IDCompositionAnimation::AddCubic method

Adds a cubic polynomial segment to the animation function.

Syntax


HRESULT AddCubic(
  [in]  double beginOffset,
  [in]  float constantCoefficient,
  [in]  float linearCoefficient,
  [in]  float quadraticCoefficient,
  [in]  float cubicCoefficient
);

Parameters

beginOffset [in]

Type: double

The offset, in seconds, from the beginning of the animation function to the point when this segment should take effect.

constantCoefficient [in]

Type: float

The constant coefficient of the polynomial.

linearCoefficient [in]

Type: float

The linear coefficient of the polynomial.

quadraticCoefficient [in]

Type: float

The quadratic coefficient of the polynomial.

cubicCoefficient [in]

Type: float

The cubic coefficient of the polynomial.

Return value

Type: HRESULT

If the function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code. See DirectComposition Error Codes for a list of error codes.

Remarks

A cubic segment transitions time along a cubic polynomial. For a given time input (t), the output value is given by the following equation.

x(t) = at3 + bt2 + ct + d

This method fails if any of the parameters are NaN, positive infinity, or negative infinity.

Because animation segments must be added in increasing order, this method fails if the beginOffset parameter is less than or equal to the beginOffset parameter of the previous segment, if any.

This animation segment remains in effect until the begin time of the next segment in the animation function. If the animation function contains no more segments, this segment remains in effect indefinitely.

If all coefficients except constantCoefficient are zero, the value of this segment remains constant over time, and the animation does not cause a recomposition for the duration of the segment.

Examples

The following example creates an animation function with two cubic polynomial segments.


HRESULT DoAnimatedRotation(IDCompositionDevice *pDevice,
                           IDCompositionRotateTransform *pRotateTransform,
                           IDCompositionVisual *pVisual, 
                           float animationTime) 
{
    HRESULT hr = S_OK;
    IDCompositionAnimation *pAnimation = nullptr;

    // Create an animation object. 
    hr = pDevice->CreateAnimation(&pAnimation);

    if (SUCCEEDED(hr)) 
    {
        // Create the animation function by adding cubic polynomial segments.
        // For a given time input (t), the output value is
        // a*t^3 + b* t^2 + c*t + d.
        // 
        // The following segment will rotate the visual clockwise.
        pAnimation->AddCubic(
            0.0,                                // Begin offset
            0.0,                                // Constant coefficient - d
            (360.0f * 1.0f) / animationTime,    // Linear coefficient - c
            0.0,                                // Quadratic coefficient - b
            0.0);                               // Cubic coefficient - a

        // The following segment will rotate the visual counterclockwise.
        pAnimation->AddCubic(
            animationTime,
            0.0,
            -(360.0f * 1.0f) / animationTime,
            0.0,
            0.0);

        // Set the end of the animation.
        pAnimation->End(
            2 * animationTime,  // End offset
            0.0);               // End value

        // Apply the animation to the Angle property of the
        // rotate transform. 
        hr = pRotateTransform->SetAngle(pAnimation);
    }

    if (SUCCEEDED(hr))
    {
        // Apply the rotate transform object to a visual.
        hr = pVisual->SetTransform(pRotateTransform);
    }

    if (SUCCEEDED(hr))
    {
        // Commit the changes to the composition.
        hr = pDevice->Commit();
    }

    SafeRelease(&pAnimation);

    return hr;
}


Requirements

Minimum supported client

Windows 8 [desktop apps only]

Minimum supported server

Windows Server 2012 [desktop apps only]

Header

DcompAnimation.h

IDL

DcompAnimation.idl

Library

Dcomp.lib

DLL

Dcomp.dll

See also

Animation
IDCompositionAnimation

 

 

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