I have a webapp from which I'd like to insert diagrams and images quickly and easily. I expect there is, somewhere out there, a webservice which will take a URL with a parameter that describes the vector graphics or diagram and returns an image.
No unlike what google charts does for graphing data.
Any resources or ideas on this?
If I had to build it myself, do you have some ideas of how I might accomplish that?
For instance, does PHP/asp/etc have a graphics library that's capable of rendering simple vector graphics?
-Adam
Check out Raphael. Done by a bloke here in Australia.
No unlike what google charts does for graphing data.
Why not just use the Google Chart API?
http://code.google.com/apis/chart/
Have you considered something like http://www.walterzorn.com/jsgraphics/jsgraphics_e.htm to produce actual vector graphics on the client side, instead of making requests to a server?
One possibility would be to generate SVG in realtime in the browser. This decreases browser compatibility, but that will decrease over time.
Related
I am trying to create graphs on timecards, which can be shown on Google Glass. Wat would be the best way to go about this? I tried using d3.js, but was unsure how to integrate the library.
Any help would be highly appreciated
Since you cannot run JavaScript inside a card on Glass, d3.js probably isn't the best choice.
Seek out a graphing library that generates images. You can then attach or source those images into the timeline cards you create.
This is deprecated, but could work nicely for your use case: https://developers.google.com/chart/image/
I want to create an web application through which i have to access tools like Gimp for my image processing. Is it possible to manage my need with client-server (Gimp at server) approach?
I am not restricting with the Gimp,however i prefer any opensource with basic functionality(zoom out/in,selection tool, cropping tool, transparent tool etc).
Sorry if the question is so wage as i am not much familiar with these kind of architectures.
And i hope this(stackoverflow) is the platform to get help from people.
There are several ways of doing image processing in the server of a web application.
One approach would be to invoke a tool through command-line (I think that is what you are trying to do with gimp).
Second approach would be to use a image manipulation library in the language you are using for developing the application. (Sometimes I did this with Java)
Use a combination of the above depending on the kind of manipulation you wish.
But with today browser capabilities, some processing can be done using HTML5 (canvas) + Javascript in the client itself. For instance you can use something like this for cropping:
http://www.webresourcesdepot.com/jquery-image-crop-plugin-jcrop/
Or something like this for image maniplation in Javascript:
http://pixastic.com/
So, there are plenty of choices. There is no a better approach, it all depends on the kind of processings, the size of the images, the hardware you have, etc.
Wish it helps...
I am trying to make a few interactive graph visualisations in my Django web application using Python. I found Graphviz and was able to output a static graph (as a .png image) on my application using Pydot (Python interface to Graphviz's dot language).
However, I am looking to make my graphs more interactive, like being able to highlight nodes when passing my mouse over it, making the nodes click-able, dragging the nodes to a different location and zooming on the graph.
Is there a way I could do this in Graphviz? Or in general is there way to make an interactive graph for my Django application without having to use Flash? I don't want to use flash since I'm not that familiar with it and also since I want to visualise a fairly large dataset.
Try The Javascript Infovis Toolkit. It is all implemented in a browser canvas, so no Flash is needed, only a decent browser with support for the <canvas> tag. Graph visualization examples are here, here and here, other demos are here.
There is Canviz (source). However, nodes are not yet clickable (they were in an older version that used image maps. The code base has changed and now the rendering is happenning client side using javascript, which is why clickable links is not yet re enabled.
This is the best I found, however they are plenty of others.
mxGraph (Not free)
You can use D3.js for graph visualization (see here for examples of graph visualizations in D3js, and look at How to Make an Interactive Network Visualization).
For back-end (if it is necessary to have something more than just a json file to represent the graph - i.e. if it is large), then you can use a Python module for graphs, NetworkX.
Side note, here is my simple interactive graph visualization example:
You can do something like this very simply just with DOT and HTML.
Generate client-side maps and overlay them over your PNG images. (Insert the map code into the HTML page.)
dot test.dot -Tpng -o test.png -Tcmapx -o test.map
SVG exports are directly clickable.
It seems like an approach that fits what you are trying to do might be to use svg in the browser an/or javascript. I think most of the modern browsers support SVG and would allow you to do some pretty cool interactive graphs. The server could provide a json feed of the datapoints needed to render the graph. I don't know off hand the tools that are available, but I've seen some pretty cool graph demos constructed without flash through client-side approaches.
As an alternative, you could pre-render a bunch of graph images that the user would likely view and then just fetch those as the user interacts with the graph. This might work if the graphs don't change that frequently and if the number of alterations that the user would make is small, but you'd have to re-render every time the graph changes.
I've did what you are trying to do not too long ago. The context was visualizing a gnarly SalesForce schema.
First thing, graphviz is only good for plotting, not really for drawing. You can generate SVG, but I could not get it to work with I.E. after a considerable of (what turned out to be fruitless) effort.
I DID find this Java Applet ZGRViewer to suffice, and while applets feel a bit dated for my taste, it worked very well cross browser.
I basically hand coded a process invoking service that generated the dot files and ran them thought (dotty, is think?) - the visulazation applet reads the native dot file format.
I also came accross something that I thought about for a V2 (which never happened) - it is part of the AJAX control toolkit - Seadragon.
If you want to see the code in ASP.NET, I can post it.
I want to display a map in a MFC application (Visual Studo 2008 with MFC Feature Pack).
Off the top of my head I have the following requirements:
I have to be able to add my own markers (plain lat/lon positions), preferrably with different colors/icons so one can distinguish between different types of markers.
If the map data is fetched from an online source, it has to be cache-able, i.e. I can pre-load maps for an area at a certain (or several) zoom-level(s) and then switch to "offline mode". Alternatively all map data is installed together with the application.
The standard operations like zoom in/out and pan should be possible for the user.
The user has to be able to select my markers, preferably by dragging a rectangle around them.
Since the whole app is written in C++/MFC I don't want to have to use the .NET runtime for this plugin.
It shouldn't cost a fortune.
I am currently using an ActiveX plugin called "ESRI MapObjects LT2" which can do all that in some way but it's very tedious to implement, the development seems to have stopped around the time when Visual Studio 6 was available and map material is either very basic or very expensive.
I thought about using Google Maps or Google Earth but I think they don't really support being used by non-web based applications.
I found ArcView to be some sort of successor of the plugin I use currently but I don't think I belong to the target audience since the functionality it offers is way more than what I need. Also I didn't find any information on pricing.
I have written an open-source Geocaching app ( it's in c++ ) that renders maps, the source is at:
http://code.google.com/p/gpsturbo/
It uses my own custom rendering but you could rip out the map parsing if you want. It renders map using google tiles ( and caches the tiles for offline use), as well as Garmin format GPS maps, there is also an Openstreetmap format renderer as well.
Reconsider google if you have internet access. You can make an instance of the IE browser appear in a frame within your application. I believe you can use an ActiveX control. Also Google Earth has a way to embed itself into a web page, and possibly an application as well.
Another option is Global Mapper which is not anywhere near as nice as Google Maps or Google Earth.
We used ESRI for a long time before abandoning it due to a lack of performance and lack of support. It was such a big pain to pay $10k for a license, and then be told they need $2k more so that we can actually use the thing. Oh, and then $2k more to add some extra functionality. Even when it didn't work, their support was dismal to lack-luster.
If you are not bound to Google Maps, you could choose OpenStreetMap.
There are couple of known applications for rendering OSM maps:
http://wiki.openstreetmap.org/wiki/Cobra
Kosmos
osmclient (on SourceForge)
First two render map directly, last one uses OpenStreetMap.org tiles.
You can cache as many tiles or data as you want, you are not restricted to do so.
We have created an OpenGL application in C++ which visualizes some physical simulations. The basic application is contained within a DLL which is used by a simple GUI. It currently runs on a desktop PC, but we have the idea to turn it into a web service.
Since the simulations require dedicated hardware, the idea is that a user, through his/her browser can interact with our application as a service and this service then renders the result to an image (jpg or anything appropriate) that can then be displayed/updated in the browser.
My question:
How can I "easily" turn a c++ application as described into a web-service that runs on some server so that I can approach it over the web? What kind of technologies/APIs should I look at? And are there any real-life examples that tackle a similar problem?
This is possible, but one major difficulty you'll have is trying to use OpenGL from a web service. You'll need to port this to do 100% offscreen rendering and work without a windowing context. That would be my first step, and it's not always a trivial one.
Also, it is very difficult to maintain and manage your opengl contexts from a webservice correctly, and the overhead involved can be quite painful. Depending on the number and types of renderings, you may run into some issues there.
If you need it to scale up well CGI would probably be kind of slow & hacky.
There are some C++ web frameworks out there, see this question.
As far as the OpenGL goes, you'll probably need to use the frame buffer extension as Jay said.
You could then render your image to a texture, and use use glGetTexImage() to grab the pixel data. From there just save into what ever image format you want with the accompanying library.
I had a similar project/question, that although it wasn't a web service, it required OpenGL rendering in a windows service. I had tons of problems getting it to work on Vista, although eventually it did work on XP with regular OpenGL.
I finally tried using Mesa, which I built to work as a private DLL for my service. It was a great decision because I could now actually step into the OpenGL calls and see where things were going wrong. It ran fine in software mode under the service, and while it wasn't hardware accelerated, it worked very well.
If your user-interaction needs are simple, I'd just look at CGI. It should be pretty easy to understand.
As far as getting the output of the OpenGL program, I'd take a look at the framebuffer extension. That should make it easy for you to render into memory, which could then be fed into a JPEG compressor.
I guess you already have access to some webserver, e.g. Apache or similar. In that case you could try out CppServ.
You just need to configure your webserver so it can communicate with CppServ. I'd then propose that you develop a servlet (check the documentation on the site) which in turn communicates with your already existing dll. Since the dll knows everything about OpenGL it should be no problem to create jpeg images etc.
How about using something like Flex to create a web-enabled 'control interface', with a server backend that streams the opengl rendering as video? Basically, you are redirecting keyboard/mouse input via the Flex app, and using it to display 'realtime' 3D activity using a standard movie component.
The devil's in the details, of course....
You can try to use O3D API from google and don't do anysort of service, it would be much more simple.
This answer might sound very basic and elementary, have you tried this approach
Send the vector data from the server to the client or vice versa (just co-ordinates and so on)
Render it on the client side.
This means that the server is only doing the calculations and the numbers are passed to and fro.
I agree that is not a trivial method of trying to vectorize every object/model and texture, but is very fast since instead of heavy graphical images going across, only vector data is being sent across.