Hello,
I work with Java2D for CAD/CAM style applications where antialiasing is not
desirable. Since Java 6 the rasterizer for Bézier curves changed:
-
Java 5: non-antialiased Bézier curves produced very regular, uniform “ladder”
steps (each pixel step had the same length).
-
Java 6 and later: the rasterizer switched, and now the visible steps are
irregular — some longer, some shorter.
For my use case, the old behavior was much cleaner and easier to interpret
visually. Rendering hints such as KEY_STROKE_CONTROL and KEY_FRACTIONALMETRICS
do not restore this, since the difference lies in the rasterizer implementation
itself.
Minimal test case:
import java.awt.*;import java.awt.geom.*;import javax.swing.*;
public class CurveTest extends JPanel { @Override protected void
paintComponent(Graphics g) { super.paintComponent(g); Graphics2D
g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_OFF);
g2.setStroke(new BasicStroke(1f));
// Flatter cubic curve across the panel CubicCurve2D curve = new
CubicCurve2D.Double( 50, 400, // start 200,
350, // control1 600, 450, // control2 750, 400
// end ); g2.draw(curve); }
public static void main(String[] args) { JFrame f = new
JFrame("Curve Test"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(800, 800); f.add(new CurveTest());
f.setVisible(true); }}
Expected (Java 5): uniform, even “ladder” steps when antialiasing is off.
Actual (Java 6+): irregular steps of varying length, harder to read.
Request:
Would it be possible to expose an option (for example, a rendering hint or
system property) to select the old Java 5 rasterizer mode, or otherwise
reproduce its uniform step behavior for non-antialiased curve rendering?
This would help applications that rely on crisp pixel stair-steps as a visual
aid, rather than smooth antialiasing.
Thank you for considering,
Francisco
