I’ve been noticing a glitch that the monsters would show their death graphic when entering a room for a split second if the player just killed that exact corresponding monster in the last room that he or she was in. This was a simple fix. I just made all the monsters appear completely black when the player first enters the room for a single frame before the bank is called to draw what the monsters are actually suppose to look like. (Update: This was a sloppy way to “fix” this, I did it the right way later)
I was running out of space again so I readjusted alot of code into different banks and changed different bank calls. I also got rid of a very bad screen jump/flicker bug. It always ran smooth in the Stella emulator, but if I ran the game on actual Atari 2600 hardware, sometimes the whole screen would jump around when entering a new room. The reason for this was I was sometimes going over my 262 cycle limit. Say the player walked up into a door to the North, but was also entering it diagonally by going North-East. This would run a bit more code then it normally would to walk through a door because it was running the collision detection for the North and for the East as the player was also walking through the door and loading the next room. Just that little bit of extra code was too much for the Atari and would cause the screen to jump a bit. This was very ugly and bothered me a lot. I really wanted to fix it for a while now but everything I tried wasn’t working and seemed like it might not be possible. What I ended up doing was made the code check the player’s x and y position when near a doorway, and if it was just a couple pixels from the door then it would ignore the diagonal code and just go straight through the door. This saved cycles by avoiding cycle heavy collision detection that was not necessary when traveling through a doorway.
One thing I am really pleased and excited about is I added a running ability to the player. I haven’t decided yet if the player will always be able to run or maybe have a hidden item like Boots or some type of suit that will allow him to move a lot quicker. For now though you have the ability from the start. If you hold in the fire button for two seconds the player will begin to run until you let go of the fire button. This was a bit more complicated then it sounds. I had to learn about 4.4 and 8.8 fixed point integers on the Random Terrain website and adjust how the player’s overall movement and collision detection worked so that they would work properly with the fixed point integers. When I switched to the fixed point to handle movement, the collision detection hit the bucket because the numbers were no longer solid integers anymore, they were floats. But now that I got that figured out, the game I find is a lot more fun to play and it will make it easier and quicker to run through rooms that the player has already cleared.
Now that I have complete understanding of Fixed point integers, I need to go into how the monster movement and collision works and implement the fixed point in there. This will allow me to have much more precision on monster’s speeds the deeper the player goes down the dungeon. This will make the game much more challenging and fun as the player gets better at the game mechanics.
I’ve worked on this game for about 14 days now, teaching myself how to code for Atari and writing the game as I go along. Each day I usually spent around 12 hours of researching and coding. So according to that I have spent about 168 hours on this game so far! That doesn’t actually sound half bad to me, considering I can see the finish line over the horizon. Very exciting stuff 🙂