CTheEscape/!TheEsc/c/Sound

#include <stdio.h>
#include "swis.h"
#include <kernel.h>
#include "Sound.h"

// SWI Registers
extern _kernel_swi_regs inreg;
extern _kernel_swi_regs outreg;

int current_element = 0;
int current_playback_element = 0;
int composition_startcent = -1;

struct CompositionElement composition[COMPOSITION_MAX];

char *notes[] = {"AX","A#","BX","CX","C#","DX","D#","EX","FX","F#","GX","G#"};

void sound_on()
{
  inreg.r[0] = 2;
  _kernel_swi(Sound_Enable,&inreg,&outreg);
}

void sound_voices(int num)
{
  inreg.r[0] = num;
  inreg.r[1] = 0;
  inreg.r[2] = 0;
  inreg.r[3] = 0;
  inreg.r[4] = 0;
  _kernel_swi(Sound_Configure,&inreg,&outreg);
}

void sound_set_voice(int voicenum, char* voicename)
{
  inreg.r[0] = voicenum;
  inreg.r[1] = (int) voicename;
  _kernel_swi(Sound_AttachNamedVoice,&inreg,&outreg);
}

void sound_play(unsigned char Channel, signed char Volume, unsigned char Note, unsigned short int Length)
{
  inreg.r[0] = Channel;
  inreg.r[1] = Volume;
  inreg.r[2] = Note;
  inreg.r[3] = Length;
  _kernel_swi(Sound_Control,&inreg,&outreg);
}


void sound_composition_element_play(struct CompositionElement element)
{
  sound_play(element.Channel, element.Volume, element.Note, element.Length);
}


void sound_composition_init()
{
  int i;
  for(i = 0; i <= COMPOSITION_MAX; i++)
  {
    composition[i].Start = -1;
  }
}

void sound_composition_element_add(int start, int channel, int note, int length)
{
  composition[current_element].Start = start;
  composition[current_element].Note = note;
  composition[current_element].Volume = -10;
  composition[current_element].Channel = channel;
  composition[current_element].Length = length;
  current_element++;
}

void sound_composition_debug()
{
  int i;

  printf("------------------------------\n");
  
  for(i = 0; i <= COMPOSITION_MAX; i++)
  {
    if(composition[i].Start >= 0)
    {
      printf("%5d: %3d %4d %3d %4d\n", 
        composition[i].Start,
        composition[i].Note,
        composition[i].Volume,
        composition[i].Channel,
        composition[i].Length
      );
    }
  }
  
  printf("%i elements at %i bytes each\n",current_element,sizeof(composition[0]));

  printf("------------------------------\n");
}

void sound_composition_start(int cent)
{
  composition_startcent = cent;
}

void sound_composition_stop()
{
  current_playback_element = COMPOSITION_MAX;
}

void sound_composition_tick(int cents)
{
  int offset_cents = cents - composition_startcent;
  int i;

  for(i = current_playback_element; i <= COMPOSITION_MAX; i++)
  {
    if(composition[i].Start <= offset_cents)
    {
      if(composition[i].Start >= 0)
      {
        sound_composition_element_play(composition[i]);
        current_playback_element = i + 1;
      }
    }
  }
}

int sound_note(char* note)
{
  int octave = note[1] - 48;
  char *basenote = "ZZ";
  int index = 1;
  int indexi = 0;
  int len = sizeof(notes)/sizeof(notes[0]);
  basenote[0] = note[0];
  if(strlen(note) == 3)
  {
    basenote[1] = '#';
  }else{
    basenote[1] = 'X';
  }
  for(indexi = 0; indexi < len; indexi++)
  {
    if(strcmp(notes[indexi],basenote) == 0)
      index = indexi;
  }
  return 41 + (4 * index) + ((octave - 2) * 48);
}

int sound_composition_incomplete()
{
  if(composition[current_playback_element].Start < 0)
    return 0;
  else
    return 1;
}