[Kst] Kst2DPlot brainstorming
Ted Kisner
tskisner.public at gmail.com
Sat Oct 8 03:39:36 CEST 2005
On Friday 07 October 2005 17:43, Barth Netterfield wrote:
> I think part of the reason they are all together is that these tasks share
> data to such a large extent.
ok, I don't have much experience playing with kst2Dplot yet, so I was just
throwing out ideas for discussion...
> There are two aspects that have to be addressed related to projections:
> -Drawing (which your idea seems to handle *very* well
> -Mouse position feedback in, eg, data mode and zoom modes
Let's say for the purposes of projection discussion that Kst2Dplot stays
exactly the same except for the addition of a "KstProjectionObject". In this
scenario, drawing is handled as previously stated. Mouse position feedback
info just involves standard coordinate pair mappings.
For example, the coordinates of a new zoom box would be given to Kst2DPlot in
the form of (X,Y) coordinates. Kst2DPlot would have to call
"KstProjectionObject::reverseProjection" to get the coordinates in (U,V), and
then adjust the scale in U/V space and repaint.
> As a modification to your idea: How about giving KstPlots a
> kstProjectedDrawArea which has both drawing primitives and mouse coordinate
> transformations.
How does this differ functionally from above? A "mouse coordinate
transformation" seems to just be a set of one or a few coordinate pair
transformations, that are done with a simple function call...
Maybe you are suggesting putting *all* the mouse handling inside the projected
drawing area? So in this case, Kst2DPlot would simply have its member
functions called by the projected drawing area, and Kst2DPlot would have no
knowledge of anything except the (U,V) coordinate space. The only issue I
could see with this is how do we draw directly to the QPainter for things
like labels, etc, since these positions are specified in (X,Y) screen
coordinates?
> The problem is a very thorny one, and we are just scratching the surface of
> the problems that are to be faced, I fear.
I don't think it's *that* bad, we just have to plan carefully and think ahead
about what details we might have problems with. Whatever we do will be
temporarily disruptive to 2dplot, but maybe that's good :-)
> I think that 2D plot is a beast
> at least as much because of the complexity and inherent interconnectedness
> of the the problem as because of bad planning.
yes, but it still would be nice to modularize somewhat- even splitting things
into a couple of files would be better than scrolling through 6000 lines of
code or having to regex search for everything...
-Ted
More information about the Kst
mailing list