1 files changed, 153 insertions, 0 deletions
diff --git a/org.fox.ttcomics/src/main/java/org/fox/ttcomics2/junrar/unpack/ppm/RangeCoder.java b/org.fox.ttcomics/src/main/java/org/fox/ttcomics2/junrar/unpack/ppm/RangeCoder.java
new file mode 100755
index 0000000..57b0013
--- /dev/null
+++ b/org.fox.ttcomics/src/main/java/org/fox/ttcomics2/junrar/unpack/ppm/RangeCoder.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
+ * Original author: Edmund Wagner
+ * Creation date: 31.05.2007
+ *
+ * Source: $HeadURL$
+ * Last changed: $LastChangedDate$
+ * 
+ * the unrar licence applies to all junrar source and binary distributions 
+ * you are not allowed to use this source to re-create the RAR compression algorithm
+ * 
+ * Here some html entities which can be used for escaping javadoc tags:
+ * "&":  "&#038;" or "&amp;"
+ * "<":  "&#060;" or "&lt;"
+ * ">":  "&#062;" or "&gt;"
+ * "@":  "&#064;" 
+ */
+package org.fox.ttcomics2.junrar.unpack.ppm;
+
+import org.fox.ttcomics2.junrar.exception.RarException;
+import org.fox.ttcomics2.junrar.unpack.Unpack;
+
+import java.io.IOException;
+
+
+public class RangeCoder {
+    public static final int TOP = 1 << 24;
+
+    public static final int BOT = 1 << 15;
+
+    private static final long uintMask = 0xFFFFffffL;
+    private final SubRange subRange = new SubRange();
+    // uint low, code, range;
+    private long low, code, range;
+    private Unpack unpackRead;
+
+    public SubRange getSubRange() {
+        return subRange;
+    }
+
+    public void initDecoder(Unpack unpackRead) throws IOException, RarException {
+        this.unpackRead = unpackRead;
+
+        low = code = 0L;
+        range = 0xFFFFffffL;
+        for (int i = 0; i < 4; i++) {
+            code = ((code << 8) | getChar()) & uintMask;
+        }
+    }
+
+    public int getCurrentCount() {
+        range = (range / subRange.getScale()) & uintMask;
+        return (int) ((code - low) / (range));
+    }
+
+    public long getCurrentShiftCount(int SHIFT) {
+        range = range >>> SHIFT;
+        return ((code - low) / (range)) & uintMask;
+    }
+
+    public void decode() {
+        low = (low + (range * subRange.getLowCount())) & uintMask;
+        range = (range * (subRange.getHighCount() - subRange.getLowCount())) & uintMask;
+    }
+
+    private int getChar() throws IOException, RarException {
+        return (unpackRead.getChar());
+    }
+
+    public void ariDecNormalize() throws IOException, RarException {
+//		while ((low ^ (low + range)) < TOP || range < BOT && ((range = -low & (BOT - 1)) != 0 ? true : true)) 
+//		{
+//			code = ((code << 8) | unpackRead.getChar()&0xff)&uintMask;
+//			range = (range << 8)&uintMask;
+//			low = (low << 8)&uintMask;
+//		}
+
+        // Rewrote for clarity
+        boolean c2 = false;
+        while ((low ^ (low + range)) < TOP || (c2 = range < BOT)) {
+            if (c2) {
+                range = (-low & (BOT - 1)) & uintMask;
+                c2 = false;
+            }
+            code = ((code << 8) | getChar()) & uintMask;
+            range = (range << 8) & uintMask;
+            low = (low << 8) & uintMask;
+        }
+    }
+
+    // Debug
+    public String toString() {
+        StringBuilder buffer = new StringBuilder();
+        buffer.append("RangeCoder[");
+        buffer.append("\n  low=");
+        buffer.append(low);
+        buffer.append("\n  code=");
+        buffer.append(code);
+        buffer.append("\n  range=");
+        buffer.append(range);
+        buffer.append("\n  subrange=");
+        buffer.append(subRange);
+        buffer.append("]");
+        return buffer.toString();
+    }
+
+    public static class SubRange {
+        // uint LowCount, HighCount, scale;
+        private long lowCount, highCount, scale;
+
+        public long getHighCount() {
+            return highCount;
+        }
+
+        public void setHighCount(long highCount) {
+            this.highCount = highCount & uintMask;
+        }
+
+        public long getLowCount() {
+            return lowCount & uintMask;
+        }
+
+        public void setLowCount(long lowCount) {
+            this.lowCount = lowCount & uintMask;
+        }
+
+        public long getScale() {
+            return scale;
+        }
+
+        public void setScale(long scale) {
+            this.scale = scale & uintMask;
+        }
+
+        public void incScale(int dScale) {
+            setScale(getScale() + dScale);
+        }
+
+        // Debug
+        public String toString() {
+            StringBuilder buffer = new StringBuilder();
+            buffer.append("SubRange[");
+            buffer.append("\n  lowCount=");
+            buffer.append(lowCount);
+            buffer.append("\n  highCount=");
+            buffer.append(highCount);
+            buffer.append("\n  scale=");
+            buffer.append(scale);
+            buffer.append("]");
+            return buffer.toString();
+        }
+    }
+}