class HT_Extent

class HT_Extent_Metrics

This class provides the data which tells the application the ascent, descent, leading and trailing spaces in the

extent_metrics

returned by the

get_text_extent

method of class

HT_Font_Engine

. The extent metrics in addition returns the widths of each character in the string, which is useful for the application to do text layout and formatting.

For more information on implementing fonts, including code examples, see chapter 5, "The Font Engine."

See Also HT_Font_Engine::get_text_extent, Synopsis

 class HT_Extent_Metrics {
    public:
        float           m_ascent;
        float           m_descent;
        float           m_leading_space;
        float           m_trailing_space;
        float *         m_character_widths;

        HT_Extent_Metrics ():
            m_character_widths (null) {}
};

Constructor

HT_Extent_Metrics

Creates an HT_Extent_Metrics object.