Processing binding for oberonjs

Processing.ob

MODULE Processing;
  IMPORT JS;
   
  TYPE
    ProcessingType* = POINTER TO RECORD END; (* dummy type *)
    CallbackType*   = PROCEDURE;
  VAR
    MouseX*   : REAL;
    MouseY*   : REAL;
    Width*    : INTEGER;
    Height*   : INTEGER;

    DrawProc  : CallbackType;
    SetupProc : CallbackType;
    Instance  : ProcessingType;
    Started   : BOOLEAN;

  (* callbacks *)

  PROCEDURE SetSetupProc*(s : CallbackType);
  BEGIN
    SetupProc := s
  END SetSetupProc;
    
  PROCEDURE SetDrawProc*(d : CallbackType);
  BEGIN
     DrawProc := d
  END SetDrawProc;

  (* global *)
  PROCEDURE SetFrameRate* (fps : INTEGER);
  BEGIN
    JS.do("Instance.frameRate(fps);")
  END SetFrameRate;

  PROCEDURE SetBackground*(argb : INTEGER);
  BEGIN
    JS.do("Instance.background(argb)")
  END SetBackground;

  PROCEDURE SetSize*(w, h : INTEGER);
  BEGIN
    JS.do("Instance.size(w,h);")
  END SetSize;
    
  PROCEDURE Stroke*(argb : INTEGER);
  BEGIN
    JS.do("Instance.stroke(argb)")
  END Stroke;

  (* drawing *)

  PROCEDURE Line*(x0,y0,x1,y1 : REAL);
  BEGIN
    JS.do("Instance.line(x0,y0,x1,y1);");
  END Line;

  (* math *)
  PROCEDURE Radians*(angle : REAL) : REAL;
  VAR
    ret : REAL;
  BEGIN
    JS.do("ret = Instance.radians(angle)");
    RETURN ret
  END Radians;

  (* transform *)
  PROCEDURE Translate*(x,y : REAL);
  BEGIN
    JS.do("Instance.translate(x,y);")
  END Translate;

  PROCEDURE PushMatrix*;
  BEGIN
    JS.do("Instance.pushMatrix();")
  END PushMatrix;

  PROCEDURE PopMatrix*;
  BEGIN
    JS.do("Instance.popMatrix();")
  END PopMatrix;

  PROCEDURE Rotate*(angle : REAL);
  BEGIN
    JS.do("Instance.rotate(angle);")
  END Rotate;
   
  (* internal engine *)

  PROCEDURE InnerDraw;
  BEGIN
    IF DrawProc # NIL THEN
      JS.do("MouseX = Instance.mouseX; MouseY = Instance.mouseY;");
      JS.do("Width = Instance.width; Height = Instance.height;");
      DrawProc
    END
  END InnerDraw;

  PROCEDURE InnerSetup;
  BEGIN
    IF SetupProc # NIL THEN
      SetupProc
    END
  END InnerSetup;
  
  (* start routine *)
  PROCEDURE Start*;
  BEGIN
     ASSERT(~Started);
     JS.do("function sketchProc(p){p.draw=InnerDraw; p.setup=InnerSetup; Instance=p;}");
     JS.do("var canvas = document.getElementById('processingCanvas');");
     JS.do("var processingInstance = new JS.Processing(canvas, sketchProc)");
     Started := TRUE
  END Start;
    
END Processing.