Seeing CLOUDS: But outside the sky is clear.  How?
lazarus / 39-Graphics

----------------------------------------------------------------------
Boleeman · 2025-04-25 03:25

Ah ........ that's because the clouds are in digital form.


A Lazarus program to make clouds.

SHARPNESS  --->  Lower is fluffier. Higher is sharper.
DENSITY       --->  0.7=Nearly clear sky, 0.2=Nearly full of clouds.


Enjoy.

----------------------------------------------------------------------
Lulu · 2025-04-25 17:57

Hi Boleeman, thank you for all your graphic demos!

I compiled the clouds demo in debug mode and an exception occurs on
the line:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Timer1Timer(Sender: TObject);...col := RGBToColor(R + Round(z *
(256 - R)), G + Round(z * (256 - G)), B + Round(z * (256 - B)));...
if I replace this line by this one, no more exception:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i col :=
RGBToColor(R + Round(z * (255 - R)), G + Round(z * (255 - G)), B +
Round(z * (255 - B)));
Heaptrc report 102 unfreed memory block at the termination of the
program.
If we add:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.FormDestroy(Sender: TObject);var  i: Integer;begin 
SkyBmp.Free;  for i := 0 to 3 do  begin    OctavesA[i].Free;   
OctavesB[i].Free;  end;  Clouds.Free;end; its not enough, there still
remain 70 unfreed blocks.
Nothing serious, but it's better when the code ends cleanly.

----------------------------------------------------------------------
Boleeman · 2025-04-26 04:12

Thanks Lulu. for finding those errors. For some reason they did not
happen on my Dell AMD Cpu laptop.
I was in a hurry to upload yesterday, as I made quite a number of
other programs.

For the clouds program I also forgot the destructor:

type
  TArray2D = class
  private
    FWidth, FHeight: Integer;
    FData: array of Double;
  public
    constructor Create(AWidth, AHeight: Integer);
    destructor Destroy; override;

and under implementation

{$R *.lfm} 

Add this:

destructor TArray2D.Destroy;
begin
  SetLength(FData, 0); // Or use Finalize(FData);
  inherited Destroy;
end;  




Thank you Lulu for letting me know.

TRon:  Yes it is confusing, but I like the clouds produced and thought
it would be cool to share what I had to others.

----------------------------------------------------------------------
TRon · 2025-04-26 04:20

Funny that when added (though right decision) it makes matters worse 

The 'problem' is that T2darray is a class and in the code it gets
created, stored into a variable and that variable is used to for
example smooth the data, which returns a new instance of T2darray and
assigning to that same variable.

At quick glance there is not an easy fix. E.g. I dunno if it is
possible to for instance apply the effect to the existing instance of
the t2array that will achieve the same results.