[[ Bug 13220 ]] Make sure we give Cairo a minimal path - if lineTo is followed by close and lineTo target is original moveTo of subpath, then ignore the last lineTo.

runrevmark · runrevmark · commit 8fdbe9698a20 · 2014-08-19T10:17:58.000+01:00
diff --git a/docs/notes/bugfix-13220.md b/docs/notes/bugfix-13220.md
@@ -0,0 +1 @@
+# Polyline with same starting point as ending point draws as degenerate dot in PDF printing.
diff --git a/revpdfprinter/src/revpdfprinter.cpp b/revpdfprinter/src/revpdfprinter.cpp
@@ -18,6 +18,7 @@ along with LiveCode.  If not see <http://www.gnu.org/licenses/>.  */
 
 #include <cairo-pdf.h>
 #include <stdio.h>
+#include <float.h>
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -750,26 +751,47 @@ void transform_point(double &x, double &y, const MCCustomPrinterTransform &p_tra
 	x = t_x;
 }
 
+// MW-2014-08-19: [[ Bug 13220 ]] It seems Cairo doesn't like (M p) (L _)* (L p) (C)
+//   as it ends up treating it is as a degenerate point. Therefore we clean up this
+//   case - if there is a lineTo which returns to the original moveTo then a close
+//   it ignores the final lineTo.
 bool MCPDFPrintingDevice::draw_path(const MCCustomPrinterPath &p_path)
 {
 	bool t_success = true;
 	
 	MCCustomPrinterPathCommand *t_commands = p_path.commands;
 	MCCustomPrinterPoint *t_points = p_path.coords;
 
+    double t_first_x, t_first_y;
+    t_first_x = t_first_y = DBL_MAX;
+    
+    double t_last_x, t_last_y;
+    t_last_x = t_last_y = DBL_MAX;
+    
 	while (t_success && *t_commands != kMCCustomPrinterPathEnd)
 	{
 		switch (*t_commands++)
 		{
 		case kMCCustomPrinterPathMoveTo:
 			{
 				cairo_move_to(m_context, t_points->x, t_points->y);
+                t_first_x = t_points -> x;
+                t_first_y = t_points -> y;
 				t_points++;
 			}
 			break;
 		case kMCCustomPrinterPathLineTo:
 			{
-				cairo_line_to(m_context, t_points->x, t_points->y);
+                if (t_last_x != t_points -> x || t_last_y != t_points -> y)
+                {
+                    if (*t_commands != kMCCustomPrinterPathClose ||
+                        (t_first_x != t_points -> x || t_first_y != t_points -> y))
+                    {
+                        cairo_line_to(m_context, t_points->x, t_points->y);
+                        t_last_x = t_points -> x;
+                        t_last_y = t_points -> y;
+                    }
+                }
 				t_points++;
 			}
 			break;

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+# Polyline with same starting point as ending point draws as degenerate dot in PDF printing.`