On Thursday 27 January 2005 07:50, Timothy Miller wrote:
> Quick note regarding aliased lines:  It's not exactly bresenham, but
> the vertical rasterizer can be programmed to generate the same set of
> points with the same efficiency.  That's why there's a "swap_xy" flag
> in there to support x-major lines.

Hi Timothy

There is no magic advantage for Bresenham vs a fixed point line 
iterator, I only used the term because "aliased line" didn't occur to 
me.  With a fixed point line iterator you need a divide per line, but 
the iterator logic is simpler, is that correct?  Based on my 
pathetically limited knowledge of hardware logic, I guess the fixed 
point iterator is a slightly better approach.

What eventually happened to the DRAM row addressing question, was it 
decided to address the RAM in rectangles?  This looks like a big win 
for small triangles as well as lines.

And where did the divide implementation end up?  Based on a little web 
research, it looks to me that Newton-Raphson is the way to go.  A 512 
entry lookup plus one iteration gets 18 bits precision.  Unfortunately, 
it's completely beyond me to estimate the logic propagation delay.

Regards,

Daniel
_______________________________________________
Open-graphics mailing list
[email protected]
http://lists.duskglow.com/mailman/listinfo/open-graphics
List service provided by Duskglow Consulting, LLC (www.duskglow.com)

Reply via email to