ID2D1Geometry::ComputePointAtLength(FLOAT,constD2D1_MATRIX_3X2_F*,D2D1_POINT_2F*,D2D1_POINT_2F*) method (d2d1.h)
Calculates the point and tangent vector at the specified distance along the geometry after it has been transformed by the specified matrix and flattened using the default tolerance.
Syntax
HRESULT ComputePointAtLength(
FLOAT length,
const D2D1_MATRIX_3X2_F *worldTransform,
D2D1_POINT_2F *point,
D2D1_POINT_2F *unitTangentVector
);
Parameters
length
Type: [in] FLOAT
The distance along the geometry of the point and tangent to find. If this distance is less than 0, this method calculates the first point in the geometry. If this distance is greater than the length of the geometry, this method calculates the last point in the geometry.
worldTransform
Type: [in, optional] const D2D1_MATRIX_3X2_F*
The transform to apply to the geometry before calculating the specified point and tangent, or NULL.
point
Type: [out, optional] D2D1_POINT_2F*
The location at the specified distance along the geometry. If the geometry is empty, this point contains NaN as its x and y values.
unitTangentVector
Type: [out, optional] D2D1_POINT_2F*
The tangent vector at the specified distance along the geometry. If the geometry is empty, this vector contains NaN as its x and y values.
Return value
Type: HRESULT
If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows 7, Windows Vista with SP2 and Platform Update for Windows Vista [desktop apps | UWP apps] |
Minimum supported server | Windows Server 2008 R2, Windows Server 2008 with SP2 and Platform Update for Windows Server 2008 [desktop apps | UWP apps] |
Target Platform | Windows |
Header | d2d1.h |
Library | D2d1.lib |
DLL | D2d1.dll |
See also
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