Java gaming and graphics

The entire drawing is rendered when needed, as usual, in paintComponent. Notice the call to repaint when dragging. This tells Java to redraw the panel as soon as it can. Buttons are boring.

Here is a program that reacts for each change to its input field. Java2D is the informal name given to the parts of the Java standard library dealing with drawing and printing 2D lines, shapes, images, gradients, and textures, together with fun options like compositing, filtering, transforming these objects.

Basic Java Graphics The Java platform has dozens of classes for graphics programming. The most common methods are drawString , drawImage and fillXxx. These methods can be broadly divided into two categories. The first type of Graphics method is, it provides draw and fills features that enable the Users to render the basic shapes, text, and images.

The other type of method is for attribute settings which lets you change the effect of how the drawing appears in the console. Methods such as setColor and setFont lets you decide how the draw and fill renders. Double 6, 31, 61, ; graphics2D.

Double , 31, 76, , 51, 51 ; graphics2D. CYAN ; graphics2D. Double , 30, 75, , 0, , Arc2D. BOLD, 18, Color. Double center. WindowAdapter; import java. WindowEvent; import java. FontRenderContext; import java. The Shape interface declares a method called getPathIterator to retrieve a PathIterator object that can be used to iterate along the Shape boundary. The popular legacy java. Polygon class was retrofitted to implement Shape interface. The Graphisc2D 's stroke attribute control the pen-stroke used for the outline of a shape.

It is set via the Graphis2D 's setStroke. A Stroke object implements java. Stroke interface. Java 2D provides a built-in java. The Graphics2D 's paint attribute determines the color used to render the shape. It is set via the Graphics2D 's setPaint method. A Paint object implements the java. Paint interface. A bitmap image is a 2D rectangular array of pixels.

The dimension of the image is represented by its width and length in pixels. In Java, the origin 0, 0 of an image is positioned at the top-left corner, like all other components.

Most of the image display and processing methods work on java. Image is an abstract class that represent an image as a rectangular array of pixels. The most commonly-used implementation subclass is java. BufferedImage , which stores the pixels in memory buffer so that they can be directly accessed. The ColorModel provides a color interpretation of the image's pixel data. Image is typically read in from an external image file into a BufferedImage although you can create a BufferedImage based on algorithm.

Image file formats supported by JDK include:. BufferedImage supports image filtering operations such as convolution. The resultant image can be painted on the screen, sent to printer, or save to an external file. JPEG does not. They maintain a list of palettes and map each palette number to a RGB color value. Every image pixel is then labeled with a palette number, which is then mapped to the actual RGB values. One of the palette number can be designated as transparent.

Pixels with this transparent palette value will not be displayed. Instead, the background of the image is displayed. The easiest way to load an image into your program is to use the static method ImageIO.

ImageIO class, which returns a java. Similar, you can use ImageIO. Instead of using java. File class to handle a disk file, it is better to use java.

URL is more flexible and can handle files from more sources, such as disk file and JAR file used for distributing your program. It works on application as well as applet. On the other hand, you can also construct an ImageIcon from an Image object via constructor:. Graphics class declares 6 versions of drawImage for drawing bitmap images. The subclass java.

Graphics2D adds a few more. The coordinates involved is shown in the above diagram. The ImageObserver receives notification about the Image as it is loaded. In most purposes, you can set it to null , or the custom drawing JPanel via this. The ImageObserver is not needed for BufferedImage , and shall be set to null.

Graphics2D supports affine transform and image filtering operations on images, as follows:. Java 2D's affine transform works on bitmap image as well as vector graphics.

However, instead of manipulating the Graphics2D 's current transform context which operates on vector-graphics only via rendering methods drawXxx and fillXxx , you need to allocate an AffineTransform object to perform transformation on images.

Graphics2D supports image filtering operations via the following drawImage method:. In a typical game, the actor has a x, y position, move at a certain speed in pixels per move-step and direction in degrees , and may rotate at a rotationSpeed in degrees per move-step.

In this example, all the frames of an animated sequence are kept in a single file organized in rows and columns. You could check if full-screen mode is supported in your graphics environment by invoking isFullScreenSupported of the screen GraphicsDevice :.

To leave the fullscreen mode and return to windowed mode, use setFullScreenWindow null. You should not try to setSize or resize the window in full screen mode. You could run your program in fullscreen without the window's title bar by invoking JFrame 's setUndecorated true.

The common way to resolve these display rendering problem is via so-called double buffering. To show a splash screen before launching your application, include command-line VM argument " -splash: splashImagefilename " to display the image.

To show a progress bar over the splash screen, need to write some codes to overlay the progress bar on top of the splash screen. The following shows a simulation:. The pre-requisite knowledge needed to for game programming includes: OOP, in particular the concepts of inheritance and polymorphism for designing classes. GUI and custom graphics programming javax.

Event-handling, in particular mouse-event and key-event handling java. Graphics programming using Java 2D java. Paying sounds javax. Transformation, collision detection and reaction algorithms.

Revisit java. It manages the graphics context such as color, font and clip area and provides methods for rendering of three types of graphical objects: Texts: via drawString.