G.T.A.2 Map Editor

[SilverWarior]

Oh you mean altering the texture data directly. Well, you might have glTexSubImage2D(), but i don't have experience of that.

To be honest I also don't have much expirience with this, especially on OpenGL level. I did try once achiving this using Aphyre Sphinx TAsphyreLockableTexture which provides you with acces to each pictures pixel if needed but I don't know which OpenGL cal the Asphyre Sphinx makes for this to work.
Another way would be to simply use ordinary TBitmap to store minimaps data and then render this butmap on screen (many graphical engines alows doing this).

Besides when you're editing the map you are watching the main screen where cursor is. By the time you move your eyes to minimap, with 500ms interval it would already be updated.

@User137 if you need 500ms to change your eyes focus from one point on the monitor to another you gotta be getting realy old
Plese don't be ofended by my previous statement but 500ms is enough for average human not ony change the focus of his eyes from one point to another but to even turn his head for about 30 degres.
Also you have to asume that user decides to change his eyes focus at the same time he decides to do a mouse click. And since it takes a bit of time from the pint when you decide to do mouse click and actually do it your eyes could already be on the half way to destination focus point.

And in the playing mode the minimap is normally not changing. Or if it, you can have an additional transparent map texture for dynamic objects.

Yes using multiple layers for ingame minimaps is quite often especially if the minimap background is made from series of so caled minisprites.