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Asked: 2026-05-11T09:54:07+00:00

I’ve got a set of Java2D calls that draw vectors on a graphics context.

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I’ve got a set of Java2D calls that draw vectors on a graphics context. I’d like for the image to be doubled in size and then rotated 90 degrees.

I’m using the following code to do this:

Graphics2D g2 = // ... get graphics 2d somehow ... AffineTransform oldTransform = g2.getTransform(); AffineTransform newTransform = (AffineTransform)oldTransform.clone(); newTransform.concatenate(AffineTransform.getTranslateInstance(x1, x2)); newTransform.concatenate(AffineTransform.getScaleInstance((double)newW/(double)iconW, (double)newH/(double)iconH)); newTransform.concatenate(AffineTransform.getRotateInstance(Math.toRadians(rotationAngle), (double)iconW/2.0d, (double)iconH/2.0d)); // ... do my drawing ...

This rotates and scales, however, the scale isn’t applied the way I would like. It is as if it is rotated before scaling, thus making the image wider on the wrong axis.

Is there a better way to do this?

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1 Answer

  1. I believe those transforms are implemented like a stack – so the last transform is performed first. Try reversing the order of the rotate and scale transformations and you should get what you are looking for.

    newTransform.concatenate(AffineTransform.getTranslateInstance(x1, x2)); newTransform.concatenate(AffineTransform.getRotateInstance(Math.toRadians(rotationAngle), (double)iconW/2.0d, (double)iconH/2.0d)); newTransform.concatenate(AffineTransform.getScaleInstance((double)newW/(double)iconW, (double)newH/(double)iconH));
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