From ac6cda4d205160cf649c8fc016ee6282c6f44053 Mon Sep 17 00:00:00 2001
From: Viktor Lidholt <viktorl@google.com>
Date: Wed, 23 Sep 2015 08:33:48 -0700
Subject: [PATCH] Removes some of the artifacts from textured lines

---
 .../flutter_sprites/lib/textured_line.dart    | 24 +++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/packages/flutter_sprites/lib/textured_line.dart b/packages/flutter_sprites/lib/textured_line.dart
index ed11f21d6a7..104c65ee26e 100644
--- a/packages/flutter_sprites/lib/textured_line.dart
+++ b/packages/flutter_sprites/lib/textured_line.dart
@@ -75,6 +75,8 @@ class TexturedLinePainter {
     _calculatedTextureStops = null;
   }
 
+  bool removeArtifacts = true;
+
   sky.TransferMode transferMode = sky.TransferMode.srcOver;
 
   Paint _cachedPaint = new Paint();
@@ -184,8 +186,26 @@ class TexturedLinePainter {
     Offset offset0 = new Offset(miter[0] * halfWidth, miter[1] * halfWidth);
     Offset offset1 = new Offset(-miter[0] * halfWidth, -miter[1] * halfWidth);
 
-    vertices.add(point + offset0);
-    vertices.add(point + offset1);
+    Point vertex0 = point + offset0;
+    Point vertex1 = point + offset1;
+
+    int vertexCount = vertices.length;
+    if (removeArtifacts && vertexCount >= 2) {
+      Point oldVertex0 = vertices[vertexCount - 2];
+      Point oldVertex1 = vertices[vertexCount - 1];
+
+      Point intersection = GameMath.lineIntersection(oldVertex0, oldVertex1, vertex0, vertex1);
+      if (intersection != null) {
+        if (GameMath.pointQuickDist(vertex0, intersection) < GameMath.pointQuickDist(vertex1, intersection)) {
+          vertex0 = oldVertex0;
+        } else {
+          vertex1 = oldVertex1;
+        }
+      }
+    }
+
+    vertices.add(vertex0);
+    vertices.add(vertex1);
   }
 
   void _calculateTextureStops() {