Hi Alan
Yes, but not just as background images, as plot images too. For example I have
in the past used plplot to overplot wind vectors from a weather model on
satellite views of the earth. So I would want an API call where I set the world
coordinates of the top left and bottom right corners of the image and plplot
draws it cropped to the viewport. A similar API call for rendering to the
subpage and the page would be good.
There are transparency issues that I will add to the other thread, because they
only occur if the background it transparent.
Phil
-----Original Message-----
From: "Alan W. Irwin" <ir...@beluga.phys.uvic.ca>
Sent: 06/02/2016 21:28
To: "Phil Rosenberg" <p.d.rosenb...@gmail.com>
Cc: "Greg Jung" <gvj...@gmail.com>; "Jim Dishaw" <j...@dishaw.org>;
"plplot-devel@lists.sourceforge.net" <plplot-devel@lists.sourceforge.net>
Subject: RGBA background images
On 2016-02-06 10:09-0000 Phil Rosenberg wrote:
> Hi Greg
> Sorry I haven't replied earlier. Jim may have to confirm this. But
it sounds like what you are aiming to do isn't really supported by
Plplot. Basically it sounds like you are trying to add your own
graphics commands (i.e. Draw the background) part way through a
replot. Although that can work for direct drawing there is currently
no way to intercept the drawing part way through. That said i think
that for drivers where the user has access to the "canvas" this
possibly should be supported. I also think that adding some form of
drawing an rgb image would be good too. Alan do you think these are
things we should consider adding to the API?
Hi Phil:
If you are talking about the goal of having potentially different RGBA
images for each different page's background, then I really like that
long-term goal because you can get some really cool effects that way.
But I am concerned about the speed since it currently takes us an
extremely long time to display even a low-resolution image for example
20. So I encourage you to think about the image display speed issue.
For example, I presume many of our device drivers (e.g., cairo, qt,
and wxwidgets) potentially could display an image using the
(presumably fast) capabilities of the underlying pango/cairo, Qt[45],
and wxwidgets libraries. So I think one potential way forward is to
implement that "native" image rendering capability in each of those
device drivers (and others as well whose underlying library has the
native capability). Then plimage lets the driver render the image if
the driver advertises it has the capability, and otherwise falls back
to the extremely slow current method of displaying images.
Meanwhile, I have thought of a closely related topic concerning the
"A" in "RGBA" which I would like to discuss which is how to improve
our current methods of handling uniformly coloured semitransparent
backgrounds. But I will present my thoughts on that topic in a
separate thread so as not to hijack this one.
Alan
__________________________
Alan W. Irwin
Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).
Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________
Linux-powered Science
__________________________
------------------------------------------------------------------------------
Site24x7 APM Insight: Get Deep Visibility into Application Performance
APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
Monitor end-to-end web transactions and take corrective actions now
Troubleshoot faster and improve end-user experience. Signup Now!
http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
_______________________________________________
Plplot-devel mailing list
Plplot-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/plplot-devel
