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# -*- coding: utf-8 -*-
"""
Created on Mon Jun 18 13:22:38 2012
@author: pietro
"""
import ctypes
import grass.lib.rowio as librowio
import grass.lib.raster as librast
from grass.pygrass.errors import GrassError
from grass.pygrass.raster.raster_type import TYPE as RTYPE
CMPFUNC = ctypes.CFUNCTYPE(ctypes.c_int,
ctypes.c_int, ctypes.c_void_p,
ctypes.c_int, ctypes.c_int)
def getmaprow_CELL(fd, buf, row, l):
librast.Rast_get_c_row(fd, ctypes.cast(buf, ctypes.POINTER(librast.CELL)),
row)
return 1
def getmaprow_FCELL(fd, buf, row, l):
librast.Rast_get_f_row(fd, ctypes.cast(buf, ctypes.POINTER(librast.FCELL)),
row)
return 1
def getmaprow_DCELL(fd, buf, row, l):
librast.Rast_get_d_row(fd, ctypes.cast(buf, ctypes.POINTER(librast.DCELL)),
row)
return 1
get_row = {
'CELL': CMPFUNC(getmaprow_CELL),
'FCELL': CMPFUNC(getmaprow_FCELL),
'DCELL': CMPFUNC(getmaprow_DCELL),
}
class RowIO(object):
def __init__(self):
self.c_rowio = librowio.ROWIO()
self.fd = None
self.rows = None
self.cols = None
self.mtype = None
self.row_size = None
def open(self, fd, rows, cols, mtype):
self.fd = fd
self.rows = rows
self.cols = cols
self.mtype = mtype
self.row_size = ctypes.sizeof(RTYPE[mtype]['grass def'] * cols)
if (librowio.Rowio_setup(ctypes.byref(self.c_rowio), self.fd,
self.rows,
self.row_size,
get_row[self.mtype],
get_row[self.mtype]) == -1):
raise GrassError('Fatal error, Rowio not setup correctly.')
def release(self):
librowio.Rowio_release(ctypes.byref(self.c_rowio))
self.fd = None
self.rows = None
self.cols = None
self.mtype = None
def get(self, row_index, buf):
rowio_buf = librowio.Rowio_get(ctypes.byref(self.c_rowio), row_index)
ctypes.memmove(buf.p, rowio_buf, self.row_size)
return buf
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