Hello Cocoers,
I have just finished coding a sprite demo engine for the CoCo 3, it has been uploaded here:
http://www.coco3.com/community/wp-content/uploads/2009/11/REMDISK_Sprite_Demo.zip
The demo features:
- Fullscreen resolution of 256×192 in 16 colors
- Fast and smooth scrolling background
- Up to 8 sprites, 16×16 pixels, with transparency support
- Very large background: 5440 pixels wide by 192 pixels = 522240 bytes of graphic compressed using tile maps
- 60 frames per second at all time
- Multiple animated background tiles
- Runs on a stock CoCo 3 with 128KB
- Color palette designed for RGB monitor
To control the demo:
At startup, the demo displays 6 sprites. You can’t control them, they circle around the screen.
Move joystick to the right to scroll (scrolling only works in one direction)
Use joystick buttons to add or remove sprites: Button #0 add 1 sprite (up to 8 on the screen), Button #1 remove 1 sprite.
Known bugs or limitations:
- When removing a sprite, sometimes a little bit of ‘garbage’ may be left on the screen
- Some sprites may flicker slightly when reaching the top of screen while scrolling, with background animated tiles.
The source code is 37,779 bytes long and took me countless hours to optimize. I believe this demo can prove a CoCo 3 is so versatile it could outperform a Commodore 64 at graphics.
Comments and suggestions are welcome!
Thank you,
Rem
This post was submitted by remz.
Hi Rem.
Just loaded the demo up. It is wicked mate. The scrolling and sprite movements are way smooth. As for the flickering of some sprites easy fixed for someone like yourself to do. Overall the demo is awesome.
The more you do these demo the more I see a fully fledged Mario type clone been done on the coco 3. you have the Sprite character already designed. now you have background maps done. All I see now is adding them together and a score bar being added.
You make a game for the coco 3 I will buy a copy for sure.
laters
Briza
Just amazing
I sure hope this eventuates into a game someday. I know that’s far easier said than done, but looks like you have the nuts and bolts side of it worked out. Great reuse of colors too. Very impressive
Very nice RemÃ!
The minimum horizontal scroll of several pixels via $FF9F does not seem to have caused you too much trouble.
Is the background effect just $FF9F or are you also shifting the screen data?
It is just $FF9F scrolling, with virtual screen enabled, and drawing next portion of map just outside the screen in front of the scrolling.
The “minimum horizontal scroll problem” would have allowed to scroll slower
Shifting the screen data is not possible at 60 frames per second, unless you shift only some portion of the screen (like Sockmaster’s Moon Patrol demo seems to do)
this is cool… how do you do sprite transparencies?
Hi Paul
The sprite transparency is automatic and free. It could even draw a 16 colors sprite + transparency. The sprite are actually “Compiled sprite”: they are a chunk of STA and LEA,… of precalculated code, so there is no branching and no testing at all during rendering. The transparent pixels are simply non-existent in the code.
The actual sprite processor is a small Perl script I wrote.