/// <summary>
/// Returns a list of all keyframe data belonging to this specific layer.
/// </summary>
/// <param name="layer">The layer to get the keyframes for.</param>
/// <param name="header">Header of the file from which the keyframes are sourced.</param>
/// <param name="keySpan">The buffer to place the keyframes in.</param>
/// <returns>The supplied buffer, sliced.</returns>
public static unsafe Span <BlittablePointer <Keyframe> > GetKeyFrames(Layer *layer, MetadataHeader *header, Span <BlittablePointer <Keyframe> > keySpan)
{
int remainingFrames = layer->NumKeyframes;
var currentPointer = (byte *)(layer + 1);
int numItems = 0;
if (layer->MaybeAnimationDurationFrames <= 0 && remainingFrames <= 0)
{
return(keySpan.Slice(0, numItems));
}
while (remainingFrames > 1)
{
var keyFramePtr = (Keyframe *)currentPointer;
var keyFrameLength = Keyframe.GetKeyframeSize(keyFramePtr, layer, header);
var keyFrameType = (short)(keyFramePtr->KeyframeType & (KeyframeType)0x7FFF);
keySpan[numItems++] = keyFramePtr;
// Animation ends if no duration, unless keyframes type 0/1
if (keyFramePtr->AnimationActivationPointFrames < 1 && keyFrameType != 0 && keyFrameType != 1)
{
break;
}
remainingFrames--;
currentPointer += keyFrameLength;
}
return(keySpan.Slice(0, numItems));
}
/// <summary>
/// Gets the size of this keyframe, in bytes.
/// </summary>
/// <param name="keyframe">The keyframe for which to get the size for.</param>
/// <param name="layer">The layer in question.</param>
/// <param name="header">The header.</param>
/// <returns></returns>
public static unsafe int GetKeyframeSize(Keyframe *keyframe, Layer *layer, MetadataHeader *header)
{
switch ((keyframe->KeyframeType & (KeyframeType)0x7FFF))
{
default:
case KeyframeType.HalfByteCount:
return(layer->NumBytes + sizeof(Keyframe)); // +8 may be an error here, but parses existing files.
case KeyframeType.SizeFromHeader:
return(header->AnimationType1Offset * 4); // Typically 0x14 * 4
case KeyframeType.SizeFromSameStructSimpleHeader:
case KeyframeType.SizeFromSameStructComplexHeader:
return(keyframe->NumberOfBytesDivBy4 * 4);
}
}
/// <summary>
/// Gets the individual data items for a given keyframe.
/// </summary>
/// <param name="keyframe">Pointer to the keyframe in question.</param>
/// <param name="layer">Pointer to the layer in question.</param>
/// <param name="header">Pointer to the archive header.</param>
/// <param name="stack">Preallocated stack memory. Recommend 32 items.</param>
/// <returns></returns>
public unsafe Span <DataHeaderWrapper> GetData(Keyframe *keyframe, Layer *layer, MetadataHeader *header, Span <DataHeaderWrapper> stack)
{
// Invalid.
if (keyframe->NumberOfChangedProperties < 0)
{
return(stack.Slice(0, 0));
}
var keyframeType = (keyframe->KeyframeType & (KeyframeType)0x7FFF);
switch (keyframeType)
{
default:
case KeyframeType.HalfByteCount: // 0
{
var result = new DataHeaderWrapper()
{
DataType = DataHeaderWrapper.InvalidDataType,
NumBytes = layer->NumBytes,
DataPtr = (byte *)(keyframe + 1)
};
stack[0] = result;
return(stack.Slice(0, 1));
}
case KeyframeType.SizeFromHeader: // 1
{
var result = new DataHeaderWrapper()
{
DataType = DataHeaderWrapper.InvalidDataType,
NumBytes = (short)(header->AnimationType1Offset * 4),
DataPtr = (byte *)(keyframe + 1)
};
stack[0] = result;
return(stack.Slice(0, 1));
}
case KeyframeType.SizeFromSameStructSimpleHeader: // 2
{
var headersPtr = (Type2DataHeader *)(keyframe + 1);
var valuesOffset = ((keyframe->NumberOfBytesDivBy4 - keyframe->NumberOfChangedProperties) * 4);
var valuesPtr = (int *)((byte *)keyframe + valuesOffset);
for (int x = 0; x < keyframe->NumberOfChangedProperties; x++)
{
stack[x] = new DataHeaderWrapper()
{
DataType = headersPtr->DataType,
NumBytes = sizeof(int),
DataPtr = (byte *)valuesPtr,
};
valuesPtr++;
headersPtr++;
}
return(stack.Slice(0, keyframe->NumberOfChangedProperties));
}
case KeyframeType.SizeFromSameStructComplexHeader: // 3
{
var headersPtr = (Type3DataHeader *)(keyframe + 1);
var valuesOffset = (keyframe->NumberOfChangedProperties * sizeof(Type3DataHeader));
var valuesPtr = (byte *)headersPtr + valuesOffset;
for (int x = 0; x < keyframe->NumberOfChangedProperties; x++)
{
stack[x] = new DataHeaderWrapper()
{
DataType = headersPtr->DataType,
NumBytes = headersPtr->NumBytes,
DataPtr = valuesPtr,
};
valuesPtr += headersPtr->NumBytes;
headersPtr++;
}
return(stack.Slice(0, keyframe->NumberOfChangedProperties));
}
}
}