[GRASS-dev] Re: a better console and better diff

[Michael Barton]

Hi Dylan,

Thanks very much for trying this out. A few responses below.



On Dec 15, 2009, at 12:07 PM, Dylan Beaudette wrote:

> 
> Hi Michael,
> 
> I applied the patch, and it almost works. After running a command, I am not 
> presented with a new line-- I need to erase the last command in order to 
> enter a new one. 

This seemed weird so I tried it out. This only happens with d.* commands. I don't know why, but am sure that it is fixable.

> 
> Also, there is about a 45 second delay between a d.rast command and output on 
> the canvas... Do you know what could be causing this?

Mine shows up in a second or two. I'm not sure what is causing this but can speculate a little. First, have you turned on the 'constrain display resolution to computational region settings' in the preferences? If so, and if you have a map with a lot of cells, this will render slowly because d.rast has to write out a file with that many pixels, then on the fly compress them into the size that fits into your screen window. This would be the case with any image renderer. The default is to turn this off and have intelligent rendering, where the graphic file rendered by d.rast is sized to match the display window in advance. So it writes comparatively few pixels. For most purposes, GRASS should stay in this mode because you can only see the number of pixels in your display window, regardless of the number of cells in your map. 

If you do not have the 'constrain display resolution..' mode set this way, I'm don't know what the problem is. Even very large maps display quite quickly for me--in a couple seconds at the most. Could be you are out of disk space or RAM???

> 
> Finally, after about 30 seconds I received a warning that d.erase wasn't yet 
> supported. 

This may be related to the slow rendering issue. I get the message that d.erase is not implemented immediately. Note that d.erase should be easy to implement.

> 
> I like the idea here, but the speed of rendering is far too slow for standard 
> usage.

Clearly this is far too slow, but the rendering speed (or rather its lack) is not a function of either the console or wxPython canvas in this case. Is it that slow when you display from the layer manager too? 

Have you tried it for other commands -- all the non display commands? Other shell commands? Any thoughts?

Michael