Christmas demo

Wilson · Post by **Wilson** » Thu Dec 24, 2009 2:25 pm

Runs unexpanded. I will not blame you if you turn the volume off

. I just made this demo to say thanks to everyone here at Denial. Happy holidays everyone.

http://cid-d168f0017befba15.skydrive.li ... xmas09.d64

nbla000 · Post by **nbla000** » Thu Dec 24, 2009 4:57 pm

Nice work, Merry Vic-Christmas to you

Post by **Jeff-20** » Fri Dec 25, 2009 12:33 am

I love the snow effect. How did you do that? Bitmap the whole screen?

Mike · Post by **Mike** » Fri Dec 25, 2009 4:44 am

Cool!

Two Xmas demos for the VIC in one year! Thanks for the greetings.

Jeff-20 wrote:I love the snow effect. How did you do that? Bitmap the whole screen?

This is a screen with 16x16 characters. The first 15 lines form a bitmap, while the last line with the wavy ground is done with randomly selected UDGs.

Michael

Wilson · Post by **Wilson** » Fri Dec 25, 2009 7:30 am

Thanks guys

.
You can press the fire button and move the joystick on the snow effect to see something that I almost got working fully.

Mike · Post by **Mike** » Fri Dec 25, 2009 1:18 pm

Cute!

You might consider re-ordering the text screen column-wise, instead of row-wise. This gives a simpler address function and is well covered by the Indirect,Y address mode.

Currently, to plot a point you'll need to calculate:

Code: Select all

AD=$1000+INT(Y/8)*128+INT(X/8)*8+(YAND7)

with a transposed text screen this becomes:

Code: Select all

AD=$1000+INT(X/8)*128+Y

If you also organise the sprite data column-wise, you won't have that many irregularities, which crop up with both bitmap, and sprite being row-wise organised.

Wilson · Post by **Wilson** » Fri Dec 25, 2009 5:44 pm

A very good idea, Mike. This would also simplify shifting the snow down since the last row of each character would be right next to the first row of the next character down. Row-organized, it is 128 bytes away from the character beneath it.

I'm happy to know there's someone examining my humble project in such detail

. I'll keep this in mind for future bitmapping (and next year's Christmas demo!).

Happy holidays,
Wilson