Line endcaps for AA lines are now antialiased.

Also fixed other minor issues with AA and line rendering.

Change-Id: Icd4638d27c70e2ee0f28b5d9a2b97d8b29e8ac4d
diff --git a/libs/hwui/Vertex.h b/libs/hwui/Vertex.h
index c120428..38455dc 100644
--- a/libs/hwui/Vertex.h
+++ b/libs/hwui/Vertex.h
@@ -68,6 +68,25 @@
     }
 }; // struct AlphaVertex
 
+/**
+ * Simple structure to describe a vertex with a position and an alpha value.
+ */
+struct AAVertex : Vertex {
+    float width;
+    float length;
+
+    static inline void set(AAVertex* vertex, float x, float y, float width, float length) {
+        Vertex::set(vertex, x, y);
+        vertex[0].width = width;
+        vertex[0].length = length;
+    }
+
+    static inline void setColor(AAVertex* vertex, float width, float length) {
+        vertex[0].width = width;
+        vertex[0].length = length;
+    }
+}; // struct AlphaVertex
+
 }; // namespace uirenderer
 }; // namespace android