Java 2D Graphics API that can provide zooming facilities? - java

Actually, my work is based on displaying a diagram in the screen, and while zooming in/out, the information in the diagram becomes more/less (just like Google Map).
May anyone guide to a 2D Graphics API that can allow me zoom in/out my drawings in Java easily?
I have used Graphics2D with AffineTransform, but showing more/less details in the diagram is somehow difficult using these stuff. I actually mean that Java Graphics API does not help in showing more/less details, positioning them, changing their size, etc. I have to write code for everything and every change in my design requires too much effort to modify my code.

You should use the MVC pattern where the diagram class representing the diagram with all the details is your model, the displayed image is your view and the zoom buttons/wheel are your controllers.
Here are some quick ideas:
You could have some method that builds the rendered image always using the same "internal" size, with more or less details depending on the zoom required and then use the AffineTransform to enlarge it (which is the easiest way to zoom an image as far as I know). Each time the zoom is changed this method is invoked passing the new zoom and the image is rebuilt.
If this is not feasible (e.g. because the coordinates of the additional information are not easy to compute on a small image) you can try the other way round: first build the basic image, enlarge it, then use the method to incrementally add new informations to this image. You can even cache the images built from smaller zoom values to speed up the process.

Related

Barrel distortion effect for image (JavaFX)

I'm looking for some way to set background image with barrel distortion effect(FishEye/FOV) for node using JavaFX. I found algorithm with pixel manipulation, but I want to find some another way(some hack) for reach it. This effect will be use for create node background high definition image changing animation(animation wil be change factor(power/value/degree?)) of this effect.
I'd like to offer an alternative approach which is much more efficient (real-time capable). Any solution which is based on direct pixel manipulations is doomed to be very inefficient especially for a "high definition image".
Instead I'd propose to use a TriangleMesh for this and use the image as its texture. You can then apply any kind of distortion you like by just manipulating the texture coordinates. This approach can be easily integrated into any 2D graphics via the JavaFX scene graph.
I am actively using this concept for on-the-fly reprojection of raster map tiles, so I know it works.
I will answer this question in the spirit that it was asked, i.e. no code.
JavaFX has an effect framework.
There is no in-built fisheye effect.
You could create your own custom fisheye effect implementation and plug it into the effect framework if you are a skilled developer.
Easier would be to apply your algorithm using a WritableImage with a PixelWriter or Canvas. Perhaps that could even plug into the effect framework (if you actually needed to do that, which you probably don't) using an ImageInput.
For an example of applying an algorithm to the pixels in an input image see:
Reduce number of colors and get color of a single pixel
Of course, you would use a fisheye algorithm (coded for JavaFX instead of the linked implementations) for a fisheye transform.
To animate use an AnimationTimer or, again for skilled developers, create a custom transition that plugs into the JavaFX animation framework.
You can add properties to your custom effect and manipulate them using additional properties defined on the custom transition you create.
Providing a complete solution is out of scope for a StackOverflow answer. To get help with individual tasks, split the problem up into different pieces, e.g. creating a custom effect, manipulating pixels to create a fisheye, animating an effect on an image or timeline, etc. Write the code and ask questions about the actual code with a minimal example for the problem portion you are trying to solve when you get stuck.

Confused with image scaling and positioning in libgdx

I'm having quite a bit of difficulty wrapping my head around the actual display side of things with libgdx. That is, it just seems fairly jumbled in terms of what needs to be done in order to actually put something up onto the screen. I guess my confusion can sort of be separated into two parts:
What exactly needs to be done in terms of creating an image? There's
Texture, TextureRegion, TextureAtlas, Sprite, Batch, and probably a
few other art related assets that I'm missing. How do these all
relate and tie into each other? What's the "production chain" among
these I guess would be a way of putting it.
In terms of putting
whatever is created from the stuff above onto the monitor or
display, how do the different coordinate and sizing measures relate
and translate to and from each other? Say there's some image X that
I want to put on the screen. IT's got it's own set of dimensions and
coordinates, but then there's also a viewport size (is there a
viewport position?) and a camera position (is there a camera size?).
On top of all that, there's also the overall dispaly size that's
from Gdx.graphics. A few examples of things I might want to do could
be as follow:
X is my "global map" that is bigger than my screen
size. I want to be able to scroll/pan across it. What are the
coordinates/positions I should use when displaying it?
Y is bigger
than my screen size. I want to scale it down and have it always be
in the center of the screen/display. What scaling factor do I use
here, and which coordinates/positions?
Z is smaller than my screen
size. I want to stick it in the upper left corner of my screen and
have it "stick" to the global map I mentioned earlier. Which
positioning system do I use?
Sorry if that was a bunch of stuff... I guess the tl;dr of that second part is just which set of positions/coordinates, sizes, and scales am I supposed to do everything in terms of?
I know this might be a lot to ask at once, and I also know that most of this stuff can be found online, but after sifting through tutorial after tutorial, I can't seem to get a straight answer as to how these things all relate to each other. Any help would be appreciated.
Texture is essentially the raw image data.
TextureRegion allows you to grab smaller areas from a larger texture. For example, it is common practice to pack all of the images for your game/app into a single large texture (the LibGDX “TexturePacker” is a separate program that does this) and then use regions of the larger texture for your individual graphics. This is done because switching textures is a heavy and slow operation and you want to minimize this process.
When you pack your images into a single large image with the TexturePacker it creates a “.atlas” file which stores the names and locations of your individual images. TextureAtlas allows you to load the .atlas file and then extract your original images to use in your program.
Sprite adds position and color capabilities to the texture. Notice that the Texture API has no methods for setting/getting position or color. Sprites will be your characters and other objects that you can actually move around and position on the screen.
Batch/SpriteBatch is an efficient way of drawing multiple sprites to the screen. Instead of making drawing calls for each sprite one at a time the Batch does multiple drawing calls at once.
And hopefully I’m not adding to the confusion, but another I option I really like is using the “Actor” and “Stage” classes over the “Sprite” and “SpriteBatch” classes. Actor is similar to Sprite but adds additional functionality for moving/animating, via the act method. The Stage replaces the SpriteBatch as it uses its own internal SpriteBatch so you do not need to use the SpriteBatch explicitly.
There is also an entire set of UI components (table, button, textfield, slider, progress bar, etc) which are all based off of Actor and work with the Stage.
I can’t really help with question 2. I stick to UI-based apps, so I don’t know the best practices for working with large game worlds. But hopefully someone more knowledgeable in that area can help you with that.
This was to long to reply as a comment so I’m responding as another answer...
I think both Sprite/SpriteBatch and Actor/Stage are equally powerful as you can still animate and move with Sprite/SpriteBatch, but Actor/Stage is easier to work with. The stage has two methods called “act” and “draw” which allows the stage to update and draw every actor it contains very easily. You override the act method for each of your actors to specify what kind of action you want it to do. Look up a few different tutorials for Stage/Actor with sample code and it should become clear how to use it.
Also, I was slightly incorrect before that “Actor” is equivalent to Sprite, because Sprite includes a texture, but Actor by itself does not have any kind of graphical component. There is an extension of Actor called “Image” that includes a Drawable, so the Image class is actually the equivalent to Sprite. Actor is the base class that provides the methods for acting (or “updating”), but it doesn’t have to be graphical. I've used Actors for other purposes such as triggering audio sounds at specific times.
Atlas creates the large Texture containing all of your png files and then allows you to get regions from it for individual png's. So the pipeline for getting a specific png graphic would be Atlas > Region > Sprite/Image. Both Image and Sprite classes have constructors that take a region.

Java image/map object

Using Java and SWT, I am trying to display a map (provided as an image) and mark points on it. First idea is to use a canvas, draw the image (scaled to the largest possible size for this canvas) and then draw the markings (fixed size) to the scaled coordinates. However I would also like to zoom in and move the image, and would prefer not to develop all this functionality from scratch. However I am not having much luck finding an existing solution, though I would guess there should be something out there.
The criteria would be:
based on SWT (or compatible)
allows exchange of the image (possibly with different sizes)
handles user interaction (selection a point on the image, zooming in/out of the image)
Does anybody know a standard/common solution?
Depending on how complex your system will potentially grow, maybe using GEF is an option.
The whole rendering is done on SWT.Canvas and it provides Zooming/Scrolling/Moving out of the Box.
Downside: Its dependant on RCP, so this is likely to be only an option if you need to build an otherwise complex application - in all other cases GEF will be quite heavyweight to set up.

Zoom in Java Swing application

I am looking for ways to zoom in a Java Swing application. That means that I would like to resize all components in a given JPanel by a given factor as if I would take an screenshot of the UI and just applied an "Image scale" operation. The font size as well as the size of checkboxes, textboxes, cursors etc. has to be adjusted.
It is possible to scale a component by applying transforms to a graphics object:
protected Graphics getComponentGraphics(Graphics g) {
Graphics2D g2d=(Graphics2D)g;
g2d.scale(2, 2);
return super.getComponentGraphics(g2d);
}
That works as long as you don't care about self-updating components. If you have a textbox in your application this approach ceases to work since the textbox updates itself every second to show the (blinking) cursor. And since it doesn't use the modified graphics object this time the component appears at the old location. Is there a possibility to change a components graphics object permanently? There is also a problem with the mouse click event handlers.
The other possibility would be to resize all child components of the JPanel (setPreferredSize) to a new size. That doesn't work for checkboxes since the displayed picture of the checkbox doesn't change its size.
I also thought of programming my own layout manager but I don't think that this will work since layout managers only change the position (and size) of objects but are not able to zoom into checkboxes (see previous paragraph). Or am I wrong with this hypothesis?
Do you have any ideas how one could achieve a zoomable Swing GUI without programming custom components? I looked for rotatable user interfaces because the problem seems familiar but I also didn't find any satisfying solution to this problem.
Thanks for your help,
Chris
You could give a try to the JXLayer library.
There are several tools in it, which could help you to make a zoom. Check the examples shown here. I would recommend you to read more about the TransformUI, from this library. From the example, it seems like it could help solving your problem.
Scaling the view is easy enough; transforming mouse coordinates is only slightly more difficult. Here's an elementary example. I'd keep JComponents out, although it might make sense to develop an analogous ScaledComponent that knows about the geometry. That's where #Gnoupi's suggestion of using a library comes in.
hey you can try this if you want to zoom a image like any other image viewer the use a JPanel draw an image using drawImage() method now create a button and when you click the button increase the size of the panel on the frame it appears as if the image is being viewed in Zoom
You might find Piccolo2D.java API useful: http://code.google.com/p/piccolo2d/
It is very simple.
It touts in particular its smooth zooming. You essentially make a "canvas" that can contain various elements, and can then zoom by just holding right-click and panning the mouse back and forth.
I worked on a team that used it to create this: http://sourceforge.net/apps/mediawiki/guitar/index.php?title=WebGuitar#EFG.2FGUI_Visualizer
The nodes you see there are clickable links themselves.
Since Java 9, there are VM arguments (actually meant to be used for high dpi scaling) that can render a application with a higher scaling factor:
java -Dsun.java2d.uiScale=2.0 -jar MyApplication.jar
Or:
java -Dsun.java2d.win.uiScaleX=2.0 -Dsun.java2d.win.uiScaleY=2.0 -jar MyApplication.jar

android opengl game

I'm trying to develop a 2D game to android using opengl.
I know how to print images on the screen and animate them. But in my game I have a map and a want to zoom in and out and scroll the map. But I can't figure out the best way of doing it.
Can anybody help me?
I don't have any api examples but I did games design at college so I'll give my two bits.
The method you use will depend on your map style, size, functionality and format.
For example if you are looking for a very static non changing map, use a simple picture image. You can use the API frame for a picture view, enabling you to zoom in and out as you do in the gallery and to scroll on zoomed images, or in this case, zoom locations on your map.
Alternatively, if your map is based off a tiling system, a good example of this is the original Pokémon and Legend of Zelda games from the old game boy, then each area stores a tile 'thumbnail' for itself as a bitmap. These are then put into their appropriate locations on a grid depending on what areas are discovered.
This is the probably the most flexible way to build your map as you are not relying on a set bitmap for the entirety your map meaning it can change its look efficiently; you can build it as desired to show areas of choice (useful for if the map only reveals places the gamer has covered) and it also means you can do tile based overlay:
ie - if a certain area should contain treasure, theres a treasure icon overlayed on that tiles x,y position on the map grid.
I used the tiling option in my game projects from college and it made everything else map related easier. It also made the map side of things smaller storage wise.
The simplest approach would be to just call glTranslatef(-scrollX,-scrollY,0) followed by glScalef(zoom,zoom,zoom) before you render your map.

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