LinearGradientBrush::SetTransform method (gdiplusbrush.h)

The LinearGradientBrush::SetTransform method sets the transformation matrix of this linear gradient brush.

Syntax

Status SetTransform(
  [in] const Matrix *matrix
);

Parameters

[in] matrix

Type: const Matrix*

Pointer to a Matrix object that specifies the transformation matrix.

Return value

Type: Status

If the method succeeds, it returns Ok, which is an element of the Status enumeration.

If the method fails, it returns one of the other elements of the Status enumeration.

Remarks

A LinearGradientBrush object has a rectangle that specifies the starting and ending boundaries of the gradient and a mode or angle that affects the direction. If the brush's transformation matrix is set to represent any transformation other than the identity, then the boundaries and direction are transformed according to that matrix during rendering.

The transformation applies only during rendering. The boundaries stored by the LinearGradientBrush object are not altered by the LinearGradientBrush::SetTransform method.

Examples

The following example creates a linear gradient brush and uses it to fill a rectangle. Next, the code modifies the brush's transformation matrix and fills a rectangle with the transformed brush.

VOID Example_SetTransform(HDC hdc)
{
   Graphics myGraphics(hdc);

   LinearGradientBrush linGrBrush( 
      Rect(0, 0, 100, 50),
      Color(255, 255, 0, 0),  // red
      Color(255, 0, 0, 255),  // blue
      LinearGradientModeHorizontal);

   Matrix matrix(2.0, 0, 0, 1, 0, 0);  // horizontal doubling

   // Fill a large area with the linear gradient brush (no transformation).
   myGraphics.FillRectangle(&linGrBrush, 0, 0, 800, 50);

   linGrBrush.SetTransform(&matrix);

   // Fill a large area with the transformed linear gradient brush.
   myGraphics.FillRectangle(&linGrBrush, 0, 75, 800, 50);
}

Requirements

See also

Brushes and Filled Shapes

Creating a Linear Gradient

Filling Shapes with a Gradient Brush

LinearGradientBrush

LinearGradientBrush::GetTransform

LinearGradientBrush::ResetTransform

Matrix

Matrix Representation of Transformations

Rect

Transformations