[ZMapServer-Developers] ReferenceMap

[Florian E. <Flo...@ui...>]

Hi list!

Because we need a reference-map for our application, we extended the PCL-0.7
source code:
to manage this, we added a 'createRefMap'-function in
cartography/engine/mapserver/mapserver.py and extended cartography/mapping.py
for a ReferenceMap class. These functions are close to the mapscript-attributes
and far from intention of independent use of map-engines. Has anyone better
sugestions for implementing a refernce-map? If someone want's to improve the
code, please tell us about the changes.

florian & michael

#### mapserver.py: ###########################################
def createRefMap( mapSize, mapExt, srs, img, refSize, refExt, imgType = 'PNG'):
	"""Draw Reference Map"""
	mo = mapscript.mapObj()
	# set map-attributes
	mo.setSize(  mapSize[ 0 ], mapSize[ 1 ] )
	mo.setExtent( mapExt[ 0 ], mapExt[ 1 ], mapExt[ 2 ], mapExt[ 3 ] )
	mo.setImageType( imgType )
	mo.setProjection( 'init=%s' % srs )
	# set refMap-attributes
	mo.reference.image = img
	mo.reference.width = refSize[ 0 ]
	mo.reference.height = refSize[ 1 ]
	mo.reference.extent.minx = refExt[ 0 ]
	mo.reference.extent.miny = refExt[ 1 ]
	mo.reference.extent.maxx = refExt[ 2 ]
	mo.reference.extent.maxy = refExt[ 3 ]
	# box-attributes are default
	mo.reference.outlinecolor.setRGB( 255, 0, 0 )
	mo.reference.color.setRGB( -1, -1, -1 )
	# draw image
	im = mo.drawReferenceMap()

	image = mapping.Image()
	#for the upcoming mapserver function
	if hasattr(im, 'getBytes'):
		image.data.write(im.getBytes())
	else:
		im.write(image.data)

	image.size = [im.width, im.height]
	image.mimetype = im.format.mimetype

	del im
	del mo
	return image

### mapping.py: ##################################################
class ReferenceMap:

    """ReferenceMap from createRefMap() in mapserver.py

    Attributes
    ----------
    mapSize : list
        image.width, image.height of map

    mapExt : list
        map bounding box like '[xmin, ymin, xmax, ymax]'

    srs : string
        like: 'EPSG=31294'

    img : string
        path to image-object like 'context/irmi/img/...'

    refSize: list
        image.width, image.height of ReferenceMap

    refExt : list
        ReferenceMap bounding box like '[xmin, ymin, xmax, ymax]'

    imgType : string
       default is 'PNG'

    """

    def __init__( self, mapSize, srs, img, refSize, refExt, imgType = 'PNG' ):
        self.__mapSize = mapSize
        self.__mapExt = []
        self.__srs = srs
        self.__img = img
        self.__refSize = refSize
        self.__refExt = refExt
        self.__imgType = imgType

    def draw( self, mapExt, refExt=None ):
        self.__mapExt = mapExt
        if refExt:
            self.__refExt = refExt
        ref = engine.mapserver.mapserver.createRefMap( self.__mapSize,
self.__mapExt, self.__srs,
                                      self.__img, self.__refSize, self.__refExt,
self.__imgType )

        return ref