[poppler] [PATCH] fix CairoOutputDevice text clipping

[Jeff Muizelaar]

This patch fixes the following fixme in CairoOutputDevice.

// FIXME: This is quite right yet, we need to accumulate all
// glyphs within one text object before we clip.  Right now this
// just add this one string.

It fixes it following a strategy similar to the one the Splash backend
does. textClipPath is used to store the appended path from each call to
endString(). The accumulated path is clipped in endTextObject.


--

 poppler/CairoOutputDev.cc |   22 ++++++++++++++++++----
 poppler/CairoOutputDev.h  |    1 +
 2 files changed, 19 insertions(+), 4 deletions(-)

ac2f3a50c44d8e401a6f3ed0b1c1bcd97b0920e3
diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index a006385..c6525fe 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -57,6 +57,7 @@ CairoOutputDev::CairoOutputDev() {
   stroke_pattern = NULL;
   stroke_opacity = 1.0;
   fill_opacity = 1.0;
+  textClipPath = NULL;
 }
 
 CairoOutputDev::~CairoOutputDev() {
@@ -411,12 +412,17 @@ void CairoOutputDev::endString(GfxState 
 
   // clip
   if (render & 4) {
-    // FIXME: This is quite right yet, we need to accumulate all
-    // glyphs within one text object before we clip.  Right now this
-    // just add this one string.
     LOG (printf ("clip string\n"));
+    // set up the clipping path
+    if (textClipPath) {
+      cairo_append_path (cairo, textClipPath);
+      cairo_path_destroy (textClipPath);
+    }
     cairo_glyph_path (cairo, glyphs, glyphCount);
-    cairo_clip (cairo);
+   
+    // move the path into textClipPath
+    textClipPath = cairo_copy_path (cairo);
+    cairo_new_path (cairo);
   }
   
   gfree (glyphs);
@@ -440,6 +446,14 @@ void CairoOutputDev::type3D1(GfxState *s
 }
 
 void CairoOutputDev::endTextObject(GfxState *state) {
+  if (textClipPath) {
+    // clip the accumulated text path
+    cairo_append_path (cairo, textClipPath);
+    cairo_clip (cairo);
+    cairo_path_destroy (textClipPath);
+    textClipPath = NULL;
+  }
+
 }
 
 
diff --git a/poppler/CairoOutputDev.h b/poppler/CairoOutputDev.h
index ab79046..78f77eb 100644
--- a/poppler/CairoOutputDev.h
+++ b/poppler/CairoOutputDev.h
@@ -150,6 +150,7 @@ protected:
   cairo_surface_t *surface;
   cairo_glyph_t *glyphs;
   int glyphCount;
+  cairo_path_t *textClipPath;
 };
 
 #endif