formatStrideForWidth

This function provides a stride value that will respect all alignment requirements of the accelerated image-rendering code within cairo. Typical usage will be of the form:

<informalexample><programlisting>

int stride; unsigned char *data; cairo_surface_t *surface;

stride = cairo_format_stride_for_width (format, width); data = malloc (stride * height); surface = cairo_image_surface_create_for_data (data, format, width, height, stride);

</programlisting></informalexample>

Parameters

format	A #cairo_format_t value
width	The desired width of an image surface to be created.

Returns

the appropriate stride to use given the desired

format and width, or -1 if either the format is invalid or the width too large.