// Private: Create a blank magick wand with size width and height
//
// Params:
// - format: format of the new image
// - width: width of the new image
// - height: height of the new image
//
// Examples
// blankWand("jpg", 100, 100)
//
// Return *C.MagickWand
func blankWand(format string, width, height int) *C.MagickWand {
wand := C.NewMagickWand()
cformat := C.CString(format)
noneBackground := C.CString("none")
defer C.free(unsafe.Pointer(cformat))
defer C.free(unsafe.Pointer(noneBackground))
C.MagickSetFormat(wand, C.CString(format))
pixel := C.NewPixelWand()
defer C.DestroyPixelWand(pixel)
C.PixelSetColor(pixel, noneBackground)
C.MagickSetSize(wand, C.size_t(width), C.size_t(height))
C.MagickNewImage(wand, C.size_t(width), C.size_t(height), pixel)
return wand
}
/*
Sets the file or blob format (e.g. "BMP") to be used when a file or blob is read. Usually this is
not necessary because GraphicsMagick is able to auto-detect the format based on the file header
(or the file extension), but some formats do not use a unique header or the selection may be ambigious.
Use MagickSetImageFormat() to set the format to be used when a file or blob is to be written.
format: The file or blob format
*/
func (this *Image) SetFormat(format string) error {
if this.magickWand == nil {
return errors.New("error set image format:magickwand is nil")
}
var cs *C.char = C.CString(format)
defer C.free(unsafe.Pointer(cs))
status := C.MagickSetFormat(this.magickWand, cs)
if status == 0 {
var etype int
descr := C.MagickGetException(this.magickWand, (*C.ExceptionType)(unsafe.Pointer(&etype)))
defer C.MagickRelinquishMemory(unsafe.Pointer(descr))
return errors.New(fmt.Sprintf("error set image format: %s (ExceptionType = %d)", C.GoString(descr), etype))
}
return nil
}
// Sets the format of the magick wand.
func (mw *MagickWand) SetFormat(format string) error {
csformat := C.CString(format)
defer C.free(unsafe.Pointer(csformat))
C.MagickSetFormat(mw.mw, csformat)
return mw.GetLastError()
}