Cruiser X-79 – Migrating to another base

From Richard's C64 blog!

2nd-3rd June 2019

Sunday, I came home and was wondering what I should do. I decided on doing some more work on Cruiser-X 79. I decided to carefully look at the code, and copy/paste it it from CBMPRGStudio to Endurion’s C64Studio. I created a new C64Studio project and called it CruiserX79_2019 and copied and pasted the necessary files. Then afterwards, the hard work was to be done. I had to rename commands to match the ACME syntax. This took about an hour of my time. Then there was the correcting of syntax errors. The labels were mixed case. So I had to relabel those. The errors were then fixed. I compiled, compressed (with Exomizer) and then run the program. The game title screen was running perfectly, but when it come to starting the game. It crashed. I investigated the problem. The culprit was – an incorrect music file was copied. So I corrected this by copying the correct in-game music file and placed it into the bin folder. The game now worked.

While I was testing the migrated build of Cruiser-X 79. I had come across a nasty bug, which I came across a long while ago. The bug was pretty much unknown to me at the time. The issue was where after the player had lost a life. When the shield had run out, the player exploded straight away, without even hitting an enemy, bullet or deadly background. I investigating further into this bug and I found the main culprit that caused it. That was the player death and shield code. After the player was killed by an enemy a pointer PlayerIsDead is set as 1, indicating that the player explodes. All I needed to do was initialize the PlayerIsDead to zero. So that every time the player’s shield is activated, the player should not be dead. That is of course until an alien or deadly background hits the player.

I’m happy very happy to present you with the result and show you a video of the game in action, with a vertical scrolling test map, with all collision working in place. I deliberately set the game into cheat mode, so that you can see that I have indeed fixed the nasty bug. Although there are still one or two minor bugs inside the game preview. Nothing too serious though. Enjoy!

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