/// <summary>
/// Writes the graphics control extension to the stream.
/// </summary>
/// <param name="metaData">The metadata of the image or frame.</param>
/// <param name="writer">The stream to write to.</param>
/// <param name="transparencyIndex">The index of the color in the color palette to make transparent.</param>
private void WriteGraphicalControlExtension(ImageFrameMetaData metaData, EndianBinaryWriter writer, int transparencyIndex)
{
var extension = new GifGraphicsControlExtension
{
DisposalMethod = metaData.DisposalMethod,
TransparencyFlag = transparencyIndex > -1,
TransparencyIndex = unchecked ((byte)transparencyIndex),
DelayTime = metaData.FrameDelay
};
// Write the intro.
this.buffer[0] = GifConstants.ExtensionIntroducer;
this.buffer[1] = GifConstants.GraphicControlLabel;
this.buffer[2] = 4;
writer.Write(this.buffer, 0, 3);
var field = default(PackedField);
field.SetBits(3, 3, (int)extension.DisposalMethod); // 1-3 : Reserved, 4-6 : Disposal
// TODO: Allow this as an option.
field.SetBit(6, false); // 7 : User input - 0 = none
field.SetBit(7, extension.TransparencyFlag); // 8: Has transparent.
writer.Write(field.Byte);
writer.Write((ushort)extension.DelayTime);
writer.Write(extension.TransparencyIndex);
writer.Write(GifConstants.Terminator);
}
private void EncodeGlobal <TPixel>(Image <TPixel> image, QuantizedFrame <TPixel> quantized, int transparencyIndex, Stream stream)
where TPixel : struct, IPixel <TPixel>
{
var palleteQuantizer = new PaletteQuantizer(this.quantizer.Diffuser);
for (int i = 0; i < image.Frames.Count; i++)
{
ImageFrame <TPixel> frame = image.Frames[i];
ImageFrameMetaData metaData = frame.MetaData;
GifFrameMetaData frameMetaData = metaData.GetFormatMetaData(GifFormat.Instance);
this.WriteGraphicalControlExtension(frameMetaData, transparencyIndex, stream);
this.WriteImageDescriptor(frame, false, stream);
if (i == 0)
{
this.WriteImageData(quantized, stream);
}
else
{
using (QuantizedFrame <TPixel> paletteQuantized
= palleteQuantizer.CreateFrameQuantizer(image.GetConfiguration(), () => quantized.Palette).QuantizeFrame(frame))
{
this.WriteImageData(paletteQuantized, stream);
}
}
}
}
public void CloneIsDeep()
{
var metaData = new ImageFrameMetaData();
ImageFrameMetaData clone = metaData.DeepClone();
Assert.False(metaData.GetFormatMetaData(GifFormat.Instance).Equals(clone.GetFormatMetaData(GifFormat.Instance)));
}
public void ConstructorImageFrameMetaData()
{
ImageFrameMetaData metaData = new ImageFrameMetaData();
metaData.FrameDelay = 42;
ImageFrameMetaData clone = new ImageFrameMetaData(metaData);
Assert.Equal(42, clone.FrameDelay);
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="width">The width of the image in pixels.</param>
/// <param name="height">The height of the image in pixels.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(int width, int height, ImageFrameMetaData metaData)
{
Guard.MustBeGreaterThan(width, 0, nameof(width));
Guard.MustBeGreaterThan(height, 0, nameof(height));
Guard.NotNull(metaData, nameof(metaData));
this.pixelBuffer = Buffer2D <TPixel> .CreateClean(width, height);
this.MetaData = metaData;
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="memoryManager">The <see cref="MemoryManager"/> to use for buffer allocations.</param>
/// <param name="width">The width of the image in pixels.</param>
/// <param name="height">The height of the image in pixels.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(MemoryManager memoryManager, int width, int height, ImageFrameMetaData metaData)
{
Guard.NotNull(memoryManager, nameof(memoryManager));
Guard.MustBeGreaterThan(width, 0, nameof(width));
Guard.MustBeGreaterThan(height, 0, nameof(height));
Guard.NotNull(metaData, nameof(metaData));
this.MemoryManager = memoryManager;
this.PixelBuffer = memoryManager.AllocateClean2D <TPixel>(width, height);
this.MetaData = metaData;
}
public void ConstructorImageFrameMetaData()
{
ImageFrameMetaData metaData = new ImageFrameMetaData();
metaData.FrameDelay = 42;
metaData.DisposalMethod = DisposalMethod.RestoreToBackground;
ImageFrameMetaData clone = new ImageFrameMetaData(metaData);
Assert.Equal(42, clone.FrameDelay);
Assert.Equal(DisposalMethod.RestoreToBackground, clone.DisposalMethod);
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class wrapping an existing buffer.
/// </summary>
internal ImageFrame(
Configuration configuration,
int width,
int height,
IBuffer <TPixel> consumedBuffer,
ImageFrameMetaData metaData)
{
Guard.NotNull(configuration, nameof(configuration));
Guard.MustBeGreaterThan(width, 0, nameof(width));
Guard.MustBeGreaterThan(height, 0, nameof(height));
Guard.NotNull(metaData, nameof(metaData));
this.configuration = configuration;
this.MemoryAllocator = configuration.MemoryAllocator;
this.PixelBuffer = new Buffer2D <TPixel>(consumedBuffer, width, height);
this.MetaData = metaData;
}
public void ConstructorImageFrameMetaData()
{
const int frameDelay = 42;
const int colorTableLength = 128;
const GifDisposalMethod disposalMethod = GifDisposalMethod.RestoreToBackground;
var metaData = new ImageFrameMetaData();
GifFrameMetaData gifFrameMetaData = metaData.GetFormatMetaData(GifFormat.Instance);
gifFrameMetaData.FrameDelay = frameDelay;
gifFrameMetaData.ColorTableLength = colorTableLength;
gifFrameMetaData.DisposalMethod = disposalMethod;
var clone = new ImageFrameMetaData(metaData);
GifFrameMetaData cloneGifFrameMetaData = clone.GetFormatMetaData(GifFormat.Instance);
Assert.Equal(frameDelay, cloneGifFrameMetaData.FrameDelay);
Assert.Equal(colorTableLength, cloneGifFrameMetaData.ColorTableLength);
Assert.Equal(disposalMethod, cloneGifFrameMetaData.DisposalMethod);
}
private void EncodeLocal <TPixel>(Image <TPixel> image, QuantizedFrame <TPixel> quantized, Stream stream)
where TPixel : struct, IPixel <TPixel>
{
ImageFrame <TPixel> previousFrame = null;
GifFrameMetaData previousMeta = null;
foreach (ImageFrame <TPixel> frame in image.Frames)
{
ImageFrameMetaData metaData = frame.MetaData;
GifFrameMetaData frameMetaData = metaData.GetFormatMetaData(GifFormat.Instance);
if (quantized is null)
{
// Allow each frame to be encoded at whatever color depth the frame designates if set.
if (previousFrame != null && previousMeta.ColorTableLength != frameMetaData.ColorTableLength &&
frameMetaData.ColorTableLength > 0)
{
quantized = this.quantizer.CreateFrameQuantizer <TPixel>(
image.GetConfiguration(),
frameMetaData.ColorTableLength).QuantizeFrame(frame);
}
else
{
quantized = this.quantizer.CreateFrameQuantizer <TPixel>(image.GetConfiguration())
.QuantizeFrame(frame);
}
}
this.bitDepth = ImageMaths.GetBitsNeededForColorDepth(quantized.Palette.Length).Clamp(1, 8);
this.WriteGraphicalControlExtension(frameMetaData, this.GetTransparentIndex(quantized), stream);
this.WriteImageDescriptor(frame, true, stream);
this.WriteColorTable(quantized, stream);
this.WriteImageData(quantized, stream);
quantized?.Dispose();
quantized = null; // So next frame can regenerate it
previousFrame = frame;
previousMeta = frameMetaData;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
/// <param name="size">The <see cref="Size"/> of the frame.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(Configuration configuration, Size size, ImageFrameMetaData metaData)
: this(configuration, size.Width, size.Height, metaData)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrameMetaData"/> class
/// by making a copy from other metadata.
/// </summary>
/// <param name="other">
/// The other <see cref="ImageFrameMetaData"/> to create this instance from.
/// </param>
internal ImageFrameMetaData(ImageFrameMetaData other)
{
DebugGuard.NotNull(other, nameof(other));
this.FrameDelay = other.FrameDelay;
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="configuration">The <see cref="Configuration"/> to use for buffer allocation and parallel options to clear the buffer with.</param>
/// <param name="width">The width of the image in pixels.</param>
/// <param name="height">The height of the image in pixels.</param>
/// <param name="backgroundColor">The color to clear the image with.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(Configuration configuration, int width, int height, TPixel backgroundColor, ImageFrameMetaData metaData)
{
Guard.NotNull(configuration, nameof(configuration));
Guard.MustBeGreaterThan(width, 0, nameof(width));
Guard.MustBeGreaterThan(height, 0, nameof(height));
Guard.NotNull(metaData, nameof(metaData));
this.MemoryManager = configuration.MemoryManager;
this.PixelBuffer = this.MemoryManager.Allocate2D <TPixel>(width, height, false);
this.Clear(configuration.ParallelOptions, backgroundColor);
this.MetaData = metaData;
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="size">The <see cref="Size"/> of the frame.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(Size size, ImageFrameMetaData metaData)
: this(size.Width, size.Height, metaData)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
/// <param name="width">The width of the image in pixels.</param>
/// <param name="height">The height of the image in pixels.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(Configuration configuration, int width, int height, ImageFrameMetaData metaData)
: this(configuration, width, height, default(TPixel), metaData)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
/// <param name="width">The width of the image in pixels.</param>
/// <param name="height">The height of the image in pixels.</param>
/// <param name="backgroundColor">The color to clear the image with.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(Configuration configuration, int width, int height, TPixel backgroundColor, ImageFrameMetaData metaData)
{
Guard.NotNull(configuration, nameof(configuration));
Guard.MustBeGreaterThan(width, 0, nameof(width));
Guard.MustBeGreaterThan(height, 0, nameof(height));
this.configuration = configuration;
this.MemoryAllocator = configuration.MemoryAllocator;
this.PixelBuffer = this.MemoryAllocator.Allocate2D <TPixel>(width, height);
this.MetaData = metaData ?? new ImageFrameMetaData();
this.Clear(configuration.GetParallelOptions(), backgroundColor);
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="memoryManager">The <see cref="MemoryManager"/> to use for buffer allocations.</param>
/// <param name="size">The <see cref="Size"/> of the frame.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(MemoryManager memoryManager, Size size, ImageFrameMetaData metaData)
: this(memoryManager, size.Width, size.Height, metaData)
{
}
