Pango.Matrix.transform_rectangle
Description: Reference for Pango.Matrix.transform_rectangle

### Method

# Pango.Matrix.transform_rectangle

#### Declaration [src]

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

#### Description [src]

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).

#### Parameters

`rect` | `PangoRectangle`
| in/out bounding box in Pango units, or `NULL`
| Direction: in-out
| Ownership of the data is transferred to the callee