/// <include file='../docs.xml'
/// path='docs/doc[@name="M:PeterO.Png4BitIndexed.Save(System.String)"]/*'/>
public void Save(string filename)
{
if (filename == null)
{
throw new ArgumentNullException("filename");
}
if (filename.Length == 0)
{
throw new ArgumentException("filename" + " is empty.");
}
using (var fs = new FileStream(filename, FileMode.Create)) {
fs.Write(this.subdata1, 0, this.subdata1.Length);
var crc32 = Png.Crc32(this.subdata1, 12, 17, 0);
byte[] deflated = null;
fs.Write(this.GetBE(crc32), 0, 4);
// Write the color data
fs.Write(this.GetBE(48), 0, 4);
fs.Write(new byte[] { 0x50, 0x4c, 0x54, 0x45 }, 0, 4);
crc32 = Png.Crc32(new byte[] { 0x50, 0x4c, 0x54, 0x45 }, 0, 4, 0);
crc32 = Png.Crc32(this.colors, 0, 48, crc32);
fs.Write(this.colors, 0, 48);
fs.Write(this.GetBE(crc32), 0, 4);
// Write the transparent color
if (this.transparent >= 0 && this.transparent < 16)
{
fs.Write(this.GetBE(1), 0, 4);
fs.Write(new byte[] { 0x74, 0x52, 0x4e, 0x53 }, 0, 4);
crc32 = Png.Crc32(new byte[] { 0x74, 0x52, 0x4e, 0x53 }, 0, 4, 0);
crc32 = Png.Crc32(new[] { (byte)this.transparent }, 0, 1, crc32);
fs.Write(new[] { (byte)this.transparent }, 0, 1);
fs.Write(this.GetBE(crc32), 0, 4);
}
// Write the image data
using (var ms = new MemoryStream()) {
// PNG compression uses a ZLIB stream not a DEFLATE stream
ms.WriteByte(0x78);
ms.WriteByte(0x9c);
using (
var ds = new DeflateStream(
ms,
CompressionMode.Compress,
true)) {
ds.Write(this.data, 0, this.data.Length);
}
ms.Write(Png.Adler32(this.data, 0, this.data.Length), 0, 4);
deflated = ms.ToArray();
}
var defLength = new[] { (byte)((deflated.Length >> 24) & 255),
(byte)((deflated.Length >> 16) & 255),
(byte)((deflated.Length >> 8) & 255),
(byte)((deflated.Length >> 0) & 255) };
fs.Write(defLength, 0, defLength.Length);
fs.Write(new byte[] { 0x49, 0x44, 0x41, 0x54 }, 0, 4);
fs.Write(deflated, 0, deflated.Length);
var crc = Png.Crc32(deflated, 0, deflated.Length, this.idatCrc);
var subdcrc = this.GetBE(crc);
fs.Write(subdcrc, 0, subdcrc.Length);
fs.Write(this.subdata2, 0, this.subdata2.Length);
}
}
/// <include file='../docs.xml'
/// path='docs/doc[@name="M:PeterO.Png8BitIndexed.#ctor(System.Int32,System.Int32)"]/*'/>
public Png8BitIndexed(int width, int height)
{
if (width < 1)
{
throw new ArgumentException("width (" + width +
") is less than 1");
}
if (width > 65535)
{
throw new ArgumentException("width (" + width + ") is more than 65535");
}
if (height < 1)
{
throw new ArgumentException("height (" + height +
") is less than 1");
}
if (height > 65535)
{
throw new ArgumentException("height (" + height + ") is more than 65535");
}
this.colors = new byte[256 * 3];
this.transparent = -1;
this.subdata1 = new byte[] { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0,
0, 0, 0xd,
0x49, 0x48, 0x44, 0x52,
0, 0, (byte)(width >> 8), (byte)(width & 255),
0, 0, (byte)(height >> 8), (byte)(height & 255),
8, 3, 0, 0, 0 };
this.width = width;
this.height = height;
this.realRowSize = this.width + 1;
this.blockSize = this.realRowSize;
this.rowSize = this.realRowSize;
this.imageData = new byte[this.rowSize * this.height];
this.data = this.imageData;
this.idatCrc = Png.Crc32(
new byte[] { 0x49,
0x44,
0x41,
0x54 },
0,
4,
0);
this.subdata2 = new byte[] { 0, 0, 0, 0, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42,
0x60, 0x82 };
}
