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Found a bug that can kill you



During the Vertical Blank the program converts the paddle reading to x-y sprite coordinates as well as setting the X sprite position of the top players and calculating the X positioning values for the bottom players. However, the sequence isn't in the correct order. It's not a major deal, unless you have captured a fireball. If you're holding a fireball then you run the risk of killing yourself even if you've not lost a single brick!The program does the following:
1) Positions the X position of the top players
2) Precalculates the X position of the bottom players
3) Converts all paddle readings to X-Y values
4) starts drawing the visible portion of the screen, where the Y values are used.

The problem occurs when you(as the yellow player) are all the way to the left

And you're trying to move all the way to the right to attack the opposite player

The problem is the paddle readings are converted before the Y value is used, but after the X value is used. By doing this the X value of a paddle reading displayed with the Y value of the next paddle reading and your shield can end up within the wall

or worse, by the king.

If you are holding the fireball and end up by your king then you just killed him. This problem happens to all players.

blogentry-3056-0-86080900-1536163807.png blogentry-3056-0-02722200-1536163812.png blogentry-3056-0-69536800-1536163816.png


The fix is to move step 3 to step 1, and move step 1 and 2 down to steps 2 and 3.


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I have seen this bug before. Most notably at the Philly Classic 5 Warlords Tournament. The player in the top left had the fireball and hadn't lost one brick. When he released the fireball, he killed his warlord. It was harsh because the rules were one and done. He protested but we didn't restart the game.


I can't wait to see more developments on this hack. I'm assuming you're going to fix this bug along with the other improvements.

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That is the plan ;)


At the rate I'm going(and with prior engagements this month) it'll be March or April before I'm done documenting the source code and can start the hacking.

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Just realized all the images were gone as they linked to the defunct photo gallery on my website. I'd removed the gallery a while back as it stopped working after my host updated PHP.


I've replaced the broken links with new images, and added additional images which show the bug occurring with players 2-4.

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