1 /*
   2  * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.marlin;
  27 
  28 import com.sun.javafx.geom.PathConsumer2D;
  29 
  30 public final class PathSimplifier implements PathConsumer2D {
  31 
  32     // distance threshold in pixels (device)
  33     private static final float PIX_THRESHOLD = MarlinProperties.getPathSimplifierPixelTolerance();
  34     // squared tolerance in pixels
  35     private static final float SQUARE_TOLERANCE = PIX_THRESHOLD * PIX_THRESHOLD;
  36 
  37     // members:
  38     private PathConsumer2D delegate;
  39     // current reference point
  40     private float cx, cy;
  41     // flag indicating if the given point was skipped
  42     private boolean skipped;
  43     // last skipped point
  44     private float sx, sy;
  45 
  46     PathSimplifier() {
  47     }
  48 
  49     public PathSimplifier init(final PathConsumer2D delegate) {
  50         this.delegate = delegate;
  51         skipped = false;
  52         return this; // fluent API
  53     }
  54 
  55     private void finishPath() {
  56         if (skipped) {
  57             _lineTo(sx, sy);
  58         }
  59     }
  60 
  61     @Override
  62     public void pathDone() {
  63         finishPath();
  64         delegate.pathDone();
  65     }
  66 
  67     @Override
  68     public void closePath() {
  69         finishPath();
  70         delegate.closePath();
  71     }
  72 
  73     @Override
  74     public void moveTo(final float xe, final float ye) {
  75         finishPath();
  76         delegate.moveTo(xe, ye);
  77         cx = xe;
  78         cy = ye;
  79     }
  80 
  81     @Override
  82     public void lineTo(final float xe, final float ye) {
  83         // Test if segment is too small:
  84         float dx = (xe - cx);
  85         float dy = (ye - cy);
  86 
  87         if ((dx * dx + dy * dy) <= SQUARE_TOLERANCE) {
  88             skipped = true;
  89             sx = xe;
  90             sy = ye;
  91             return;
  92         }
  93         _lineTo(xe, ye);
  94     }
  95 
  96     private void _lineTo(final float xe, final float ye) {
  97         delegate.lineTo(xe, ye);
  98         cx = xe;
  99         cy = ye;
 100         skipped = false;
 101     }
 102 
 103     @Override
 104     public void quadTo(final float x1, final float y1,
 105                        final float xe, final float ye)
 106     {
 107         // Test if curve is too small:
 108         float dx = (xe - cx);
 109         float dy = (ye - cy);
 110 
 111         if ((dx * dx + dy * dy) <= SQUARE_TOLERANCE) {
 112             // check control points P1:
 113             dx = (x1 - cx);
 114             dy = (y1 - cy);
 115 
 116             if ((dx * dx + dy * dy) <= SQUARE_TOLERANCE) {
 117                 skipped = true;
 118                 sx = xe;
 119                 sy = ye;
 120                 return;
 121             }
 122         }
 123         delegate.quadTo(x1, y1, xe, ye);
 124         cx = xe;
 125         cy = ye;
 126         skipped = false;
 127     }
 128 
 129     @Override
 130     public void curveTo(final float x1, final float y1,
 131                         final float x2, final float y2,
 132                         final float xe, final float ye)
 133     {
 134         // Test if curve is too small:
 135         float dx = (xe - cx);
 136         float dy = (ye - cy);
 137 
 138         if ((dx * dx + dy * dy) <= SQUARE_TOLERANCE) {
 139             // check control points P1:
 140             dx = (x1 - cx);
 141             dy = (y1 - cy);
 142 
 143             if ((dx * dx + dy * dy) <= SQUARE_TOLERANCE) {
 144                 // check control points P2:
 145                 dx = (x2 - cx);
 146                 dy = (y2 - cy);
 147 
 148                 if ((dx * dx + dy * dy) <= SQUARE_TOLERANCE) {
 149                     skipped = true;
 150                     sx = xe;
 151                     sy = ye;
 152                     return;
 153                 }
 154             }
 155         }
 156         delegate.curveTo(x1, y1, x2, y2, xe, ye);
 157         cx = xe;
 158         cy = ye;
 159         skipped = false;
 160     }
 161 }