I know Im not the first person to ask this type of question, but I think mines a little bit different.
I have a png image I drew on MS paint that is a player and I want the background of the image to be transparent when I use a graphics objects to draw the image. I tried some stuff with magic pink but It doesn't seem to be working the same in java. Im not new to java, but Im inexperienced so could you explain any packages or methods that you use thanks!
You will need to use AlphaComposite to have the transparency effect:
Assuming that you already know Graphics2D and Graphics uses BufferedImage
Creating temporary graphics object g.create() and then dispose the object for safely restore the state of graphics object changed after the object creation.
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setComposite(AlphaComposite.SrcOver.derive(0.5f));
g2d.drawImage(tileImage, 0, 0, getWidth(), getHeight());
g2d.dispose();
// draw player image
}
With Java6, a PNG picture should be used for TrayIcon, but as mentioned in this SO question, check:
the background color chosen to represent the transparent pixels
the transparency options
the resolution of the icon
alternate format like SVG (provided you are using external library like Batik, and
conversion mechnism to java.awt.Image)
Related
I want to do efficient 2D drawing in Java. I would like to have some kind of surface which I may draw freely without having to let the view hierarchy traverse and update, which may cause stutter.
I have used a JPanel at first and called repaint() but I find it not to be optimal (and it is the reason I ask). The closest thing I have worked with is the Android's SurfaceView and it gives me a dedicated drawing surface.
To achieve this dedicated drawing surface, do I need to use OpenGL or is there any equivalent SurfaceView?
If you don't need Accelerated Graphics, you can draw onto a BufferedImage with Graphics2D. Once you have your data in the BufferedImage, you can simply paint the BufferedImage onto the component. This will avoid any sort of flickering you are talking about.
Creating the BufferedImage is easy:
int w = 800;
int h = 600;
BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Then you can draw objects onto it with a graphics context (Possibly in your own render function):
Graphics2D g = bi.createGraphics();
g.drawImage(img, 0, 0, null);
//img could be your sprites, or whatever you'd like
g.dipose();//Courtesy of MadProgrammer
//You own this graphics context, therefore you should dispose of it.
Then when you repaint your component, you draw the BufferedImage onto it as one piece:
public void paintComponent(Graphics g){
super.paintComponent(g);
g.drawImage(bi, 0, 0, null);
}
Its sort of like using BufferedImage as a back buffer, and then once you are done drawing to it, you repaint it onto the component.
When I apply canvas.getContext2d().scale(1.5, 1.5), then my objects in the canvas gets bigger as expected, but are somehow blurred.
What do I have to do to make the canvas draw my objects as sharp as it is when not scaled?
Use the antialiasing rendering hint:
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
So when you scale, it will look really better.
The images of the right use the RenderingHints.VALUE_ANTIALIAS_ON
I discovered that there are ctx.transform() and ctx.scale()methods for a Canvas. Which work fine, but as they behave like just scaling an image up, the result is not sharp. Guess due to (anti)alasing and stuff like that.
So I decided to rewrite all my ctx.draw() methods to respect a GLOBAL_OFFSET, which changes value when user zooms in and out. This way, the canvas objects can keep their original coordiante point values, but respecting the zoom level and offset it is possible to draw them bigger or thinner, which kind of "simmulates" the zooming and panning.
I wanna know... is there a way to draw the components style outside from Frame/Applet?
I'm making a application that uses OpenGL, and I need a GUI with a good look, like AWT or Swing. Yes, I know that there are many libraries like Nifty and TWL, but I really want use AWT/Swing look.
Thanks. (And sorry for my bad english, I'm brazilian.)
You can render a component to an image, even if it is not displayable (although you will have to manually set the size to the preferred size):
c.setSize(c.getPreferredSize());
BufferedImage img = new BufferedImage(c.getWidth(), c.getHeight(),
BufferedImage.TYPE_INT_ARGB);
Graphics2D g = image.createGraphics();
g.setComposite(AlphaComposite.Clear);
g.fillRect(0, 0, c.getWidth(), c.getHeight());
g.setComposite(AlphaComposite.SrcOver);
c.paintComponent(g);
g.dispose();
You can then use that image as a texture in OpenGL.
Of course, this will only give you a picture of the component; you won't be able to interact with it as you could with a "real" swing component.
Well I've got my game engine running smoothly, and perfectly on all machines! Before I continue adding functionality to the engine, I want to enhance the engine's graphical capabilities. The one I'm focused on is fading and blending images. I'm going to need some smooth transitions, so without using any 3rd party libraries like OpenGL, how does one apply opacity to images when drawing to a graphics object?
thanks for any replies :D
Perhaps using an AlphaComposite could be what you're looking for?
Image image = new Image(...);
float alpha = 0.5;
#Override
public void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D)g;
AlphaComposite composite = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha);
g2d.setComposite(composite);
g2d.drawImage(image, 0, 0, null);
}
You would set your alpha to whatever transparency level you desire (between 0.0 and 1.0). In this case, you would probably want to be using AlphaComposite.SRC_OVER to be able to overlay your transparent image and see behind it, unless your going for something else (if so, you can easily see all available constants and their explanations on the first link provided).
is there a possibility to draw a JPanel on a specific location op a Graphics (or Graphics2D) object?
I override the paint method of my canvas, and call panel.paint(g) in there, but it does not work the way I woul hope.
#Override
public void paint(Graphics g){
Dimension size = panel.getPreferredSize();
panel.setBounds(pos.x, pos.y, size.width, size.height);
panel.paint(g);
}
the size object is correctly defined as I would wish, so that's not the problem. Also, the pos contains a correct x and y on the screen.
You should probably be using paintComponent instead of paint, since the latter is the AWT method, and the former is the Swing method.
One nice thing about Swing's paintComponent is that the Graphics passed is actually always going to be a Graphics2D, so you can:
Graphics2D g = (Graphics2D)lg;
Now you can use the getTransform to save the old transform, then modify the transform of the Graphics2D using either setTranform or the scale, translate and rotate methods. Don't forget to restore the old transform, or you'll likely fudge the next thing being drawn by that context.
I'll throw in that, depending on the circumstance, drawing to a BufferedImage might be appropriate. You can get a Graphics context using BufferedImage.getGraphics(). Then you can draw the BufferedImage's context by whatever means suit you.