public Pixel GetPixel(int x, int y)
{
if (palette != null)
{
var pixelsPerByte = (8 / bitDepth);
var bytesInRow = (1 + (width / pixelsPerByte));
var byteIndexInRow = x / pixelsPerByte;
var paletteIndex = (1 + (y * bytesInRow)) + byteIndexInRow;
var b = data[paletteIndex];
if (bitDepth == 8)
{
return(palette.GetPixel(b));
}
var withinByteIndex = x % pixelsPerByte;
var rightShift = 8 - ((withinByteIndex + 1) * bitDepth);
var indexActual = (b >> rightShift) & ((1 << bitDepth) - 1);
return(palette.GetPixel(indexActual));
}
var rowStartPixel = (rowOffset + (rowOffset * y)) + (bytesPerPixel * width * y);
var pixelStartIndex = rowStartPixel + (bytesPerPixel * x);
var first = data[pixelStartIndex];
switch (bytesPerPixel)
{
case 1:
return(new Pixel(first, first, first, 255, true));
case 2:
switch (colorType)
{
case ColorType.None:
{
byte second = data[pixelStartIndex + 1];
var value = ToSingleByte(first, second);
return(new Pixel(value, value, value, 255, true));
}
default:
return(new Pixel(first, first, first, data[pixelStartIndex + 1], true));
}
case 3:
return(new Pixel(first, data[pixelStartIndex + 1], data[pixelStartIndex + 2], 255, false));
case 4:
switch (colorType)
{
case ColorType.None | ColorType.AlphaChannelUsed:
{
var second = data[pixelStartIndex + 1];
var firstAlpha = data[pixelStartIndex + 2];
var secondAlpha = data[pixelStartIndex + 3];
var gray = ToSingleByte(first, second);
var alpha = ToSingleByte(firstAlpha, secondAlpha);
return(new Pixel(gray, gray, gray, alpha, true));
}
default:
return(new Pixel(first, data[pixelStartIndex + 1], data[pixelStartIndex + 2], data[pixelStartIndex + 3], false));
}
case 6:
return(new Pixel(first, data[pixelStartIndex + 2], data[pixelStartIndex + 4], 255, false));
case 8:
return(new Pixel(first, data[pixelStartIndex + 2], data[pixelStartIndex + 4], data[pixelStartIndex + 6], false));
default:
throw new InvalidOperationException($"Unreconized number of bytes per pixel: {bytesPerPixel}.");
}
}
public Pixel GetPixel(int x, int y)
{
var rowStartPixel = (rowOffset * y) + (bytesPerPixel * width * y);
var pixelStartIndex = rowStartPixel + (bytesPerPixel * x);
byte first = data[pixelStartIndex];
if (palette != null)
{
return(palette.GetPixel(first));
}
switch (bytesPerPixel)
{
case 1:
return(new Pixel(first, first, first, 255, true));
case 2:
switch (colorType)
{
case ColorType.None:
{
byte second = data[pixelStartIndex + 1];
var value = ToSingleByte(first, second);
return(new Pixel(value, value, value, 255, true));
}
default:
return(new Pixel(first, first, first, data[pixelStartIndex + 1], true));
}
case 3:
return(new Pixel(first, data[pixelStartIndex + 1], data[pixelStartIndex + 2], 255, false));
case 4:
switch (colorType)
{
case ColorType.None | ColorType.AlphaChannelUsed:
{
var second = data[pixelStartIndex + 1];
var firstAlpha = data[pixelStartIndex + 2];
var secondAlpha = data[pixelStartIndex + 3];
var gray = ToSingleByte(first, second);
var alpha = ToSingleByte(firstAlpha, secondAlpha);
return(new Pixel(gray, gray, gray, alpha, true));
}
default:
return(new Pixel(first, data[pixelStartIndex + 1], data[pixelStartIndex + 2], data[pixelStartIndex + 3], false));
}
case 6:
return(new Pixel(first, data[pixelStartIndex + 2], data[pixelStartIndex + 4], 255, false));
case 8:
return(new Pixel(first, data[pixelStartIndex + 2], data[pixelStartIndex + 4], data[pixelStartIndex + 6], false));
default:
throw new InvalidOperationException($"Unreconized number of bytes per pixel: {bytesPerPixel}.");
}
}
