Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Matrix Functions /

TransformRect

The TransformRect function allows your application to transform the upper-left and lower-right points of a rectangle through a specified matrix.

pascal Boolean TransformRect (MatrixRecordPtr m, Rect *r, 
                              FixedPoint *fpp);

m

Specifies the matrix for this operation.

r

Contains a pointer to the structure that defines the rectangle to be transformed. The TransformRect function returns the updated coordinates into the structure referred to by this parameter. If the resulting rectangle has been rotated or skewed (that is, the transformation involves operations other than scaling and translation), the function sets the returned Boolean value to false and returns the coordinates of the rectangle that encloses the transformed rectangle. The function then updates the points specified by the fpp parameter to contain the coordinates of the four corners of the transformed rectangle.

fpp

Contains a pointer to an array of four fixed points. The TransformRect function returns the coordinates of the four corners of the rectangle after the transformation operation.

If you do not want this information, set this parameter to nil.

DESCRIPTION

The TransformRect function returns a Boolean value indicating the nature of the result rectangle. If the matrix defines transformations other than translation and scaling, the TransformRect function sets the returned value to false, updates the rectangle specified by the r parameter to define the boundary box of the resulting rectangle, and places the coordinates of the corners of the resulting rectangle in the points specified by the fpp parameter. If the transformed rectangle and its boundary box are the same, the function sets the returned value to true.

ERROR CODES

None