internal void DownHeap(short[] tree, int nodeIndex)
{
int index = nodeIndex << 1;
int nodeIndex1 = this.Heap[nodeIndex];
for (; index <= this.HeapLength; index <<= 1)
{
if (index < this.HeapLength && DeflateCompressor.IsSmaller(tree, this.Heap[index + 1], this.Heap[index], this.Depth))
{
++index;
}
if (!DeflateCompressor.IsSmaller(tree, nodeIndex1, this.Heap[index], this.Depth))
{
this.Heap[nodeIndex] = this.Heap[index];
nodeIndex = index;
}
else
{
break;
}
}
this.Heap[nodeIndex] = nodeIndex1;
}
internal void BuildTree(DeflateCompressor manager)
{
short[] dynamicTree = this.DynamicTree;
short[] treeCodes = this.StaticTree.TreeCodes;
int elements = this.StaticTree.Elements;
int maxCode = -1;
manager.HeapLength = 0;
manager.HeapMax = Tree.HeapSize;
for (int index = 0; index < elements; ++index)
{
if (dynamicTree[index * 2] != (short)0)
{
manager.Heap[++manager.HeapLength] = maxCode = index;
manager.Depth[index] = (sbyte)0;
}
else
{
dynamicTree[index * 2 + 1] = (short)0;
}
}
while (manager.HeapLength < 2)
{
int[] heap = manager.Heap;
int index1 = ++manager.HeapLength;
int num1;
if (maxCode >= 2)
{
num1 = 0;
}
else
{
maxCode = num1 = maxCode + 1;
}
int num2 = num1;
heap[index1] = num1;
int index2 = num2;
dynamicTree[index2 * 2] = (short)1;
manager.Depth[index2] = (sbyte)0;
--manager.OptimalLength;
if (treeCodes != null)
{
manager.StaticLength -= (int)treeCodes[index2 * 2 + 1];
}
}
this.MaxCode = maxCode;
for (int nodeIndex = manager.HeapLength / 2; nodeIndex >= 1; --nodeIndex)
{
manager.DownHeap(dynamicTree, nodeIndex);
}
int index3 = elements;
do
{
int index1 = manager.Heap[1];
manager.Heap[1] = manager.Heap[manager.HeapLength--];
manager.DownHeap(dynamicTree, 1);
int index2 = manager.Heap[1];
manager.Heap[--manager.HeapMax] = index1;
manager.Heap[--manager.HeapMax] = index2;
dynamicTree[index3 * 2] = (short)((int)dynamicTree[index1 * 2] + (int)dynamicTree[index2 * 2]);
manager.Depth[index3] = (sbyte)((int)Math.Max((byte)manager.Depth[index1], (byte)manager.Depth[index2]) + 1);
dynamicTree[index1 * 2 + 1] = dynamicTree[index2 * 2 + 1] = (short)index3;
manager.Heap[1] = index3++;
manager.DownHeap(dynamicTree, 1);
}while (manager.HeapLength >= 2);
manager.Heap[--manager.HeapMax] = manager.Heap[1];
this.GenerateBitLengths(manager);
Tree.GenerateCodes(dynamicTree, maxCode, manager.BitLengthCount);
}
private void GenerateBitLengths(DeflateCompressor manager)
{
short[] dynamicTree = this.DynamicTree;
short[] treeCodes = this.StaticTree.TreeCodes;
int[] extraBits = this.StaticTree.ExtraBits;
int extraBase = this.StaticTree.ExtraBase;
int maxLength = this.StaticTree.MaxLength;
int num1 = 0;
for (int index = 0; index <= 15; ++index)
{
manager.BitLengthCount[index] = (short)0;
}
dynamicTree[manager.Heap[manager.HeapMax] * 2 + 1] = (short)0;
int index1;
for (index1 = manager.HeapMax + 1; index1 < Tree.HeapSize; ++index1)
{
int num2 = manager.Heap[index1];
int index2 = (int)dynamicTree[(int)dynamicTree[num2 * 2 + 1] * 2 + 1] + 1;
if (index2 > maxLength)
{
index2 = maxLength;
++num1;
}
dynamicTree[num2 * 2 + 1] = (short)index2;
if (num2 <= this.MaxCode)
{
++manager.BitLengthCount[index2];
int num3 = 0;
if (num2 >= extraBase)
{
num3 = extraBits[num2 - extraBase];
}
short num4 = dynamicTree[num2 * 2];
manager.OptimalLength += (int)num4 * (index2 + num3);
if (treeCodes != null)
{
manager.StaticLength += (int)num4 * ((int)treeCodes[num2 * 2 + 1] + num3);
}
}
}
if (num1 == 0)
{
return;
}
do
{
int index2 = maxLength - 1;
while (manager.BitLengthCount[index2] == (short)0)
{
--index2;
}
--manager.BitLengthCount[index2];
manager.BitLengthCount[index2 + 1] = (short)((int)manager.BitLengthCount[index2 + 1] + 2);
--manager.BitLengthCount[maxLength];
num1 -= 2;
}while (num1 > 0);
for (int index2 = maxLength; index2 != 0; --index2)
{
int num2 = (int)manager.BitLengthCount[index2];
while (num2 != 0)
{
int num3 = manager.Heap[--index1];
if (num3 <= this.MaxCode)
{
int index3 = num3 * 2;
int index4 = index3 + 1;
if ((int)dynamicTree[index4] != index2)
{
manager.OptimalLength = (int)((long)manager.OptimalLength + ((long)index2 - (long)dynamicTree[index4]) * (long)dynamicTree[index3]);
dynamicTree[index4] = (short)index2;
}
--num2;
}
}
}
}
