I want to open libraries, because currently I want to see the algorithms used for drawing, modify them and implement them in my program. For example: I have tried to create an algorithm on my own for lines. But I failed. And even if I had succeeded, I fear that it might not give the same result as the algorithm in the libraries. And I don't want this to happen. That's why I want to copy the algorithms used for the methods in libraries. And I really hope that this will help me create the application I'm currently working on and with other applications in the future.
I tried to open the libraries with a code editor. But I had troubles finding the libraries- I don't really know where are they placed nor in what files are their codes stored.
How to open a Java library? Or is there a place in the Internet where the code is uploaded?
It sounds like what you want is to get inside the standard Java libraries (so you can see the code for methods like Graphics.drawLine()).
You can download the source files from the same place you got the JDK, if you are on Windows or Linux. For the Mac, see this question. You can even set up Eclipse so that you can debug into that source as if it were your own code.
However, you will probably not find line-drawing code in Java in these libraries - the Graphics implementation will almost certainly use native methods, and may just call existing methods in the OS.
If you are specifically looking for line drawing algorithms, another option would be to look at the Wikipedia page for the Bresenham (aliased) or Wu (antialiased) algorithm.
Edit:
The part of a Graphics2D call that actually puts pixels on the screen is probably inside a system call and therefore the source would not be available.
A java vector graphics library like Batik might have source for some of these algorithms, but probably relies on the Graphics2D calls for most of them. So, you might look for a comprehensive vector graphics library written in a language other than Java, where those graphics calls do not already exist by default.
Alternately, checking the table of contents for a computer graphics book might point you at a variety of algorithms that you could look up on Wikipedia.
For any given library:
Make sure to obey all licenses when using another's code
If you are referring to the Java SDK source code, you can find it here: http://grepcode.com/
If the project is open source, you can usually just get the source from the project website. No problem, though make sure to obey their license.
If the project is NOT open source, well, then you're in a pickle licensing wise, so I do NOT endorse this, however, you would need to use a Java Decompiler such as JD-Gui
As far as what drawing algorithms to use, there are so many different ones (obviously, people have been trying to draw quickly for many many years), your best bet is to figure out exactly what you need to do and then search for that specific need separately. There isn't really a good repository of ALL of them, except maybe wikipedia.
If you are using the libraries they are on your classpath. Check out how to figure out your classpath in whichever IDE you are using and you can find the JARs you depend on. If they are packaged with sources all you need to do it unjar them and look at the sources.
If you don't have access to the sources you can get the code using a Java Decompiler.
If you are trying to look at a standard Java library, see the other answers about getting the source to the JDK.
If you are interested in an open source library (such as something maintained by the Apache project), look on the site of the project for a 'source jar' which you can open with a standard zip utility.
If the library you want is not open source or you cannot find the source for it, you can try to decompile it. If you are using Eclipse, try this decompiler.
Related
BACKGROUND
One of the very useful tools for reproducible work in R is the "here" library.
https://malco.io/2018/11/05/why-should-i-use-the-here-package-when-i-m-already-using-projects/
http://jenrichmond.rbind.io/post/how-to-use-the-here-package/
https://here.r-lib.org/
https://here.r-lib.org/articles/rmarkdown.html
I was hooked by the part in the first link where they said this:
The "here" library is encoded in Anaconda as "r-here"
I'm not sure which came first, but Python has a "here" library as well.
https://pypi.org/project/pyhere/
https://github.com/wildland-creative/pyhere
"Here" makes relative paths a trivial matter, which is really useful for reproducible data-science and analysis work.
QUESTION
What is the Julia equivalent for clean handling of relative paths for files?
Is there a clean way to integrate that with project packaging, like RStudio does?
Based on the description, it sounds like DrWatson.jl does what you're looking for. From the website:
[DrWatson] is a Julia package created to help people increase the consistency of their scientific projects, navigate them and share them faster and easier, manage scripts, existing simulations as well as project source code. DrWatson helps establishing reproducibility, and in general it makes managing a scientific project a simple job.
Like the description implies, it's more ambitious than here seems to be, having functionality to also manage data, simulation runs, etc. But they're optional, and you can use only the directory handling part if you need.
The Navigating a Project describes the projectdir function which works similar to here. projectdir("foo", "bar") resolves to foo/bar under the current project's root directory, just like with here.
There's also datadir(), srcdir(), and others to directly handle common subdirectories under a project for eg. datadir("foo", "test.jld2") resolves to data/foo/test.jld2 under the project's root directory.
It doesn't exist, as far as I'm aware (Here.jl doesn't return any Google hits), but it seems like it would a simple enough for someone to implement. Maybe you!
i am new to Unity and i am try to understand plugins. I have got the difference between a managed plugin and a native plugin, but what is not very clear to me is:
what is the difference between a plugin and a dll? what should i expect to find in an sdk to make it usable in my unity project?
Thanks a lot
To expand on #Everts comment instead of just copying it into an answer, I'll go a little into details here
What is a plugin?
It's a somewhat vague word for a third-party library that is somehow integrated with the rest of your game. It means that it neither is officialy supported by Unity, nor is it a part of your core code. It can be "plugged" in or out without altering its internals, so it must provide some kind of API that can be used by the game code.
For example, you'll find many plugins that handle external services like ads, notifications, analytics etc. You'll also find a couple of developer-tools that can also be called plugins, like tile-based map editors and such.
Plugins come in many forms - DLL files are one example but some plugins actually provide full source code for easier use. And of course, other plugins will provide native code for different platforms, like Objective-C for iOS or .jars for Android.
So to answer your first question:
DLL is simply a pre-compiled source file that can be a part of a plugin
A plugin is a whole library that can consist of multiple files with different formats (.cs, .dll, .jar, .m etc)
What do you need to use an sdk?
First of all - documentation. Like I said before, and like you noticed yourself, not all plugins give you access to the source code. And unfortunately, not many sdks have extensive and developer-friendly documentations so it can be a tough task to actually understand how to use a given sdk.
Secondly - the code. Many sdks give you some kind of "drag & drop" library, a single folder with all the neccessary files inside that you simply add to your Unity projects. I've also seen sdks that use Unity packages that you have to import via Assets > Import Package > Custom Package.
Once you have the code and documentation it's time to integrate it with your game. I strongly recommend using an abstract lyer in your game as, in my experience, you often have to change sdks for various reasons and you don't want to rewrite your game logic every time. So I suggest encapsulating sdk-related code in a single class so that you have to change only one class in your code when switching from, say, one ad provider to another (and keep the old class in case you need to switch back).
So you basically need three things:
Documentation (either a readme file or an online documentation)
The code (precompiled or source)
A versatile integration
I have a large application to manage consisting of of three or four executables and as many as fifty .dlls. Many of the source code files are shared across many of the projects.
The problem is a familiar one to many of us - if I change some source code I want to be able to identify which of the binaries will change and, therefore, what it is appropriate to retest.
A simple approach would be simply to compare file sizes. That is an 80% acceptable solution, but there is at least a theoretical possibility of missing something. Secondly, it gives me very little indication as to WHAT has changed; It would be ideal to get some form of report on this so I can then filter out irrelevant (e.g. dates/versions copyrights etc..)
On the plus side :
all my .dcus are in a row - I mean they are all built into a single folder
the build is controlled by a script (.bat)(easy, for example, to emit .obj files if that helps)
svn makes it easy to collect together any (two) revisions for comparison
On the minus side
There is no policy to include all used units in all projects; some units get included because they are on a search path.
Just knowing that a changed unit is used/compiled by a project is not sufficient proof that the binary is affected.
Before I begin writing some code to solve the problem I would like to ask the panel what suggestions they might have as to how to approach this.
The rules of StackOverflow forbid me to ask for recommended software, but if anyone has any positive experiences of continuous integration tools that would help - great
I am open to any suggestion or observation that is relevant in this context.
It seems to me that your question boils down to knowing which units are contained in your various executables. Since you are using search paths, it will be hard for you to work this out ahead of time. The most robust way to find out is to consult the .map file that the compiler emits. This contains a list of all units contained in your executable.
Once you know which units are contained in each executable, you need to know whether or not anything has changed in those units. That information is contained in your revision control system. Put this all together and you have the information that you need.
Of course, just because the source code for a unit has changed, you might argue that re-testing is not needed. Perhaps the only change made was the version, or the date in a copyright label or some such. But it is asking too much to be able to ask a computer to make such a judgement. At some point you need a human to step up and take responsibility.
What is odd about this though is that you are asking the question at all. It seems to me to be enormously risky to attempt partial testing. I cannot understand why you don't simply retest the entire product.
After using it for > 10 years for commercial in-house and freelancer work in large projects, I can recommend to try Apache Ant. It is a build tool which supports dependencies, and has many very helpful features.
Apache Ant also integrates nicely with CI tools such as Hudson/Jenkins, Bamboo etc.
Another suggestion - based on experience with Maven - is to design the general software architecture as modular as possible. If modules (single or multiple source or DCU files in one directory) use a version number in the directory name as a version number, it is possible to control exactly how application are composed from these modules.
If you want to program such a tool yourself the approach would be something like this:
First you need to detect wheter there were any changes made to seperate source files. As you already figured out comparing the file size is bad idea as the file size can stay the same despite lots of changes made to it (as long as there is same amount of text in pas file its size won't change). So instead you could check the last modification time for specific file or create some hash value like MD5 hash for comparison (can be quite slow).
Then you need to generate yourself a dependancy tree which will tell you which files are used for which project/subproject.
Finally based on changes detected in seperate files you check the dependancy tree to see which projects needs to be recompiled.
The problem of such approach is that you would probably have to update the dependancy tree manually each time when new unit is added to the project or an existing one is removed from the project.
But the best way would be to go and use some version controll software istead of reinventing the wheel. I myself like the way how GIT works and I belive that with proper implementation of GIT into the project mannager itself could be quite powerfull do to GIT support of branching/subbranching (each project is its own branch, each version of your software can be its own subbranch).
Now latest version of Delphi does have GIT integration done though SVN but this unfortunately limits some of best GIT functionality. So if you maybe decide to go and integrate GIT support directly into Delphi I'm first in line to use it.
I want to write a simple editor with basic autocomplete functionality for the Go language as a pet project. How would one go about doing it? I took a look at the Go plugins for Eclipse and IntelliJ, but they were too big for me to comprehend (not to mention getting one to compile).
The Go standard library offers the building blocks for a Go parser which
you can use to parse the source files and look for function definitions and the like.
There's also the godoc command which
already does what you want: extracting method definitions and it's documentation. You may look in the
source code to see how godoc is
working or use godoc directly.
This editor written in Go projects has a manageable amount of code,
you may look into it.
The de facto standard approach to this problem is to use nsf's gocode. I have tried it only in Vim - it works very well.
Even though there's ready made support for specific editors, gocode is not editor specific. It's a daemon with a communication protocol. It is thus usable from any program.
I've got simple java-based ppt->swf sub-project that basically works. The open source software out there, OpenOffice.org and JODConverter do the job great.
The thing is, to do this I need to install OO.o and run it in server mode. And to do that I have to install OO.o, which is allot of software (~160MB) just to convert the source PPT files to an intermediate format. Also, the public OO.o distributions are platform specific and I'd really like a single, cross platform set of files. And, I'd like to not interfer with a system's current settings, like file extension associations.
As things are now, my project is not particularly 'software distribution friendly'.
So, the questions are:
Is it possible to create a custom distribution of OpenOffice? How would one about this?
How lightweight and unobtrusive can I make the installation?
Would it be possible to have a truly cross platform distribution since there would be no OO.o UI?
Are there any licensing issues I need to be aware of? (On my list of things to check out, but if you them already then TIA!)
I have no idea to accomplish such task, but Microsoft has its PPT viewer that is for free and very small, maybe in .NET (C#) you can use some kinda function to save into a intermediate file that you need...
and by the way, how are you handling slide transictions?
I found a software that does that but you need MS PPT installed.
this was just an idea, now regarding your actually question:
you can create your own installation of OO, just jump to the Installation project and follow the lines.
I did not read 'til the end, but from the 1st paragraph it seams what you are searching for.
No, not unless you are neck deep coding in the OpenOffice project.