GeezerVison

void
pango_matrix_transform_rectangle (
  const PangoMatrix* matrix,
  PangoRectangle* rect
)

First transforms rect using matrix, then calculates the bounding box of the transformed rectangle.

This function is useful for example when you want to draw a rotated PangoLayout to an image buffer, and want to know how large the image should be and how much you should shift the layout when rendering.

If you have a rectangle in device units (pixels), use pango_matrix_transform_pixel_rectangle().

If you have the rectangle in Pango units and want to convert to transformed pixel bounding box, it is more accurate to transform it first (using this function) and pass the result to pango_extents_to_pixels(), first argument, for an inclusive rounded rectangle. However, there are valid reasons that you may want to convert to pixels first and then transform, for example when the transformed coordinates may overflow in Pango units (large matrix translation for example).

Available since: 1.16

matrix

Type: PangoMatrix

A PangoMatrix.

The argument can be NULL.

rect

Type: PangoRectangle

In/out bounding box in Pango units.

The argument will be modified by the function.

The argument can be NULL.

The caller of the method takes ownership of the returned data, and is responsible for freeing it.