index
for a
gradient pattern. Values of index
are 0 to 1 less than the number
returned by cairoPatternGetColorStopCount
.cairoPatternGetColorStopRgba(pattern, index)
pattern
index
CairoStatus
] CAIRO_STATUS_SUCCESS
, or CAIRO_STATUS_INVALID_INDEX
if index
is not valid for the given pattern. If the pattern is
not a gradient pattern, CAIRO_STATUS_PATTERN_TYPE_MISMATCH
is
returned.offset
NULL
red
NULL
green
NULL
blue
NULL
alpha
NULL