Sets the source pattern within cr to a translucent color. This color will then be used for any subsequent drawing operation until a new source pattern is set. The color and alpha 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_rgba(cr, 0.0, 0.0, 0.0, 1.0)). Since 1.0

class Context
double red
double green
double blue
double alpha


red double

red component of color

green double

green component of color

blue double

blue component of color

alpha double

alpha component of color