using System; using System.IO; namespace MAME.Core { public class OKI6295 { public struct adpcm_state { public int signal; public int step; }; public struct ADPCMVoice { public bool playing; public uint base_offset; public uint sample; public uint count; public uint volume; }; public struct okim6295Struct { public ADPCMVoice[] voice; public int command; public int bank_offset; public uint master_clock; }; public static byte[] okirom; public static okim6295Struct OKI; public static adpcm_state[] adpcm; private static int[] index_shift = new int[8] { -1, -1, -1, -1, 2, 4, 6, 8 }; private static int[] diff_lookup = new int[49 * 16]; private static uint[] volume_table = new uint[16]; private static int tables_computed = 0; private static void compute_tables() { int[,] nbl2bit = new int[16, 4] { { 1, 0, 0, 0}, { 1, 0, 0, 1}, { 1, 0, 1, 0}, { 1, 0, 1, 1}, { 1, 1, 0, 0}, { 1, 1, 0, 1}, { 1, 1, 1, 0}, { 1, 1, 1, 1}, {-1, 0, 0, 0}, {-1, 0, 0, 1}, {-1, 0, 1, 0}, {-1, 0, 1, 1}, {-1, 1, 0, 0}, {-1, 1, 0, 1}, {-1, 1, 1, 0}, {-1, 1, 1, 1} }; int step, nib; for (step = 0; step <= 48; step++) { int stepval = (int)Math.Floor(16.0 * Math.Pow(11.0 / 10.0, (double)step)); for (nib = 0; nib < 16; nib++) { diff_lookup[step * 16 + nib] = nbl2bit[nib, 0] * (stepval * nbl2bit[nib, 1] + stepval / 2 * nbl2bit[nib, 2] + stepval / 4 * nbl2bit[nib, 3] + stepval / 8); } } for (step = 0; step < 16; step++) { double dout = 256.0; int vol = step; while (vol-- > 0) dout /= 1.412537545; volume_table[step] = (uint)dout; } tables_computed = 1; } private static void reset_adpcm(int i) { if (tables_computed == 0) { compute_tables(); } adpcm[i].signal = -2; adpcm[i].step = 0; } private static short clock_adpcm(int i, byte nibble) { adpcm[i].signal += diff_lookup[adpcm[i].step * 16 + (nibble & 15)]; if (adpcm[i].signal > 2047) adpcm[i].signal = 2047; else if (adpcm[i].signal < -2048) adpcm[i].signal = -2048; adpcm[i].step += index_shift[nibble & 7]; if (adpcm[i].step > 48) adpcm[i].step = 48; else if (adpcm[i].step < 0) adpcm[i].step = 0; return (short)(adpcm[i].signal << 4); } private static void generate_adpcm(int i, short[] buffer, int samples) { int i1 = 0; if (OKI.voice[i].playing) { int bbase = (int)(OKI.bank_offset + OKI.voice[i].base_offset); int sample = (int)OKI.voice[i].sample; int count = (int)OKI.voice[i].count; while (samples != 0) { int nibble = okirom[bbase + sample / 2] >> (((sample & 1) << 2) ^ 4); buffer[i1] = (short)(clock_adpcm(i, (byte)nibble) * OKI.voice[i].volume / 256); i1++; samples--; if (++sample >= count) { OKI.voice[i].playing = false; break; } } OKI.voice[i].sample = (uint)sample; } while ((samples--) != 0) { buffer[i1] = 0; i1++; } } //TODO 移动到这里，但是大小，还需要考虑 static short[] sample_data = new short[10000]; public unsafe static void okim6295_update(int offset, int length) { int i; for (i = 0; i < length; i++) { Sound.okistream.streamoutput_Ptrs[0][offset + i] = 0; } for (i = 0; i < 4; i++) { //不每次new，避免GC，排除问题。待验证影响 //short[] sample_data = new short[10000]; int remaining = length; while (remaining != 0) { int samples1 = (remaining > 10000) ? 10000 : remaining; int samp; generate_adpcm(i, sample_data, samples1); for (samp = 0; samp < length; samp++) { Sound.okistream.streamoutput_Ptrs[0][offset + samp] += sample_data[samp]; } remaining -= samples1; } } } public static void okim6295_start() { int voice; compute_tables(); OKI.command = -1; OKI.bank_offset = 0; OKI.master_clock = 1000000; OKI.voice = new ADPCMVoice[4]; adpcm = new adpcm_state[4]; for (voice = 0; voice < 4; voice++) { OKI.voice[voice].volume = 255; reset_adpcm(voice); } } public static void okim6295_reset() { int i; Sound.okistream.stream_update(); for (i = 0; i < 4; i++) { OKI.voice[i].playing = false; } } public static void okim6295_set_bank_base(int base1) { Sound.okistream.stream_update(); OKI.bank_offset = base1; } public static void okim6295_set_pin7(int pin7) { int divisor = pin7 != 0 ? 132 : 165; //stream_set_sample_rate(info->stream, info->master_clock / divisor); } public static int okim6295_status_r() { int i, result; result = 0xf0; Sound.okistream.stream_update(); for (i = 0; i < 4; i++) { ADPCMVoice voice = OKI.voice[i]; if (voice.playing) result |= 1 << i; } return result; } private static void okim6295_data_w(int num, int data) { if (OKI.command != -1) { int temp = data >> 4, i, start, stop; int baseoffset; Sound.okistream.stream_update(); for (i = 0; i < 4; i++, temp >>= 1) { if ((temp & 1) != 0) { baseoffset = OKI.bank_offset + OKI.command * 8; start = ((okirom[baseoffset + 0] << 16) + (okirom[baseoffset + 1] << 8) + okirom[baseoffset + 2]) & 0x3ffff; stop = ((okirom[baseoffset + 3] << 16) + (okirom[baseoffset + 4] << 8) + okirom[baseoffset + 5]) & 0x3ffff; if (start < stop) { if (!OKI.voice[i].playing) { OKI.voice[i].playing = true; OKI.voice[i].base_offset = (uint)start; OKI.voice[i].sample = 0; OKI.voice[i].count = (uint)(2 * (stop - start + 1)); reset_adpcm(i); OKI.voice[i].volume = volume_table[data & 0x0f]; } else { } } else { OKI.voice[i].playing = false; } } } OKI.command = -1; } else if ((data & 0x80) != 0) { OKI.command = data & 0x7f; } else { int temp = data >> 3, i; Sound.okistream.stream_update(); for (i = 0; i < 4; i++, temp >>= 1) { if ((temp & 1) != 0) { OKI.voice[i].playing = false; } } } } public static byte okim6295_status_0_r() { int i; byte result; result = 0xf0; Sound.okistream.stream_update(); for (i = 0; i < 4; i++) { if (OKI.voice[i].playing) { result |= (byte)(1 << i); } } return result; } public static int okim6295_status_0_lsb_r() { return okim6295_status_r(); } public static void okim6295_data_0_w(byte data) { okim6295_data_w(0, data); } public static void okim6295_data_0_lsb_w(byte data) { //if (ACCESSING_BITS_0_7) okim6295_data_w(0, data & 0xff); } public static void SaveStateBinary(BinaryWriter writer) { int i; writer.Write(OKI.command); writer.Write(OKI.bank_offset); for (i = 0; i < 4; i++) { writer.Write(OKI.voice[i].playing); writer.Write(OKI.voice[i].sample); writer.Write(OKI.voice[i].count); writer.Write(OKI.voice[i].volume); writer.Write(OKI.voice[i].base_offset); writer.Write(adpcm[i].signal); writer.Write(adpcm[i].step); } } public static void LoadStateBinary(BinaryReader reader) { int i; OKI.command = reader.ReadInt32(); OKI.bank_offset = reader.ReadInt32(); for (i = 0; i < 4; i++) { OKI.voice[i].playing = reader.ReadBoolean(); OKI.voice[i].sample = reader.ReadUInt32(); OKI.voice[i].count = reader.ReadUInt32(); OKI.voice[i].volume = reader.ReadUInt32(); OKI.voice[i].base_offset = reader.ReadUInt32(); adpcm[i].signal = reader.ReadInt32(); adpcm[i].step = reader.ReadInt32(); } } } }