Re: [PyOpenGL-Users] DrawArrays for a bunch of (unconnected) lines]

[Philippe S. <ph...@ph...>]

On Sun, Jan 30, 2005 at 07:10:49PM -0500, Mike C. Fletcher wrote:

You're right, it's the way I was building the data set.
I was building [(x1, y1, x2, y2), (....)] and now that
I use [(x1, y1), (x2, y2), ...] it works as expected.

I take any doco about the data type that should be used
with pyopengl functions, there's plenty of opengl doco around,
but few running examples of glDrawXXX usage with a lot of
different data sets. In case you have some pointer.. 

thanks!

> This would be much easier to debug with example code I could run. 
> However, it looks as though the second problem may be related to using a 
> list instead of a string or array with the glVertexPointer variant. That 
> should probably either work or raise a TypeError rather than silently 
> failing.
> 
> That doesn't explain the problems with the grid, but that looks more 
> like a data issue. You should be aware that you're defining points in 4 
> dimensions, not 2. That is, the points are x1,y1,z1,w1 as you are 
> passing the parameters into glVertexPointer, not x1,y1,x2,y2, if you've 
> defined them as though they were pairs of 2-coordinate points then the 
> result will likely be dots rather than lines that are way off in the 
> middle of nowhere.
> 
> Feel free to forward a running example to me. I'll try to get to looking 
> at it sometime this week.
> 
> Good luck,
> Mike