Golang C.GDALDataType类(方法)实例源码

// Advise driver of upcoming read requests
func (dataset Dataset) AdviseRead(
	rwFlag RWFlag,
	xOff, yOff, xSize, ySize, bufXSize, bufYSize int,
	dataType DataType,
	bandCount int,
	bandMap []int,
	options []string,
) error {
	length := len(options)
	cOptions := make([]*C.char, length+1)
	for i := 0; i < length; i++ {
		cOptions[i] = C.CString(options[i])
		defer C.free(unsafe.Pointer(cOptions[i]))
	}
	cOptions[length] = (*C.char)(unsafe.Pointer(nil))

	err := C.GDALDatasetAdviseRead(
		dataset.cval,
		C.int(xOff), C.int(yOff), C.int(xSize), C.int(ySize),
		C.int(bufXSize), C.int(bufYSize),
		C.GDALDataType(dataType),
		C.int(bandCount),
		(*C.int)(unsafe.Pointer(&bandMap[0])),
		(**C.char)(unsafe.Pointer(&cOptions[0])))
	if err != 0 {
		return error(err)
	}

	return nil
}

// Create a new dataset with this driver.
func (driver Driver) Create(
	filename string,
	xSize, ySize, bands int,
	dataType DataType,
	options []string,
) Dataset {
	name := C.CString(filename)
	defer C.free(unsafe.Pointer(name))

	length := len(options)
	opts := make([]*C.char, length+1)
	for i := 0; i < length; i++ {
		opts[i] = C.CString(options[i])
		defer C.free(unsafe.Pointer(opts[i]))
	}
	opts[length] = (*C.char)(unsafe.Pointer(nil))

	h := C.GDALCreate(
		driver.cval,
		name,
		C.int(xSize), C.int(ySize), C.int(bands),
		C.GDALDataType(dataType),
		(**C.char)(unsafe.Pointer(&opts[0])),
	)
	return Dataset{h}
}

// Read / write a region of image data from multiple bands
func (dataset Dataset) IO(
	rwFlag RWFlag,
	xOff, yOff, xSize, ySize int,
	buffer interface{},
	bufXSize, bufYSize int,
	bandCount int,
	bandMap []int,
	pixelSpace, lineSpace, bandSpace int,
) error {
	var dataType DataType
	var dataPtr unsafe.Pointer
	switch data := buffer.(type) {
	case []uint8:
		dataType = Byte
		dataPtr = unsafe.Pointer(&data[0])
	case []int16:
		dataType = Int16
		dataPtr = unsafe.Pointer(&data[0])
	case []uint16:
		dataType = UInt16
		dataPtr = unsafe.Pointer(&data[0])
	case []int32:
		dataType = Int32
		dataPtr = unsafe.Pointer(&data[0])
	case []uint32:
		dataType = UInt32
		dataPtr = unsafe.Pointer(&data[0])
	case []float32:
		dataType = Float32
		dataPtr = unsafe.Pointer(&data[0])
	case []float64:
		dataType = Float64
		dataPtr = unsafe.Pointer(&data[0])
	case []complex64:
		dataType = CFloat32
		dataPtr = unsafe.Pointer(&data[0])
	case []complex128:
		dataType = CFloat64
		dataPtr = unsafe.Pointer(&data[0])
	default:
		return fmt.Errorf("Error: buffer is not a valid data type (must be a valid numeric slice)")
	}

	err := C.GDALDatasetRasterIO(
		dataset.cval,
		C.GDALRWFlag(rwFlag),
		C.int(xOff), C.int(yOff), C.int(xSize), C.int(ySize),
		dataPtr,
		C.int(bufXSize), C.int(bufYSize),
		C.GDALDataType(dataType),
		C.int(bandCount),
		(*C.int)(unsafe.Pointer(&bandMap[0])),
		C.int(pixelSpace), C.int(lineSpace), C.int(bandSpace))
	if err != 0 {
		return error(err)
	}

	return nil
}

// Add a band to a dataset
func (dataset Dataset) AddBand(dataType DataType, options []string) error {
	length := len(options)
	cOptions := make([]*C.char, length+1)
	for i := 0; i < length; i++ {
		cOptions[i] = C.CString(options[i])
		defer C.free(unsafe.Pointer(cOptions[i]))
	}
	cOptions[length] = (*C.char)(unsafe.Pointer(nil))

	return C.GDALAddBand(
		dataset.cval,
		C.GDALDataType(dataType),
		(**C.char)(unsafe.Pointer(&cOptions[0])),
	).Err()
}

// Read / Write a region of image data for this band
func (rasterBand RasterBand) IO(
	rwFlag RWFlag,
	xOff, yOff, xSize, ySize int,
	buffer interface{},
	bufXSize, bufYSize int,
	pixelSpace, lineSpace int,
) error {
	var dataType DataType
	var dataPtr unsafe.Pointer
	switch data := buffer.(type) {
	case []int8:
		dataType = Byte
		dataPtr = unsafe.Pointer(&data[0])
	case []uint8:
		dataType = Byte
		dataPtr = unsafe.Pointer(&data[0])
	case []int16:
		dataType = Int16
		dataPtr = unsafe.Pointer(&data[0])
	case []uint16:
		dataType = UInt16
		dataPtr = unsafe.Pointer(&data[0])
	case []int32:
		dataType = Int32
		dataPtr = unsafe.Pointer(&data[0])
	case []uint32:
		dataType = UInt32
		dataPtr = unsafe.Pointer(&data[0])
	case []float32:
		dataType = Float32
		dataPtr = unsafe.Pointer(&data[0])
	case []float64:
		dataType = Float64
		dataPtr = unsafe.Pointer(&data[0])
	default:
		return fmt.Errorf("Error: buffer is not a valid data type (must be a valid numeric slice)")
	}

	return C.GDALRasterIO(
		rasterBand.cval,
		C.GDALRWFlag(rwFlag),
		C.int(xOff), C.int(yOff), C.int(xSize), C.int(ySize),
		dataPtr,
		C.int(bufXSize), C.int(bufYSize),
		C.GDALDataType(dataType),
		C.int(pixelSpace), C.int(lineSpace),
	).Err()
}

func (dataType DataType) Name() string {
	return C.GoString(C.GDALGetDataTypeName(C.GDALDataType(dataType)))
}

func (dataType DataType) IsComplex() int {
	return int(C.GDALDataTypeIsComplex(C.GDALDataType(dataType)))
}

// Get data type size in bits.
func (dataType DataType) Size() int {
	return int(C.GDALGetDataTypeSize(C.GDALDataType(dataType)))
}

func (dataType DataType) Union(dataTypeB DataType) DataType {
	return DataType(
		C.GDALDataTypeUnion(C.GDALDataType(dataType), C.GDALDataType(dataTypeB)),
	)
}