AddStroke function
Adds an ink stroke to the RecognizerContext.
Syntax
HRESULT WINAPI 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 |
|---|---|
|
Success. |
|
One of the parameters is an invalid pointer. |
|
Unable to allocate memory to complete the operation. |
|
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. |
|
The call to the method was made out of order. |
|
An unspecified error occurred. |
|
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
|
Minimum supported client |
Windows XP Tablet PC Edition [desktop apps only] |
|---|---|
|
Minimum supported server |
None supported |
|
Header |
|
See also