Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On Thu, Mar 18, 2010 at 5:34 PM, Alan W. Irwin ir...@beluga.phys.uvic.ca wrote: On 2010-03-18 16:26-0400 Hezekiah M. Carty wrote: [...] From what I have read so far, having nicely window-manager independent transparent backgrounds for the xcairo (and xwin and possiblt qtwidget) devices would require pulling in more X dependencies and would only work with window managers which support such niceties. I read some stuff like that as well on the web, but I think it must be quite dated information. To show this, note that the ImageMagick display application is a GUI that ultimately interacts with the X server on Linux. Now that -dev pngcairo is working properly, you can test whether your X server renders transparent backgrounds by running examples/c/x02c -dev pngcairo -bg ff_0.3 -fam -o test.png followed by display -immutable test.png.2 In my case I have access to two different X servers for two very different boxes. I use the Debian Lenny X server/kernel 2.6.26 for my newish Intel box with g33 chipset/gma 3100 and the Debian Testing X server/kernel 2.6.32 with my old shuttle box (the X-terminal) with embedded SiS hardware with reverse-engineered 2D X driver. In both cases, I get transparent results with display -immutable. David had similar success with display -immutable, although in his case display might be interacting with something different than X (glitz?), but at minimum his result showed that transparent backgrounds can be properly rendered on Mac OS X. [out of order] Should I back-out the xcairo device change [to insert an obscuring layer between pages]? Yes, please. Of course, you first have to figure out a way to not stack xcairo pages on top of previous pages. I was thinking along the lines that when a page was started the widget/GUI associated with the previous page should be properly terminated and a whole new widget/GUI initialized for the new page. But maybe you would not have to go to that extreme... I think we may be talking about two different kinds of transparency here, or I am using a differently configured version of imagemagick (6.5.1.0-1.1ubuntu3). Do you mean transparent backgrounds as in (a)I can watch a movie in the window under my translucent plot! or (b)I see a checkerboard pattern through my plot, but not the windows underneath it? In the case of (a), which some applications support (for example, recent versions of the Gnome terminal support this), the xcairo device would have to pull in some extra outside support from X libraries. For (b), no special X support is required, we would just have to change the xcairo device to draw some sort of checkboard pattern at the start of each plot page, like Gnome's eog or imagemagick's display does when displaying an image with a transparent background. For (b), the only change from the current situation is that the user would get a checkboard pattern under their plot rather than a plain white background. Hez -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-18 17:55-0400 Hezekiah M. Carty wrote: On Thu, Mar 18, 2010 at 5:34 PM, Alan W. Irwin ir...@beluga.phys.uvic.ca wrote: On 2010-03-18 16:26-0400 Hezekiah M. Carty wrote: [...] From what I have read so far, having nicely window-manager independent transparent backgrounds for the xcairo (and xwin and possiblt qtwidget) devices would require pulling in more X dependencies and would only work with window managers which support such niceties. I read some stuff like that as well on the web, but I think it must be quite dated information. To show this, note that the ImageMagick display application is a GUI that ultimately interacts with the X server on Linux. Now that -dev pngcairo is working properly, you can test whether your X server renders transparent backgrounds by running examples/c/x02c -dev pngcairo -bg ff_0.3 -fam -o test.png followed by display -immutable test.png.2 In my case I have access to two different X servers for two very different boxes. I use the Debian Lenny X server/kernel 2.6.26 for my newish Intel box with g33 chipset/gma 3100 and the Debian Testing X server/kernel 2.6.32 with my old shuttle box (the X-terminal) with embedded SiS hardware with reverse-engineered 2D X driver. In both cases, I get transparent results with display -immutable. David had similar success with display -immutable, although in his case display might be interacting with something different than X (glitz?), but at minimum his result showed that transparent backgrounds can be properly rendered on Mac OS X. [out of order] Should I back-out the xcairo device change [to insert an obscuring layer between pages]? Yes, please. Of course, you first have to figure out a way to not stack xcairo pages on top of previous pages. I was thinking along the lines that when a page was started the widget/GUI associated with the previous page should be properly terminated and a whole new widget/GUI initialized for the new page. But maybe you would not have to go to that extreme... I think we may be talking about two different kinds of transparency here, or I am using a differently configured version of imagemagick (6.5.1.0-1.1ubuntu3). Do you mean transparent backgrounds as in (a)I can watch a movie in the window under my translucent plot! or (b)I see a checkerboard pattern through my plot, but not the windows underneath it? For my two X servers display -immutable test.png.2 gives me (a), i.e., a semi-transparent view where I can see the desktop underneath the image. If I drop the immutable option, then display gives me (b), i.e., a checkerboard background. Do you get (a) or (b) for display --immutable test.png.2 with your X server? If (b), what X server is that? In the case of (a), which some applications support (for example, recent versions of the Gnome terminal support this), the xcairo device would have to pull in some extra outside support from X libraries. If that is correct, then all we have to do is follow how display (or more likely its plug-in for displaying PNG's) and Gnome terminal are linked. This may not actually be an issue since our build system uses the CMake find_package(X11) command to find the X libraries, and this issue may have already been addressed by CMake. For (b), no special X support is required, we would just have to change the xcairo device to draw some sort of checkboard pattern at the start of each plot page, like Gnome's eog or imagemagick's display does when displaying an image with a transparent background. I guess that answers my question above about what display -immutable does for your X server. Here (for two different X servers), eog always produces a checkerboard pattern, but display only does that without the -immutable option (or if the example is too large). For a png that fits on the page, display -immutable produces (a) here. Ideally, I think we want to implement both (a) and (b) results under control of the PLplot user. So I think the development steps should be in the following order. (1) Remove the obscuring layer and unstack the pages so the previous pages don't interfere with the current page's transparent background results. This change just makes sense regardless of the next steps. (2) See if (a) can be made to work. I notice in cairo.c there are still references to RGB24 rather than ARGB32 so that may be a trivial fix. On the other hand if one of us does the remaining ARGB32 conversions we might end up with a checkerboard by default (depending on how X is initialized) if that checkerboard is being supplied by X (see next comment). I can try the ARGB32 conversion myself here with my two different X servers once (1) is completed by somebody more knowledgeable about cairo.c than I am. (3) Implement (b) (probably as the default with (a) optional) if necessary. However, since the checkerboard seems to be the same for both convert (without -immutable) and eog, I wonder if that
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
Alan W. Irwin wrote: For my two X servers display -immutable test.png.2 gives me (a), i.e., a semi-transparent view where I can see the desktop underneath the image. This is slightly off topic, but this effect really doesn't seem to work that well on Gnome, at least for me. This plot has a completely opaque background: ./examples/c/x01c -dev pngcairo -bg FF_0.6 -o ex1.png display -immutable ex1.png This plot has a completely transparent background: ./examples/c/x01c -dev pngcairo -bg FF_0.4 -o ex1.png display -immutable ex1.png This plot is also completely opaque: ./examples/c/x01c -dev svgcairo -bg FF_0.2 -o ex1.svg display -immutable ex1.svg As is this plot: ./examples/c/x01c -dev svg -bg FF_0.2 -o ex1.svg display -immutable ex1.svg I'm running GNOME 2.41.1 / ubuntu 8.10. Even further off topic, the effect is not that great with the terminal program either. It seems to handle a variable transparency background but you will always see the desktop background, even if there is something else (window, icon, etc) underneath it. So, while I agree that we should support this feature I don't think it is going to be that cool for most linux users for a while yet. -Hazen -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
Hi, Hez, On Mar 18, 2010, at 21:16 , Hezekiah M. Carty wrote: The checkerboard background seems to be a semi-standard approach for viewing transparent images (Gimp uses something similar). I'm not sure it is a good idea for our interactive devices though, as it makes it very difficult to see the details of a plot. I would prefer to keep the white background as the standard for non-transparent windows as it maintains better readability. I agree that a checkerboard (or even transparent) back-background makes it harder to see the details of a plot with a non-opaque background on interactive devices, but I think one use case for even requesting a non-opaque background on an interactive device in the first place is to preview how different alpha values would look on a non-interactive device. In this case, some type of patterned back- background (e.g. a checkerboard) would be more useful than a single color background, IMHO. If one is primarily interested in actually visualizing data on an interactive device (oh, what a concept! :-)), one would probably choose to use the default opaque background. Dave -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On Thu, Mar 18, 2010 at 7:31 PM, Alan W. Irwin ir...@beluga.phys.uvic.ca wrote: On 2010-03-18 17:55-0400 Hezekiah M. Carty wrote: On Thu, Mar 18, 2010 at 5:34 PM, Alan W. Irwin ir...@beluga.phys.uvic.ca wrote: On 2010-03-18 16:26-0400 Hezekiah M. Carty wrote: [...] From what I have read so far, having nicely window-manager independent transparent backgrounds for the xcairo (and xwin and possiblt qtwidget) devices would require pulling in more X dependencies and would only work with window managers which support such niceties. I read some stuff like that as well on the web, but I think it must be quite dated information. To show this, note that the ImageMagick display application is a GUI that ultimately interacts with the X server on Linux. Now that -dev pngcairo is working properly, you can test whether your X server renders transparent backgrounds by running examples/c/x02c -dev pngcairo -bg ff_0.3 -fam -o test.png followed by display -immutable test.png.2 In my case I have access to two different X servers for two very different boxes. I use the Debian Lenny X server/kernel 2.6.26 for my newish Intel box with g33 chipset/gma 3100 and the Debian Testing X server/kernel 2.6.32 with my old shuttle box (the X-terminal) with embedded SiS hardware with reverse-engineered 2D X driver. In both cases, I get transparent results with display -immutable. David had similar success with display -immutable, although in his case display might be interacting with something different than X (glitz?), but at minimum his result showed that transparent backgrounds can be properly rendered on Mac OS X. [out of order] Should I back-out the xcairo device change [to insert an obscuring layer between pages]? Yes, please. Of course, you first have to figure out a way to not stack xcairo pages on top of previous pages. I was thinking along the lines that when a page was started the widget/GUI associated with the previous page should be properly terminated and a whole new widget/GUI initialized for the new page. But maybe you would not have to go to that extreme... I think we may be talking about two different kinds of transparency here, or I am using a differently configured version of imagemagick (6.5.1.0-1.1ubuntu3). Do you mean transparent backgrounds as in (a)I can watch a movie in the window under my translucent plot! or (b)I see a checkerboard pattern through my plot, but not the windows underneath it? For my two X servers display -immutable test.png.2 gives me (a), i.e., a semi-transparent view where I can see the desktop underneath the image. If I drop the immutable option, then display gives me (b), i.e., a checkerboard background. Do you get (a) or (b) for display --immutable test.png.2 with your X server? If (b), what X server is that? Using Ubuntu 9.10, Xorg 7.4 on an Intel 965GM with Gnome with the Compiz composited window manager (3D acceleration, transparent windows, etc) I get (b) for both uses of display. Using the Gnome terminal's transparency, I get true transparency with other windows, etc. showing up underneath. I guess that answers my question above about what display -immutable does for your X server. Here (for two different X servers), eog always produces a checkerboard pattern, but display only does that without the -immutable option (or if the example is too large). For a png that fits on the page, display -immutable produces (a) here. On my desktop both eog and display show the same checkerboard pattern. This pattern, I am almost completely certain, is provided by the application and not something intrinsic to X. Ideally, I think we want to implement both (a) and (b) results under control of the PLplot user. So I think the development steps should be in the following order. (1) Remove the obscuring layer and unstack the pages so the previous pages don't interfere with the current page's transparent background results. This change just makes sense regardless of the next steps. The obscuring layer is required to keep the previous plot pages from showing through to the new plot pages. The other option is to repeatedly open new windows for each page, but I think that it would be better to allow the user to create multiple windows by just creating multiple plot streams. New pages within a plot stream would continue to show up in the same window. (2) See if (a) can be made to work. I notice in cairo.c there are still references to RGB24 rather than ARGB32 so that may be a trivial fix. On the other hand if one of us does the remaining ARGB32 conversions we might end up with a checkerboard by default (depending on how X is initialized) if that checkerboard is being supplied by X (see next comment). I can try the ARGB32 conversion myself here with my two different X servers once (1) is completed by somebody more knowledgeable about cairo.c than I am. This is where extra X work is
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-14 11:32-0700 Alan W. Irwin wrote: On 2010-03-14 10:50-0500 Hezekiah M. Carty wrote: Revision 10866 should fix this. If the background color has an alpha value 1.0 then a white surface is drawn before the transparent background color. This produces good looking results for all of the Cairo devices on my system (Ubuntu 9.10, Cairo 1.8.8). This fix obscures the underlying layers as advertised so stops the leaking through of the first page onto the second. However, I don't like this way of dealing with the issue (which from your comments, qtwidget uses as well). We want transparent backgrounds to be transparent because we would like to implement the absolutely cool effect of seeing the plot superimposed on the desktop underneath the GUI. I researched the goal of having semi-transparent backgrounds under complete PLplot control some more using -dev pngcairo (since that file device implementation is simpler than xcairo). ./x01c -dev pngcairo -bg ff_0.0 -o test.png -drvopt set_background=1 should produce a white but completely transparent PLplot background if the the pango/cairo stack of libraries has been initialized properly. However, it produces a black completely opaque background instead. (Removing the -drvopt option or setting set_background=0 gives identical results which seems to be contradictory with the code which appears to do different things about setting the background depending on set_background). I can use ImageMagick to replace all black colours with complete transparency like this: convert -transparent black test.png test_transparent.png Then display -immutable test_transparent.png really does show the desktop underneath the plot which indeed is a really cool-looking effect. (Without that -immutable option, display replaces a transparent background with a checkerboard background which apparently is something of an industry standard to signal you really do have a transparent background.) eog also renders a checkerboard background for test_transparent.png, but in that case there doesn't seem to be any equivalent of the -immutable option to allow you to see the unmodified image with an actual transparent background. It appears from this additional research that all we need to realize the goal of a transparent background completely under PLplot control for cairo file devices like pngcairo is a way to initialize the pango/cairo libraries so they do not impose a black background of their own. And similarly for xcairo once the issue of reinitializing the surface for each page is addressed. An additional question is why set_background=1 or 0 seems to produce an identical plot. I also did similar tests for -dev pngqt with identical results (a black background is imposed underneath the plot which can be made transparent by convert) so something similar has to be done in the qt file devices case and also in the qtwidget case to get rid of the extra backgrounds that are being imposed below the PLplot background. Finally, I did some tests using -dev svg, -dev svgcairo, and -dev/svgqt. In the case of SVG results the files are in human-readable XML form so it is easy to confirm these three devices (with no external library, with the pango/cairo libraries, and the Qt libraries) are all doing the right thing without imposing any additional layers. (eog confirmed these good results by giving a checkboard background signaling there was actually a transparent background. ImageMagick display or display -immutable could not confirm these good results but apparently that is a bug in how display ignores transparent *.svg results on my platform). Hopefully these good svg transparent background results for the cases of -dev svgcairo and -dev svgqt will inspire the cairo and qt experts here to solve the remaining transparent background issues for the non-svg cairo and qt devices. 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On Mar 15, 2010, at 14:32 , Alan W. Irwin wrote: Then display -immutable test_transparent.png really does show the desktop underneath the plot which indeed is a really cool-looking effect. Using a very recent ImageMagick (6.6.0), display gives me the checkerboard background without the -immutable option and a black background with that option when looking at an image with a transparent background. This might be an X server limitation or window manager limitation, but it shows that this feature is not universally available. (Without that -immutable option, display replaces a transparent background with a checkerboard background which apparently is something of an industry standard to signal you really do have a transparent background.) I agree that this *can be* a really cool-looking effect, but IMHO it can also be a really annoying/confusing looking effect (depending on what's underneath/behind). I think it would be nice to provide the user the ability to choose how transparent backgrounds are rendered (i.e. either see-through to windows underneath/behind or use a predefined opaque background, e.g. checkerboard). Dave -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
David MacMahon wrote: (Without that -immutable option, display replaces a transparent background with a checkerboard background which apparently is something of an industry standard to signal you really do have a transparent background.) I agree that this *can be* a really cool-looking effect, but IMHO it can also be a really annoying/confusing looking effect (depending on what's underneath/behind). I think it would be nice to provide the user the ability to choose how transparent backgrounds are rendered (i.e. either see-through to windows underneath/behind or use a predefined opaque background, e.g. checkerboard). The problem is that we currently do not allow any choices. The cairo driver is explicitly starting with a non-transparent white background. It is not as clear to me exactly what the Qt driver is doing when it starts a new page, though I don't believe that the driver itself sets the background to be white. -Hazen -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-15 15:49-0700 David MacMahon wrote: On Mar 15, 2010, at 14:32 , Alan W. Irwin wrote: Then display -immutable test_transparent.png really does show the desktop underneath the plot which indeed is a really cool-looking effect. Using a very recent ImageMagick (6.6.0), display gives me the checkerboard background without the -immutable option and a black background with that option when looking at an image with a transparent background. This might be an X server limitation or window manager limitation, but it shows that this feature is not universally available. Please be explicit about exactly what you did because our devices other than the three different svg ones are producing bad transparent background results that depend very much on details. Is this a -bg ff_0.0 result from -dev pngcairo or -dev pngqt with black transformed to transparent using convert -transparent black ...? Note, the -convert black option will not work if you use ff_0.1 because the (bad) mixed opaque colour background result produced by -dev pngcairo is no longer black in this case. My imagemagick version is 7:6.3.7.9.dfsg2-1~lenny3. I think that translates to 6.3.7 for the upstream version so it is much older than yours. Therefore, I assume this is not an ImageMagick issue. My two different Linux X servers (one for very old equipment with embedded SiS video that has a reverse-engineered 2D-only driver for that hardware) both give transparent results for the display -immutable option in that case, but do not give that result in any other case (including SVG where our three SVG devices produce correct results). From my reading there are transparency limitations to the X server on Mac OS X so perhaps that is what you are running into in the (corrected) -dev pngcairo case. (Without that -immutable option, display replaces a transparent background with a checkerboard background which apparently is something of an industry standard to signal you really do have a transparent background.) I agree that this *can be* a really cool-looking effect, but IMHO it can also be a really annoying/confusing looking effect (depending on what's underneath/behind). I think it would be nice to provide the user the ability to choose how transparent backgrounds are rendered (i.e. either see-through to windows underneath/behind or use a predefined opaque background, e.g. checkerboard). This would not be a good idea for file devices. There, you want the user running the file viewing application (say with something like the display -immutable option) to control how transparent backgrounds are rendered. In the separate case of interactive devices we should probably just follow what is done by the underlying external stack of libraries (such as the pango/cairo stack of libraries for -dev xcairo and the Qt4 stack of libraries for -dev qtwidget). Of course, if that external stack of libraries does offer the option of rendering transparent backgrounds as checkerboard (which I believe from my reading is a de facto standard started by Adobe photoshop) or as actually transparent for interactive devices, then it makes sense to give PLplot users interactive control over that choice via a driver option. Anyhow, our current list of devices that treat transparent background properly is limited to just svg, svgcairo, and svgqt as far as I can tell. I hope we can soon expand that list both to the xcairo and qtwidget interactive devices as well as many other file devices. 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-15 20:38-0400 Hazen Babcock wrote: The problem is that we currently do not allow any choices. The cairo driver is explicitly starting with a non-transparent white background. It is not as clear to me exactly what the Qt driver is doing when it starts a new page, though I don't believe that the driver itself sets the background to be white. Hazen, wouldn't it be fairly straightforward to infer from the good svgcairo results what to do for the other cairo file devices to get proper transparent backgrounds for those devices? My feeling is it would be easier to deal with the cairo file devices first since their code is similar to the svgcairo case and much simpler than in the xcairo case. Similarly, I think that whoever tackles the qt case should attempt to expand the good svgqt transparent background results to the other qt devices before finally attempting to deal with the complicated qtwidget case. 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
Hi, Alan, On Mar 15, 2010, at 17:49 , Alan W. Irwin wrote: On 2010-03-15 15:49-0700 David MacMahon wrote: Using a very recent ImageMagick (6.6.0), display gives me the checkerboard background without the -immutable option and a black background with that option when looking at an image with a transparent background. This might be an X server limitation or window manager limitation, but it shows that this feature is not universally available. Please be explicit about exactly what you did because our devices other than the three different svg ones are producing bad transparent background results that depend very much on details. Thanks for pressing me on this one. It looks like I found a quirk with the display program. I was using an image I had created with GIMP that I knew had a transparent background. This image happens to be rather large (in pixels). It seems that the window created by display -immutable foo.png will have a non-opaque background if foo.png is non-opaque and the window's size fits in the root X window (i.e. needs no panner). Because my test file was large in pixels, it showed up in the display window with a black background and a little panner window for navigating around. When I followed the steps you gave to create test_transparent.png, then display -immutable did indeed show it using a transparent window background (neat, except that I see my very cluttered desktop underneath! :-)). If I run display -immutable -resize 1440x900! test_transparent.png it still comes up with transparency (my root window is 1440x900 as shown by xwininfo -root). If I change either (or both) resize dimension to exceed the root window size, then I'm back to the solid black background. Therefore, I assume this is not an ImageMagick issue. See what happens when you assume! :-) I agree that this *can be* a really cool-looking effect, but IMHO it can also be a really annoying/confusing looking effect (depending on what's underneath/behind). I think it would be nice to provide the user the ability to choose how transparent backgrounds are rendered (i.e. either see-through to windows underneath/behind or use a predefined opaque background, e.g. checkerboard). This would not be a good idea for file devices. There, you want the user running the file viewing application (say with something like the display -immutable option) to control how transparent backgrounds are rendered. Yes, obviously(?) for file devices we want real transparency. In the separate case of interactive devices we should probably just follow what is done by the underlying external stack of libraries (such as the pango/cairo stack of libraries for -dev xcairo and the Qt4 stack of libraries for -dev qtwidget). I'm no expert on the PLplot devices, but my understanding is that the xcairo device is a cairo widget or surface drawn in a regular X window that has its own background. If that's the case, then perhaps we would need to create the window with either a transparent or checkerboard background before drawing in it with cairo? Of course, if that external stack of libraries does offer the option of rendering transparent backgrounds as checkerboard (which I believe from my reading is a de facto standard started by Adobe photoshop) or as actually transparent for interactive devices, then it makes sense to give PLplot users interactive control over that choice via a driver option. IMHO, the choice of transparent or non-transparent window backgrounds transcends the particular interactive device chosen. PLplot already has generic -nopixmap and -db options for X-based drivers. A similar PLplot option (i.e not a driver option) to choose between opaque and non-opaque *window* backgrounds seems appropriate (again, IMHO). Given that transparent window backgrounds are more resource intensive (does it even work without an accelerated graphics driver?), I think the default should be an opaque (of some sort) window background even when the plot background is non-opaque. Anyhow, our current list of devices that treat transparent background properly is limited to just svg, svgcairo, and svgqt as far as I can tell. I hope we can soon expand that list both to the xcairo and qtwidget interactive devices as well as many other file devices. I certainly agree that it would be good to expand the list of devices that treat transparent background properly. For file outputs, there seems to be little ambiguity, but defining proper treatment for interactive devices seems not so clear (pun partially intended! :-)). Dave -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-15 21:44-0700 David MacMahon wrote: I'm no expert on the PLplot devices, but my understanding is that the xcairo device is a cairo widget or surface drawn in a regular X window that has its own background. If that's the case, then perhaps we would need to create the window with either a transparent or checkerboard background before drawing in it with cairo? Let's go for the low-hanging fruit first and wait and see on the rest. Thus, I feel the priorities should be implementing correct transparent background for cairo file devices, then see what is possible with xcairo in this regard, then at that point if necessary (after all, transparent backgrounds might not be possible at all with xcairo) decide on the issue you are concerned about. 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On Sat, Mar 13, 2010 at 5:12 PM, Alan W. Irwin ir...@beluga.phys.uvic.ca wrote: On 2010-03-13 13:16-0800 Alan W. Irwin wrote: On 2010-03-13 14:45-0500 Hazen Babcock wrote: Alan W. Irwin wrote: Hazen, will you have a look at this issue, please? This transparent background issue does not appear for, e.g., -dev pscairo so it appears this issue may be specific within the cairo devices to just -dev xcairo although I haven't checked the other cairo device possibilities beside pscairo. Looks like it was an issue with the driver not using the good PLplot core fallback clear capability. Hmm. after updating to get your fix and make cairo I still get the same (bad) result (with page 1 still visible underneath) for examples/c/x02c -dev xcairo -bg FF_0.1 examples/c/x02c -dev qtwidget -bg FF_01 was fine. I haven't tried a completely clean build yet, but make cairo did create a new cairo device driver so your fix should be properly built. [...] Yep, same (bad) results for an absolutely clean build tree, and I double-checked the cairo.c code had your fix. In fact, no change in the results is expected as a result of your change since the default value of pls-dev_clear is zero in any case. Just in case, I also tried a direct (rather than X-terminal) display and continued to get the same bad xcairo and good qtwidget transparent background results. Do you currently get good results for the above test with -dev xcairo? Currently, there are problems with Hez's recent cairo change (see my next post) so that the cairo file devices all segfault. However, if I revert back to --revision 10861 for cairo.c, then the segfaults disappear and then pngcairo does not have this transparent background issue while xcairo still does. The conclusion from this test is the transparent background issue is likely due to some difference in treatment between the cairo file devices and xcairo, and whatever the xcairo issue, it is independent of Hez's recent changes. I get similar results on a fresh trunk source tree. What should the default background color be? The qtwidget device seems to assume white as the default background, regardless of the base color palette: Both: ./x11c -cmap0 cmap0_default.pal -bg ff_0.3 -dev qtwidget and ./x11c -cmap0 cmap0_alternate.pal -bg ff_0.3 -dev qtwidget produce output with the same light-blue background color. This is probably the best approach from the standpoint of least surprise from the user. I have the few lines of changes ready to address this once the background color to overlay the transparent color over is decided on. Hez -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On Sun, Mar 14, 2010 at 9:54 AM, Hezekiah M. Carty hezekiahca...@users.sourceforge.net wrote: On Sat, Mar 13, 2010 at 5:12 PM, Alan W. Irwin ir...@beluga.phys.uvic.ca wrote: On 2010-03-13 13:16-0800 Alan W. Irwin wrote: On 2010-03-13 14:45-0500 Hazen Babcock wrote: Alan W. Irwin wrote: Hazen, will you have a look at this issue, please? This transparent background issue does not appear for, e.g., -dev pscairo so it appears this issue may be specific within the cairo devices to just -dev xcairo although I haven't checked the other cairo device possibilities beside pscairo. Looks like it was an issue with the driver not using the good PLplot core fallback clear capability. Hmm. after updating to get your fix and make cairo I still get the same (bad) result (with page 1 still visible underneath) for examples/c/x02c -dev xcairo -bg FF_0.1 examples/c/x02c -dev qtwidget -bg FF_01 was fine. I get similar results on a fresh trunk source tree. What should the default background color be? The qtwidget device seems to assume white as the default background, regardless of the base color palette: Revision 10866 should fix this. If the background color has an alpha value 1.0 then a white surface is drawn before the transparent background color. This produces good looking results for all of the Cairo devices on my system (Ubuntu 9.10, Cairo 1.8.8). Hez -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-14 10:50-0500 Hezekiah M. Carty wrote: Hmm. after updating to get your fix and make cairo I still get the same (bad) result (with page 1 still visible underneath) for examples/c/x02c -dev xcairo -bg FF_0.1 examples/c/x02c -dev qtwidget -bg FF_01 was fine. I get similar results on a fresh trunk source tree. What should the default background color be? The qtwidget device seems to assume white as the default background, regardless of the base color palette: Revision 10866 should fix this. If the background color has an alpha value 1.0 then a white surface is drawn before the transparent background color. This produces good looking results for all of the Cairo devices on my system (Ubuntu 9.10, Cairo 1.8.8). This fix obscures the underlying layers as advertised so stops the leaking through of the first page onto the second. However, I don't like this way of dealing with the issue (which from your comments, qtwidget uses as well). We want transparent backgrounds to be transparent because we would like to implement the absolutely cool effect of seeing the plot superimposed on the desktop underneath the GUI. To work toward that goal, we must avoid putting in any obscuring layers. Actually, the previous cairo version did not put in an obscuring layer which was good, but the problem was the plot from the previous page was not removed. Shouldn't you be able to deal with this issue by closing the old page and initiating a completely new one each time there is a new page in the example? I think that is what the cairo file devices do. Furthermore, is there a cairo page setup feature you could use that initiated the GUI with no cairo (as opposed to PLplot) background? If so, then the PLplot background would be the absolutely first layer of the GUI so that if it were transparent, you would see through to the underlying desktop. In sum, that is potentially a very cool effect which I hope we will be able to implement by initiating pango/cairo correctly and by not putting in any obscuring layers. Same comment for qt. 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
Alan W. Irwin wrote: On 2010-03-13 13:16-0800 Alan W. Irwin wrote: On 2010-03-13 14:45-0500 Hazen Babcock wrote: Alan W. Irwin wrote: Hazen, will you have a look at this issue, please? This transparent background issue does not appear for, e.g., -dev pscairo so it appears this issue may be specific within the cairo devices to just -dev xcairo although I haven't checked the other cairo device possibilities beside pscairo. Looks like it was an issue with the driver not using the good PLplot core fallback clear capability. Hmm. after updating to get your fix and make cairo I still get the same (bad) result (with page 1 still visible underneath) for examples/c/x02c -dev xcairo -bg FF_0.1 examples/c/x02c -dev qtwidget -bg FF_01 was fine. I haven't tried a completely clean build yet, but make cairo did create a new cairo device driver so your fix should be properly built. [...] Yep, same (bad) results for an absolutely clean build tree, and I double-checked the cairo.c code had your fix. In fact, no change in the results is expected as a result of your change since the default value of pls-dev_clear is zero in any case. Just in case, I also tried a direct (rather than X-terminal) display and continued to get the same bad xcairo and good qtwidget transparent background results. Do you currently get good results for the above test with -dev xcairo? Well I thought I did, otherwise I would not have checked in the change claiming that it fixed the problem... However I am mistaken as I am now getting the same bad result as you. -Hazen -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
Alan W. Irwin wrote: On 2010-03-10 00:43-0800 David MacMahon wrote: I just ran this... x02c -dev xcairo -bg ff_0.3 ...and noticed on the second plot I can see through to the first plot. I don't think I have any other non-cairo, alpha-capable drivers built so I can't tell if it's cairo-related or more general. 12 svgScalable Vector Graphics (SVG 1.1) Can someone with qt devices please try this? Good spotting. It's a rendering bug that appears to be specific to -dev xcairo. -dev qtwidget does not have this problem, and neither does -dev svg. (For the latter, you must use the familying option -fam which will generate two files corresponding to the two pages.) An even more spectacular example of this xcairo bug is example 8. The first four pages look okay (since they duplicate each other in most respects), but then for pages 5 through 8, the page 4 plot gently fades away in the background as more and more partially transparent layers are added on top of it. Hazen, will you have a look at this issue, please? This transparent background issue does not appear for, e.g., -dev pscairo so it appears this issue may be specific within the cairo devices to just -dev xcairo although I haven't checked the other cairo device possibilities beside pscairo. Looks like it was an issue with the driver not using the good PLplot core fallback clear capability. -Hazen -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-13 14:45-0500 Hazen Babcock wrote: Alan W. Irwin wrote: Hazen, will you have a look at this issue, please? This transparent background issue does not appear for, e.g., -dev pscairo so it appears this issue may be specific within the cairo devices to just -dev xcairo although I haven't checked the other cairo device possibilities beside pscairo. Looks like it was an issue with the driver not using the good PLplot core fallback clear capability. Hmm. after updating to get your fix and make cairo I still get the same (bad) result (with page 1 still visible underneath) for examples/c/x02c -dev xcairo -bg FF_0.1 examples/c/x02c -dev qtwidget -bg FF_01 was fine. I haven't tried a completely clean build yet, but make cairo did create a new cairo device driver so your fix should be properly built. Do you currently get good results for the above test with -dev xcairo? 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-13 13:16-0800 Alan W. Irwin wrote: On 2010-03-13 14:45-0500 Hazen Babcock wrote: Alan W. Irwin wrote: Hazen, will you have a look at this issue, please? This transparent background issue does not appear for, e.g., -dev pscairo so it appears this issue may be specific within the cairo devices to just -dev xcairo although I haven't checked the other cairo device possibilities beside pscairo. Looks like it was an issue with the driver not using the good PLplot core fallback clear capability. Hmm. after updating to get your fix and make cairo I still get the same (bad) result (with page 1 still visible underneath) for examples/c/x02c -dev xcairo -bg FF_0.1 examples/c/x02c -dev qtwidget -bg FF_01 was fine. I haven't tried a completely clean build yet, but make cairo did create a new cairo device driver so your fix should be properly built. [...] Yep, same (bad) results for an absolutely clean build tree, and I double-checked the cairo.c code had your fix. In fact, no change in the results is expected as a result of your change since the default value of pls-dev_clear is zero in any case. Just in case, I also tried a direct (rather than X-terminal) display and continued to get the same bad xcairo and good qtwidget transparent background results. Do you currently get good results for the above test with -dev xcairo? Currently, there are problems with Hez's recent cairo change (see my next post) so that the cairo file devices all segfault. However, if I revert back to --revision 10861 for cairo.c, then the segfaults disappear and then pngcairo does not have this transparent background issue while xcairo still does. The conclusion from this test is the transparent background issue is likely due to some difference in treatment between the cairo file devices and xcairo, and whatever the xcairo issue, it is independent of Hez's recent changes. 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
Thanks for confirming this, Alan! On Mar 10, 2010, at 8:09 , Alan W. Irwin wrote: -dev qtwidget does not have this problem, and neither does -dev svg. (For the latter, you must use the familying option -fam which will generate two files corresponding to the two pages.) I don't know how qtwidget does it's plots, so I can't comment on that, but for svg, I think the fact that the second plot comes out OK is not so conclusive. The pdfcairo driver also produces a two page output file. Page 2 of that file looks OK, too, but it is a separate page after all. I'm not really sure how to interpret alpha for the background of a GUI window. What's behind the background to see through too? For graphics files (e.g. .png or .svg) they might be overlaid on something else so background transparency there is more intuitive. Perhaps if the background is non-opaque, GUIs could draw an opaque checkerboard backbackground (like the gimp does) before drawing the non-opaque background? Or maybe the GUI widgets being rendered into have their own alpha channel and could therefore be layered in a way that would give the background's alpha channel an obvious meaning? In this case, the GUI widget would need to be cleared before drawing the non-opaque background of a subsequent plot. Dave -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On 2010-03-10 10:15-0800 David MacMahon wrote: I'm not really sure how to interpret alpha for the background of a GUI window. What's behind the background to see through too? For graphics files (e.g. .png or .svg) they might be overlaid on something else so background transparency there is more intuitive. Perhaps if the background is non-opaque, GUIs could draw an opaque checkerboard backbackground (like the gimp does) before drawing the non-opaque background? Or maybe the GUI widgets being rendered into have their own alpha channel and could therefore be layered in a way that would give the background's alpha channel an obvious meaning? In this case, the GUI widget would need to be cleared before drawing the non-opaque background of a subsequent plot. I think the best way to state this is that PLplot implements transparent backgrounds for its modern devices, but other applications have to do their part as well to allow overall background transparency. There are already some neat transparent background effects being deployed on the desktop (e.g., if you move a KDE GUI it becomes transparent so you can see underneath it) that show this is possible. Thus, for example, I assume some file viewers may already allow transparent background options of their own so that when that is combined with a transparent PLplot background you could see through to the application below. Similarly, I assume there are GUI options for GNOME and KDE to allow transparent GUI backgrounds. But I have not researched any of this yet. 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); PLplot scientific plotting software package (plplot.org); 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 __ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
Re: [Plplot-devel] -bg with alpha gives strange overlay effect on x02c
On Mar 10, 2010, at 11:05 , Alan W. Irwin wrote: There are already some neat transparent background effects being deployed on the desktop (e.g., if you move a KDE GUI it becomes transparent so you can see underneath it) that show this is possible. I think this might be a property of the window manager rather than the window itself or the application displaying in the window. Thus, for example, I assume some file viewers may already allow transparent background options of their own so that when that is combined with a transparent PLplot background you could see through to the application below. Similarly, I assume there are GUI options for GNOME and KDE to allow transparent GUI backgrounds. If there is a window manager independent way of making a window's background transparent then it would be great to use. Not sure how this would work on MS Windows vs X Windows. But I have not researched any of this yet. Me neither! :-) Dave -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
