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Solider Stations


SpiceWare

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One issue with the station graphics is the gaps in the image which are used to create a shadow effect. They look great, but play havoc with collision testing. I built a test version, available below, that lets you move a horizontal shot around with the right joystick. It denotes a collision by changing the score to 888888:

blogentry-3056-0-26158600-1399588804_thumb.png

 

If the shot ends up in a shadow there's nothing to collide with, so the score shows 0:

blogentry-3056-0-46207200-1399588809_thumb.png

 

Collision tests are done row-by-row, so I got to thinking that a way to handle that would be to also consider the rows above and below the row being tested. I should be able to fill in the shadows by ANDing the above and below rows together then ORing that with the row being tested. In pseudo code that'd be (row-1 & row+1) | row.

 

To test the idea, I wrote a quick a command line program. It first outputs the rows of the station using ASCII graphics:

............XXXX................
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..........XXXX..................
..........XXXXXXXX..............
..........XXXX..................
..........XXXXXXXX..............
................................
............XXXX................
 

 

then again as each row would appear for collision testing:

............XXXX................
............XXXX................
..........XXXXXXXX..............
..........XXXXXXXX..............
..........XXXXXXXX..............
..........XXXXXXXX..............
..........XXXXXXXX..............
..........XXXXXXXX..............
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The test can be found in the source in subdirectory quadtest. The results looked good, so I dropped it in. We now get a collision in the shadows:

blogentry-3056-0-17868900-1399588814_thumb.png

 

but not in empty spaces outside the image.

blogentry-3056-0-64880600-1399588819_thumb.png

 

I also changed it so that flying into the station will destroy the station as well as the ship.

 

ROMs

draconian_20140508.bin

draconian_20140508_test.bin

 

Source

Draconian_20140508.zip

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