// Copies a drawing surface to the canvas.
func (self *Canvas) Update() error {
success := C.MagickDrawImage(self.wand, self.drawing)
if success == C.MagickFalse {
return fmt.Errorf("Could not update image: %s", self.Error())
}
return nil
}
func (self *Canvas) DrawAnnotation(content string, width, height uint) error {
ccontent := C.CString("caption:" + content)
defer C.free(unsafe.Pointer(ccontent))
C.DrawAnnotation(self.drawing, 20, 20, (*C.uchar)(unsafe.Pointer(ccontent)))
if C.MagickDrawImage(self.wand, self.drawing) == C.MagickFalse {
return fmt.Errorf(`Could not draw annotation: %s`, self.Error())
}
return nil
}
func (self *Canvas) SetCaption(content string) error {
ccontent := C.CString("caption:" + content)
defer C.free(unsafe.Pointer(ccontent))
if C.MagickReadImage(self.wand, ccontent) == C.MagickFalse {
return fmt.Errorf(`Could not open image "%s": %s`, content, self.Error())
}
C.MagickDrawImage(self.wand, self.drawing)
return nil
}
// Copies a drawing surface to the canvas.
func (cv Canvas) Update() {
C.MagickDrawImage(cv.wand, cv.drawing)
}