Log inRegister an accountBrowse CSDbHelp & documentationFacts & StatisticsThe forumsAvailable RSS-feeds on CSDbSupport CSDb Commodore 64 Scene Database
You are not logged in - nap
CSDb User Forums


Forums > C64 Coding > LDA (ZP,x)
2016-05-16 14:31
oziphantom

Registered: Oct 2014
Posts: 502
LDA (ZP,x)

Has anybody ever used this opcode and if so what for?
 
... 40 posts hidden. Click here to view all posts....
 
2016-05-20 16:30
oziphantom

Registered: Oct 2014
Posts: 502
Ah that doc in a round about way defines what H is. I've seen it on other sites but nothing defined H. Although it seems to be a typo and it should be H+1. Thanks
2016-05-20 22:13
HCL

Registered: Feb 2003
Posts: 731
Quoting lft
Another thing I've had in mind, but never actually implemented, is this: Suppose you're doing something like kefrens bars with open sideborders. You repeat the last line of a row of characters and modify the font on the fly. But in the borders, you repeat sprite data, let's say one sprite on either side. That means you have a single graphics buffer consisting of 46 bytes, but those bytes are distributed somewhat irregularly in RAM. So make a table in zp consisting of 46 pointers to them. Then use (zp,x) in the drawing operations. You can even access neighbouring cells with (zp-2,x) and (zp+2,x).

Yepp, Slammer is right.. That's what i did in Royal Arte :), but without border :P. Totally forgot about that, and i never thought i ever used (zp,x) :).
2016-05-21 08:56
Wisdom

Registered: Dec 2001
Posts: 91
Used it in Thread Over and in Matrix 16. Might be useful in some size-coding cases.
Previous - 1 | 2 | 3 | 4 | 5 - Next
RefreshSubscribe to this thread:

You need to be logged in to post in the forum.

Search the forum:
Search   for   in  
All times are CET.
Search CSDb
Advanced
Users Online
Krill/Plush
csabanw
Knut Clausen/SHAPE/F..
Guests online: 321
Top Demos
1 Next Level  (9.7)
2 13:37  (9.7)
3 Codeboys & Endians  (9.7)
4 Mojo  (9.6)
5 Coma Light 13  (9.6)
6 Edge of Disgrace  (9.6)
7 Signal Carnival  (9.6)
8 Wonderland XIV  (9.5)
9 Uncensored  (9.5)
10 Comaland 100%  (9.5)
Top onefile Demos
1 Nine  (9.7)
2 Layers  (9.6)
3 Cubic Dream  (9.6)
4 Party Elk 2  (9.6)
5 Copper Booze  (9.5)
6 Scan and Spin  (9.5)
7 Onscreen 5k  (9.5)
8 Grey  (9.5)
9 Dawnfall V1.1  (9.5)
10 Rainbow Connection  (9.5)
Top Groups
1 Artline Designs  (9.3)
2 Booze Design  (9.3)
3 Oxyron  (9.3)
4 Performers  (9.3)
5 Censor Design  (9.3)
Top Logo Graphicians
1 t0m3000  (10)
2 Sander  (9.8)
3 Shine  (9.5)
4 Mermaid  (9.5)
5 Pal  (9.4)

Home - Disclaimer
Copyright © No Name 2001-2025
Page generated in: 0.045 sec.