--- /dev/null	2017-04-22 10:40:35.471249043 +0200
+++ new/src/java.desktop/share/classes/sun/java2d/marlin/DCollinearSimplifier.java	2017-04-22 13:16:10.104582150 +0200
@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.java2d.marlin;
+
+
+final class DCollinearSimplifier implements DPathConsumer2D {
+
+    enum SimplifierState {
+
+        Empty, PreviousPoint, PreviousLine
+    };
+    // slope precision threshold
+    static final double EPS = 1e-4d; // aaime proposed 1e-3d
+
+    DPathConsumer2D delegate;
+    SimplifierState state;
+    double px1, py1, px2, py2;
+    double pslope;
+
+    DCollinearSimplifier() {
+    }
+
+    public DCollinearSimplifier init(DPathConsumer2D delegate) {
+        this.delegate = delegate;
+        this.state = SimplifierState.Empty;
+
+        return this; // fluent API
+    }
+
+    @Override
+    public void pathDone() {
+        emitStashedLine();
+        state = SimplifierState.Empty;
+        delegate.pathDone();
+    }
+
+    @Override
+    public void closePath() {
+        emitStashedLine();
+        state = SimplifierState.Empty;
+        delegate.closePath();
+    }
+
+    @Override
+    public long getNativeConsumer() {
+        return 0;
+    }
+
+    @Override
+    public void quadTo(double x1, double y1, double x2, double y2) {
+        emitStashedLine();
+        delegate.quadTo(x1, y1, x2, y2);
+        // final end point:
+        state = SimplifierState.PreviousPoint;
+        px1 = x2;
+        py1 = y2;
+    }
+
+    @Override
+    public void curveTo(double x1, double y1, double x2, double y2,
+                        double x3, double y3) {
+        emitStashedLine();
+        delegate.curveTo(x1, y1, x2, y2, x3, y3);
+        // final end point:
+        state = SimplifierState.PreviousPoint;
+        px1 = x3;
+        py1 = y3;
+    }
+
+    @Override
+    public void moveTo(double x, double y) {
+        emitStashedLine();
+        delegate.moveTo(x, y);
+        state = SimplifierState.PreviousPoint;
+        px1 = x;
+        py1 = y;
+    }
+
+    @Override
+    public void lineTo(final double x, final double y) {
+        switch (state) {
+            case Empty:
+                delegate.lineTo(x, y);
+                state = SimplifierState.PreviousPoint;
+                px1 = x;
+                py1 = y;
+                return;
+
+            case PreviousPoint:
+                state = SimplifierState.PreviousLine;
+                px2 = x;
+                py2 = y;
+                pslope = getSlope(px1, py1, x, y);
+                return;
+
+            case PreviousLine:
+                final double slope = getSlope(px2, py2, x, y);
+                // test for collinearity
+                if ((slope == pslope) || (Math.abs(pslope - slope) < EPS)) {
+                    // merge segments
+                    px2 = x;
+                    py2 = y;
+                    return;
+                }
+                // emit previous segment
+                delegate.lineTo(px2, py2);
+                px1 = px2;
+                py1 = py2;
+                px2 = x;
+                py2 = y;
+                pslope = slope;
+                return;
+            default:
+        }
+    }
+
+    private void emitStashedLine() {
+        if (state == SimplifierState.PreviousLine) {
+            delegate.lineTo(px2, py2);
+        }
+    }
+
+    private static double getSlope(double x1, double y1, double x2, double y2) {
+        double dy = y2 - y1;
+        if (dy == 0.0d) {
+            return (x2 > x1) ? Double.POSITIVE_INFINITY
+                   : Double.NEGATIVE_INFINITY;
+        }
+        return (x2 - x1) / dy;
+    }
+}