for my current work, I need to add images on top of other images at runtime. I already searched and I don't want to draw it on a Swing component, I use it in an external API.
Ideally, I would like a library (or a java-native way) with which I can specify several images to "layer", and it would return me a BufferedImage (or any Image object by the way).
If you want a single image (BufferedImage) in return, then you need to compose your images.
This answer may help you stackoverflow.com/questions/2318020/merging-two-images.
Have a look at the documentation for method drawImage to control position and scaling of any drawing through the Graphics object.
Related
I'm currently using a Canvas with an associated BufferStrategy. How can I copy the contents (image) of the Canvas and save it to a BufferedImage. So far I've only tried
BufferedImage image = ...
g = image.createGraphics();
canvas.printAll(g); //or paintAll
However, it appears that only a 'blank' (filled with the background color) screen is being drawn; I it's assume because that's the default behavior of Canvas.paint(). Is there as way for me to retrieve the image currently on screen (the last one shown with BufferStrategy.show()), or do I need to draw to a BufferedImage and copy the image to the BufferStrategy's graphics. It seems like that would/could be a big slow down; would it?
Why (because I know someone wants to ask): I already have a set of classes set up as a framework, using Canvas, for building games that can benefit from rapidly refreshing screens, and I'm looking to make an addon framework to have one of these canvases tied into a remote server, sending it's displayed image to other connected clients. (Along the lines of remotely hosting a game.) I'm sure there are better ways to do this in given particular cases (e.g. why does the server need to display the game at all?) But I've already put in a lot of work and am wondering if this method is salvageable without modifying (to much of) the underlying Game framework code I already have.
I need Your help in generating offscreen images from graphics class and converting them to binary data without setting them visible on screen.
I want to generate large amounts of labels and send them to a printer as binary data. If i create the image, show it on screen and then send it, everything is ok, but i generate 100 labels in one minute and it is annoying when they flicker on the screen of my java aplication.
I want it to be generated by a seperate thread, without visible efects.
If i don't show them, the labels are send black. I tried to generate them, and then show them off screen, that did not match my expectations.
Is there a way to generate "invisible" images from Graphics2d??
or
Is there another way You could suggest me?
Thank You in advance
Qba
You can use a BufferedImage and use getGraphics() to get hold of a Graphics2D object that paints onto this image.
If you're after painting GUI components (if your "label" refers to JLabel for instance) you could have a look at these questions:
How to get a BufferedImage from a Component in java?
Java/Swing offscreen rendering (Cobra HTMLPanel -> BufferedImage) Problem: Component doesn't finish redrawing first
I've read the java api, but I still do not understand the main difference between:
1) ImageIcon
2) BufferedImage
3) VolatileImage
4) Image
Can someone tell me when each one is used?
I wouldn't call this explanation below the absolute standard of using Java Image types, but these are the rules of thumb that I follow:
1. ImageIcon
This is typically used when you have small images that you want to add to buttons or to use as window icons. These may be created directly from anything that implements the Image interface.
2. BufferedImage
Typically used when you need to manipulate individual pixels within an image, or when you want to double-buffer a custom paint(Graphics g) method. The image resides in RAM, so it can take up a lot of space, and modifications to BufferedImage instances are not typically hardware-accelerated.
3. VolatileImage
Hardware-accelerated image, so it's fast, but you run the risk of the hardware-backed buffer being overwritten before you're done painting (although this rarely happens and according to Oracle, is only an issue for Windows-based machines). It's a little more difficult to use than BufferedImage for double-buffering custom paint(Graphics g) methods, but is well worth it if you find yourself doing a lot of pre-processing before rendering to screen.
4. Image
This is basically just an interface that defines some bare-bones functionality that every Image should have. You should use this when you don't need to modify an image's contents and/or want to make methods that handle read-only-image data most flexible.
Also, ImageIcon implements serializable so you can send it through java sockets. If you have Image objects, you have to convert them to ImageIcon and send. When the client side took the ImageIcons, it can convert them to Images again.
I have these several images which I need to be combined using BufferedImage in java. The logic of the program is this:
The user will be asked to input data (5 times) then the inputted value will be generated to image (I'm done coding with this part). My problem is how can I Combine them into one image only. Thanks!
You can create another new image. Depending on how you would like to combine the images you have two possibilities:
Call getGraphics() on the newly create BufferedImage and use drawImage() multiple times to draw your other images into the newly created one (for example to create a tiled image with all the images you create beforehand)
Call getRaster() on the newly create BufferedImage and use the methods of this object to draw information from your other images into this image (this way you can achieve any blend effects you might need)
For a game I'm making I am storing all the sprites for the map inside one large(er) image. I want to be able to create an instance of Image for each image inside of the larger image that has all the sprites.
So how would I create an instance of Image from a set position of another Image.
The basic solution (if all tiles in your tilesheet have the same size) is to use the getSubimage(xpos, ypos, XSIZE, YSIZE) method from the class BufferedImage.
Otherwise, you'll have to store a set of position and size for all sprites in another file.
Your question is similar to this others one.
Since you are using the java.awt.Image-class i am guessing you are trying to create a reasonable game using AWT? You really should take a look at a different technology like http://en.wikipedia.org/wiki/Java_OpenGL. The problem you ran into (partitioning a sprite-sheet) is typical for a lot of other problems (rotation...) you will run into if you try to develop a game without something like Open-GL.
Considering only the problem at-hand: you can easily solve this in Open-GL by binding the whole sprite-sheet as texture (glBindTexture()) and giving for each glVertex() a glTexCoord2f(), no need to cut-out parts of the sprite-sheet.