[PDFBOX-1960] Matrix and AffineTransform have confusing differences

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Later
• Affects Version/s: 2.0.0
• Assignee: Unassigned
• Reporter: John Hewson
• Created: 04/Mar/14 23:16
• Updated: 27/May/14 07:18
• Resolved: 27/May/14 07:17

Description

I've been driven insane recently by trying to get pattern fills to render correctly. Patterns have their own matrix which is concatenated to the CTM and no matter how I applied the transformation, the results were wrong.

It turns out that org.apache.pdfbox.util.Matrix is not behaving as expected, here's an example from a pattern I'm working on. I performed the same concatenation (i.e. multiplication) using our Matrix and Java's AffineTransform, the results are as follows:

Java AffineTransform:
[[2.0, 0.0, 1.251E-12], [0.0, 2.0, 1684.0]] *
[[0.6, 0.0, 302.6], [0.0, 0.6, 1091.38]] =
[[1.2, 0.0, 605.2000000000013], [0.0, 1.2, 3866.76]]

PDFBox Matrix:
[[2.0,0.0,0.0][0.0,2.0,0.0][1.251E-12,1684.0,1.0]] *
[[0.6,0.0,0.0][0.0,0.6,0.0][302.6,1091.38,1.0]] =
[[1.2,0.0,0.0][0.0,1.2,0.0][302.6,2101.78,1.0]]

I suggest that we remove Matrix and replace it with AffineTransform.

Issue Links

• is related to: PDFBOX-1094 Pattern colorspace support