/// <summary>
/// Creates a brush with the given dimensions given bit depth, alpha
/// data, and name.
/// </summary>
/// <param name="width">Desired width.</param>
/// <param name="height">Desired height.</param>
/// <param name="bitDepth">Bit depth of the data.</param>
/// <param name="alphaData">
/// The pixel data, stored only as an alpha channel and flattened to a
/// 1-d array.
/// </param>
/// <param name="name">Desired brush name.</param>
/// <returns>
/// An AbrBrush with a bitmap constructed from the alpha data.
/// </returns>
private static unsafe AbrBrush CreateSampledBrush(
int width,
int height,
int bitDepth,
byte[] alphaData,
string name)
{
AbrBrush brush = new AbrBrush(width, height, name);
BitmapData bd = brush.Image.LockBits(
new Rectangle(0, 0, width, height),
ImageLockMode.WriteOnly,
PixelFormat.Format32bppPArgb);
try
{
fixed(byte *ptr = alphaData)
{
byte *scan0 = (byte *)bd.Scan0.ToPointer();
int stride = bd.Stride;
if (bitDepth == 16)
{
int srcStride = width * 2;
for (int y = 0; y < height; y++)
{
byte *src = ptr + (y * srcStride);
byte *dst = scan0 + (y * stride);
for (int x = 0; x < width; x++)
{
ushort val = (ushort)((src[0] << 8) | src[1]);
dst[0] = dst[1] = dst[2] = 0;
dst[3] = (byte)((val * 10) / 1285);
src += 2;
dst += 4;
}
}
}
else
{
for (int y = 0; y < height; y++)
{
byte *src = ptr + (y * width);
byte *dst = scan0 + (y * stride);
for (int x = 0; x < width; x++)
{
dst[0] = dst[1] = dst[2] = 0;
dst[3] = *src;
src++;
dst += 4;
}
}
}
}
}
finally
{
brush.Image.UnlockBits(bd);
}
return(brush);
}
/// <summary>
/// Decodes the descriptor-based brushes in version 6 and later.
/// </summary>
/// <param name="reader">The reader.</param>
/// <param name="majorVersion">The major version.</param>
/// <returns>An <see cref="AbrBrushCollection"/> containing the brushes.</returns>
/// <exception cref="FormatException">The ABR version is not supported.</exception>
private static AbrBrushCollection DecodeVersion6(BigEndianBinaryReader reader, short majorVersion)
{
short minorVersion = reader.ReadInt16();
long unusedDataLength;
switch (minorVersion)
{
case 1:
// Skip the Int16 bounds rectangle and the unknown Int16.
unusedDataLength = 10L;
break;
case 2:
// Skip the unknown bytes.
unusedDataLength = 264L;
break;
default:
throw new FormatException(string.Format(
CultureInfo.CurrentCulture,
Localization.Strings.AbrUnsupportedMinorVersionFormat,
majorVersion, minorVersion));
}
BrushSectionParser parser = new BrushSectionParser(reader);
List <AbrBrush> brushes = new List <AbrBrush>(parser.SampledBrushes.Count);
long sampleSectionOffset = parser.SampleSectionOffset;
if (parser.SampledBrushes.Count > 0 && sampleSectionOffset >= 0)
{
reader.Position = sampleSectionOffset;
uint sectionLength = reader.ReadUInt32();
long sectionEnd = reader.Position + sectionLength;
while (reader.Position < sectionEnd)
{
uint brushLength = reader.ReadUInt32();
// The brush data is padded to 4 byte alignment.
long paddedBrushLength = ((long)brushLength + 3) & ~3;
long endOffset = reader.Position + paddedBrushLength;
string tag = reader.ReadPascalString();
// Skip the unneeded data that comes before the Int32 bounds rectangle.
reader.Position += unusedDataLength;
Rectangle bounds = reader.ReadInt32Rectangle();
if (bounds.Width <= 0 || bounds.Height <= 0)
{
// Skip any brushes that have invalid dimensions.
reader.Position += (endOffset - reader.Position);
continue;
}
short depth = reader.ReadInt16();
if (depth != 8 && depth != 16)
{
// Skip any brushes with an unknown bit depth.
reader.Position += (endOffset - reader.Position);
continue;
}
SampledBrush sampledBrush = parser.SampledBrushes.FindLargestBrush(tag);
if (sampledBrush != null)
{
BrushCompression compression = (BrushCompression)reader.ReadByte();
int height = bounds.Height;
int width = bounds.Width;
byte[] alphaData = null;
if (compression == BrushCompression.RLE)
{
short[] compressedRowLengths = new short[height];
for (int y = 0; y < height; y++)
{
compressedRowLengths[y] = reader.ReadInt16();
}
int alphaDataSize = width * height;
int bytesPerRow = width;
if (depth == 16)
{
alphaDataSize *= 2;
bytesPerRow *= 2;
}
alphaData = new byte[alphaDataSize];
for (int y = 0; y < height; y++)
{
RLEHelper.DecodedRow(reader, alphaData, y * width, bytesPerRow);
}
}
else if (compression == BrushCompression.None)
{
int alphaDataSize = width * height;
if (depth == 16)
{
alphaDataSize *= 2;
}
alphaData = reader.ReadBytes(alphaDataSize);
}
else
{
// Skip any brushes with an unknown compression type.
reader.Position += (endOffset - reader.Position);
continue;
}
AbrBrush brush = CreateSampledBrush(width, height, depth, alphaData, sampledBrush.Name);
brushes.Add(brush);
// Some brushes only store the largest item and scale it down.
var scaledBrushes = parser.SampledBrushes.Where(i => i.Tag.Equals(tag, StringComparison.Ordinal) && i.Diameter < sampledBrush.Diameter);
if (scaledBrushes.Any())
{
int originalWidth = brush.Image.Width;
int originalHeight = brush.Image.Height;
foreach (SampledBrush item in scaledBrushes.OrderByDescending(p => p.Diameter))
{
Size size = Utils.ComputeBrushSize(originalWidth, originalHeight, item.Diameter);
AbrBrush scaledBrush = new AbrBrush(size.Width, size.Height, item.Name);
using (Graphics gr = Graphics.FromImage(scaledBrush.Image))
{
gr.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
gr.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
gr.DrawImage(brush.Image, 0, 0, size.Width, size.Height);
}
brushes.Add(scaledBrush);
}
}
}
long remaining = endOffset - reader.Position;
// Skip any remaining bytes until the next sampled brush.
if (remaining > 0)
{
reader.Position += remaining;
}
}
}
return(new AbrBrushCollection(brushes));
}