import element.*; import java.awt.Color; // must be imported to include Color public class Grayscale { public static Color gray(double intensity) // pre: 0 <= intensity <= 1.0 // post: returns a gray with indicated intensity level (1.0=white) { return new Color((float)intensity,(float)intensity,(float)intensity); } public static void main(String args[]) { DrawingWindow d = new DrawingWindow(); d.setForeground(new Color((float)1.0,(float)0.85,(float)0.85)); d.fill(new Rect(0,0,200,200)); d.awaitMousePress(); int i; // draw vertical lines, each with a fixed gray color // that varies from left (black) to right (white) for (i = 0; i < d.bounds().width(); i++) { d.setForeground(gray(i*1.0/d.bounds().width())); d.moveTo(i,0); d.lineTo(i,d.bounds().height()); } } } /* */