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| author | Robin Watts <Robin.Watts@artifex.com> | 2011-07-06 13:58:16 +0100 |
|---|---|---|
| committer | Robin Watts <Robin.Watts@artifex.com> | 2011-07-06 14:57:54 +0100 |
| commit | 2f8acb0010c469c46682a298d66b108cc4c6cdd0 (patch) | |
| tree | 7e6f07c13df5037e29203d00d115981638cb802d /pdf/pdf_interpret.c | |
| parent | 28e88083d782eba796ec9af2469e57011dc4aa89 (diff) | |
| download | mupdf-2f8acb0010c469c46682a298d66b108cc4c6cdd0.tar.xz | |
Tweak mupdf clip path handling.
In the existing mupdf clip path code, it would be possible for us to
render incorrectly; consider the following fragment of a content
stream:
0 0 100 100 re
W
50 50 100 100 re
f
That should set the clip path to the (0, 0) -> (100, 100) rectangle,
and then attempt to fill both the (0,0) -> (100,100) rectangle and the
(50,50) -> (150,150) rectangle, resulting in just the (0,0) -> (100,100)
rectangle being filled.
In the existing mupdf code, it would actually fill both rectangles as
the path after the W operation (the addition of the second rectangle)
would also affect the stored clip path.
We solve this by doing the clip operation on the W operator, rather than
deferred to when the path is actually disposed of.
Diffstat (limited to 'pdf/pdf_interpret.c')
| -rw-r--r-- | pdf/pdf_interpret.c | 29 |
1 files changed, 12 insertions, 17 deletions
diff --git a/pdf/pdf_interpret.c b/pdf/pdf_interpret.c index 9887ee6f..7d2caed2 100644 --- a/pdf/pdf_interpret.c +++ b/pdf/pdf_interpret.c @@ -83,8 +83,6 @@ struct pdf_csi_s /* path object state */ fz_path *path; - int clip; - int clip_even_odd; /* text object state */ fz_text *text; @@ -243,6 +241,14 @@ pdf_show_image(pdf_csi *csi, fz_pixmap *image) pdf_end_group(csi); } +static void pdf_show_clip(pdf_csi *csi, int even_odd) +{ + pdf_gstate *gstate = csi->gstate + csi->gtop; + + gstate->clip_depth++; + fz_clip_path(csi->dev, csi->path, even_odd, gstate->ctm); +} + static void pdf_show_path(pdf_csi *csi, int doclose, int dofill, int dostroke, int even_odd) { @@ -261,13 +267,6 @@ pdf_show_path(pdf_csi *csi, int doclose, int dofill, int dostroke, int even_odd) else bbox = fz_bound_path(path, NULL, gstate->ctm); - if (csi->clip) - { - gstate->clip_depth++; - fz_clip_path(csi->dev, path, even_odd, gstate->ctm); - csi->clip = 0; - } - pdf_begin_group(csi, bbox); if (dofill) @@ -669,8 +668,6 @@ pdf_new_csi(pdf_xref *xref, fz_device *dev, fz_matrix ctm, char *target) csi->in_array = 0; csi->path = fz_new_path(); - csi->clip = 0; - csi->clip_even_odd = 0; csi->text = NULL; csi->tlm = fz_identity; @@ -1071,7 +1068,7 @@ pdf_run_xobject(pdf_csi *csi, fz_obj *resources, pdf_xobject *xobj, fz_matrix tr fz_lineto(csi->path, xobj->bbox.x1, xobj->bbox.y1); fz_lineto(csi->path, xobj->bbox.x0, xobj->bbox.y1); fz_closepath(csi->path); - csi->clip = 1; + pdf_show_clip(csi, 0); pdf_show_path(csi, 0, 0, 0, 0); /* run contents */ @@ -1717,14 +1714,12 @@ static void pdf_run_TJ(pdf_csi *csi) static void pdf_run_W(pdf_csi *csi) { - csi->clip = 1; - csi->clip_even_odd = 0; + pdf_show_clip(csi, 0); } static void pdf_run_Wstar(pdf_csi *csi) { - csi->clip = 1; - csi->clip_even_odd = 1; + pdf_show_clip(csi, 1); } static void pdf_run_b(pdf_csi *csi) @@ -1860,7 +1855,7 @@ static void pdf_run_m(pdf_csi *csi) static void pdf_run_n(pdf_csi *csi) { - pdf_show_path(csi, 0, 0, 0, csi->clip_even_odd); + pdf_show_path(csi, 0, 0, 0, 0); } static void pdf_run_q(pdf_csi *csi) |