FlatUIUtils: replaced quadratic curves with bezier curves in createRoundRectanglePath() to get perfect circle when using large arcs

(currently only used for SwingX)
This commit is contained in:
Karl Tauber
2020-11-20 11:50:03 +01:00
parent ccd4f99aea
commit 2177ee45cc

View File

@@ -519,15 +519,31 @@ public class FlatUIUtils
float x2 = x + width;
float y2 = y + height;
// same constant as in java.awt.geom.EllipseIterator.CtrlVal used to paint circles
double c = 0.5522847498307933;
double ci = 1. - c;
double ciTopLeft = arcTopLeft * ci;
double ciTopRight = arcTopRight * ci;
double ciBottomLeft = arcBottomLeft * ci;
double ciBottomRight = arcBottomRight * ci;
Path2D rect = new Path2D.Float();
rect.moveTo( x2 - arcTopRight, y );
rect.quadTo( x2, y, x2, y + arcTopRight );
rect.lineTo( x2, y2 - arcBottomRight );
rect.quadTo( x2, y2, x2 - arcBottomRight, y2 );
rect.lineTo( x + arcBottomLeft, y2 );
rect.quadTo( x, y2, x, y2 - arcBottomLeft );
rect.lineTo( x, y + arcTopLeft );
rect.quadTo( x, y, x + arcTopLeft, y );
rect.moveTo( x2 - arcTopRight, y );
rect.curveTo( x2 - ciTopRight, y,
x2, y + ciTopRight,
x2, y + arcTopRight );
rect.lineTo( x2, y2 - arcBottomRight );
rect.curveTo( x2, y2 - ciBottomRight,
x2 - ciBottomRight, y2,
x2 - arcBottomRight, y2 );
rect.lineTo( x + arcBottomLeft, y2 );
rect.curveTo( x + ciBottomLeft, y2,
x, y2 - ciBottomLeft,
x, y2 - arcBottomLeft );
rect.lineTo( x, y + arcTopLeft );
rect.curveTo( x, y + ciTopLeft,
x + ciTopLeft, y,
x + arcTopLeft, y );
rect.closePath();
return rect;