don't depend on sharedrawweb

use directly sharedrawweb java code here Signed-off-by: philippe lhardy <philippe.lhardy@astrolabe.coop>
2025-11-02 18:03:10 +01:00
parent e78da6ec76
commit 36e58808d5
16 changed files with 1383 additions and 13 deletions
--- a/java/org/artisanlogiciel/compression/graphics/DrawLineExpander.java
+++ b/java/org/artisanlogiciel/compression/graphics/DrawLineExpander.java
@@ -0,0 +1,149 @@
+/*
+    This file is part of ShareDrawWeb.
+
+    ShareDrawWeb is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    ShareDrawWeb 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 for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with ShareDrawWeb; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+ */
+
+/*
+ DrawingLineExpander
+ decompress a draw line from a stream
+
+ main algorithm is to code only delta displacement in littlest possible size.
+*/
+package org.artisanlogiciel.compression.graphics;
+
+import java.awt.Point;
+import java.io.InputStream;
+import java.util.ArrayList;
+
+public class DrawLineExpander {
+
+  ArrayList<Point> expandedLines;
+  int currentSize;
+  int scode[] = {3,6,14,30,64};
+  final static int SCODE_MAX = 4;
+  private BitFieldReader fieldReader = null;
+
+  public DrawLineExpander() {
+    expandedLines = new ArrayList<>();
+    fieldReader = new BitFieldReader();
+  }
+
+  /* create a List of points */
+  public ArrayList<Point> expand( InputStream input ) throws java.io.IOException {
+    fieldReader.setInputStream( input);
+    int point_count = fieldReader.read( 32);
+    // System.out.println( point_count);
+    expandedLines.add( readAbs( 64));
+    for ( int i = 1; i < point_count; i ++ ) {
+      Point point = readRel();
+      if ( currentSize == 64 ) {
+        // absolute
+        expandedLines.add( point);
+      }
+      else {
+        // relative
+        Point previous = (Point) expandedLines.get(expandedLines.size()-1);
+        point.x = point.x + previous.x;
+        point.y = point.y + previous.y;
+        expandedLines.add( point);
+      }
+    }
+    return expandedLines;
+  }
+
+  /*
+    read point with size encoding depending on first bits
+   */
+  private Point readRel() throws java.io.IOException {
+
+    int index;
+
+    /* 11 : next, 10 : previous ; 0* : same
+        6 -> 14->30
+        ^        |
+        |        v
+        3   <-  64
+    */
+    // find index of current size
+    for ( index = 0; index < SCODE_MAX; index ++) {
+      if ( scode[index] == currentSize ) break;
+    }
+
+    // read size modifier until it is good one
+    while ( fieldReader.read(1) != 0 ) {
+      index = index + ( ( fieldReader.read(1) == 0 ) ? -1 : 1);
+      // handle circularity
+      if ( index > SCODE_MAX ) {
+        index = 0;
+      }
+      if ( index < 0 ) {
+        index = SCODE_MAX;
+      }
+    }
+    return readAbs( scode[index]);
+  }
+
+  /* write given Point with size */
+  Point readAbs( int size) throws java.io.IOException {
+    int codeval;
+    int center, max;
+
+    currentSize = size;
+
+    Point point = new Point();
+    if ( size > 32 ) {
+      point.x = fieldReader.read(32);
+      point.y = fieldReader.read(32);
+    }
+    else {
+	boolean nocenter=false;
+      codeval = fieldReader.read( size); 
+      // System.out.println( codeval);
+      /* 
+        for coding/decoding scheme see
+           org.artisanlogiciel.graphics.DrawLineKompressor.java 
+      */
+      if ( size == 3 ) {
+        max = 3;
+	center = 1;
+	nocenter=true;
+      }
+      else {
+        max = ( 1 << (  size  / 2  ) );
+	center = (max / 2) - 1;
+      }
+      // central hole impossible but we don't really care
+      if ( nocenter )
+	  {
+
+	      if ( codeval > ( center * max  ) ) {
+		  codeval ++;
+	      }
+	      if ( codeval >= ( max * max  )) {
+		  System.out.println(
+				     "!!! reserved value for decompression should not occur !!!");
+	      }
+	  }
+      point.x = ( codeval  %  max) - center;
+      point.y = ( codeval   / max) - center;
+      // System.out.println( point.toString());
+    }
+    return point;
+  }
+
+}
+