mode 1, 2, 3 */ INT8 duty; /* Mode 1, 2, 4 */ INT32 env_value; INT8 env_direction; INT32 env_length; INT32 env_count; INT8 signal; /* Mode 1 */ UINT32 frequency; INT32 swp_shift; INT32 swp_direction; INT32 swp_time; INT32 swp_count; /* Mode 3 */ INT8 level; UINT8 offset; UINT32 dutycount; /* Mode 4 */ INT32 ply_step; INT16 ply_value; }; struct SOUNDC { UINT8 on; UINT8 vol_left; UINT8 vol_right; UINT8 mode1_left; UINT8 mode1_right; UINT8 mode2_left; UINT8 mode2_right; UINT8 mode3_left; UINT8 mode3_right; UINT8 mode4_left; UINT8 mode4_right; }; static struct SOUND snd_1; static struct SOUND snd_2; static struct SOUND snd_3; static struct SOUND snd_4; static struct SOUNDC snd_control; static UINT8 snd_regs[0x30]; static void gameboy_update(void *param,stream_sample_t **inputs, stream_sample_t **_buffer,int length); READ8_HANDLER( gb_wave_r ) { /* TODO: properly emulate scrambling of wave ram area when playback is active */ return ( snd_regs[ AUD3W0 + offset ] | snd_3.on ); } WRITE8_HANDLER( gb_wave_w ) { snd_regs[ AUD3W0 + offset ] = data; } READ8_HANDLER( gb_sound_r ) { switch( offset ) { case 0x05: case 0x0F: return 0xFF; case NR52: return 0x70 | snd_regs[offset]; default: return snd_regs[offset]; } } void gb_sound_w_internal(int offset, UINT8 data ) { /* Store the value */ snd_regs[offset] = data; switch( offset ) { /*MODE 1 */ case NR10: /* Sweep (R/W) */ snd_1.swp_shift = data & 0x7; snd_1.swp_direction = (data & 0x8) >> 3; snd_1.swp_direction |= snd_1.swp_direction - 1; snd_1.swp_time = swp_time_table[ (data & 0x70) >> 4 ]; break; case NR11: /* Sound length/Wave pattern duty (R/W) */ snd_1.duty = (data & 0xC0) >> 6; snd_1.length = length_table[data & 0x3F]; break; case NR12: /* Envelope (R/W) */ snd_1.env_value = data >> 4; snd_1.env_direction = (data & 0x8) >> 3; snd_1.env_direction |= snd_1.env_direction - 1; snd_1.env_length = env_length_table[data & 0x7]; break; case NR13: /* Frequency lo (R/W) */ snd_1.frequency = ((snd_regs[NR14]&0x7)<<8) | snd_regs[NR13]; snd_1.period = period_table[snd_1.frequency]; break; case NR14: /* Frequency hi / Initialize (R/W) */ snd_1.mode = (data & 0x40) >> 6; snd_1.frequency = ((snd_regs[NR14]&0x7)<<8) | snd_regs[NR13]; snd_1.period = period_table[snd_1.frequency]; if( data & 0x80 ) { if( !snd_1.on ) snd_1.pos = 0; snd_1.on = 1; snd_1.count = 0; snd_1.env_value = snd_regs[NR12] >> 4; snd_1.env_count = 0; snd_1.swp_count = 0; snd_1.signal = 0x1; snd_regs[NR52] |= 0x1; } break; /*MODE 2 */ case NR21: /* Sound length/Wave pattern duty (R/W) */ snd_2.duty = (data & 0xC0) >> 6; snd_2.length = length_table[data & 0x3F]; break; case NR22: /* Envelope (R/W) */ snd_2.env_value = data >> 4; snd_2.env_direction = (data & 0x8 ) >> 3; snd_2.env_direction |= snd_2.env_direction - 1; snd_2.env_length = env_length_table[data & 0x7]; break; case NR23: /* Frequency lo (R/W) */ snd_2.period = period_table[((snd_regs[NR24]&0x7)<<8) | snd_regs[NR23]]; break; case NR24: /* Frequency hi / Initialize (R/W) */ snd_2.mode = (data & 0x40) >> 6; snd_2.period = period_table[((snd_regs[NR24]&0x7)<<8) | snd_regs[NR23]]; if( data & 0x80 ) { if( !snd_2.on ) snd_2.pos = 0; snd_2.on = 1; snd_2.count = 0; snd_2.env_value = snd_regs[NR22] >> 4; snd_2.env_count = 0; snd_2.signal = 0x1; snd_regs[NR52] |= 0x2; } break; /*MODE 3 */ case NR30: /* Sound On/Off (R/W) */ snd_3.on = (data & 0x80) >> 7; break; case NR31: /* Sound Length (R/W) */ snd_3.length = length_mode3_table[data]; break; case NR32: /* Select Output Level */ snd_3.level = (data & 0x60) >> 5; break; case NR33: /* Frequency lo (W) */ snd_3.period = period_mode3_table[((snd_regs[NR34]&0x7)<<8) + snd_regs[NR33]]; break; case NR34: /* Frequency hi / Initialize (W) */ snd_3.mode = (data & 0x40) >> 6; snd_3.period = period_mode3_table[((snd_regs[NR34]&0x7)<<8) + snd_regs[NR33]]; if( data & 0x80 ) { if( !snd_3.on ) { snd_3.pos = 0; snd_3.offset = 0; snd_3.duty = 0; } snd_3.on = 1; snd_3.count = 0; snd_3.duty = 1; snd_3.dutycount = 0; snd_regs[NR52] |= 0x4; } break; /*MODE 4 */ case NR41: /* Sound Length (R/W) */ snd_4.length = length_table[data & 0x3F]; break; case NR42: /* Envelope (R/W) */ snd_4.env_value = data >> 4; snd_4.env_direction = (data & 0x8 ) >> 3; snd_4.env_direction |= snd_4.env_direction - 1; snd_4.env_length = env_length_table[data & 0x7]; break; case NR43: /* Polynomial Counter/Frequency */ snd_4.period = period_mode4_table[data & 0x7][(data & 0xF0) >> 4]; snd_4.ply_step = (data & 0x8) >> 3; break; case NR44: /* Counter/Consecutive / Initialize (R/W) */ snd_4.mode = (data & 0x40) >> 6; if( data & 0x80 ) { if( !snd_4.on ) snd_4.pos = 0; snd_4.on = 1; snd_4.count = 0; snd_4.env_value = snd_regs[NR42] >> 4; snd_4.env_count = 0; snd_4.signal = mame_rand(Machine); snd_4.ply_value = 0x7fff; snd_regs[NR52] |= 0x8; } break; /* CONTROL */ case NR50: /* Channel Control / On/Off / Volume (R/W) */ snd_control.vol_left = data & 0x7; snd_control.vol_right = (data & 0x70) >> 4; break; case NR51: /* Selection of Sound Output Terminal */ snd_control.mode1_right = data & 0x1; snd_control.mode1_left = (data & 0x10) >> 4; snd_control.mode2_right = (data & 0x2) >> 1; snd_control.mode2_left = (data & 0x20) >> 5; snd_control.mode3_right = (data & 0x4) >> 2; snd_control.mode3_left = (data & 0x40) >> 6; snd_control.mode4_right = (data & 0x8) >> 3; snd_control.mode4_left = (data & 0x80) >> 7; break; case NR52: /* Sound On/Off (R/W) */ /* Only bit 7 is writable, writing to bits 0-3 does NOT enable or disable sound. They are read-only */ snd_control.on = (data & 0x80) >> 7; if( !snd_control.on ) { gb_sound_w_internal( NR10, 0x80 ); gb_sound_w_internal( NR11, 0x3F ); gb_sound_w_internal( NR12, 0x00 ); gb_sound_w_internal( NR13, 0xFE ); gb_sound_w_internal( NR14, 0xBF ); // gb_sound_w_internal( NR20, 0xFF ); gb_sound_w_internal( NR21, 0x3F ); gb_sound_w_internal( NR22, 0x00 ); gb_sound_w_internal( NR23, 0xFF ); gb_sound_w_internal( NR24, 0xBF ); gb_sound_w_internal( NR30, 0x7F ); gb_sound_w_internal( NR31, 0xFF ); gb_sound_w_internal( NR32, 0x9F ); gb_sound_w_internal( NR33, 0xFF ); gb_sound_w_internal( NR34, 0xBF ); // gb_sound_w_internal( NR40, 0xFF ); gb_sound_w_internal( NR41, 0xFF ); gb_sound_w_internal( NR42, 0x00 ); gb_sound_w_internal( NR43, 0x00 ); gb_sound_w_internal( NR44, 0xBF ); gb_sound_w_internal( NR50, 0x00 ); gb_sound_w_internal( NR51, 0x00 ); snd_1.on = 0; snd_2.on = 0; snd_3.on = 0; snd_4.on = 0; snd_regs[offset] = 0; } break; } } WRITE8_HANDLER( gb_sound_w ) { /* change in registers so update first */ stream_update(channel); /* Only register NR52 is accessible if the sound controller is disabled */ if( !snd_control.on && offset != NR52 ) { return; } gb_sound_w_internal( offset, data ); } static void gameboy_update(void *param,stream_sample_t **inputs, stream_sample_t **buffer,int length) { stream_sample_t sample, left, right, mode4_mask; while( length-- > 0 ) { left = right = 0; /* Mode 1 - Wave with Envelope and Sweep */ if( snd_1.on ) { sample = snd_1.signal * snd_1.env_value; snd_1.pos++; if( snd_1.pos == (UINT32)(snd_1.period / wave_duty_table[snd_1.duty]) >> FIXED_POINT) { snd_1.signal = -snd_1.signal; } else if( snd_1.pos > (snd_1.period >> FIXED_POINT) ) { snd_1.pos = 0; snd_1.signal = -snd_1.signal; } if( snd_1.length && snd_1.mode ) { snd_1.count++; if( snd_1.count >= snd_1.length ) { snd_1.on = 0; snd_regs[NR52] &= 0xFE; } } if( snd_1.env_length ) { snd_1.env_count++; if( snd_1.env_count >= snd_1.env_length ) { snd_1.env_count = 0; snd_1.env_value += snd_1.env_direction; if( snd_1.env_value < 0 ) snd_1.env_value = 0; if( snd_1.env_value > 15 ) snd_1.env_value = 15; } } if( snd_1.swp_time ) { snd_1.swp_count++; if( snd_1.swp_count >= snd_1.swp_time ) { snd_1.swp_count = 0; if( snd_1.swp_direction > 0 ) { snd_1.frequency -= snd_1.frequency / (1 << snd_1.swp_shift ); if( snd_1.frequency <= 0 ) { snd_1.on = 0; snd_regs[NR52] &= 0xFE; } } else { snd_1.frequency += snd_1.frequency / (1 << snd_1.swp_shift ); if( snd_1.frequency >= MAX_FREQUENCIES ) { snd_1.frequency = MAX_FREQUENCIES - 1; } } snd_1.period = period_table[snd_1.frequency]; } } if( snd_control.mode1_left ) left += sample; if( snd_control.mode1_right ) right += sample; } /* Mode 2 - Wave with Envelope */ if( snd_2.on ) { sample = snd_2.signal * snd_2.env_value; snd_2.pos++; if( snd_2.pos == (UINT32)(snd_2.period / wave_duty_table[snd_2.duty]) >> FIXED_POINT) { snd_2.signal = -snd_2.signal; } else if( snd_2.pos > (snd_2.period >> FIXED_POINT) ) { snd_2.pos = 0; snd_2.signal = -snd_2.signal; } if( snd_2.length && snd_2.mode ) { snd_2.count++; if( snd_2.count >= snd_2.length ) { snd_2.on = 0; snd_regs[NR52] &= 0xFD; } } if( snd_2.env_length ) { snd_2.env_count++; if( snd_2.env_count >= snd_2.env_length ) { snd_2.env_count = 0; snd_2.env_value += snd_2.env_direction; if( snd_2.env_value < 0 ) snd_2.env_value = 0; if( snd_2.env_value > 15 ) snd_2.env_value = 15; } } if( snd_control.mode2_left ) left += sample; if( snd_control.mode2_right ) right += sample; } /* Mode 3 - Wave patterns from WaveRAM */ if( snd_3.on ) { /* NOTE: This is extremely close, but not quite right. The problem is for GB frequencies above 2000 the frequency gets clipped. This is caused because snd_3.pos is never 0 at the test.*/ sample = snd_regs[AUD3W0 + (snd_3.offset/2)]; if( !(snd_3.offset % 2) ) { sample >>= 4; } sample = (sample & 0xF) - 8; if( snd_3.level ) sample >>= (snd_3.level - 1); else sample = 0; snd_3.pos++; if( snd_3.pos >= ((UINT32)(((snd_3.period ) >> 21)) + snd_3.duty) ) { snd_3.pos = 0; if( snd_3.dutycount == ((UINT32)(((snd_3.period ) >> FIXED_POINT)) % 32) ) { snd_3.duty--; } snd_3.dutycount++; snd_3.offset++; if( snd_3.offset > 31 ) { snd_3.offset = 0; snd_3.duty = 1; snd_3.dutycount = 0; } } if( snd_3.length && snd_3.mode ) { snd_3.count++; if( snd_3.count >= snd_3.length ) { snd_3.on = 0; snd_regs[NR52] &= 0xFB; } } if( snd_control.mode3_left ) left += sample; if( snd_control.mode3_right ) right += sample; } /* Mode 4 - Noise with Envelope */ if( snd_4.on ) { /* Similar problem to Mode 3, we seem to miss some notes */ sample = snd_4.signal & snd_4.env_value; snd_4.pos++; if( snd_4.pos == (snd_4.period >> (FIXED_POINT + 1)) ) { /* Using a Polynomial Counter (aka Linear Feedback Shift Register) Mode 4 has a 7 bit and 15 bit counter so we need to shift the bits around accordingly */ mode4_mask = (((snd_4.ply_value & 0x2) >> 1) ^ (snd_4.ply_value & 0x1)) << (snd_4.ply_step ? 6 : 14); snd_4.ply_value >>= 1; snd_4.ply_value |= mode4_mask; snd_4.ply_value &= (snd_4.ply_step ? 0x7f : 0x7fff); snd_4.signal = (INT8)snd_4.ply_value; } else if( snd_4.pos > (snd_4.period >> FIXED_POINT) ) { snd_4.pos = 0; mode4_mask = (((snd_4.ply_value & 0x2) >> 1) ^ (snd_4.ply_value & 0x1)) << (snd_4.ply_step ? 6 : 14); snd_4.ply_value >>= 1; snd_4.ply_value |= mode4_mask; snd_4.ply_value &= (snd_4.ply_step ? 0x7f : 0x7fff); snd_4.signal = (INT8)snd_4.ply_value; } if( snd_4.length && snd_4.mode ) { snd_4.count++; if( snd_4.count >= snd_4.length ) { snd_4.on = 0; snd_regs[NR52] &= 0xF7; } } if( snd_4.env_length ) { snd_4.env_count++; if( snd_4.env_count >= snd_4.env_length ) { snd_4.env_count = 0; snd_4.env_value += snd_4.env_direction; if( snd_4.env_value < 0 ) snd_4.env_value = 0; if( snd_4.env_value > 15 ) snd_4.env_value = 15; } } if( snd_control.mode4_left ) left += sample; if( snd_control.mode4_right ) right += sample; } /* Adjust for master volume */ left *= snd_control.vol_left; right *= snd_control.vol_right; /* pump up the volume */ left <<= 6; right <<= 6; /* Update the buffers */ *(buffer[0]++) = left; *(buffer[1]++) = right; } snd_regs[NR52] = (snd_regs[NR52]&0xf0) | snd_1.on | (snd_2.on << 1) | (snd_3.on << 2) | (snd_4.on << 3); } void *gameboy_sh_start(int clock, const struct CustomSound_interface *config) { int I, J; memset(&snd_1, 0, sizeof(snd_1)); memset(&snd_2, 0, sizeof(snd_2)); memset(&snd_3, 0, sizeof(snd_3)); memset(&snd_4, 0, sizeof(snd_4)); channel = stream_create(0, 2, Machine->sample_rate, 0, gameboy_update); rate = Machine->sample_rate; /* Calculate the envelope and sweep tables */ for( I = 0; I < 8; I++ ) { env_length_table[I] = (I * ((1 << FIXED_POINT) / 64) * rate) >> FIXED_POINT; swp_time_table[I] = (((I << FIXED_POINT) / 128) * rate) >> (FIXED_POINT - 1); } /* Calculate the period tables */ for( I = 0; I < MAX_FREQUENCIES; I++ ) { period_table[I] = ((1 << FIXED_POINT) / (131072 / (2048 - I))) * rate; period_mode3_table[I] = ((1 << FIXED_POINT) / (65536 / (2048 - I))) * rate; } /* Calculate the period table for mode 4 */ for( I = 0; I < 8; I++ ) { for( J = 0; J < 16; J++ ) { /* I is the dividing ratio of frequencies J is the shift clock frequency */ period_mode4_table[I][J] = ((1 << FIXED_POINT) / (524288 / ((I == 0)?0.5:I) / (1 << (J + 1)))) * rate; } } /* Calculate the length table */ for( I = 0; I < 64; I++ ) { length_table[I] = ((64 - I) * ((1 << FIXED_POINT)/256) * rate) >> FIXED_POINT; } /* Calculate the length table for mode 3 */ for( I = 0; I < 256; I++ ) { length_mode3_table[I] = ((256 - I) * ((1 << FIXED_POINT)/256) * rate) >> FIXED_POINT; } gb_sound_w_internal( NR52, 0x00 ); snd_regs[AUD3W0] = 0xac; snd_regs[AUD3W1] = 0xdd; snd_regs[AUD3W2] = 0xda; snd_regs[AUD3W3] = 0x48; snd_regs[AUD3W4] = 0x36; snd_regs[AUD3W5] = 0x02; snd_regs[AUD3W6] = 0xcf; snd_regs[AUD3W7] = 0x16; snd_regs[AUD3W8] = 0x2c; snd_regs[AUD3W9] = 0x04; snd_regs[AUD3WA] = 0xe5; snd_regs[AUD3WB] = 0x2c; snd_regs[AUD3WC] = 0xac; snd_regs[AUD3WD] = 0xdd; snd_regs[AUD3WE] = 0xda; snd_regs[AUD3WF] = 0x48; return (void *) ~0; }