Re: SDL::Surface::new_from and PLot question

Hi David,

Can you give a small script ( a sin function ) that is ready for me to  
grab get_dataref? Some to test SV to Surface pixels conversions.

Kartik Thakore

On 16-Nov-09, at 4:39 PM, David Mertens <[email protected]> wrote:

> On Mon, Nov 16, 2009 at 1:54 PM, Kartik Thakore <[email protected] 
> > wrote:
> Hi,
>
> So I fixed new_from to prevent it from segfaulting. Now as for  
> direct write from PLot to Surface, where can I see the how the raw  
> data is stored and made acessible in PDL.
>
> Kartik Thakore
>
> Kartik -
>
> I've never looked too closely at the internals of PDL to know  
> precisely how it stores the data, but as I understand, the data is  
> typically stored in a packed scalar.  The proper way to get at this  
> data is using the get_dataref and upd_data member functions.  These  
> functions are discussed here: http://search.cpan.org/~chm/PDL-2.4.5/Basic/Core/Core.pm.PL#get_dataref
>
> For the PDL folks, who probably don't know what's going on, I am  
> trying to make PLplot play with SDL.  I would like to quickly draw  
> animations of plots.  Doug wrote an option into PLplot that allows  
> it to plot to a memory location, and PDL::Graphics::PLplot is  
> capable of specifying a piddle for this purpose.  His original  
> intention was to allow him to load an image into a piddle and  
> overlay a graph.  My intention is to make an SDL surface that uses  
> the same memory location as a PLplot output, so that I can use SDL's  
> quick redrawing mechanisms for fast interactive plotting.  I don't  
> actually need to get PDL involved in this - SDL would do well to  
> interact directly with PLplot - but it's probably a good idea to  
> interface SDL::Surfaces with PDL while we're at it.
>
> David