func (this *WaterMarkProcessor) Process(img *img4g.Image) error {
l4g.Debug("process watermark")
var err error = nil
tran := this.Cat.NewTransaction(Image, "Watermark")
defer func() {
this.Logo.DestoryWand()
tran.SetStatus(err)
tran.Complete()
}()
this.Logo.CreateWand()
if this.Location == 0 {
this.Location = 9
}
if this.Location < 1 || this.Location > 9 {
err = errors.New("Logo location(" + string(this.Location) + ") isn't right!")
return err
}
var x, y int64
x, y, err = getLocation(this.Location, img, this.Logo)
if err != nil {
return err
}
if this.Dissolve > 0 && this.Dissolve < 100 {
this.Logo.Dissolve(this.Dissolve)
}
err = img.Composite(this.Logo, x, y)
return err
}