cairoShowTextGlyphs: cairoShowTextGlyphs
Description
This operation has rendering effects similar to cairoShowGlyphs
but, if the target surface supports it, uses the provided text and
cluster mapping to embed the text for the glyphs shown in the output.
If the target does not support the extended attributes, this function
acts like the basic cairoShowGlyphs as if it had been passed
glyphs and num.glyphs.Usage
cairoShowTextGlyphs(cr, utf8, glyphs, clusters, cluster.flags)
Arguments
utf8
[char] a string of text encoded in UTF-8
Details
The mapping between utf8 and glyphs is provided by a list of
clusters. Each cluster covers a number of
text bytes and glyphs, and neighboring clusters cover neighboring
areas of utf8 and glyphs. The clusters should collectively cover utf8
and glyphs in entirety.
The first cluster always covers bytes from the beginning of utf8.
If cluster.flags do not have the CAIRO_TEXT_CLUSTER_FLAG_BACKWARD
set, the first cluster also covers the beginning
of glyphs, otherwise it covers the end of the glyphs list and
following clusters move backward.
See CairoTextCluster for constraints on valid clusters.
Since 1.8