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Lightweight C++ Library For SVG On Windows?
redblue writes "I would like to display vector graphics in my Windows C++ programs with minimal system requirements. Some of the possibilities are: 1. Enhanced Metafile Format format/EMF+, 2. Flash/SWG, 3. Silverlight/XAML, 4. SVG. The non-open proprietary nature of #2 & #3 make them unattractive. Since EMF+ is not amenable to easy editing, it leaves SVG as the only format worth pursuing. The trouble is that the major vendors have a lock on the market with their proprietary formats; leaving SVG high and dry with no easy native OS support. At least not on Windows. From what I could learn on the intertubes, Cairo is the best, if not only, reasonable system that may enable compiled SVG support. Unfortunately, AFAIK, it comes with a price tag of >2MB overhead and the C++ bindings are not straightforward." Read on for the rest of redblue's question; can you improve on his home-brewed solution?
"In a flash of the NIH syndrome, I rolled my own SVG processing engine and it has addressed my needs. You can see the result on http://www.arosmagic.com/Solitaire. A simple breakdown is: Framework+CRT(150K), SVG engine(100k), SVG art(350k). My SVG library is sufficient for me for now. But I can't help wonder:
1. Is there a better SVG library out there already available for easy inclusion?
2. If not, is there a need, i.e. market demand, for a lightweight (~200K) C++ SVG library that does not have the baggage of Silverlight or Flash?
If the answers are No/Yes, it may be worth it to make this library fully SVG compliant and release it as an open source alternative to the offerings from the entities that we shall not name but just collectively refer to as The Microbe. Please help out by letting me know if such a component is something that you would personally want to use in your current/future projects."
1. Is there a better SVG library out there already available for easy inclusion?
2. If not, is there a need, i.e. market demand, for a lightweight (~200K) C++ SVG library that does not have the baggage of Silverlight or Flash?
If the answers are No/Yes, it may be worth it to make this library fully SVG compliant and release it as an open source alternative to the offerings from the entities that we shall not name but just collectively refer to as The Microbe. Please help out by letting me know if such a component is something that you would personally want to use in your current/future projects."
I haven't looked at the code, but is there something that you can leverage from Inkscape?
It's a simple matter of complex programming.
It looks like your needs/game only use basic vectors, nothing fancy like blends, blurs. Could you just strip out much of the code from the SVG source that does stuff you don't foresee using?
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IÍ'd say QT/Webkit is the best bet currently. That will give you XML tools and a decent SVG view(er).
Religion is regarded by the common people as true, by the wise as false, and by rulers as useful.
That's just ideological drivel. The point is, SVG is a " standard " with a nice w3c.org - hosted spec and a nice diversified, academy-industry panel of contributors, but the fact remains, that in the 10 years since it became a standard, nobody really cares. Even browsers that support it officially only support subsets of it. The pragmatic reality is that it's a standard only in name, not in fact. If you want something with a clean, complete, consistent documentation describing a real, working, complete, multi-platform implementation, then what you call " proprietary" solutions are actually the way to go. Read the actual license terms for them and you'll see there's actually NOTHING that they prevent you to do, that you'll likely to have any interest in doing.
..about ripping the V8 and Skia engines from Chrome and making a standalone vector graphics system. Skia is light by design. V8 is fast and easy to embed by design. It's all C++ from the ground up. Implement the SVG interpreter in Javascript. Provide a JSON based alternative for the XML haters. Merge ongoing improvements from Chrome et al.
Just need a year of funding...
minimal system requirements
2. Flash/SWG, 3. Silverlight/XAML
Does not compute.
2 megabytes of overhead? It ain't 1988 anymore, 2MB barely even registers these days.
I get the whole Slashdot obsession with bloat, but there's a limit.
But please make it work cross-platform through SDL and/or OpenGL or AGG.
If it is cross-platform, I could see there being some interest at least in the indie game development community.
The pragmatic reality is that SVG is becoming standard very quickly. Have a look at wikipedia.org. (Have you heard of it?)
" proprietary" solutions are actually the way to go. Read the actual license terms for them and you'll see there's actually NOTHING that they prevent you to do, that you'll likely to have any interest in doing.
Yes, I'm sure that Adobe will have no problem with him using their library in his program that he gives out to all his friends and clients.
While on the subject, I would like to ask what other open formats there are for vector graphics. I'm especially interested in efficient formats (avoiding the overhead of XML) and in formats that do more than just represent images (e.g. that allow animation and/or scripting).
Please correct me if I got my facts wrong.
Read the actual license terms for them and you'll see there's actually NOTHING that they prevent you to do, that you'll likely to have any interest in doing.
Maybe not but I'd argue it's a tad naive. Out here in the real world, there's nothing stopping a for-profit company from changing terms on their proprietary format license. After all, it's theirs. If they can make a profit by altering the terms in the future then why shouldn't they?
And proprietary formats work surprisingly well. Witness .doc as well as AutoDesk's venerable .dwg format. A truly obfuscated mess and they're still number one because of it.
I'd suggest looking at projects for bringing SVG to smartphones. You may find an SVG library for Windows CE that would compile under (vanilla) Windows -- probably not feature complete, but chances are the Mobile SVG specs are enough for your needs. I believe there is at least one very trim branch of Firefox underway, though SVG support may be one of the things that it trimmed. Good luck.
Like SDL_svg? http://www.linuxmotors.com/SDL_svg/
We're using Batik and it's great. It's real, working, (mostly) complete, and multi-platform. Does it cover absolutely everything? No, it doesn't (see their status page), but it has done everything that we want it to do.
The more people I meet, the better I like my dog.
try using Qt library. It has some SVG support. Although I am not sure how complete it is...
> Windows
> can you improve
Well...
The author of Antigrain is a perfectionist.
Just look here - http://www.antigrain.com/svg/index.html . And version 2.4 is under BSD license.
RTFA. And wipe up that drool, you're not in high school any more.
Christ, Slashdotters just keep getting dumber.
I've used this one, the svg_plot library in the boost sandbox, developed as part of the google summer of code 2007
http://svn.boost.org/svn/boost/sandbox/SOC/2007/visualization/libs/svg_plot/doc/pdf/svg_plot.pdf
Read the actual license terms for them and you'll see there's actually NOTHING that they prevent you to do, that you'll likely to have any interest in doing.
For now.
But they may change them which they can do because they own them.
My Brother got stung badly developing for a 'community' game engine which was subsequently sold, and the new owner started charging to distribute the libraries.
If its open source your development can't be marooned like this.
You might want to look at Cairo. It has a Win32 backend as well as many other platforms. It is written in C and has bindings for C++ and lots of other languages as well. http://cairographics.org/
How neat, an Ask Slashdot post, but when you go into it you find that it's really a product announcement disguised as a question. (With a few FOSS-related platitudes throw in to seal the deal.)
So let me get this straight: This guy has Windows C++ programs he's written, and he desperately wants to find an open, non-proprietary library to enhance his programs that run on a closed, proprietary OS? Oh I only want to add sugar-free sweetener to my non-diet cola because I'm trying to cut back on sugar!
Yeah, I guess the OP would just have to convert his C++ project over to Java which is pretty much trivial! (since they both use C-based syntax)
That was the turning point of my life--I went from negative zero to positive zero.
CGM exists since about 1985, is standardized by ISO and supported by many applications (Corel, AI, Freehand,...). Binary and ascii representations exist.
Might be worth a look.
works for me. http://sdlsvg.sourceforge.net/
And of course, while he's worried about Cairo eating 2 MB of RAM, I'm sure the massive amount of RAM consumed by the JVM won't bother him in the least...
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If you have to upgrade your hardware to account for a 2 meg overhead in a program, you should consider upgrading to technology at least from the late 90s.
A lot of handheld platforms still in use have capabilities comparable to that of technology from the mid-1990s. For example, Nintendo DS has 4 MB of RAM and similar GPU throughput to the original PlayStation and N64.
OTOH, you could simply use librsvg to render the SVG graphics to PNG (or some other supported format) and display with the appropriate library calls.
You bash Cairo for being "too immature" (wtf, really? It's one of the most advanced 2D vector libraries out there), and then recommend a rendering library that is written exclusively to render to Cairo. Well played sir.
"Victory means exit strategy, and it's important for the President to explain to us what the exit strategy is." G.W.Bush
The story mentions WINDOWS
Perhaps the game for Windows is merely a prototype of something eventually intended to run on Windows Mobile or the like.
2 megabytes of overhead? It ain't 1988 anymore, 2MB barely even registers these days.
A lot of people outside metropolitan areas still can't get an Internet connection faster than 0.05 Mbps.
I would like to ask what other open formats there are for vector graphics. I'm especially interested in efficient formats (avoiding the overhead of XML) and in formats that do more than just represent images (e.g. that allow animation and/or scripting).
There are representations of an element tree other than XML; one of them is called JSON. You could represent the SVG DOM in one of those, and then you could gzip it for further savings. And then use JavaScript to manipulate the DOM.
...it's going to run on a fucking 64-core monstrosity with 100 Petabytes of fucking RAM.
Or we could STOP READING OUR OWN ASSUMPTIONS INTO THE FUCKING SUMMARY.
How about we do that, huh?
http://libboard.sourceforge.net/
...Even browsers that support it officially only support subsets of it.
Exactly. The root cause is that "lightweight" and "SVG" are mutually exclusive. SVG is an incredibly complex standard, and implementing it to spec is going to take incredibly complex code.
Inkscape uses Cairo for all its rendering. Thus it is not going to be lighter weight than Cairo. There may be code in there that would provide a more useful interface, especially for C++ code. Reuse is always a good idea...
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
Yes, I'm sure that Adobe will have no problem with him using their library in his program that he gives out to all his friends and clients.
The Flash player? Go right ahead: "Adobe provides a free license to allow you to redistribute Adobe Flash Player or Adobe Shockwave Player on your company's intranet, or with your software product or service." (here)
Ditto the XAML solution: the render is included in .NET 3.
The pragmatic reality, to borrow your phrase, is that more people have a Flash player installed than an SVG renderer.
Im surprised no one has mentioned the Juce library. It has svg support for multiple platforms.
http://www.rawmaterialsoftware.com/juce/index.php
At the risk of offending the geek-gods, would anyone be able to answer the same question, but for C#/.NET? Everything I've found so far for rendering SVG written in C# is either "under development" or "abandoned".
You've never tried implementing a w3c spec I think. HELLOOOOO SWISS CHEEZE!
Some of you have responded negatively to the need of rejecting a library with >2M overhead. Allow me to address that instead of responding individually.
Regrettably, I was unclear about what that 2M referred to. I totally meant the file size, not the memory footprint. The real utility of vector graphics shows up on large displays, meaning large buffers in the 5-30M RAM range, so imposing a RAM limitation is not wise per se.
The reasons for wanting a small file size are threefold:
1. Lower bandwidth cost
2. Better NUMA optimization
3. Smaller surface area for bugs
1. Bandwidth: As an online publisher, you have to pay for every byte that is served over the wire to the customers. It's a minuscule cost when there are only a thousand downloads. But if you ever dream of millions or more of downloads, the cost of that adds up rapidly. That's when a library that is only 200K is better than a 2M one.
2. Faster Memory performance: Given the NUMA nature of modern computers, you get better performance the higher up in the hierarchy you are. Hence, there is a greater chance of your program's working set sitting in the L1 cache if it is small.
3. Bugs: This is probably doesn't need much explaining, since smaller programs are easier to make bug free.
I think there are four major inflection points today as far as file size for programs is concerned:
size < 100K
100K <= size < 5M
5M <= size < 50M
size >= 50M
Without a doubt Cairo is appropriate for the latter two, i.e. if your project is >=5M in size.
But if your SVG artwork+code is already <1M, it makes no sense to add >2M code overhead when a 200K library can do the job. I think a lot of software is (or should be) in that category. The only reason it isn't so is because everybody is using bitmaps that up the file size when vector art is more appropriate. They do that because there is no easy native OS support.
Now someone possibly more knowledgeable than I mentioned here that Cairo's footprint might actually be smaller (maybe 1M) if you tweak with it enough, so it might be worth taking a second look at. But I hope my thoughts will convince you that pursuing a smaller binary size is a worthy endeavour, especially in a library.
http://www.khronos.org/openvg/
It's as easy as 1-2-3 to use the many variety of bitmap formats because there is either built-in OS support for them or good focused free open source libraries out there. :-).
It has not been so for vector art. I just can't do a Draw(VectorFile, HDC/Gdiplus::Graphics), though I can do so for bitmaps. EMF+ gives you that functionality, but is non-portable and non-editable.
GDI+ implements so many SVG contructs close to spec it's scary. It's almost as if XAML was designed to spite SVG. That "intent" is so clear to me now that I have implemented a GDI+ based SVG renderer that I can't help marvel that someone like you would willingly drink the Microbe cool-aid. Unless you are their agent, of course. As I once was, in another life time.
No it is quite clear that The Microbe strategy is to Embrace, Extend and Extinguish and they will do (or not do) anything in their power to extend their defacto cartel on the graphics market.
Even if SVG, and my minor inconsequential efforts at building a rendering library for it are just a thorn at the side of the evil empire, I'm just happy to do my bit in twisting it in.
Unless, of course, they are willing to pay me billions to quit. In which case I'll refer to them as a Symbiote. But I don't think they are willing to do the name change just yet
A minor correction. The 2MB issue was for file size. Rendering vector graphics can be very RAM intensive. I have posted my thoughts on this in a separate place. Sorry about the confusion.
To remain in context, I'm hoping to do for C/C++ what Batik has done for JVM. Or at least a usable approximation of such. In a very light package. Or be pointed to the same if someone else has already done that work.
You may be right, but...
Having implemented a subset of SVG I found that most of the hard parts were in the absence of certain functions/functionality in GDI+. But I never felt that they can't be made whole with focused effort. It might require better brains than mine, and it might take a whole year. But it's doable.
As long as you are clear and focused about the objectives -- render {static,dynamic} SVG on {GDI+,OpenGL, Quartz, etc}. The key is to be focused.
I've been working on a similar problem in my spare time for quite some time now. I needed a SVG library that was BSD-compatible, could draw any Adobe Illustrator SVG, and selectively enable or disable objects by their ID that was suitable for inclusion in a 3D game.
I couldn't find any library that fit the requirements, so I ended up writing a C++ library called Donner SVG. It is heavily based on librsvg except written with SVG DOM in mind and for minimal dependencies. It's only dependencies are Cairo, rapidxml, and libcroco, but none of libcroco's dependencies as I wrote a compatibility layer. Additionally, the renderer can be easily swapped out to eliminate the Cairo requirement.
Some notable features:
- Ability to access the SVG document tree and modify it after loading an SVG.
- Supports all shapes and paint server types (radial and linear gradients with stops, solid colors, and transparency).
- CSS2 selector support.
- Bounding box calculation.
It renders static SVGs very well, but I don't consider it to be releasable yet. My goal is to fully implement the #SVG-static feature string and use the library to implement a SVG extension for skeletal animation and inverse kinematics.
I'm willing to send a copy of the source over if anyone is interested, just contact me at "donner (at) jeffrules (dot) com". It is licensed under the LGPL as parts of it are borrowed from librsvg.
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An updated libsvg library can be found here http://svg2swf.sourceforge.net/. With a little work the dependencies can be reduced to just expat and uriparser.
I would think that if you are looking at C++ in Windows that you would probably consider using GDI+ as the basis for an SVG style render. GDI+ fits in nicely with Windows DC model, but is very cleanly object oriented.
And um, I would think that, by its nature, SVG is not going to be all that small....
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