epic/OpenRA
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Implement a simple managed png writer.

Browse Source
This commit is contained in:
Paul Chote
2019-03-05 21:03:55 +00:00
committed by reaperrr
parent 9f419fca34
commit 5cc81f7bf7
1 changed files with 86 additions and 91 deletions
Download Patch File Download Diff File Expand all files Collapse all files

177
OpenRA.Game/FileFormats/Png.cs
View File

@@ -14,7 +14,6 @@ using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Runtime.InteropServices;
using System.Text;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
@@ -24,6 +23,8 @@ namespace OpenRA.FileFormats
{
public class Png
{
static readonly byte[] Signature = { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a };
public int Width { get; set; }
public int Height { get; set; }
public Color[] Palette { get; set; }
@@ -197,8 +198,7 @@ namespace OpenRA.FileFormats
public static bool Verify(Stream s)
{
var pos = s.Position;
var signature = new[] { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a };
var isPng = signature.Aggregate(true, (current, t) => current && s.ReadUInt8() == t);
var isPng = Signature.Aggregate(true, (current, t) => current && s.ReadUInt8() == t);
s.Position = pos;
return isPng;
}
@@ -246,109 +246,104 @@ namespace OpenRA.FileFormats
throw new InvalidDataException("Unknown pixel format");
}
void WritePngChunk(Stream output, string type, Stream input)
{
input.Position = 0;
var typeBytes = Encoding.ASCII.GetBytes(type);
output.Write(IPAddress.HostToNetworkOrder((int)input.Length));
output.WriteArray(typeBytes);
var data = input.ReadAllBytes();
output.WriteArray(data);
var crc32 = new Crc32();
crc32.Update(typeBytes);
crc32.Update(data);
output.Write(IPAddress.NetworkToHostOrder((int)crc32.Value));
}
public byte[] Save()
{
var pixelFormat = Palette != null ? System.Drawing.Imaging.PixelFormat.Format8bppIndexed : System.Drawing.Imaging.PixelFormat.Format32bppArgb;
// Save to a memory stream that we can then parse to add the embedded data
using (var bitmapStream = new MemoryStream())
using (var output = new MemoryStream())
{
using (var bitmap = new System.Drawing.Bitmap(Width, Height, pixelFormat))
output.WriteArray(Signature);
using (var header = new MemoryStream())
{
if (Palette != null)
{
// Setting bitmap.Palette.Entries directly doesn't work
var bPal = bitmap.Palette;
for (var i = 0; i < 256; i++)
bPal.Entries[i] = System.Drawing.Color.FromArgb(Palette[i].ToArgb());
header.Write(IPAddress.HostToNetworkOrder(Width));
header.Write(IPAddress.HostToNetworkOrder(Height));
header.WriteByte(8); // Bit depth
bitmap.Palette = bPal;
var bd = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, Width, Height), System.Drawing.Imaging.ImageLockMode.WriteOnly,
pixelFormat);
for (var i = 0; i < Height; i++)
Marshal.Copy(Data, i * Width, IntPtr.Add(bd.Scan0, i * bd.Stride), Width);
var colorType = Palette != null
? PngColorType.Indexed | PngColorType.Color
: PngColorType.Color | PngColorType.Alpha;
header.WriteByte((byte)colorType);
bitmap.UnlockBits(bd);
}
else
{
unsafe
{
var bd = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, Width, Height), System.Drawing.Imaging.ImageLockMode.WriteOnly, pixelFormat);
var colors = (int*)bd.Scan0;
for (var y = 0; y < Height; y++)
{
for (var x = 0; x < Width; x++)
{
var i = y * Width + x;
header.WriteByte(0); // Compression
header.WriteByte(0); // Filter
header.WriteByte(0); // Interlacing
// Convert RGBA to ARGB
colors[i] = Color.FromArgb(Data[4 * i + 3], Data[4 * i + 0], Data[4 * i + 1],
Data[4 * i + 2]).ToArgb();
}
}
bitmap.UnlockBits(bd);
}
}
bitmap.Save(bitmapStream, System.Drawing.Imaging.ImageFormat.Png);
WritePngChunk(output, "IHDR", header);
}
if (!EmbeddedData.Any())
return bitmapStream.ToArray();
// Add embedded metadata to the end of the image
bitmapStream.Position = 0;
var outputStream = new MemoryStream();
using (var bw = new BinaryWriter(outputStream))
bool alphaPalette = false;
if (Palette != null)
{
bw.Write(bitmapStream.ReadBytes(8));
var crc32 = new Crc32();
for (;;)
using (var palette = new MemoryStream())
{
var length = IPAddress.NetworkToHostOrder(bitmapStream.ReadInt32());
var type = Encoding.UTF8.GetString(bitmapStream.ReadBytes(4));
var content = bitmapStream.ReadBytes(length);
var crc = bitmapStream.ReadUInt32();
switch (type)
foreach (var c in Palette)
{
case "tEXt":
break;
case "IEND":
bitmapStream.Close();
foreach (var kv in EmbeddedData)
{
bw.Write(IPAddress.NetworkToHostOrder(kv.Key.Length + 1 + kv.Value.Length));
bw.Write("tEXt".ToCharArray());
bw.Write(kv.Key.ToCharArray());
bw.Write((byte)0x00);
bw.Write(kv.Value.ToCharArray());
crc32.Reset();
crc32.Update(Encoding.ASCII.GetBytes("tEXt"));
crc32.Update(Encoding.ASCII.GetBytes(kv.Key + (char)0x00 + kv.Value));
bw.Write((uint)IPAddress.NetworkToHostOrder((int)crc32.Value));
}
bw.Write(0);
bw.Write(type.ToCharArray());
bw.Write(crc);
return outputStream.ToArray();
default:
bw.Write(IPAddress.NetworkToHostOrder(length));
bw.Write(type.ToCharArray());
bw.Write(content);
bw.Write(crc);
break;
palette.WriteByte(c.R);
palette.WriteByte(c.G);
palette.WriteByte(c.B);
alphaPalette |= c.A > 0;
}
WritePngChunk(output, "PLTE", palette);
}
}
if (alphaPalette)
{
using (var alpha = new MemoryStream())
{
foreach (var c in Palette)
alpha.WriteByte(c.A);
WritePngChunk(output, "tRNS", alpha);
}
}
using (var data = new MemoryStream())
{
using (var compressed = new DeflaterOutputStream(data))
{
var stride = Width * (Palette != null ? 1 : 4);
for (var y = 0; y < Height; y++)
{
// Write uncompressed scanlines for simplicity
compressed.WriteByte(0);
compressed.Write(Data, y * stride, stride);
}
compressed.Flush();
compressed.Finish();
WritePngChunk(output, "IDAT", data);
}
}
foreach (var kv in EmbeddedData)
{
using (var text = new MemoryStream())
{
text.WriteArray(Encoding.ASCII.GetBytes(kv.Key + (char)0 + kv.Value));
WritePngChunk(output, "tEXt", text);
}
}
WritePngChunk(output, "IEND", new MemoryStream());
return output.ToArray();
}
}