From d2789c1696f36efc13d0df53b98d2370e7476738 Mon Sep 17 00:00:00 2001
From: Camil Staps
Date: Wed, 25 Mar 2015 20:52:19 +0100
Subject: Week 8 done

---
 Week8/src/qtrees/QTree.java | 74 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 71 insertions(+), 3 deletions(-)

(limited to 'Week8/src/qtrees/QTree.java')

diff --git a/Week8/src/qtrees/QTree.java b/Week8/src/qtrees/QTree.java
index ab11898..24fa5e0 100644
--- a/Week8/src/qtrees/QTree.java
+++ b/Week8/src/qtrees/QTree.java
@@ -3,32 +3,100 @@ package qtrees;
 import java.io.IOException;
 import java.io.Reader;
 import java.io.Writer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
+/**
+ * Representation of a Quad-tree
+ * @author Camil Staps, s4498062
+ */
 public class QTree {
+    /** the root of the tree */
     QTNode root;
     
+    /**
+     * Construct the tree based on an ASCII representation of a bitstream on a reader
+     * @param input the reader
+     */
     public QTree( Reader input ) {
         root = readQTree( input );
     }
     
+    /**
+     * Construct the tree based on a bitmap
+     * @param bitmap the bitmap
+     */
     public QTree( Bitmap bitmap ) {
         root = bitmap2QTree( 0, 0,  bitmap.getWidth(), bitmap );
     }
 
+    /**
+     * Fill a bitmap based on this tree
+     * @param bitmap the bitmap
+     */
     public void fillBitmap ( Bitmap bitmap ) {
         root.fillBitmap(0, 0, bitmap.getWidth(), bitmap);
     }
 
-    public void writeQTree( Writer sb ) {
+    /**
+     * Write the quad-tree as compressed bitstream
+     * @param sb the Writer to write to
+     * @throws IOException is passed on from Writer
+     */
+    public void writeQTree( Writer sb ) throws IOException {
         root.writeNode( sb );
     }
     
+    /**
+     * Read a Quad-tree node based on an ASCII representation of a bitstream on a Reader
+     * @param input the Reader
+     * @return the node
+     */
     private static QTNode readQTree( Reader input ) {
-        return null;
+        try {
+            int read = input.read();
+            if (read == '1') {
+                GreyNode node = new GreyNode();
+                for (int i = 0; i < 4; i++)
+                    node.setChild(i, readQTree(input));
+                return node;
+            } else {
+                read = input.read();
+                if (read == '1') {
+                    return new WhiteLeaf();
+                } else {
+                    return new BlackLeaf();
+                }
+            }
+        } catch (IOException ex) {
+            Logger.getLogger(QTree.class.getName()).log(Level.SEVERE, null, ex);
+            return null;
+        }
     }
     
+    /**
+     * Get a (compressed) node from a (part of a) bitmap
+     * @param x the x coordinate of the top left corner
+     * @param y the y coordinate of the top left corner
+     * @param width the width of the part to read
+     * @param bitmap the bitmap
+     * @return the (compressed) node
+     */
     public static QTNode bitmap2QTree( int x, int y, int width, Bitmap bitmap ) {
-        return null;
+        if (width == 1) {
+            if (bitmap.getBit(x,y)) {
+                return new WhiteLeaf();
+            } else {
+                return new BlackLeaf();
+            }
+        } else {
+            GreyNode node = new GreyNode();
+            node.setChild(0, bitmap2QTree(x, y, width / 2, bitmap));
+            node.setChild(1, bitmap2QTree(x + width / 2, y, width / 2, bitmap));
+            node.setChild(2, bitmap2QTree(x + width / 2, y + width / 2, width / 2, bitmap));
+            node.setChild(3, bitmap2QTree(x, y + width / 2, width / 2, bitmap));
+            return node.compress();
+        }
     }
 
 }
-- 
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