Attachment 109520 Details for Bug 243588 – Test class for the line drawing performance problem.

Test class for the line drawing performance problem.

PolylineBug.java (text/plain), 3.06 KB, created by Howard Hellyer

on 2008-08-08 10:08:20 EDT

(hide)

Description:

Filename:

MIME Type:

Creator: Howard Hellyer

Created: 2008-08-08 10:08:20 EDT

Size: 3.06 KB

patch

obsolete

>import org.eclipse.swt.SWT;
>import org.eclipse.swt.events.PaintEvent;
>import org.eclipse.swt.events.PaintListener;
>import org.eclipse.swt.graphics.Color;
>import org.eclipse.swt.graphics.GC;
>import org.eclipse.swt.graphics.Rectangle;
>import org.eclipse.swt.widgets.Canvas;
>import org.eclipse.swt.widgets.Display;
>import org.eclipse.swt.widgets.Shell;
>
>public class PolylineBug {
>
>	public static void main(String[] args) {
>
>		final Display display = new Display();
>		final Shell shell = new Shell(display);
>		shell.addPaintListener(new PaintListener() {
>			public void paintControl(PaintEvent event) {
>				Rectangle rect = shell.getClientArea();
>				drawTwoLines(event.gc, rect);
>			}
>		});
>		shell.setBounds(100, 100, 200, 200);
>		shell.open();
>		while (!shell.isDisposed()) {
>			if (!display.readAndDispatch())
>				display.sleep();
>		}
>		display.dispose();
>	}
>
>	protected static void drawTwoLines(GC gc, Rectangle rect) {
>		// With advanced set to true performance is better and the machine
>		// does not lock up while the lines are being drawn.
>		gc.setAdvanced(false);
>		
>		int[] points = new int[rect.width * 8];
>		int[] points2 = new int[rect.width * 8];
>		int maxy = rect.height - 1;
>		int miny = 0;
>
>		// Create a line which zig-zags between min and max y.
>		for (int i = 0; i < points.length - 3; i += 4) {
>			int x = i / 8;
>			points[i] = x;
>			points[i + 1] = miny;
>			points[i + 2] = x + 1;
>			points[i + 3] = maxy;
>			// Create the other line going the other way.
>			points2[i] = x;
>			points2[i + 1] = maxy;
>			points2[i + 2] = x + 1;
>			points2[i + 3] = miny;
>		}
>		int style = gc.getLineStyle();
>		Color color = gc.getForeground();
>		Color blue = new Color(gc.getDevice(), 0, 0, 128);
>		Color green = new Color(gc.getDevice(), 0, 128, 0);
>
>		long startTime = System.currentTimeMillis();
>		long endTime;
>
>		System.err
>				.println("If setAdvanced is false the machine may be non-responsive while the styled lines are drawn.");
>		System.err
>				.println("The effect is more noticeable the larger the window is.");
>		System.err
>				.println("Try moving the mouse around while the image is being drawn on a maximised window.");
>
>		// If the line style is SWT.SOLID there is no problem.
>		gc.setLineStyle(SWT.LINE_DASH);
>		gc.setForeground(blue);
>		gc.drawPolyline(points);
>		endTime = System.currentTimeMillis();
>		System.err.println("First line complete.");
>		System.err.println("First line took " + (endTime - startTime)
>				+ " milliseconds with " + (points.length / 2)
>				+ " points and gc.setAdvanced(" + gc.getAdvanced() + ")");
>		startTime = System.currentTimeMillis();
>		gc.setLineStyle(SWT.LINE_DOT);
>		gc.setForeground(green);
>		gc.drawPolyline(points2);
>		endTime = System.currentTimeMillis();
>		System.err.println("Second line complete.");
>		System.err.println("Second line took " + (endTime - startTime)
>				+ " milliseconds with " + (points.length / 2)
>				+ " points and gc.setAdvanced(" + gc.getAdvanced() + ")");
>
>		blue.dispose();
>		green.dispose();
>
>		gc.setLineStyle(style);
>		gc.setForeground(color);
>
>	}
>
>}

Actions: View

Attachments on bug 243588: 109520