[postgis-tickets] r17185 - Avoid final point duplicates for circle stroking

[Paul Ramsey]

Author: pramsey
Date: 2019-01-18 12:41:13 -0800 (Fri, 18 Jan 2019)
New Revision: 17185

Modified:
   trunk/liblwgeom/cunit/cu_lwstroke.c
   trunk/liblwgeom/lwstroke.c
Log:
Avoid final point duplicates for circle stroking
References #4283


Modified: trunk/liblwgeom/cunit/cu_lwstroke.c
===================================================================
--- trunk/liblwgeom/cunit/cu_lwstroke.c	2019-01-18 18:05:36 UTC (rev 17184)
+++ trunk/liblwgeom/cunit/cu_lwstroke.c	2019-01-18 20:41:13 UTC (rev 17185)
@@ -135,9 +135,10 @@
 
 	/* 10 segments per quadrant (circular) */
 	in = lwgeom_from_text("CIRCULARSTRING(0 0,1 0,0 0)");
+	// out = lwcurve_linearize(in, 10, toltype, 0);
 	out = lwcurve_linearize(in, 10, toltype, 0);
-
-	ASSERT_INT_EQUAL(1 + 10*4, lwgeom_count_vertices(out));
+	// printf("OUT: %s\n", lwgeom_to_wkt(out, WKT_EXTENDED, 5, NULL));
+	ASSERT_INT_EQUAL(10*4, lwgeom_count_vertices(out));
 	lwgeom_free(out);
 	lwgeom_free(in);
 

Modified: trunk/liblwgeom/lwstroke.c
===================================================================
--- trunk/liblwgeom/lwstroke.c	2019-01-18 18:05:36 UTC (rev 17184)
+++ trunk/liblwgeom/lwstroke.c	2019-01-18 20:41:13 UTC (rev 17185)
@@ -409,9 +409,9 @@
 	/* Override angles for circle case */
 	if( is_circle )
 	{
+		increment = fabs(increment);
 		a3 = a1 + 2.0 * M_PI;
 		a2 = a1 + M_PI;
-		increment = fabs(increment);
 		clockwise = LW_FALSE;
 	}
 
@@ -450,7 +450,15 @@
 		++points_added;
 	}
 
-	if ( reverse ) {{
+	/* Ensure the final point is EXACTLY the same as the first for the circular case */
+	if ( is_circle )
+	{
+		ptarray_remove_point(pa, pa->npoints - 1);
+		ptarray_append_point(pa, p1, LW_FALSE);
+	}
+
+	if ( reverse )
+	{
 		int i;
 		ptarray_append_point(to, p3, LW_FALSE);
 		for ( i=pa->npoints; i>0; i-- ) {
@@ -458,7 +466,7 @@
 			ptarray_append_point(to, &pt, LW_FALSE);
 		}
 		ptarray_free(pa);
-	}}
+	}
 
 	return points_added;
 }
@@ -517,7 +525,7 @@
 		}
 	}
 	getPoint4d_p(icurve->points, icurve->points->npoints-1, &p1);
-	ptarray_append_point(ptarray, &p1, LW_TRUE);
+	ptarray_append_point(ptarray, &p1, LW_FALSE);
 
 	oline = lwline_construct(icurve->srid, NULL, ptarray);
 	return oline;