Work-around for HighlightAnnotations without a top-level /ExtGState-entry (issue 13242) #13457
Conversation
…ntry (issue 13242) For HighlightAnnotations with a built-in appearance stream, we still rely on it to specify the opacity correctly via a suitable blend mode. However, if the Annotation-drawing operators are placed *within* a /XObject of the /Form-type, the /ExtGState won't apply to the final rendering and the result is that the highlighting obscures the underlying text. The more *correct* and general solution would likely be to somehow modify the implementation in `src/display/canvas.js`, to special-case handling of /Form-type /XObjects when rendering Annotations. Since we can very easily work-around this problem for now by using the "no appearance stream" code-path, doing *something* here ought to be preferable. This patch is (obviously) merely a work-around, but given that the referenced issue is (as far as I know) the first case we've seen of this problem a simple solution will hopefully suffice for now.
|
/botio test |
From: Bot.io (Linux m4)ReceivedCommand cmd_test from @timvandermeij received. Current queue size: 0 Live output at: http://54.67.70.0:8877/9f30b7b47f142eb/output.txt |
From: Bot.io (Windows)ReceivedCommand cmd_test from @timvandermeij received. Current queue size: 0 Live output at: http://3.101.106.178:8877/644a522025abd13/output.txt |
From: Bot.io (Linux m4)FailedFull output at http://54.67.70.0:8877/9f30b7b47f142eb/output.txt Total script time: 26.04 mins
Image differences available at: http://54.67.70.0:8877/9f30b7b47f142eb/reftest-analyzer.html#web=eq.log |
From: Bot.io (Windows)FailedFull output at http://3.101.106.178:8877/644a522025abd13/output.txt Total script time: 29.36 mins
Image differences available at: http://3.101.106.178:8877/644a522025abd13/reftest-analyzer.html#web=eq.log |
|
/botio-linux preview |
From: Bot.io (Linux m4)ReceivedCommand cmd_preview from @timvandermeij received. Current queue size: 0 Live output at: http://54.67.70.0:8877/178a45f414a30cc/output.txt |
From: Bot.io (Linux m4)SuccessFull output at http://54.67.70.0:8877/178a45f414a30cc/output.txt Total script time: 4.02 mins Published |
|
Thank you! This does seem like the simplest solution, especially since this is the first case we have seen so far. |
For HighlightAnnotations with a built-in appearance stream, we still rely on it to specify the opacity correctly via a suitable blend mode. However, if the Annotation-drawing operators are placed within a /XObject of the /Form-type, the /ExtGState won't apply to the final rendering and the result is that the highlighting obscures the underlying text.
The more correct and general solution would likely be to somehow modify the implementation in
src/display/canvas.js, to special-case handling of /Form-type /XObjects when rendering Annotations. Since we can very easily work-around this problem for now by using the "no appearance stream" code-path, doing something here ought to be preferable.This patch is (obviously) merely a work-around, but given that the referenced issue is (as far as I know) the first case we've seen of this problem a simple solution will hopefully suffice for now.
Fixes #13242