Databases
StackOverflow2013
Postsdbo
POLooking for a fast polygon rendering algorithm
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POLooking for a fast polygon rendering algorithm
    primarykey
    data
    text
    <p>I am working with a Microchip dsPIC33FJ128GP802. It's a small DSP-based microcontroller, and it doesn't have much power (40 million instructions per second). I'm looking for a way to render a convex (i.e. simple) polygon. I am only dealing with 2D shapes, integer math, and set or clear pixels (i.e. 1 bit per pixel.) I already have routines for drawing fast horizontal and vertical lines (writing up to 16 pixels in 88 cycles), so I would like to use a scanline algorithm. </p> <p>However, all the algorithms I have found seem to depend on division (which takes 18 cycles on this processor) and floating point math (which is emulated in software and so is very slow; it also takes up a lot of ROM), or assume that I have a large amount of memory. I only have 2K left, ~14K is used for graphics RAM of my 16K. So does anyone know of any good, embedded machine algorithms they can point me to with a simple C or pseudocode implementation which I can implement in assembly? Preferably on the 'net, I don't live near any good bookstores with many programming books.</p> <p>Thanks. :)</p> <p>EDIT: Clarification, this is a polygon filling algorithm I'm looking for. I can implement a polygon outline algorithm using Bresenham's line drawing algorithm (as Marc B suggests.)</p> <p>EDIT #2: I wanted to let everyone know I got a basic algorithm up in Python. Here's a link to the code. Public domain code.</p> <p><a href="http://dl.dropbox.com/u/1134084/bresenham_demos.py" rel="nofollow noreferrer">http://dl.dropbox.com/u/1134084/bresenham_demos.py</a> </p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USThomas O
    1. USThomas O
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POLooking for a fast polygon rendering algorithm
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POLooking for a fast polygon rendering algorithm
      1. USNate Zaugg
      1. VTFavorite
    3. VO
      singulars
      1. POLooking for a fast polygon rendering algorithm
      1. This table or related slice is empty.
      1. VTUpMod
    1. COplease see my commentary to Marc's answer.
      singulars
      1. POLooking for a fast polygon rendering algorithm
      1. USHeath Hunnicutt
    2. CONot a full answer, but http://www.cpp-home.com/tutorials/221_1.htm doesn't seem be too complex or resource intensive
      singulars
      1. POLooking for a fast polygon rendering algorithm
      1. USEarlz
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload