source/includes/lv2/lv2-midifunctions.h

   1 /****************************************************************************
   2
   3     lv2-midifunctions.h - support file for using MIDI in LV2 plugins
   4
   5     Copyright (C) 2006  Lars Luthman <lars.luthman@gmail.com>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU Lesser General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU Lesser General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 01222-1307  USA
  20
  21 ****************************************************************************/
  22
  23 #ifndef LV2_MIDIFUNCTIONS
  24 #define LV2_MIDIFUNCTIONS
  25
  26 #include "lv2-miditype.h"
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif
  31
  32 typedef struct {
  33   LV2_MIDI* midi;
  34   uint32_t frame_count;
  35   uint32_t position;
  36 } LV2_MIDIState;
  37
  38
  39 inline double lv2midi_get_event(LV2_MIDIState* state,
  40                                 double* timestamp,
  41                                 uint32_t* size,
  42                                 unsigned char** data) {
  43
  44   if (state->position >= state->midi->size) {
  45     state->position = state->midi->size;
  46     *timestamp = state->frame_count;
  47     *size = 0;
  48     *data = NULL;
  49     return *timestamp;
  50   }
  51
  52   *timestamp = *(double*)(state->midi->data + state->position);
  53   *size = (uint32_t)*(size_t*)(state->midi->data + state->position + sizeof(double));
  54   *data = state->midi->data + state->position +
  55     sizeof(double) + sizeof(size_t);
  56   return *timestamp;
  57 }
  58
  59
  60 inline double lv2midi_step(LV2_MIDIState* state) {
  61
  62   if (state->position >= state->midi->size) {
  63     state->position = state->midi->size;
  64     return state->frame_count;
  65   }
  66
  67   state->position += (uint32_t)sizeof(double);
  68   size_t size = *(size_t*)(state->midi->data + state->position);
  69   state->position += (uint32_t)sizeof(size_t);
  70   state->position += (uint32_t)size;
  71   return *(double*)(state->midi->data + state->position);
  72 }
  73
  74
  75 inline void lv2midi_put_event(LV2_MIDIState* state,
  76                              double timestamp,
  77                              uint32_t size,
  78                              const unsigned char* data) {
  79
  80   if (state->midi->size + sizeof(double) + sizeof(size_t) + size < state->midi->capacity)
  81   {
  82     *((double*)(state->midi->data + state->midi->size)) = timestamp;
  83     state->midi->size += (uint32_t)sizeof(double);
  84     *((size_t*)(state->midi->data + state->midi->size)) = size;
  85     state->midi->size += (uint32_t)sizeof(size_t);
  86     memcpy(state->midi->data + state->midi->size, data, size);
  87
  88     state->midi->size += size;
  89     state->midi->event_count++;
  90   }
  91 }
  92
  93 #ifdef __cplusplus
  94 }  /* extern "C" */
  95 #endif
  96
  97 #endif
  98