[SOLVED] SIGSEGV in TBitmap.SetSize
lazarus / 39-Graphics

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VitalArt · 2018-02-06 03:50

Good time of day,
So I needed to use the TBitMap class to create/edit a picture (it is
supposed to be passed to tAgg2d.Attach). I used roughly the following
code:
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 uses
Graphics; var   img: tbitmap;   a: tAgg2d; begin   a:= tAgg2d.Create; 
 img:= tbitmap.Create;    //img.LoadFromFile('pic.bmp'); {if you call
this, everything works fine}      img.SetSize(500,500); {SIGSEGV in
RawImage_QueryDescription}      img.BeginUpdate;  
 Agg2D.Attach(img);   //draw stuff with agg2d     img.EndUpdate; 
 img.SaveToFile('pic2.bmp'); end. 
But it when I call Setsize, which calls several more functions, I get
a SIGSEGV in iclude/lclintf.inc at line 177 which is:
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 Result :=
WidgetSet.RawImage_QueryDescription(AFlags, ADesc); 
The WidgetSet variable appears to be nil, which is understandable,
since I don't use LCL for anything else. What is interesting is that
if I call img.LoadFromFile before img.SetSize everything works fine:
no SIGSEGV, stuff gets drawn.

So my question is: can I avoid this SIGSEGV without calling
LoadFromFile? I don't want to have to include the whole LCL into my
project either.

For the record, I tried to recreate this situation in a separate
project, but failed due to 'graphics.pp(20,2) Fatal: Cannot open
include file "lcl_defines.inc" ' even though Lazarus opens it fine and
it compiles without problems in my main project.

My apologies for this potentially being a really dumb/involved
question.

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Josh · 2018-02-06 04:41

Hi

Not by machine at the moment; but I remember that I had to use .clear
before I resized a bitmap like that ie
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 a:=
tAgg2d.Create;img:= tbitmap.Create;img.clear;img.SetSize(500,500);

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VitalArt · 2018-02-06 16:19

Unfortunately, I've tried that before, and it didn't work.
Fortunately, I've stumbled onto this thread through google:
http://forum.lazarus.freepascal.org/index.php?topic=32088.0
Unfortunately, when I try to add the Interfaces unit to my project, it
fails to build again with some bizarre error messages. It says:
 'win32int.pp(8,84) Fatal: Cannot find Win32Int used by Interfaces,
incompatible ppu=C:\lazarus\lcl\units\x86_64-win64\win32\win32int.ppu,
package LCL'.
When I click on the error message, it shows another path to the 'not
found' file, which is the root directory of my project, but I just
assume that's where it looks after it decides the one in lcl/units
doesn't suit it.
From what I remember, this happens when the unit was built with
another FPC version. But this can't be, since I just reinstalled
Lazarus from scratch and I've recompiled LCL... What gives?

I even tried adding LCL to my project, but even that doesn't help...

But when I create a new project and select 'Application' there's no
problem. If I remember correctly, my original project was created with
the option 'Program'. Maybe there's some hidden option that causes
that behaviour?

Edit: problem solved here:
https://forum.lazarus.freepascal.org/index.php/topic,39998.0.html