red component of the color
green component of the color
blue component of the color
alpha component of the color
the newly created cairo_pattern_t if successful, or an error pattern in case of no memory. The caller owns the returned object and should call cairo_pattern_destroy() when finished with it. This function will always return a valid pointer, but if an error occurred the pattern status will be set to an error. To inspect the status of a pattern use cairo_pattern_status().
Creates a new cairo_pattern_t corresponding to a translucent color. 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.