/// <summary>
/// Small function that takes a Huffman tree & a TKMK00CommandWriter and writes out the tree construction information to the writer.
/// </summary>
/// <param name="node"></param>
/// <param name="writer"></param>
private static void WriteHuffmanTree(TKMK00HuffmanTreeNode node, TKMK00CommandWriter writer)
{
if (!node.IsEndNode)
{
writer.Write(1, 1);
WriteHuffmanTree(node.Left, writer);
WriteHuffmanTree(node.Right, writer);
}
else
{
writer.Write(0, 1);
writer.Write(node.Value, 5);
}
}
/// <summary>
/// Encodes RGBA5551 formatted data into the TKMK00 format. Uses a Huffman tree to store
/// color values that are added/subtracted/sometimes overwrite a predicted color for the
/// current pixel. Look up DPCM for a conceptual idea of what it's doing (the Huffman tree
/// stands in place for entropy coding.
/// </summary>
public static byte[] Encode(byte[] imageData, int width, int height, ushort alphaColor)
{
//ushort[] colors = new ushort[width * height]; //Color map that gets written to mid-conversion
ushort[] colorsRef = new ushort[width * height]; //Color map that has all image data from the beginning
byte[] colorChangeMap = new byte[width * height]; //
byte[] predictedColorsGreen = new byte[width * height]; //Contains predicted green values for all pixels
byte[] predictedColorsRed = new byte[width * height]; //Contains predicted red values for all pixels
byte[] predictedColorsBlue = new byte[width * height]; //Contains predicted blue values for all pixels
byte[] nearestIndeticalPixel = new byte[width * height]; //Used for finding pixels to copy the color down to, 0 - none, 1-5 - varying positions down one row
int[] colorCounts = new int[32]; //Contains # of times each huffman tree value is used. This is for constructing the Huffman tree to be most efficient
bool[] usedIdenticalColors = new bool[colorsRef.Length]; //True if the current pixel was copied from one a row up
//First, convert all colors from 2-bytes into 1 ushort value (colorsRef), then calculate the predicted color values
for (int row = 0; row < height; row++)
{
for (int col = 0; col < width; col++)
{
int currentPixel = row * width + col;
colorsRef[currentPixel] = ByteHelper.ReadUShort(imageData, currentPixel * 2);
//Predicted colors
int actualGreen = ((colorsRef[currentPixel] & 0x7C0) >> 6);
int actualRed = ((colorsRef[currentPixel] & 0xF800) >> 11);
int actualBlue = ((colorsRef[currentPixel] & 0x3E) >> 1);
int rgbaTop = (row == 0 ? 0 : colorsRef[currentPixel - width]);
int rgbaLeft = (row == 0 && col == 0 ? 0 : colorsRef[currentPixel - 1]);
ushort greenTop = (byte)((rgbaTop & 0x7C0) >> 6);
ushort greenLeft = (byte)((rgbaLeft & 0x7C0) >> 6);
int greenPrediction = (greenTop + greenLeft) / 2;
//Use the change between the old & new green values to project expected
// values for the red & blue colors
predictedColorsGreen[currentPixel] = (byte)ReverseColorCombine(greenPrediction, actualGreen);
int greenChange = actualGreen - greenPrediction;
//Combine red values of the pixels to make our predicted pixel color
ushort redTop = (byte)((rgbaTop & 0xF800) >> 11);
ushort redLeft = (byte)((rgbaLeft & 0xF800) >> 11);
int redPrediction = greenChange + (redTop + redLeft) / 2;
redPrediction = Math.Max(0, Math.Min(0x1F, redPrediction)); //Keep between 0 and 0x1F
predictedColorsRed[currentPixel] = (byte)ReverseColorCombine(redPrediction, actualRed);
//Combine blue values of the pixels to make our predicted pixel color
ushort blueTop = (byte)((rgbaTop & 0x3E) >> 1);
ushort blueLeft = (byte)((rgbaLeft & 0x3E) >> 1);
int bluePrediction = greenChange + (blueTop + blueLeft) / 2;
bluePrediction = Math.Max(0, Math.Min(0x1F, bluePrediction)); //Keep between 0 and 0x1F
predictedColorsBlue[currentPixel] = (byte)ReverseColorCombine(bluePrediction, actualBlue);
}
}
//Set up an rgbaBuffer to hold the last 0x40 color values used
ushort[] rgbaBuffer = new ushort[0x40];
for (int i = 0; i < 0x40; i++)
rgbaBuffer[i] = 0xFF;
ushort lastColor = 0; //Last color used
//Set up the master writer & 8 channel command writers
TKMK00CommandWriter masterWriter = new TKMK00CommandWriter();
TKMK00CommandWriter[] channelWriters = new TKMK00CommandWriter[8];
for (int i = 0; i < 8; i++)
channelWriters[i] = new TKMK00CommandWriter();
List<byte> huffmanValues = new List<byte>(); //Contains the huffman commands that will be written to channelWriters[0], but only
// after the Huffman tree is constructed.
//Main loop for determining the TKMK00 commands
for (int row = 0; row < height; row++)
{
for (int col = 0; col < width; col++)
{
int currentPixel = row * width + col;
//If this pixel has been colored already, then no commands are necessary
if (usedIdenticalColors[currentPixel])
{
lastColor = colorsRef[currentPixel];
continue;
}
//Channel index is determined from the colorChangeMap
int channelIndex = colorChangeMap[currentPixel] + 1;
if (colorsRef[currentPixel] == lastColor)
{
channelWriters[channelIndex].Write(0, 1); //Write the 'last color' command to the channel writer
}
else
{
channelWriters[channelIndex].Write(1, 1); //Write the 'new color' command to the channel writer
if (rgbaBuffer.Contains(colorsRef[currentPixel]))
{
masterWriter.Write(0, 1); //Write the 'use existing color' command to the master writer
int index = 0;
for (; index < rgbaBuffer.Length; index++)
{
if (rgbaBuffer[index] == colorsRef[currentPixel]) break;
}
masterWriter.Write(index, 6); //Write the index of the existing color to the master writer
//Move the selected color to the front of the rgba buffer
for (int k = index; k > 0; k--)
{
rgbaBuffer[k] = rgbaBuffer[k - 1];
}
rgbaBuffer[0] = colorsRef[currentPixel];
}
else
{
masterWriter.Write(1, 1); //Write the 'new color' command to the master writer
//3 color commands
huffmanValues.Add(predictedColorsGreen[currentPixel]);
huffmanValues.Add(predictedColorsRed[currentPixel]);
huffmanValues.Add(predictedColorsBlue[currentPixel]);
//Update the color counts
colorCounts[predictedColorsGreen[currentPixel]]++;
colorCounts[predictedColorsRed[currentPixel]]++;
colorCounts[predictedColorsBlue[currentPixel]]++;
//Add the new color to the front of the buffer
for (int k = rgbaBuffer.Length - 1; k > 0; k--)
{
rgbaBuffer[k] = rgbaBuffer[k - 1];
}
rgbaBuffer[0] = colorsRef[currentPixel];
}
//Add nearby pixels to the colorChangeMap
bool hasLeftCol = (col != 0);
bool hasRightCol = (col < (width - 1));
bool has2RightCols = (col < (width - 2));
bool hasDownRow = (row < (height - 1));
bool has2DownRows = (row < (height - 2));
//Right 1
if (hasRightCol)
colorChangeMap[currentPixel + 1]++;
//Right 2
if (has2RightCols)
colorChangeMap[currentPixel + 2]++;
//Down 1 Left 1
if (hasDownRow && hasLeftCol)
colorChangeMap[currentPixel + width - 1]++;
//Down 1
if (hasDownRow)
colorChangeMap[currentPixel + width]++;
//Down 1 Right 1
if (hasDownRow && hasRightCol)
colorChangeMap[currentPixel + width + 1]++;
//Down 2
if (has2DownRows)
colorChangeMap[currentPixel + width * 2]++;
lastColor = colorsRef[currentPixel];
//Determine if the current pixel has a pixel beneath it that it can be copied to
nearestIndeticalPixel[currentPixel] = setNearestPixel(currentPixel, width, colorsRef, usedIdenticalColors);
if (nearestIndeticalPixel[currentPixel] == 0)
{
masterWriter.Write(0, 1); //Write the 'don't copy' command to the master writer
}
else
{
//There's still a chance that we won't actually copy the pixel down, so don't write the 'copy' command yet
bool hasntWrittenFirstCommand = true;
int pixelOffset = currentPixel; //Contains the new pixel location to copy into
//Loop here, to continue copying down until it hits the end of the chain.
while (nearestIndeticalPixel[pixelOffset] != 0)
{
int pixelValue = nearestIndeticalPixel[pixelOffset];
switch (pixelValue)
{
case 1: //back 2
pixelOffset -= 2;
break;
case 2: //back 1
pixelOffset--;
break;
case 3://stay
break;
case 4://forward 1
pixelOffset++;
break;
case 5://forward 2
pixelOffset += 2;
break;
}
pixelOffset += width; //Down one row
if (usedIdenticalColors[pixelOffset])
break;//If the pixel in questinon has already been copied to, quit out of the loop
else
{
usedIdenticalColors[pixelOffset] = true; //Mark this pixel as having been copied to
if (hasntWrittenFirstCommand)
{
masterWriter.Write(1, 1); //Write the 'copy' command to the master writer
hasntWrittenFirstCommand = false;
}
//Write the pixel offset commands to the master writer (see the decoding process for the
// logic behind these numbers)
switch (pixelValue)
{
case 1: //back 2
masterWriter.Write(2, 4); //0010
break;
case 2: //back 1
masterWriter.Write(1, 2); //01
break;
case 3://stay
masterWriter.Write(2, 2); //10
break;
case 4://forward 1
masterWriter.Write(3, 2); //11
break;
case 5://forward 2
masterWriter.Write(3, 4); //0011
break;
}
}
nearestIndeticalPixel[pixelOffset] = setNearestPixel(pixelOffset, width, colorsRef, usedIdenticalColors);
}
if (hasntWrittenFirstCommand)
{
masterWriter.Write(0, 1); //Write the 'don't copy' command to the master writer
}
else
{
//Write the quit command to the master writer (see the decoding process for the
// logic behind this number)
masterWriter.Write(0, 3); //000
}
}
}
}
}
//Post pixel loop, now we need to finalize and save all the data
//Load the Huffman tree
TKMK00HuffmanTreeNode headNode = ConstructTree(colorCounts);
int[] huffmanTreeTraversalCommands = new int[0x20];
int[] huffmanTreeTraversalBitCounts = new int[0x20];
//Get the bits for each huffman value
GetHuffmanTreeTraversalCommands(headNode, 0, 0, huffmanTreeTraversalCommands, huffmanTreeTraversalBitCounts);
//Write in the Huffman tree here
WriteHuffmanTree(headNode, channelWriters[0]);
//Write the convertedHuffmanValues
foreach(byte index in huffmanValues)
channelWriters[0].Write(huffmanTreeTraversalCommands[index], huffmanTreeTraversalBitCounts[index]);
//Here the writers should be good, finish and combine into a single byte[]
masterWriter.Finish();
foreach (TKMK00CommandWriter writer in channelWriters)
writer.Finish();
//Set up the header here
TKMK00Header header = new TKMK00Header();
int channelOffset = 0x2C + masterWriter.FinalData.Count;
List<byte[]> channelDatas = new List<byte[]>();
byte repeatEnabledMask = 0;
for (int i = 0; i < 8; i++)
{
header.ChannelPointers[i] = channelOffset;
bool useRepeat = channelWriters[i].BytesSavedInRepeat > 0;
if (useRepeat)
{
channelOffset += channelWriters[i].FinalRepeatingData.Count;
channelDatas.Add(channelWriters[i].FinalRepeatingData.ToArray());
repeatEnabledMask |= (byte)(1 << i);
}
else
{
channelOffset += channelWriters[i].FinalData.Count;
channelDatas.Add(channelWriters[i].FinalData.ToArray());
}
}
header.Width = (ushort)width;
header.Height = (ushort)height;
header.RepeatModeMask = repeatEnabledMask;
header.Unknown = 0x0F;
//Combine all the data together
byte[] finalData = ByteHelper.CombineIntoBytes(header.GetAsBytes(), masterWriter.FinalData,
channelDatas[0], channelDatas[1], channelDatas[2], channelDatas[3],
channelDatas[4], channelDatas[5], channelDatas[6], channelDatas[7]);
return finalData;
}