the official Channel F thread!

[Mikebloke]

14 hours ago, lazzeri said:

Channel F homebrew scene is on warp speed!

 

It’s getting hard to keep up! 🙂

To be fair, historically you could probably check every leap year and not find anything new  But really good to see other developers on it. I hope to join them one day...

[+atari2600land]

Spent a whole lot of time cleaning things up and making them look better. I added the food falling down, but no collision detection yet. I decided this time instead of a well, Zyx could be on an island in the middle of the Green Sea. You've never heard of the Green Sea? It's right next to the Red one.

zyx3.bin

[Arlasoft]

Anyone come across a bug in the blit function when the background colour is set as clear ($FF) and the first pixel is clear?

 

It seems that by skipping actually outputting the pixel, but having output the row and column to the ports, I occasionally get a phantom pixel appearing near the left edge of the screen when the first solid pixel is drawn. 

 

It also seems to be related to recent joystick activity - I draw my sprite regardless of whether it's moved, but the corruption only happens if I press a joystick direction, even if the sprite isn't moving and has already been successfully drawn the previous time around the game loop. 

EDIT: Simple fix! Save the column value after the outs 4 to R0, then instead of doing ins 4 just load back in from R0. I assume this hasn't come up before because port 4 is joystick 2 and that's what I've got my controls set up on....

 

Edited Friday at 06:46 PM by Arlasoft

[+atari2600land]

It's technically a game now. There is a score, and a way to die, so it's technically a game. But I need some ideas on how to make the game play better. I tried.

• speed of food falling down randomly varies.
• cauliflower moves left to right (or right to left). The key is not to get hit by it. When it lands, it still moves horizontally until it moves off the island.
• missing a blueberry or getting hit by a cauliflower costs you a life.

zyx6.bin

[e5frog]

31 minutes ago, Arlasoft said:

Anyone come across a bug in the blit function when the background colour is set as clear ($FF) and the first pixel is clear?

 

It seems that by skipping actually outputting the pixel, but having output the row and column to the ports, I occasionally get a phantom pixel appearing near the left edge of the screen when the first solid pixel is drawn. 

 

It also seems to be related to recent joystick activity - I draw my sprite regardless of whether it's moved, but the corruption only happens if I press a joystick direction, even if the sprite isn't moving and has already been successfully drawn the previous time around the game loop. 

EDIT: Simple fix! Save the column value after the outs 4 to R0, then instead of doing ins 4 just load back in from R0. I assume this hasn't come up before because port 4 is joystick 2 and that's what I've got my controls set up on....

 

I have had that problem, rearranging the graphics or plotting a pixel has been a way to get around it, Chris had some of it in Golf, pixels showed up at the far left - mostly outside the visible area (unless the TV shows that far). 

Have never looked for why as it rarely has happened. Is the outs/ins fix related to the blit function?

 

 

[Arlasoft]

28 minutes ago, e5frog said:

 Is the outs/ins fix related to the blit function?

 

 

Yeah, when it moves onto the next column it just reads the previous value back in from port 4 and then moves the accumulator along one. So it looks like if you don't actually end up plotting that pixel it is then reading a joystick value back from port 4 instead. So what happens is the entire first row isn't drawn in the right place - I assume most of the time the pixels are not visible but if my sprite is near the corners of the screen some of them are.

I saw this before on the very first blit operation after my game started if I used a 'clear' background, and that must have been because I had just pressed fire to begin.

 

Edited Friday at 07:43 PM by Arlasoft

[e5frog]

It should be in your code I guess, will have a look and update http://channelf.se/veswiki/index.php?title=Snippet:Multiblit
 

[Arlasoft]

Here's a fixed version of Tents & Trees that should now go beyond level 20. 

tents_CF.bin