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Diffstat (limited to 'src/chips/ymfm/ymfm.h')
| -rw-r--r-- | src/chips/ymfm/ymfm.h | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/src/chips/ymfm/ymfm.h b/src/chips/ymfm/ymfm.h new file mode 100644 index 0000000..ccd0d6c --- /dev/null +++ b/src/chips/ymfm/ymfm.h @@ -0,0 +1,573 @@ +// BSD 3-Clause License +// +// Copyright (c) 2021, Aaron Giles +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this +// list of conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE +// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#ifndef YMFM_H +#define YMFM_H + +#pragma once + +#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS) + #define _CRT_SECURE_NO_WARNINGS +#endif + +#include <cassert> +#include <cstdint> +#include <cstdio> +#include <cstring> +#include <algorithm> +#include <memory> +#include <string> +#include <vector> + +namespace ymfm +{ + +//********************************************************* +// DEBUGGING +//********************************************************* + +class debug +{ +public: + // masks to help isolate specific channels + static constexpr uint32_t GLOBAL_FM_CHANNEL_MASK = 0xffffffff; + static constexpr uint32_t GLOBAL_ADPCM_A_CHANNEL_MASK = 0xffffffff; + static constexpr uint32_t GLOBAL_ADPCM_B_CHANNEL_MASK = 0xffffffff; + static constexpr uint32_t GLOBAL_PCM_CHANNEL_MASK = 0xffffffff; + + // types of logging + static constexpr bool LOG_FM_WRITES = false; + static constexpr bool LOG_KEYON_EVENTS = false; + static constexpr bool LOG_UNEXPECTED_READ_WRITES = false; + + // helpers to write based on the log type + template<typename... Params> static void log_fm_write(Params &&... args) { if (LOG_FM_WRITES) log(args...); } + template<typename... Params> static void log_keyon(Params &&... args) { if (LOG_KEYON_EVENTS) log(args...); } + template<typename... Params> static void log_unexpected_read_write(Params &&... args) { if (LOG_UNEXPECTED_READ_WRITES) log(args...); } + + // downstream helper to output log data; defaults to printf + template<typename... Params> static void log(Params &&... args) { printf(args...); } +}; + + + +//********************************************************* +// GLOBAL HELPERS +//********************************************************* + +//------------------------------------------------- +// bitfield - extract a bitfield from the given +// value, starting at bit 'start' for a length of +// 'length' bits +//------------------------------------------------- + +inline uint32_t bitfield(uint32_t value, int start, int length = 1) +{ + return (value >> start) & ((1 << length) - 1); +} + + +//------------------------------------------------- +// clamp - clamp between the minimum and maximum +// values provided +//------------------------------------------------- + +inline int32_t clamp(int32_t value, int32_t minval, int32_t maxval) +{ + if (value < minval) + return minval; + if (value > maxval) + return maxval; + return value; +} + + +//------------------------------------------------- +// array_size - return the size of an array +//------------------------------------------------- + +template<typename ArrayType, int ArraySize> +constexpr uint32_t array_size(ArrayType (&array)[ArraySize]) +{ + (void)array; + return ArraySize; +} + + +//------------------------------------------------- +// count_leading_zeros - return the number of +// leading zeros in a 32-bit value; CPU-optimized +// versions for various architectures are included +// below +//------------------------------------------------- + +#if defined(__GNUC__) + +inline uint8_t count_leading_zeros(uint32_t value) +{ + if (value == 0) + return 32; + return __builtin_clz(value); +} + +#elif defined(_MSC_VER) + +inline uint8_t count_leading_zeros(uint32_t value) +{ + unsigned long index; + return _BitScanReverse(&index, value) ? uint8_t(31U - index) : 32U; +} + +#else + +inline uint8_t count_leading_zeros(uint32_t value) +{ + if (value == 0) + return 32; + uint8_t count; + for (count = 0; int32_t(value) >= 0; count++) + value <<= 1; + return count; +} + +#endif + + +// Many of the Yamaha FM chips emit a floating-point value, which is sent to +// a DAC for processing. The exact format of this floating-point value is +// documented below. This description only makes sense if the "internal" +// format treats sign as 1=positive and 0=negative, so the helpers below +// presume that. +// +// Internal OPx data 16-bit signed data Exp Sign Mantissa +// ================= ================= === ==== ======== +// 1 1xxxxxxxx------ -> 0 1xxxxxxxx------ -> 111 1 1xxxxxxx +// 1 01xxxxxxxx----- -> 0 01xxxxxxxx----- -> 110 1 1xxxxxxx +// 1 001xxxxxxxx---- -> 0 001xxxxxxxx---- -> 101 1 1xxxxxxx +// 1 0001xxxxxxxx--- -> 0 0001xxxxxxxx--- -> 100 1 1xxxxxxx +// 1 00001xxxxxxxx-- -> 0 00001xxxxxxxx-- -> 011 1 1xxxxxxx +// 1 000001xxxxxxxx- -> 0 000001xxxxxxxx- -> 010 1 1xxxxxxx +// 1 000000xxxxxxxxx -> 0 000000xxxxxxxxx -> 001 1 xxxxxxxx +// 0 111111xxxxxxxxx -> 1 111111xxxxxxxxx -> 001 0 xxxxxxxx +// 0 111110xxxxxxxx- -> 1 111110xxxxxxxx- -> 010 0 0xxxxxxx +// 0 11110xxxxxxxx-- -> 1 11110xxxxxxxx-- -> 011 0 0xxxxxxx +// 0 1110xxxxxxxx--- -> 1 1110xxxxxxxx--- -> 100 0 0xxxxxxx +// 0 110xxxxxxxx---- -> 1 110xxxxxxxx---- -> 101 0 0xxxxxxx +// 0 10xxxxxxxx----- -> 1 10xxxxxxxx----- -> 110 0 0xxxxxxx +// 0 0xxxxxxxx------ -> 1 0xxxxxxxx------ -> 111 0 0xxxxxxx + +//------------------------------------------------- +// encode_fp - given a 32-bit signed input value +// convert it to a signed 3.10 floating-point +// value +//------------------------------------------------- + +inline int16_t encode_fp(int32_t value) +{ + // handle overflows first + if (value < -32768) + return (7 << 10) | 0x000; + if (value > 32767) + return (7 << 10) | 0x3ff; + + // we need to count the number of leading sign bits after the sign + // we can use count_leading_zeros if we invert negative values + int32_t scanvalue = value ^ (int32_t(value) >> 31); + + // exponent is related to the number of leading bits starting from bit 14 + int exponent = 7 - count_leading_zeros(scanvalue << 17); + + // smallest exponent value allowed is 1 + exponent = std::max(exponent, 1); + + // mantissa + int32_t mantissa = value >> (exponent - 1); + + // assemble into final form, inverting the sign + return ((exponent << 10) | (mantissa & 0x3ff)) ^ 0x200; +} + + +//------------------------------------------------- +// decode_fp - given a 3.10 floating-point value, +// convert it to a signed 16-bit value +//------------------------------------------------- + +inline int16_t decode_fp(int16_t value) +{ + // invert the sign and the exponent + value ^= 0x1e00; + + // shift mantissa up to 16 bits then apply inverted exponent + return int16_t(value << 6) >> bitfield(value, 10, 3); +} + + +//------------------------------------------------- +// roundtrip_fp - compute the result of a round +// trip through the encode/decode process above +//------------------------------------------------- + +inline int16_t roundtrip_fp(int32_t value) +{ + // handle overflows first + if (value < -32768) + return -32768; + if (value > 32767) + return 32767; + + // we need to count the number of leading sign bits after the sign + // we can use count_leading_zeros if we invert negative values + int32_t scanvalue = value ^ (int32_t(value) >> 31); + + // exponent is related to the number of leading bits starting from bit 14 + int exponent = 7 - count_leading_zeros(scanvalue << 17); + + // smallest exponent value allowed is 1 + exponent = std::max(exponent, 1); + + // apply the shift back and forth to zero out bits that are lost + exponent -= 1; + return (value >> exponent) << exponent; +} + + + +//********************************************************* +// HELPER CLASSES +//********************************************************* + +// various envelope states +enum envelope_state : uint32_t +{ + EG_DEPRESS = 0, // OPLL only; set EG_HAS_DEPRESS to enable + EG_ATTACK = 1, + EG_DECAY = 2, + EG_SUSTAIN = 3, + EG_RELEASE = 4, + EG_REVERB = 5, // OPQ/OPZ only; set EG_HAS_REVERB to enable + EG_STATES = 6 +}; + +// external I/O access classes +enum access_class : uint32_t +{ + ACCESS_IO = 0, + ACCESS_ADPCM_A, + ACCESS_ADPCM_B, + ACCESS_PCM, + ACCESS_CLASSES +}; + + + +//********************************************************* +// HELPER CLASSES +//********************************************************* + +// ======================> ymfm_output + +// struct containing an array of output values +template<int NumOutputs> +struct ymfm_output +{ + // clear all outputs to 0 + ymfm_output &clear() + { + for (uint32_t index = 0; index < NumOutputs; index++) + data[index] = 0; + return *this; + } + + // clamp all outputs to a 16-bit signed value + ymfm_output &clamp16() + { + for (uint32_t index = 0; index < NumOutputs; index++) + data[index] = clamp(data[index], -32768, 32767); + return *this; + } + + // run each output value through the floating-point processor + ymfm_output &roundtrip_fp() + { + for (uint32_t index = 0; index < NumOutputs; index++) + data[index] = ymfm::roundtrip_fp(data[index]); + return *this; + } + + // internal state + int32_t data[NumOutputs]; +}; + + +// ======================> ymfm_wavfile + +// this class is a debugging helper that accumulates data and writes it to wav files +template<int Channels> +class ymfm_wavfile +{ +public: + // construction + ymfm_wavfile(uint32_t samplerate = 44100) : + m_samplerate(samplerate) + { + } + + // configuration + ymfm_wavfile &set_index(uint32_t index) { m_index = index; return *this; } + ymfm_wavfile &set_samplerate(uint32_t samplerate) { m_samplerate = samplerate; return *this; } + + // destruction + ~ymfm_wavfile() + { + if (!m_buffer.empty()) + { + // create file + char name[20]; + sprintf(name, "wavlog-%02d.wav", m_index); + FILE *out = fopen(name, "wb"); + + // make the wav file header + uint8_t header[44]; + memcpy(&header[0], "RIFF", 4); + *(uint32_t *)&header[4] = m_buffer.size() * 2 + 44 - 8; + memcpy(&header[8], "WAVE", 4); + memcpy(&header[12], "fmt ", 4); + *(uint32_t *)&header[16] = 16; + *(uint16_t *)&header[20] = 1; + *(uint16_t *)&header[22] = Channels; + *(uint32_t *)&header[24] = m_samplerate; + *(uint32_t *)&header[28] = m_samplerate * 2 * Channels; + *(uint16_t *)&header[32] = 2 * Channels; + *(uint16_t *)&header[34] = 16; + memcpy(&header[36], "data", 4); + *(uint32_t *)&header[40] = m_buffer.size() * 2 + 44 - 44; + + // write header then data + fwrite(&header[0], 1, sizeof(header), out); + fwrite(&m_buffer[0], 2, m_buffer.size(), out); + fclose(out); + } + } + + // add data to the file + template<int Outputs> + void add(ymfm_output<Outputs> output) + { + int16_t sum[Channels] = { 0 }; + for (int index = 0; index < Outputs; index++) + sum[index % Channels] += output.data[index]; + for (int index = 0; index < Channels; index++) + m_buffer.push_back(sum[index]); + } + + // add data to the file, using a reference + template<int Outputs> + void add(ymfm_output<Outputs> output, ymfm_output<Outputs> const &ref) + { + int16_t sum[Channels] = { 0 }; + for (int index = 0; index < Outputs; index++) + sum[index % Channels] += output.data[index] - ref.data[index]; + for (int index = 0; index < Channels; index++) + m_buffer.push_back(sum[index]); + } + +private: + // internal state + uint32_t m_index; + uint32_t m_samplerate; + std::vector<int16_t> m_buffer; +}; + + +// ======================> ymfm_saved_state + +// this class contains a managed vector of bytes that is used to save and +// restore state +class ymfm_saved_state +{ +public: + // construction + ymfm_saved_state(std::vector<uint8_t> &buffer, bool saving) : + m_buffer(buffer), + m_offset(saving ? -1 : 0) + { + if (saving) + buffer.resize(0); + } + + // are we saving or restoring? + bool saving() const { return (m_offset < 0); } + + // generic save/restore + template<typename DataType> + void save_restore(DataType &data) + { + if (saving()) + save(data); + else + restore(data); + } + +public: + // save data to the buffer + void save(bool &data) { write(data ? 1 : 0); } + void save(int8_t &data) { write(data); } + void save(uint8_t &data) { write(data); } + void save(int16_t &data) { write(uint8_t(data)).write(data >> 8); } + void save(uint16_t &data) { write(uint8_t(data)).write(data >> 8); } + void save(int32_t &data) { write(data).write(data >> 8).write(data >> 16).write(data >> 24); } + void save(uint32_t &data) { write(data).write(data >> 8).write(data >> 16).write(data >> 24); } + void save(envelope_state &data) { write(uint8_t(data)); } + template<typename DataType, int Count> + void save(DataType (&data)[Count]) { for (uint32_t index = 0; index < Count; index++) save(data[index]); } + + // restore data from the buffer + void restore(bool &data) { data = read() ? true : false; } + void restore(int8_t &data) { data = read(); } + void restore(uint8_t &data) { data = read(); } + void restore(int16_t &data) { data = read(); data |= read() << 8; } + void restore(uint16_t &data) { data = read(); data |= read() << 8; } + void restore(int32_t &data) { data = read(); data |= read() << 8; data |= read() << 16; data |= read() << 24; } + void restore(uint32_t &data) { data = read(); data |= read() << 8; data |= read() << 16; data |= read() << 24; } + void restore(envelope_state &data) { data = envelope_state(read()); } + template<typename DataType, int Count> + void restore(DataType (&data)[Count]) { for (uint32_t index = 0; index < Count; index++) restore(data[index]); } + + // internal helper + ymfm_saved_state &write(uint8_t data) { m_buffer.push_back(data); return *this; } + uint8_t read() { return (m_offset < int32_t(m_buffer.size())) ? m_buffer[m_offset++] : 0; } + + // internal state + std::vector<uint8_t> &m_buffer; + int32_t m_offset; +}; + + + +//********************************************************* +// INTERFACE CLASSES +//********************************************************* + +// ======================> ymfm_engine_callbacks + +// this class represents functions in the engine that the ymfm_interface +// needs to be able to call; it is represented here as a separate interface +// that is independent of the actual engine implementation +class ymfm_engine_callbacks +{ +public: + // timer callback; called by the interface when a timer fires + virtual void engine_timer_expired(uint32_t tnum) = 0; + + // check interrupts; called by the interface after synchronization + virtual void engine_check_interrupts() = 0; + + // mode register write; called by the interface after synchronization + virtual void engine_mode_write(uint8_t data) = 0; +}; + + +// ======================> ymfm_interface + +// this class represents the interface between the fm_engine and the outside +// world; it provides hooks for timers, synchronization, and I/O +class ymfm_interface +{ + // the engine is our friend + template<typename RegisterType> friend class fm_engine_base; + +public: + virtual ~ymfm_interface() {} + // the following functions must be implemented by any derived classes; the + // default implementations are sufficient for some minimal operation, but will + // likely need to be overridden to integrate with the outside world; they are + // all prefixed with ymfm_ to reduce the likelihood of namespace collisions + + // + // timing and synchronizaton + // + + // the chip implementation calls this when a write happens to the mode + // register, which could affect timers and interrupts; our responsibility + // is to ensure the system is up to date before calling the engine's + // engine_mode_write() method + virtual void ymfm_sync_mode_write(uint8_t data) { m_engine->engine_mode_write(data); } + + // the chip implementation calls this when the chip's status has changed, + // which may affect the interrupt state; our responsibility is to ensure + // the system is up to date before calling the engine's + // engine_check_interrupts() method + virtual void ymfm_sync_check_interrupts() { m_engine->engine_check_interrupts(); } + + // the chip implementation calls this when one of the two internal timers + // has changed state; our responsibility is to arrange to call the engine's + // engine_timer_expired() method after the provided number of clocks; if + // duration_in_clocks is negative, we should cancel any outstanding timers + virtual void ymfm_set_timer(uint32_t tnum, int32_t duration_in_clocks) { (void)tnum; (void)duration_in_clocks; } + + // the chip implementation calls this to indicate that the chip should be + // considered in a busy state until the given number of clocks has passed; + // our responsibility is to compute and remember the ending time based on + // the chip's clock for later checking + virtual void ymfm_set_busy_end(uint32_t clocks) { (void)clocks; } + + // the chip implementation calls this to see if the chip is still currently + // is a busy state, as specified by a previous call to ymfm_set_busy_end(); + // our responsibility is to compare the current time against the previously + // noted busy end time and return true if we haven't yet passed it + virtual bool ymfm_is_busy() { return false; } + + // + // I/O functions + // + + // the chip implementation calls this when the state of the IRQ signal has + // changed due to a status change; our responsibility is to respond as + // needed to the change in IRQ state, signaling any consumers + virtual void ymfm_update_irq(bool asserted) { (void)asserted; } + + // the chip implementation calls this whenever data is read from outside + // of the chip; our responsibility is to provide the data requested + virtual uint8_t ymfm_external_read(access_class type, uint32_t address) { (void)type; (void)address; return 0; } + + // the chip implementation calls this whenever data is written outside + // of the chip; our responsibility is to pass the written data on to any consumers + virtual void ymfm_external_write(access_class type, uint32_t address, uint8_t data) { (void)type; (void)address; (void)data; } + +protected: + // pointer to engine callbacks -- this is set directly by the engine at + // construction time + ymfm_engine_callbacks *m_engine; +}; + +} + +#endif // YMFM_H |