Atari 8bit/5200 application of vector graphics

[+Cafeman]

I would really like to investigate making interesting vector-style graphics on the 5200(/8bit). What mode would you recommend for making vector visuals? Additionally, are there any articles anywhere which would help to explain how a semi-3D engine is written and works on the Atari 8bit?

 

For example, do you need a Z-axis table to determine if your sprite is colliding with objects?

 

Also, I'm unsure how to draw the vector straight lines on-the-fly, given two coordinates. Say I'm in a bitmap mode like Antic E, and I want to draw a triangle with 3 points. Do I keep X,Y,Z coordinates in a table in memory for each point?

 

Now, this question of mine need not generate a lengthy time-consuming response. I appreciate even 'basic overview' advice. I guess that I'm still thinking in terms of PLOT X,Y DrawTo ... in Atari BASIC. I have drawn lines in Koffi (the lightning) put that is from a pre-established path, not on-the-fly.

[Heaven/TQA]

hmmm... cafeman... there are a lot of optimisation needed and of course based on for what you need the stuff and what gfx mode do you use... f.e. in numen we use several gfx modes which of course have implication how the draw routines are done...

 

please have a search on all c=hacking issues for c64 which cover most of the basics (i have 16 issues...all ascii-plain text)

 

implementation on 6502 cpus are similar but you can achive a lot of optimasations depending on the machine you use...

 

http://www.ffd2.com/fridge/chacking/

 

hve

 

ps. don't ask me personally how...i know the basics but not how to programm the stuff

[Heaven/TQA]

and btw... i recommen all c=hacking issues to every atari coder as well... unfortunatly there are a lot of polish docs in several offline & disc magazines but i have no clue...

 

f.e. Mega Magazine (in english... ), Energy #1 + Energy #2 by Taquart, etc...

 

hve

[+Cafeman]

Okay, thank you. I already see that Issue #1 has a good line-drawing article. That kind of stuff will get me on my way faster than starting from scratch.

[DanBoris]

To do 3D you would start with an array of point coordinates (X,Y,Z) and a list of lines that connect these points. To render the screen you would first apply the math to each coordinate to do rotation in the three directions (Yaw, Pitch and Roll), and I believe you would also apply scaling at this point. Next you would apply another formula to each point that would project the 3D coordinates into 2D thus giving you a list of 2D coordinates for each point. Finally you draw lines connecting the points together as needed.

 

There are numerous line drawing algorithms of varying speed and complexity.

 

Dan