//Function called from the loop populate the main array chars->colors to determine the index to be considered next. It includes various arbitrary modifications increasing the security
//of the method.
private RGBInfo updateRGB(RGBInfo curRGB, List<Color> availableColors)
{
int curIndex = curStep;
if (curRGB.lastR >= 100) curIndex = curIndex + 1;
if (curRGB.lastG < 100) curIndex = curIndex + 2;
if (curRGB.lastB >= 100) curIndex = curIndex - 2;
if (curIndex + curRGB.lastIndex < availableColors.Count - 10) curIndex = curIndex + curRGB.lastIndex;
if (curLength <= 10) curIndex = curIndex - 1;
else curIndex = curIndex + 1;
if (curIndex < 0) curIndex = 0;
if (curIndex > availableColors.Count - 1) curIndex = availableColors.Count - 1;
curRGB.curIndex = curIndex;
curRGB.lastIndex = curRGB.curIndex;
return curRGB;
}
//Building the basic "hashing dictionary", charsVsColors, where each (recognised) character is related to a given color. The relationships characters->colors is different every time and varies
//on account of different variables (e.g., encrypting integer or length of the input text)
private void buildCharsVsColors()
{
charsVsColors = new Dictionary<char, Color>();
Color curColor = startColor;
int minIndex = 0;
int maxIndex = 240; //The restricted number of colors forces to choose just specific characters
RGBInfo curRGB = new RGBInfo();
curRGB.lastR = startColor.R;
curRGB.lastG = startColor.G;
curRGB.lastB = startColor.B;
curRGB.lastIndex = calculateFirst(); //Calculating the start index (from the original List of known colors) from which all the analysis will be started
reorderKnownColors(curRGB.lastIndex); //Reordering the original list with all the known colors on account of the inputs
List<Color> availableColors = new List<Color>(curColors);
for (int i = minIndex; i < maxIndex; i++)
{
if (!(i >= 127 && i <= 160)) //The restricted number of colors forces to choose just specific characters
{
string noDiacritics = WrittenByOthers.RemoveDiacritics(((char)i).ToString(), true);
if (!(noDiacritics != ((char)i).ToString())) //The restricted number of colors forces to choose just specific characters
{
curRGB = updateRGB(curRGB, availableColors);
curColor = availableColors[curRGB.curIndex];
curRGB.lastR = curColor.R;
curRGB.lastG = curColor.G;
curRGB.lastB = curColor.B;
charsVsColors.Add((char)i, curColor);
availableColors.RemoveAt(curRGB.curIndex); //Avoiding the given color to be considered for a different character
}
}
}
if (availableColors.Count > 0 && charsVsColors.ContainsValue(startColor))
{
Color replaceColor = availableColors[0]; //There has to be always unused availableColors
KeyValuePair<char, Color> tempPair = charsVsColors.FirstOrDefault(x => IO.twoColorsAreEqual(x.Value, startColor));
replacePair = new KeyValuePair<char, Color>(tempPair.Key, replaceColor);
availableColors.RemoveAt(0);
}
int afterIndex = curIO.allKnownColors.IndexOf(startColor) + encryptingNumber;
if (afterIndex > curIO.allKnownColors.Count - 1) afterIndex = encryptingNumber;
Color afterOffset = curIO.allKnownColors[afterIndex];
startOffset.afterOffset = afterOffset;
if (availableColors.Count > 0 && charsVsColors.ContainsValue(startOffset.afterOffset))
{
Color replaceColor = availableColors[0]; //There has to be always unused availableColors
KeyValuePair<char, Color> tempPair = charsVsColors.FirstOrDefault(x => IO.twoColorsAreEqual(x.Value, startOffset.afterOffset));
this.startOffset.replaceAfter = new KeyValuePair<char, Color>(tempPair.Key, replaceColor);
availableColors.RemoveAt(0);
}
}
