From 6d5ee4797bf02d5b25775e742502c1ed4045e4f1 Mon Sep 17 00:00:00 2001
From: Adrian Johnson <ajohnson@redneon.com>
Date: Sun, 26 Feb 2012 21:41:35 +1030
Subject: [PATCH] Align fills to device integer coordinates

to prevent visible seams in adjacent fills.
---
 poppler/CairoOutputDev.cc |   30 ++++++++++++++++++++++--------
 poppler/CairoOutputDev.h  |    1 +
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index bc5d3a6..d998ba4 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -646,38 +646,52 @@ void CairoOutputDev::alignStrokeCoords(double *x, double *y)
   cairo_device_to_user (cairo, x, y);
 }
 
+void CairoOutputDev::alignFillCoords(double *x, double *y)
+{
+  cairo_user_to_device (cairo, x, y);
+  *x = floor(*x + 0.5);
+  *y = floor(*y + 0.5);
+  cairo_device_to_user (cairo, x, y);
+}
+
 void CairoOutputDev::doPath(cairo_t *cairo, GfxState *state, GfxPath *path) {
   GfxSubpath *subpath;
   int i, j;
+  double x, y;
   cairo_new_path (cairo);
   for (i = 0; i < path->getNumSubpaths(); ++i) {
     subpath = path->getSubpath(i);
     if (subpath->getNumPoints() > 0) {
+      x = subpath->getX(0);
+      y = subpath->getY(0);
       if (align_stroke_coords) {
-	double x = subpath->getX(0);
-	double y = subpath->getY(0);
 	alignStrokeCoords(&x, &y);
 	cairo_move_to (cairo, x, y);
       } else {
-	cairo_move_to (cairo, subpath->getX(0), subpath->getY(0));
+	alignFillCoords(&x, &y);
+	cairo_move_to (cairo, x, y);
       }
       j = 1;
       while (j < subpath->getNumPoints()) {
 	if (subpath->getCurve(j)) {
+          x = subpath->getX(j+2);
+          y = subpath->getY(j+2);
+          if (j + 3 < subpath->getNumPoints() && !subpath->getCurve(j+3))
+            alignFillCoords(&x, &y);
 	  cairo_curve_to( cairo,
 			  subpath->getX(j), subpath->getY(j),
 			  subpath->getX(j+1), subpath->getY(j+1),
-			  subpath->getX(j+2), subpath->getY(j+2));
-
+			  x, y);
 	  j += 3;
 	} else {
+          x = subpath->getX(j);
+          y = subpath->getY(j);
 	  if (align_stroke_coords) {
-	    double x = subpath->getX(j);
-	    double y = subpath->getY(j);
 	    alignStrokeCoords(&x, &y);
 	    cairo_line_to (cairo, x, y);
 	  } else {
-	    cairo_line_to (cairo, subpath->getX(j), subpath->getY(j));
+            alignFillCoords(&x, &y);
+	    cairo_line_to (cairo, x, y);
 	  }
 	  ++j;
 	}
diff --git a/poppler/CairoOutputDev.h b/poppler/CairoOutputDev.h
index 8b379da..5645872 100644
--- a/poppler/CairoOutputDev.h
+++ b/poppler/CairoOutputDev.h
@@ -275,6 +275,7 @@ protected:
   void setMimeData(Stream *str, Object *ref, cairo_surface_t *image);
   void fillToStrokePathClip();
   void alignStrokeCoords(double *x, double *y);
+  void alignFillCoords(double *x, double *y);
 
   GfxRGB fill_color, stroke_color;
   cairo_pattern_t *fill_pattern, *stroke_pattern;
-- 
1.7.5.4