root/ocaml-remix/trunk/noteUtil.ml

(* shift takes an input note, and shifts its render window:

    <-----------------note extent------------------------->
        <------------------------shift amount-----------<---render request--->
        <---actual render--->
 *)

let shift slength note initsound remix start render_extent = 
  let raw_rstart, raw_rlength = Time.extent_to_raw_time remix render_extent in
  let raw_shift = Time.time_to_raw_time remix slength in
  note initsound remix start
          (Time.Samples (raw_rstart + raw_shift), Time.Samples raw_rlength);; 

(* repeat takes an input length and note, and duplicates the note with length 
   as the size.  e.g.

   <---------------------------------------->    (input extent)
   <---length---><---length---><---length--->    (actual note extents)

  For a render request within a single length, this is easy:

  <---length---><---length---><---length--->
                  <ren-req>

  Simply use a note extent of 
    (render_start - note_start)/length*length + note_start, length
  and the existing render request.

  For a render request that crosses multiple lengths, it's slightly harder:
  
  <---length---><---length---><---length--->
             <--render-request-->
  
  We'll use a layer, add three notes of full size:

  <---length---><---length---><---length--->

  then render the size of the render extent out as a new note
  
 *)
let repeat length note initsound remix start render_extent =
  let raw_start, raw_length = Time.extent_to_raw_time remix render_extent in
  let raw_replength = Time.time_to_raw_time remix length in
  let reps = raw_start / raw_replength in
  let repe = (raw_start + raw_length - 1) / raw_replength in
  if reps = repe then (
    note initsound remix 
                  (Time.Samples (reps * raw_replength)) render_extent 
  ) else (
    let l = Layer.empty () in
    let add n s len = Layer.add_note l n (Time.Samples s, Time.Samples len) in
    for i = reps to repe do
      add note (i * raw_replength) raw_replength
    done;
    Layer.to_note l initsound remix start render_extent
    
    (* 
    let first_seg_len = ((reps + 1) * raw_replength) - raw_start in
    let last_seg_start = repe * raw_replength in
    let last_seg_len = raw_start + raw_length - last_seg_start in

    let add n s len = Layer.add_note l n (Time.Samples s, Time.Samples len) in
    add (theshift (reps * raw_replength)) raw_start first_seg_len;
    add (theshift (repe * raw_replength)) last_seg_start last_seg_len;
    for i = reps + 1 to repe - 1 do
      add (theshift (i * raw_replength)) (i * raw_replength) raw_replength
    done;
    *)
  );;