1 files changed, 102 insertions, 0 deletions
diff --git a/Week8 Quadtrees/src/qtrees/QTree.java b/Week8 Quadtrees/src/qtrees/QTree.java
new file mode 100644
index 0000000..24fa5e0
--- /dev/null
+++ b/Week8 Quadtrees/src/qtrees/QTree.java
@@ -0,0 +1,102 @@
+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);
+    }
+
+    /**
+     * 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 ) {
+        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 ) {
+        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();
+        }
+    }
+
+}