Software sprites on the Vic

[AndyH]

I made a video showing how to draw software sprites on the Vic 20 with Turbo Rascal, thought it might be useful to link to here.

[Vic20-Ian]

Very nice. Great video. Thank you.

[nbla000]

thanks for sharing these info !

[chysn]

Nice!

After watching this, I've implemented "wait for raster" in my own (ML) sprite code, and it makes a huge difference in terms of how smooth sprites look.

[mathom]

Excellent video. Thank you. Now I just need to get TRSE set up properly on my Mac. I can't seem to get it to launch VICE properly. I think I'll make a new thread for that...

[chysn]

Excellent video. Thank you. Now I just need to get TRSE set up properly on my Mac. I can't seem to get it to launch VICE properly. I think I'll make a new thread for that...

It's pretty straightforward with VICE 3.5 (https://vice-emu.sourceforge.io/macosx.html). Install that, and in TRSE go to Tools > TRSE Settings > Emulators, and choose the path to xvic.app in the VIC-20 line. Then TRSE's "Run" button should open VICE and run the code.

[mathom]

Thank you for that. For some reason that was not working for me the other day. VICE would start but then lock up. Seems to be working fine today. Now it's time to explore!

[AndyH]

Nice!

After watching this, I've implemented "wait for raster" in my own (ML) sprite code, and it makes a huge difference in terms of how smooth sprites look.

Picking a nice location (PAL / NTSC) for where the raster is, such as when it reaches the start of the bottom border, can help give you a few more cycles before the screen refresh starts working where your bitmap is again. However, I tend to favour setting up an interrupt and incrementing a tick counter which I did not include in the video. I find this useful because:-

1. I can disable the keyboard scan in the interrupt to save on cycles (I do my own faster scan when needed)
2. I can detect a change in the tick counter to now when a refresh has occurred and soemtimes it is fine if I have gone over a little
3. I can use the tick counter to synchronsie updates of different objects on the bitmap.

[chysn]

Good ideas, thanks!

What version of TRSE is used in this video?

[AndyH]

The nightly build, but I have a dark theme, C64 font and some bespoke colouring on the BEGIN END keywords, if you are wondering about the way the editor looks.

[Noizer]

It looks like an easy task for those who can't code, but I don't think so. Surely it would help one or the other to start something.
Please always remember to respect the aspect ratio of the sprites. Looks very strange if not.
BR

[chysn]

The video starts with the Character Map. How do you get to the Character Map?

[AndyH]

You have to create a FLF file with :

File - New File - Image/charsetset/sprite

Depending upon the platform you have selected it will show some options.