source/modules/ysfx/sources/ysfx_midi.hpp

   1 // Copyright 2021 Jean Pierre Cimalando
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14 //
  15 // SPDX-License-Identifier: Apache-2.0
  16 //
  17
  18 #pragma once
  19 #include "ysfx.h"
  20 #include <vector>
  21 #include <memory>
  22
  23 struct ysfx_midi_header_t {
  24     uint32_t bus;
  25     uint32_t offset;
  26     uint32_t size;
  27 };
  28
  29 struct ysfx_midi_buffer_t {
  30     std::vector<uint8_t> data;
  31     size_t read_pos = 0;
  32     size_t read_pos_for_bus[ysfx_max_midi_buses] = {};
  33     bool extensible = false;
  34 };
  35 using ysfx_midi_buffer_u = std::unique_ptr<ysfx_midi_buffer_t>;
  36
  37 enum {
  38     ysfx_midi_message_max_size = 1 << 24,
  39 };
  40
  41 // NOTE: regarding buses,
  42 //    The buffer keeps 2 kinds of read positions: global, and per-bus.
  43 //
  44 //    These are tracked separately, so use either global/per-bus reading API,
  45 //    but not both mixed in the same piece of code.
  46 //
  47 //    The JSFX API `midi*` implementations should always use per-bus access:
  48 //    if `ext_midi_bus` is true, use the bus defined by `midi_bus`, otherwise 0.
  49
  50 void ysfx_midi_reserve(ysfx_midi_buffer_t *midi, uint32_t capacity, bool extensible);
  51 void ysfx_midi_clear(ysfx_midi_buffer_t *midi);
  52 bool ysfx_midi_push(ysfx_midi_buffer_t *midi, const ysfx_midi_event_t *event);
  53 void ysfx_midi_rewind(ysfx_midi_buffer_t *midi);
  54 bool ysfx_midi_get_next(ysfx_midi_buffer_t *midi, ysfx_midi_event_t *event);
  55 bool ysfx_midi_get_next_from_bus(ysfx_midi_buffer_t *midi, uint32_t bus, ysfx_midi_event_t *event);
  56
  57 // incremental writer into a midi buffer
  58 struct ysfx_midi_push_t {
  59     ysfx_midi_buffer_t *midi = nullptr;
  60     size_t start = 0;
  61     uint32_t count = 0;
  62     bool eob = false;
  63 };
  64 bool ysfx_midi_push_begin(ysfx_midi_buffer_t *midi, uint32_t bus, uint32_t offset, ysfx_midi_push_t *mp);
  65 bool ysfx_midi_push_data(ysfx_midi_push_t *mp, const uint8_t *data, uint32_t size);
  66 bool ysfx_midi_push_end(ysfx_midi_push_t *mp);
  67
  68 //------------------------------------------------------------------------------
  69
  70 // determine the length of a midi message according to its status byte
  71 // if length is dynamic, returns 0
  72 uint32_t ysfx_midi_sizeof(uint8_t id);