There’s a hole in the sky!

Well, I thought it was about time I started blogging again – if only to make me do more to PooperPig!

I just added the ability to change the surface (floor or roof) collision mask – this will let me set up places where certain entities can go through the floor or roof.

Why would I want to do that?

My idea here is that I can put some baddies above the roof. they will be activated when PooperPig comes close to them, and start following him (if they’re that sort of baddy) but can’t get to him.

Then, at some point, there’s a hole in the roof through which they can fall.

Depending on the roof height and textures, they may be invisible to the player, so the first they will know is when a bunch of baddies drop out of the sky 🙂

First try was sort of OK. It all works, but in testing it I changed the texture of the ‘sub-terrain’ above the roof – and what actually changed was the texture below the floor!

Time to put by debugging hat on!

That was easy!

Because roof and floor are so similar, but my C++ knowledge is so limited, I have a bunch of code for handling floor and roof that is similar but not quite identical.

Of course, I should have a single method so that changes to the calculation needn’t be done in two places – but it’s quite neet the way it works & I don’t need to change it at the moment. Perhaps one day!

What had happened was that in my ‘drawRoofSubterrain()’ method I had a call to the method ‘drawSubterrainFloorPortion();


Now that’s fixed, it looks fine (i.e. the terrain above the roof changes where the ‘hole’ should appear. Now to add a baddy!

Baddy added. He falls through the hole, fine!

Unfortunately this has revealed a bug in my baddy code; the baddy accelerates toward Poopy – but if he misses (which he does if he’s stuck above the roof) he doesn’t turn around and come back for another try!

Aha! turns out that friction was set to 0 on the roof and on the baddy so applying the opposite force never changed his direction and wold at best have bought him to a stop!

Fixed that, and (having added friction) the baddy didn’t move at all!

Of course! the force being applied for chasing Poopy was too small.

Adjusted that and now all is well. Baddy chases Poopy, while stuck above the roof, until it comes across the hole, when it drops down.

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