Thursday 20 December 2012

Winform Map Editor

Last night I finished my side project of migrating the map editor from being a game screen to being a normal windows application (Winform.)  I've been doing this when I needed a break from 3D modelling. 

At the moment all I have attempted to do is move all the features I had before in to a separate project.  I did find a few minor bug fixes but it is basically the same.

The only major change was to the controls for moving about the map.  It now works more like a 3D modelling programme, in fact the rotate, zoom and move are very similar to Blender.  I have however retained first person keyboard controls for fine adjustments.

I am doing most of the modelling in Blender so the new controls are much more familiar when I bring the models in to the editor.

I have left space to the side and bottom of the main view window to put properties.  I have not coded anything to go there yet but in time I will add something useful.

The editor is still linked to the main game.  It shares some of the rendering code and all of the map loading code.  I compile the editor project in the same solution as the main game.  This means that the map files will always remain compatible.

I find it works well.  The only peculiarity I had was that the game view control from the Microsoft sample is external.  Exceptions thrown in the game view crash the control but the rest of the Winform app continues without error.  The view window goes white with a red cross in it!

I fixed that with a simple try and catch wrapped round my update and draw code:

/// Redraws the control in response 
/// to a WinForms paint message.
protected override void OnPaint(PaintEventArgs e)
        string beginDrawError = BeginDraw();

        if (string.IsNullOrEmpty(beginDrawError))
            // Slow the game down to no more 
            // than 60 fps (16.667ms per frame)
            if (gameTime.ElapsedUpdateTime > 
                // My own version of GameTime
                // based on a stopwatch.
                // Simulate the update loop in 
                // an XNA game.
                // Draw the control using the 
                // GraphicsDevice.
            // If BeginDraw failed, show an error 
            // message using System.Drawing.
    catch (Exception ex)
        // Exceptions within external applications do 
        // not automatically break the parent form.
        // These lines trap the exception, display the 
        // error and break the parent code for debugging.
            "Exception in Update or Draw: " + 
            ex.Message + " in " + ex.Source);
            "Stack trace: " + ex.StackTrace);
        throw new Exception(ex.Message);

The whole app now crashes and the exception is displayed to help debugging.

In addition to being able to position, models, triggers, waypoints and generate the navigation mesh used by Bots, I have loads of helper overlays within the editor.  Too many to list:

I nearly forgot.  There was a point to moving the editor out of the main game. 

Every time I tried to change the game I had to keep it compatible with the editor.  There was often lots of extra code just so the game remained fast and the editor had features.

When I started looking at adding in the networking code it just got too complicated to do what I wanted and retain compatibility.  That's what kicked off this little side project.

It's how I should have done it in the first place.

No comments: