AddStroke function (recapis.h)

Adds an ink stroke to the RecognizerContext.

Syntax

HRESULT AddStroke(
  HRECOCONTEXT             hrc,
  const PACKET_DESCRIPTION *pPacketDesc,
  ULONG                    cbPacket,
  const BYTE               *pPacket,
  const XFORM              *pXForm
);

Parameters

hrc

The handle to the recognizer context.

pPacketDesc

Describes the contents of the packets. The description must match the contents of the packets in pPacket. If NULL, this function uses the GetPreferredPacketDescription function.

cbPacket

Size, in bytes, of the pPacket buffer.

pPacket

Array of packets that contain tablet space coordinates.

pXForm

Describes the transform that can be applied to ink to transform it from tablet space into ink space. A recognizer may choose to ignore this transform and implement their own ink rotation algorithms. These recognizers should still return properties calculated in the lattice data relative to this transform.

Return value

This function can return one of these values.

Return code	Description
S_OK	Success.
E_POINTER	One of the parameters is an invalid pointer.
E_OUTOFMEMORY	Unable to allocate memory to complete the operation.
TPC_E_INVALID_PACKET_DESCRIPTION	The packet description does not contain the necessary information for the packet to be considered valid. For example, it does not include a GUID_X or GUID_Y property.
TPC_E_OUT_OF_ORDER_CALL	The call to the method was made out of order.
E_FAIL	An unspecified error occurred.
E_INVALIDARG	An invalid argument was received.

Remarks

The recognizer must return properties such as Baseline in ink space coordinates rather than tablet coordinates.

It is recommended that your recognizer place a limit on the number of strokes per context and/or the points allowed in a given stroke. Limit input to 1024 strokes per context and 32767 points per stroke.

Strokes with zero points are not allowed. You should return E_FAIL in such a case.

Requirements

Requirement	Value
Minimum supported client	Windows XP Tablet PC Edition [desktop apps | UWP apps]
Minimum supported server	None supported
Target Platform	Windows
Header	recapis.h
DLL	inkobjcore.dll

See also

GetPreferredPacketDescription

PACKET_DESCRIPTION Structure