| Summary: | Transformation matrix gives wrong results for Postscript backend | ||
|---|---|---|---|
| Product: | cairo | Reporter: | Michael Wimmer <mike.wimmer> |
| Component: | postscript backend | Assignee: | Carl Worth <cworth> |
| Status: | RESOLVED FIXED | QA Contact: | cairo-bugs mailing list <cairo-bugs> |
| Severity: | normal | ||
| Priority: | high | ||
| Version: | 1.1.1 | ||
| Hardware: | x86 (IA32) | ||
| OS: | Linux (All) | ||
| Whiteboard: | |||
| i915 platform: | i915 features: | ||
| Attachments: |
Test program
Output of cairotest.c using transformation matrix Output of cairotest.c without using transformation matrix |
||
Created attachment 3827 [details]
Test program
Code to test the Bug. Using the PS backend of cairo, it draws a diagonal line
from the lower left corner to the upper right corner of the picture, first
using
a transformation matrix and the directly. It creates two ps-files:
"test1.ps" (using the transformation matrix) and "test2.ps" without the
transformation matrix.
Created attachment 3828 [details]
Output of cairotest.c using transformation matrix
ps-file, output created with transformation matrix. The diagonal line is
shifted to the left, out of the bounding box.
Created attachment 3829 [details]
Output of cairotest.c without using transformation matrix
ps-output without using a transformation matrix. The coordinates have been
calculated manually and the ps-file shows a diagonal line as expected.
Just tested. Fixed already. |
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.
I've got some problems using the Postscript backend of cairo. I guess it's a bug but it could just as well be my limited understanding of cairo ... So here's the problem: The following code snippet should produce a line from the lower left corner to the upper right corner of the picture: ------------------------------------------------------ cairo_surface_t *surface=cairo_ps_surface_create("test.ps",200,200); cairo_t *cr=cairo_create(surface); cairo_matrix_t matrix; matrix.xx=1.0; matrix.xy=0.0; matrix.yx=0.0; matrix.yy=-1.0; matrix.x0=0.0; matrix.y0=200; cairo_set_matrix(cr,&matrix); cairo_move_to(cr,0,0); cairo_line_to(cr,200,200); cairo_stroke(cr); cairo_show_page(cr); cairo_destroy(cr); cairo_surface_destroy(surface); ---------------------------------------------------- it should actually be equivalent to --------------------------------------------------- cairo_move_to(cr,0,200); cairo_line_to(cr,200,0); cairo_stroke(cr); ---------------------------------------------------- These code snippets do produce the same result for the Xlib and pdf backends, for the ps backend, the first snippet creates a diagonal line that is shifted to the left, out of the bounding box, so that it's only visible in the upper left corner. The second snippet gives the correct result. This was tested using the latest cairo version from cvs today (11/17/05) which is 1.1.1, I think. Kind regards, Mike Wimmer