Summary: | Uncolored Postscript patterns not visible with X11alpha driver | ||
---|---|---|---|
Product: | Ghostscript | Reporter: | Konstantin Shemyak <konstantin> |
Component: | Graphics Library | Assignee: | Michael Vrhel <michael.vrhel> |
Status: | RESOLVED FIXED | ||
Severity: | normal | CC: | alex, list0570 |
Priority: | P3 | Keywords: | bountiable |
Version: | 8.53 | ||
Hardware: | PC | ||
OS: | All | ||
URL: | http://www.saunalahti.fi/shemyak/tmp/pattern-bug.ps | ||
Customer: | Word Size: | --- | |
Bug Depends on: | 688933 | ||
Bug Blocks: | |||
Attachments: |
Pattern is not shown with GraphicsAlphaBits > 1
pattern4.png |
Description
Konstantin Shemyak
2006-03-02 10:47:51 UTC
Both 8.53 and SVN head silently fail (i.e. nothing displayed and no error messages) with this test file. bin/gswin32c -dGraphicsAlphaBits=4 ../test_files/688580.ps -c quit Artifex Ghostscript 8.53 (2005-10-20) Copyright (C) 2005 artofcode LLC, Benicia, CA. All rights reserved. This software comes with NO WARRANTY: see the file PUBLIC for details. This is probably a similar problem to 688588. Created attachment 2088 [details]
Pattern is not shown with GraphicsAlphaBits > 1
The file is the Adobe's example of uncolored pattern, taken from the Postscript
Language Reference Manual. GS does not show the pattern if GraphicsAlphaBits is
2 or 4. When GraphicsAlphaBits is 1, pattern is shown OK.
The bug is not related to X11 driver, but to graphics library instead. The pattern is not visible when GraphicsAlphaBits is > 1. Tested with jpeg, bmp256, png16m and tifflzw devices. Same thing happens under MS Windows, so I change OS to "All". Not sure when this changed, but now the pattern _is_ displayed (r9330), but it looks REALLY UGLY (jaggy) when GraphicsAlphaBits=2 or 4. Tested with: gswin32c -dGraphicsAlphaBits=2 -r100 bug_688580.ps Confirmed with the x11alpha, x11 and pnggray devices. It's not an x11alpha problem, but an issue with antialiasing and patterns. Specifically the bottom of the five-point star isn't rasterized correctly. Created attachment 4685 [details]
pattern4.png
Result of
gs -sDEVICE=pnggray -dGraphicsAlphaBits=4 -o pattern4.png pattern-bug.ps
Showing the rendering problem. The stars look clean with -dGraphicsAlphaBits=1.
Verified with 8.70rc1. Passing to Michael. The problem is confirmed in vv. 9.01 and 9.02 but it is fixed in the current development version. |