Sets the source pattern within cr to an opaque color. This opaque
color will then be used for any subsequent drawing operation until
a new source pattern is set.
The color components are floating point numbers in the range 0 to
1. If the values passed in are outside that range, they will be
clamped.
The default source pattern is opaque black, (that is, it is
equivalent to cairo_set_source_rgb(cr, 0.0, 0.0, 0.0)).
Since 1.0
Sets the source pattern within cr to an opaque color. This opaque color will then be used for any subsequent drawing operation until a new source pattern is set. The color components are floating point numbers in the range 0 to 1. If the values passed in are outside that range, they will be clamped. The default source pattern is opaque black, (that is, it is equivalent to cairo_set_source_rgb(cr, 0.0, 0.0, 0.0)). Since 1.0