pango:matrix-transform-pixel-rectangle (matrix rect)

matrix -- a pango:matrix instance
rect -- a pango:rectangle instance

The transformed pango:rectangle instance with the bounding box.

First transforms rect using matrix, then calculates the bounding box of the transformed rectangle. The rectangle should be in device units (pixels). This function is useful for example when you want to draw a rotated pango:layout object to an image buffer, and want to know how large the image should be and how much you should shift the layout when rendering.

For better accuracy, you should use the pango:matrix-transform-rectangle function on the original rectangle in Pango units and convert to pixels afterward using the pango:extents-to-pixels functions first argument.