improve snapping in agg backend

leejjoon · leejjoon · commit 05e3e28dd34a · 2012-03-27T16:12:52.000+09:00
diff --git a/src/path_converters.h b/src/path_converters.h
@@ -494,8 +494,8 @@ class PathSnapper
         code = m_source->vertex(x, y);
         if (m_snap && agg::is_vertex(code))
         {
-            *x = floor(*x - m_snap_value) + m_snap_value;
-            *y = floor(*y - m_snap_value) + m_snap_value;
+            *x = floor(*x + 0.5 - m_snap_value) + m_snap_value;
+            *y = floor(*y + 0.5 - m_snap_value) + m_snap_value;
         }
         return code;
     }

Original file line number	Diff line number	Diff line change
`@@ -494,8 +494,8 @@ class PathSnapper`
`494`	`494`	`code = m_source->vertex(x, y);`
`495`	`495`	`if (m_snap && agg::is_vertex(code))`
`496`	`496`	`{`
`497`		`- x = floor(x - m_snap_value) + m_snap_value;`
`498`		`- y = floor(y - m_snap_value) + m_snap_value;`
	`497`	`+ x = floor(x + 0.5 - m_snap_value) + m_snap_value;`
	`498`	`+ y = floor(y + 0.5 - m_snap_value) + m_snap_value;`
`499`	`499`	`}`
`500`	`500`	`return code;`
`501`	`501`	`}`