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Hi

There are an error if not you are using an function result, the following code (cut and somewhat modified from one of my projects) demonstrate :

Code

function Scale(Ix, Iy : longint; var Dx, Dy : longint) : extended;
var
  wf,
  ff,
  hf : extended;
 
begin
  wf := ix / dx;
  hf := iy / dy;
 
  if (wf > hf) then ff := wf
  else ff := hf;
 
  dx := round(ix / ff);
  dy := round(iy / ff);
 
  result := ff;
end;
 
Procedure TForm1.Button1OnClick (Sender: TObject);
var
  w,
  x,
  y : longint;
  f : extended;
 
Begin
  for w := 402 to 410 do
  begin
    x := 500;
    y := w;
    f := scale(2087,1691,x,y);
    memo1.lines.add(inttostr(w) + ' / ' + inttostr(x) + ' / ' + inttostr(y));
  end;
  memo1.lines.add('**********');
  for w := 402 to 410 do
  begin
    x := 500;
    y := w;
    scale(2087,1691,x,y);
    memo1.lines.add(inttostr(w) + ' / ' + inttostr(x) + ' / ' + inttostr(y));
  end;
end;

Please observe, the only difference between the two parts of the program is the "f :=" before Scale in the first part, but the result is as follows (first part is the correct one) :

402 / 496 / 402
403 / 497 / 403
404 / 499 / 404
405 / 500 / 405
406 / 500 / 405
407 / 500 / 405
408 / 500 / 405
409 / 500 / 405
410 / 500 / 405
**********
402 / 496 / 402
403 / 497 / 403
404 / 499 / 404
405 / 500 / 405
406 / 500 / 405
407 / 500 / 405
408 / 500 / 405
409 / 505 / 409
410 / 506 / 410

And not only the calculations are affected, I have been hunting many wierd errors before I found out this was the culprit.

Kim Foder