Writting map editor from scratch tutorial (With Allegro)

[SilverWarior]

Well, allegro.pas don't mix well with Lazarus' forms

None of the game graphical engines doesn't mix wel with either VCL or LCL. The main reason for this is the technology that is used for each learegly differs from others.
Most game graphical libraries use either DirectX or OpenGL as their main technology.
VCL and LCL use default system GUI which is quite slow in comparison to DirectX or OpenGL. Also the biggest problem of default OS GUI is that it laregly depends on system messages which can also be quite slow. That is why it is much better to create your own internal game messaging system rather than using OS messaging system.

[laggyluk]

I'm experimenting with forms based ui along with opengl scene rendering, so far so good

[User137]

I'm experimenting with forms based ui along with opengl scene rendering, so far so good

No problems with that, as long as you don't draw WinAPI controls, such as buttons on top of rendering scene.