drawing framework in java - java

I'm looking for a java 2d drawing framework. I'm building an application in which you load an image, and you should be able to draw on top of the image. But everything which is drawn should be selectable, modifiable, have properties etc. Actually Eclipse GEF (or Graphiti) looked really good, but that seems to be focused on drawing diagrams only. I would also need support for freehand drawing, bezier curves, lines etc.
Anybody know something like Eclipse GEF but which also supports freehand drawing and bezier curves? Or maybe it does and I didn't look quite good enough?

You can quickly write a simple editors yourself using JPanel and a custom paintComponent() method. But creating a useful editor with undo, etc. is a lot of work.
Try jfig which is shareware (free for 30 days, then $30). It has a framework with editor components plus a default editor which you can tweak.

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Customized rendering of SVGs in java

I am working on a java swing application that requires rendering images in specific locations on a JPanel. Currently, I am using PNG images with the Graphics.drawImage method. The application also requires the ability to freely move and zoom the "camera", which I am accomplishing with the Graphics2D.scale and Graphics2D.translate methods.
However, a significant issue with this approach is that the images do not scale well when the application is zoomed in. I was hoping that I could get around this by using SVGs, so I downloaded the Batik library. I have been able to display an SVG using Batik's SVGCanvas, but this doesn't really solve my problem because I am unable to freely place the SVGs in the JPanel and use the SVGs alongside the java Graphics methods.
Does Batik even apply to my use case? If not, is there some other way I can freely scale and render SVGs in a JPanel just like I would with a BufferedImage? Another option would be to just use the Graphics2D methods to try to replicate the icons I want to use, but that seems unnecessarily complicated.

Adding Text to Screen with OpenGL

Currently, I am working on a OpenGL project and here is the screenshoot what I did
The question is, I want to add texts(degrees) to compass and want to do that with pure OpenGl methods. I found TextRenderer class however, couldn't manage to download it and use it. How to use TextRenderer class in my Java project? If there is any other way of adding text besides TextRenderer, would love to hear it.
My second and most important question is about merging swing/awt methods with OpenGL and using multiple objects. I wrote the program with only using one GL2 object and worked perfectly, is it sensible to use multiple openGL objects on the same frame? Furthermore, using swing methods and openGL methods together is a good idea?
I want to add texts(degrees) to compass and want to do that with pure OpenGl methods.
Unless you can live with not very pleasantly looking center stroke fonts, you have no choice but to use help from some other library or API.
Theoretically OpenGL can collaborate with OpenVG, but so far overall support for OpenVG is very poor, and OpenGL interoperability even worse. But say you had a proper working OpenVG – OpenGL interoperability working, then OpenVG was the way to go.
Practically you have to something different. A very fruitful approach is to use a font renderer library (like FreeType) together with some layout engine (like Pango) to produce an outline stroke list of the text to be rendered, which in turn can be either rendered directly using some extension by NVidia (http://www.opengl.org/registry/specs/NV/path_rendering.txt available only on the most recent NVidia GPUs) or manually tesselated into triangles, either on the CPU or by a combination of GPU Geometry and Tesselation Shaders. A huge drawback of drawing glyphs as tesselated filled outlines with OpenGL primitives is, that they will look very dirty (due to aliasing) if the used framebuffer doesn't have a multisample format (full screen antialiasing)
The next best thing is rendering the text to an image and copying that to the GPU and overlay that over the scene by rendering a textured quad. You should apply all text transformations already when rendering the quad, so that the font hinting system can make the proper adjustments on the transformed glyphs before rasterizing them.
Another approach is using texture mapped fonts. I implemented two TMF engines myself so far, but personally I advise against using this approach these days, as TMFs are resource hogs. A 200kiB TTF font can blow up to several megabytes of texture data. Maybe one day I or somebody else implements a TrueType or OpenType rendering engine with OpenCL, CUDA or Compute Shader, but until then rendering text with OpenGL is dirty business.
It boils down to
Crisp Look
Memory Efficient
Computationally Efficient
→ choose 2
After doing little research, I ve figured out how to install it and use it correctly.
Firstly, go to that web site and download suitable version of jogl for your os in case you dont have any library:
http://jogamp.org/deployment/autobuilds/master/jogl-b1011-2013-06-19_05-41-38/
Then, download that jar file and add it to your user library.
http://www.java2s.com/Code/Jar/j/Downloadjogl20jar.htm
That file contains the TextRenderer class.
If you dont know how to make one, use that link:
http://riccardotramma.com/2011/04/setup-eclipse-to-develop-opengl-glut-apps-in-java-cc-on-windows-mac/
Then, follow the instructions: http://download.java.net/media/jogl/jogl-2.x-docs/com/sun/opengl/util/awt/TextRenderer.html
It's very easy to use, I perfectly added numbers to my compass. However, not efficient as far as I can tell.

Is it possible to make a Java SWT composite with an alpha value?

I am developing a GUI in Java SWT for use in a 3D particle physics simulator. The current GUI is quite clunky and unattractive, as it consists of multiple windows. I would like to consolidate the GUI into one window with a canvas, however to preserve functionality I must also add composites on top of this canvas. For aesthetic reasons, I would like the composites to be semi-transparent. I have done quite a bit of research, however nothing has worked so far. Is this even feasible using the composite API, and If so, how would I go about implementing it?
It is possible to set the transparency of a Shell - Shell.setAlpha(int).
Are you sure that semi-transparent composites will work if they are static? Isn't the idea to have semi-transparency on a floating window?

Turn photoshop design into Java GUI

I can't seem to find anybody who has done or posted something like this; Essentially I want to design my own UI in photoshop and then slice down the images to use it in a Java application. Essentially coding in the PSD file as the GUI. Is this possible? If so, can anybody lead me in the right direction?
I'm not sure what editor to use for this sort of stuff. I am using the Eclipse IDE and I know there is a Visual Editor but, I already have the actual design for every component in a PSD file. All I want to do is to start incorporating this into the application. Thanks.
It depends on how far your design goes. If you simply want to have normal Swing components on top of your image this is easy. Convert your PSD into (for example) PNG, create a custom JPanel subclass that loads the image and overwrite the paintComponent() method to draw the image instead of the normal background. All child components can then be set to be transparent with setOpaque(false). This puts your image into the background and puts the components float on top of it.
If you want to change how individual components look, its a lot more work. You basically need to implement a new Look&Feel for Swing. I wouldn't recommend going that route, unless you really have to, we are talking about weeks of work here, and it requires a lot of testing to really make it work properly on all platforms.
Alternately, there are already tons of custom Look&Feels available, I suggest you take a look at some freely available ones (just google "java look and feel"). Many of them can be customized to some degree (how much depends on the actual implementation, so take a close look at the source/documentation for each of them).
You might want to take a look at NetBeans which has a Swing GUI Builder. You would have to redraw your components there, and then write all the code to process the events. It is sometimes good to start with that, though often times it is less frustrating to lay them out with code by hand as it can difficult to make changes in code and have the builder keep up. There is nothing I know that will let you start from a photoshop image and proceed to building a GUI. Sounds like a good project to make someone rich. :-)

What are some techniques to create scrollable areas?

I'm getting started with OpenGL ES on Android and I'd looking to learn some techniques to have a game map larger than the visible area.
I'm assuming I've somehow got to ensure that the system isn't rendering the entire scene, including what's outside of the visible area. I'm just not sure how I'd go about designing this!
This is for simple 2D top-down tile based rendering. No real 3D except what's inherent in OpenGL ES itself.
Would anyone be able to get me started on the right path? Are there options that might scale nicely when I decide to start tilting my perspective and doing 3D?
There are many, MANY techniques for accomplishing this goal, but the base idea of what you are looking for is called Frustum Culling, that is not drawing anything the user isn't going to see anyway. Here and here are a couple of tutorials on how this works.

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