public void Load(Stream stream)
{
// Read the first 4 bytes from the stream to determine
// what kind of image we are loading.
byte[] magic = new byte [4];
stream.Read(magic, 0, 4);
if (magic[0] == (byte)'B' && magic[1] == (byte)'M')
{
// Windows bitmap image.
BmpReader.Load(stream, this);
}
else if (magic[0] == 0 && magic[1] == 0 &&
magic[2] == 1 && magic[3] == 0)
{
// Windows icon image.
IconReader.Load(stream, this, false);
}
else if (magic[0] == 0 && magic[1] == 0 &&
magic[2] == 2 && magic[3] == 0)
{
// Windows cursor image (same as icon, with hotspots).
IconReader.Load(stream, this, true);
}
else if (magic[0] == 137 && magic[1] == 80 &&
magic[2] == 78 && magic[3] == 71)
{
// PNG image.
PngReader.Load(stream, this);
}
else if (magic[0] == (byte)'G' && magic[1] == (byte)'I' &&
magic[2] == (byte)'F' && magic[3] == (byte)'8')
{
// GIF image.
GifReader.Load(stream, this);
}
else if (magic[0] == (byte)0xFF && magic[1] == (byte)0xD8)
{
// JPEG or EXIF image.
JpegReader.Load(stream, this, magic, 4);
}
else
{
// Don't know how to load this kind of file.
throw new FormatException();
}
}
// Load a Windows icon image from the specified stream. The first
// 4 bytes have already been read and discarded. If "hotspots" is
// "true", then the image is actually a Windows cursor with hotspots.
public static void Load(Stream stream, Image image, bool hotspots)
{
byte[] buffer = new byte [1024];
int offset = 4;
int numImages, index;
int width, height, bpp;
PixelFormat format;
Frame frame;
int[] palette;
int paletteCount;
int paletteIndex;
// Read the number of images in the file.
if (stream.Read(buffer, 0, 2) != 2)
{
throw new FormatException();
}
numImages = Utils.ReadUInt16(buffer, 0);
offset += 2;
// Read the resource directory.
int[] offsetList = new int [numImages];
int[] hotspotX = null;
int[] hotspotY = null;
if (hotspots)
{
hotspotX = new int[numImages];
hotspotY = new int[numImages];
}
for (index = 0; index < numImages; ++index)
{
if (stream.Read(buffer, 0, 16) != 16)
{
throw new FormatException();
}
offset += 16;
if (hotspots)
{
hotspotX[index] = Utils.ReadUInt16(buffer, 4);
hotspotY[index] = Utils.ReadUInt16(buffer, 6);
}
offsetList[index] = Utils.ReadInt32(buffer, 12);
}
// Read the contents of the images in the stream.
for (index = 0; index < numImages; ++index)
{
// Seek to the start of the image.
Utils.Seek(stream, offset, offsetList[index]);
offset = offsetList[index];
// Read the DIB header.
if (stream.Read(buffer, 0, 40) != 40)
{
throw new FormatException();
}
offset += 40;
width = Utils.ReadUInt16(buffer, 4);
// The DIB height is the mask and the bitmap.
height = Utils.ReadUInt16(buffer, 8) / 2;
bpp = Utils.ReadUInt16(buffer, 14);
if (bpp == 1)
{
format = PixelFormat.Format1bppIndexed;
}
else if (bpp == 4)
{
format = PixelFormat.Format4bppIndexed;
}
else if (bpp == 8)
{
format = PixelFormat.Format8bppIndexed;
}
else if (bpp == 24)
{
format = PixelFormat.Format24bppRgb;
}
else if (bpp == 32)
{
format = PixelFormat.Format32bppArgb;
}
else
{
throw new FormatException();
}
// Create a new frame for this icon.
frame = new Frame(image, width, height, format);
image.AddFrame(frame);
if (hotspots)
{
frame.HotspotX = hotspotX[index];
frame.HotspotY = hotspotY[index];
}
// Copy some of the format information up to the image.
if (frame.Width > image.Width)
{
image.Width = frame.Width;
}
if (frame.Height > image.Height)
{
image.Height = frame.Height;
}
if (image.NumFrames == 1)
{
image.PixelFormat = format;
}
// If indexed, get the palette.
if ((frame.pixelFormat & PixelFormat.Indexed) != 0)
{
paletteCount =
(1 << Utils.FormatToBitCount(frame.pixelFormat));
if (stream.Read(buffer, 0, paletteCount * 4)
!= paletteCount * 4)
{
throw new FormatException();
}
offset += paletteCount * 4;
palette = new int [paletteCount];
for (paletteIndex = 0; paletteIndex < paletteCount;
++paletteIndex)
{
palette[paletteIndex] = Utils.ReadBGR
(buffer, paletteIndex * 4);
}
frame.Palette = palette;
}
// Read the main part of the icon or cursor.
BmpReader.LoadBitmapData(stream, frame, false, true);
offset += frame.Height * frame.Stride;
// Read the mask.
BmpReader.LoadBitmapData(stream, frame, true, true);
offset += frame.Height * frame.MaskStride;
// Invert the mask, because we want 1 to mean "active".
InvertMask(frame);
}
// Set the appropriate load format.
if (hotspots)
{
image.LoadFormat = Image.Cursor;
}
else
{
image.LoadFormat = Image.Icon;
}
}