[PDFBOX-4449] Rotated pages produce matrix value like -0.999999999999999 instead of -1

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.13
• Fix Version/s: 2.0.14, 3.0.0 PDFBox
• Component/s: Rendering
• Assignee: Tilman Hausherr
• Reporter: Tilman Hausherr
• Created: 30/Jan/19 16:22
• Updated: 28/Feb/19 17:44
• Resolved: 31/Jan/19 20:10

Description

I was wondering why I got AffineTransform objects like

AffineTransform[[-4.371139E-8, 0.999999999999999, 7.96E-13], [0.999999999999999, 4.371139E-8, -3.4619420881E-5]]

which makes debugging difficult, instead of

AffineTransform[[0.0, 1.0, -0.0], [1.0, 0.0, -0.0]]

The cause is this code line in PDFRenderer:

graphics.rotate((float) Math.toRadians(rotationAngle));

Solution: removing the cast produces a nice AffineTransform object:

graphics.rotate(Math.toRadians(rotationAngle));

However... this resulted in rendering bugs in several files (gs-bugzilla690022-reduced-rotations.pdf, gs-bugzilla690022-reduced-rotations-cropbox.pdf, PDFJS-5811-2-p4_reduced-rotations.pdf). Researching this found that getScalingFactorX() and getScalingFactorY() return negative values which they didn't before. Using Math.abs() solves this problem and now two files are slightly better (lines no longer very slightly diagonal): PDFBOX-2376-466070.pdf page 24 and PDFBOX-4399-046615_p9_OCG-NoRotate-Annotations.pdf .