draw Round gradient

Tue Nov 11, 2008 6:50 pm

draw Round gradient

Code:: import java.awt.*; import javax.swing.*; import java.awt.geom.*; import java.awt.image.*; public class RoundGradientPaintExample extends JPanel{ public void paint(Graphics g) { Graphics2D g2d = (Graphics2D) g; Ellipse2D ellipse = new Ellipse2D.Float(5, 5, 150, 150); RoundGradientPaint roundGradientPaint = new RoundGradientPaint( 75, 75, Color.red,new Point2D.Double(0, 85), Color.cyan); g2d.setPaint(roundGradientPaint); g2d.fill(ellipse); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.getContentPane().add(new RoundGradientPaintExample()); frame.setSize(200, 200); frame.show(); } class RoundGradientPaint implements Paint { Point2D point1; Point2D point2; Color color1, color2; public RoundGradientPaint(double x, double y, Color pcolor, Point2D radius, Color bcolor) { point1 = new Point2D.Double(x, y); color1 = pcolor; point2 = radius; color2 = bcolor; } public PaintContext createContext(ColorModel colorModel, AffineTransform affineTransform) { Point2D transPoint = affineTransform.transform(point1, null); Point2D transRadius = affineTransform.deltaTransform(point2, null); return new RoundGradient(transPoint, color1,transRadius, color2); } public int getTransparency() { int a = color1.getAlpha(); int b = color2.getAlpha(); return (((a & b) == 0xff) ? OPAQUE : TRANSLUCENT); } } public class RoundGradient implements PaintContext { Point2D point3, point4; Color color3, color4; public RoundGradient(Point2D p, Color c1, Point2D r, Color c2) { point3 = p; color3 = c1; point4 = r; color4 = c2; } public void dispose() {} public ColorModel getColorModel() { return ColorModel.getRGBdefault(); } public Raster getRaster(int p, int q, int width, int height) { WritableRaster writableRaster = getColorModel() .createCompatibleWritableRaster(width, height); int[] data = new int[width * height * 4]; for (int j = 0; j < height; j++) { for (int i = 0; i < width; i++) { double distance = point3.distance(p + i,q + j); double radius = point4.distance(0, 0); double num = distance / radius; if (num > 1.0) num = 1.0; int value = (j * width + i) * 4; data[value + 0] = (int) (color3.getRed() + num * (color4.getRed() - color3.getRed())); data[value + 1] = (int) (color3.getGreen() + num * (color4.getGreen() - color3.getGreen())); data[value + 2] = (int) (color3.getBlue() + num * (color4.getBlue() - color3.getBlue())); data[value + 3] = (int) (color3.getAlpha() + num * (color4.getAlpha() - color3.getAlpha())); } } writableRaster.setPixels(0, 0, width, height, data); return writableRaster; } } }

Attachments

: the output; roundGradient.gif (11.18 KiB) Viewed 5246 times