Re[3]: Object IO, fast window redraw

[Valery A.Khamenya]

Hello Peter and clean-list,

Tuesday, May 23, 2000, 8:44:02 PM, you wrote:

PA> As I observed in my reply, much depends on the actual algorithm. I am not
PA> sure what you mean with your last remark:

>>the main delay as I guess stands for update window procedure in/after
>>every drawPoint call.

PA> drawPoint, as any StdPicture function, does nothing more than performing 
PA> the specified task.

OK, but I see slow pixel-by-pixel drawing. I'd wait that whole
the picture will be drawn (somewhere in OS area) and only then shown
at screen. "wholesale", not pixel-by-pixel: draw,show, draw,show ...

PA> The *Picture environment is a specialised sub 
PA> environment in which drawing occurs. This environment must be retrieved 
PA> from the super environment (either PSt or IOSt).This is a rather
PA> costly action. 

it is clear. However for drawing I use my function supplied via
WindowLook attribute like this:

window = Window "Bitmap" NilLS
      [ WindowViewSize  bitmapsize
      , WindowLook      True lookfunc
      , WindowClose     (noLS closeProcess)
      ]

and I do nothing for retreiving that Picture from the super
environment (either PSt or IOSt), this a problem of caller of lookfunc.

PA>  I don't know if you're doing this per pixel, but if you do then I
PA> suggest to minimise this as well.

I do. And how I can "minimize this"?

the super environment (either PSt or IOSt).


here is my code:
//---------------------------------------------
some_matrix = [[j \\ j<-[0..80] ] \\ k<-[0..80] ]
lookfunc = (\_ _ ->drawmat {x=0,y=0} some_matrix)

drawrow::Vector *Picture ->*Picture
drawrow  [] pic = pic
drawrow  [v:vs] pic = 
  ((drawrow vs) o
  (drawPoint) o
  (setPenColour (RGB {r=v,g= v,b= v})) ) pic


drawmat:: !Point2 !Matrix !*Picture -> !*Picture
drawmat _ [] pic = pic
drawmat pnt [row:rows] pic 
        = ((drawmat {x=pnt.x, y=pnt.y+1} rows) 
        o (drawrow row) 
        o (setPenSize 1) 
        o (setPenPos {x=pnt.x, y=pnt.y})) pic

//------------------------------------

Is there an advice?

thank you in advance.

-- 
Best regards,
 Valery                            mailto:khamenya@module.ru