More interesting information on boundaries

After an integration test today in Integrator 2012 for supporting boundaries, I found out that they are more flexible than what I initially thought (well, this flexibility came with LN2 as it was not present in LN to be fair).

Basically a boundary can be crossed if desired. And crossing a boundary can also trigger the execution of a handler, via a relative offset.

Can you guess what the converging lines below are used for?

Support for boundary lines in Integrator 2012 by Luigi Di Fraia

Support for boundary lines in Integrator 2012

Yes, you guessed it right. When Armakuni crosses these lines the psychotic clown throws him a knife. Yes, it is actually 4 rather than just 3!

What about the following one?

Support for boundary lines in Integrator 2012 by Luigi Di Fraia

Support for boundary lines in Integrator 2012

Correct: Armakuni can escape the “walkable area” through the gap when he is on the upper ledge.

A similar escape gap exists at the end of level 3 where Armakuni can complete the level without killing the alligator šŸ™‚

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2 Responses to More interesting information on boundaries

  1. Phil says:

    That’s really interesting. I always though there must have been some sort of ‘walk-able area map”, or clever use of colours, or something similar, to define where the ninja could walk. I didn’t think of boundary lines!

    So, with just a few bytes J.Twiddy could define lines to mark the walk-able areas. And I guess they don’t even need to be complete polygons, the ninja simply can’t cross lines. With each movement of the ninja I guess all lines for the current screen are checked and if the new position of the ninja would lie on one of the lines then the ninja isn’t moved.

    Can you give any insight into how the code works? I can imagine rounding issues when calculating points on a line which might allow the ninja to get through a line. (I suppose the code could check a block of pixels to see if they are on the line?

    • luigidifraia says:

      What matters is whether before the movement and after it the reference point of Armakuni’s position is still on the same side of the line or not. The line itself can be thought as belonging to either side: the choice does not make any difference.

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