func (i *Image) SetColor(col ...float64) {
var r, g, b, a C.double = 0, 0, 0, 1
// Single channel, use alpha
if len(col) == 1 {
if i.ColorSpace == MODE_A8 {
// When using alphas, draw on alpha
a = C.double(col[0])
} else if i.ColorSpace == MODE_G8 {
// When using grayscale, draw RGB
r = C.double(col[0])
g = r
b = r
}
} else if len(col) >= 3 {
r, g, b = C.double(col[0]), C.double(col[1]), C.double(col[2])
}
if len(col) == 4 {
a = C.double(col[3])
}
C.cairo_set_source_rgba(i.Ctx, r, g, b, a)
}
func (self *Surface) SetSourceRGBA(red, green, blue, alpha float64) {
C.cairo_set_source_rgba(self.context, C.double(red), C.double(green), C.double(blue), C.double(alpha))
}
// SetSourceRGBA is a wrapper around cairo_set_source_rgba().
func (v *Context) SetSourceRGBA(red, green, blue, alpha float64) {
C.cairo_set_source_rgba(v.native(), C.double(red), C.double(green),
C.double(blue), C.double(alpha))
}
//SetSourceColor sets the source pattern to col.
//This color will be used for any subsequent drawing operations, until a new
//source pattern is set.
//
//Originally cairo_set_source_rgba.
func (c *Context) SetSourceColor(col color.Color) *Context {
r, g, b, a := colorToAlpha(col).c()
C.cairo_set_source_rgba(c.c, r, g, b, a)
return c
}