private static byte[] Parse(int scanlineLength, int scanlineCount, byte[] pureData, int bytesPerPixel, PngFileHeader header, ColorReader reader, int bytesPerPixelOutput)
{
var width = (int)header.Size.X;
var height = (int)header.Size.Y;
var pixels = new byte[width * height * bytesPerPixelOutput];
int length = scanlineLength - 1;
var data = new Span <byte>(pureData);
// Analyze if the scanlines can be read in parallel.
byte filterMode = data[0];
for (var i = 0; i < scanlineCount; i++)
{
byte f = data[scanlineLength * i];
if (f == filterMode)
{
continue;
}
filterMode = byte.MaxValue;
break;
}
// Multiple filters or a dependency filter are in affect.
if (filterMode == byte.MaxValue || filterMode != 0 && filterMode != 1)
{
if (scanlineCount >= 1500)
{
Engine.Log.Trace("Loaded a big PNG with scanlines which require filtering. If you re-export it without filters, it will load faster.", MessageSource.ImagePng);
}
PerfProfiler.ProfilerEventStart("PNG Parse Sequential", "Loading");
var readOffset = 0;
var previousScanline = Span <byte> .Empty;
for (var i = 0; i < scanlineCount; i++)
{
// Early out for invalid data.
if (data.Length - readOffset < scanlineLength)
{
break;
}
Span <byte> scanline = data.Slice(readOffset + 1, length);
int filter = data[readOffset];
ApplyFilter(scanline, previousScanline, filter, bytesPerPixel);
reader(width, ConvertBitArray(scanline, header), pixels, i);
previousScanline = scanline;
readOffset += scanlineLength;
}
PerfProfiler.ProfilerEventEnd("PNG Parse Sequential", "Loading");
return(pixels);
}
// Single line filter
if (filterMode == 1)
{
PerfProfiler.ProfilerEventStart("PNG Parse Threaded", "Loading");
ParallelWork.FastLoops(scanlineCount, (start, end) =>
{
int readOffset = start * scanlineLength;
for (int i = start; i < end; i++)
{
// Early out for invalid data.
if (pureData.Length - readOffset < scanlineLength)
{
break;
}
Span <byte> scanline = new Span <byte>(pureData).Slice(readOffset + 1, length);
for (int j = bytesPerPixel; j < scanline.Length; j++)
{
scanline[j] = (byte)(scanline[j] + scanline[j - bytesPerPixel]);
}
reader(width, ConvertBitArray(scanline, header), pixels, i);
readOffset += scanlineLength;
}
}).Wait();
PerfProfiler.ProfilerEventEnd("PNG Parse Threaded", "Loading");
}
// No filter!
// ReSharper disable once InvertIf
if (filterMode == 0)
{
PerfProfiler.ProfilerEventStart("PNG Parse Threaded", "Loading");
ParallelWork.FastLoops(scanlineCount, (start, end) =>
{
int readOffset = start * scanlineLength;
for (int i = start; i < end; i++)
{
// Early out for invalid data.
if (pureData.Length - readOffset < scanlineLength)
{
break;
}
Span <byte> row = ConvertBitArray(new Span <byte>(pureData).Slice(readOffset + 1, length), header);
reader(width, row, pixels, i);
readOffset += scanlineLength;
}
}).Wait();
PerfProfiler.ProfilerEventEnd("PNG Parse Threaded", "Loading");
}
return(pixels);
}
private static void Parse(byte[] data, PngFileHeader fileHeader, int bytesPerPixel, IColorReader reader, byte[] pixels)
{
// Find the scan line length.
int scanlineLength = GetScanlineLength(fileHeader.Width, fileHeader) + 1;
int scanLineCount = data.Length / scanlineLength;
// Run through all scanlines.
var cannotParallel = new List <int>();
ParallelWork.FastLoops(scanLineCount, (start, end) =>
{
int readOffset = start * scanlineLength;
for (int i = start; i < end; i++)
{
// Early out for invalid data.
if (data.Length - readOffset < scanlineLength)
{
break;
}
// Get the current scanline.
var rowData = new Span <byte>(data, readOffset + 1, scanlineLength - 1);
int filter = data[readOffset];
readOffset += scanlineLength;
// Check if it has a filter.
// PNG filters require the previous row.
// We can't do those in parallel.
if (filter != 0)
{
lock (cannotParallel)
{
cannotParallel.Add(i);
}
continue;
}
reader.ReadScanline(rowData, pixels, fileHeader, i);
}
}).Wait();
if (cannotParallel.Count == 0)
{
return;
}
PerfProfiler.ProfilerEventStart("PNG Parse Sequential", "Loading");
// Run scanlines which couldn't be parallel processed.
if (scanLineCount >= 2000)
{
Engine.Log.Trace("Loaded a big PNG with scanlines which require filtering. If you re-export it without that, it will load faster.", MessageSource.ImagePng);
}
cannotParallel.Sort();
for (var i = 0; i < cannotParallel.Count; i++)
{
int idx = cannotParallel[i];
int rowStart = idx * scanlineLength;
Span <byte> prevRowData = idx == 0 ? null : new Span <byte>(data, (idx - 1) * scanlineLength + 1, scanlineLength - 1);
var rowData = new Span <byte>(data, rowStart + 1, scanlineLength - 1);
// Apply filter to the whole row.
int filter = data[rowStart];
for (var column = 0; column < rowData.Length; column++)
{
rowData[column] = ApplyFilter(rowData, prevRowData, filter, column, bytesPerPixel);
}
reader.ReadScanline(rowData, pixels, fileHeader, idx);
}
PerfProfiler.ProfilerEventEnd("PNG Parse Sequential", "Loading");
}
public static Glyph[] ParseGlyf(ByteReader reader, int[] locaOffsets)
{
var glyphs = new Glyph[locaOffsets.Length - 1];
// Go through all glyphs and resolve them, leaving composite glyphs for later.
var compositeGlyphParse = new List <CompositeGlyphRequest>();
ParallelWork.FastLoops(glyphs.Length, (start, end) =>
{
for (int i = start; i < end; i++)
{
var current = new Glyph();
glyphs[i] = current;
if (i > locaOffsets.Length)
{
continue;
}
int glyphOffset = locaOffsets[i];
int nextOffset = locaOffsets[i + 1];
// No data for glyph.
if (glyphOffset == nextOffset || glyphOffset >= reader.Data.Length)
{
current.Vertices = new GlyphVertex[0];
continue;
}
ByteReader glyphData = reader.Branch(glyphOffset, true);
int numberOfContours = glyphData.ReadShortBE();
current.XMin = glyphData.ReadShortBE();
current.YMin = glyphData.ReadShortBE();
current.XMax = glyphData.ReadShortBE();
current.YMax = glyphData.ReadShortBE();
// Non-composite
if (numberOfContours > 0)
{
ResolveTtfGlyph(numberOfContours, glyphData, current);
}
// Composite
else if (numberOfContours == -1)
{
lock (compositeGlyphParse)
{
compositeGlyphParse.Add(new CompositeGlyphRequest(glyphData, current));
}
}
// 0 is an invalid value.
}
}).Wait();
// ReSharper disable once ImplicitlyCapturedClosure
ParallelWork.FastLoops(compositeGlyphParse.Count, (start, end) =>
{
for (int i = start; i < end; i++)
{
CompositeGlyphRequest request = compositeGlyphParse[i];
ResolveCompositeTtfGlyph(request.Reader, request.Glyph, glyphs);
}
});
Debug.Assert(glyphs.All(x => x != null));
return(glyphs);
}
