[PDFBOX-4909] Don't calculate font height for every glyph

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0, 3.0.0 PDFBox
• Fix Version/s: 2.0.21, 3.0.0 PDFBox
• Component/s: Text extraction
• Labels: Optimization
• Assignee: Tilman Hausherr
• Reporter: Alfred
• Created: 06/Jul/20 13:25
• Updated: 21/Aug/20 04:54
• Resolved: 25/Jul/20 11:06

Description

LegacyPDFStreamEngine computes font height for every glyph and the computation is rather heavy, to work around all known problems.

Instead of computing for every glyph, we can recompute only when the font changes. The SetFontAndSize operator will be invoked when the font changes so we can use that to compute and store the height to have it ready when needed in showGlyph.

 

Issue Links

• links to: update pdfbox and slf4j version #325