Further compression and png work.

src/core/streams/BitStream.cpp

@@ -2,37 +2,70 @@
 
 #include "ByteUtils.h"
 
-bool BitStream::loadNextByte()
+#include <sstream>
+#include <iostream>
+
+BitStream::~BitStream()
 {
-    if (mByteOffset + 1 == mBuffer.size())
-    {
-        return false;
-    }
-    else
-    {
-        mByteOffset++;
-        mCurrentByte = mBuffer[mByteOffset];
-        return true;
-    }
+
 }
 
-bool BitStream::getNextNBits(unsigned n, unsigned char& buffer)
+unsigned char BitStream::getCurrentByte()
 {
-    int overshoot = n + mBitOffset - 7;
+    if (mByteOffset < 0)
+    {
+        readNextByte();
+    }
+    return mCurrentByte;
+}
 
+
+int BitStream::getCurrentByteOffset() const
+{
+    return mByteOffset;
+}
+
+unsigned BitStream::getCurrentBitOffset() const
+{
+    return mBitOffset;
+}
+
+std::string BitStream::logNextNBytes(unsigned n) const
+{
+    std::stringstream sstr;
+    unsigned count{0};
+    for(auto byte : peekNextNBytes(n))
+    {
+        sstr << count << " | " << ByteUtils::toString(byte) + '\n';
+        count++;
+    }
+    return sstr.str();
+}
+
+bool BitStream::readNextNBits(unsigned n, unsigned char& buffer)
+{
+    if (mByteOffset < 0)
+    {
+        if (!readNextByte())
+        {
+            return false;
+        }
+    }
+
+    int overshoot = n + mBitOffset - 8;
     if (overshoot > 0)
     {
         unsigned char last_byte = mCurrentByte;
-        if (!loadNextByte())
+        if (!readNextByte())
         {
             return false;
         }
 
-        auto num_lower = 7 - mBitOffset;
+        auto num_lower = 8 - mBitOffset;
         char lower_bits = ByteUtils::getHigherNBits(last_byte, num_lower);
         char higher_bits = ByteUtils::getLowerNBits(mCurrentByte, overshoot);
 
-        buffer = (higher_bits << (8 - num_lower)) | (lower_bits >> mBitOffset);
+        buffer = (higher_bits << num_lower) | lower_bits;
 
         mBitOffset = overshoot;
         return true;
@@ -44,13 +77,3 @@ bool BitStream::getNextNBits(unsigned n, unsigned char& buffer)
         return true;
     }
 }
-
-void BitStream::setByte(unsigned idx, unsigned char data)
-{
-    mBuffer[idx] = data;
-}
-
-void BitStream::setBufferSize(std::size_t size)
-{
-    mBuffer = std::vector<unsigned char>(size);
-}