Thuban/UI/baserenderer.py

# Copyright (c) 2001, 2002, 2003, 2004 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
# Jonathan Coles <[email protected]>
# Frank Koormann <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

"""Basic rendering logic for Thuban maps

The code in this module is completely independend of wx so that it can
be tested reasonably easily and it could make it easier to write non-wx
renderers.
"""

from __future__ import generators

__version__ = "$Revision$"
# $Source$
# $Id$

import sys
import traceback

from Thuban.Model.layer import Layer, RasterLayer
from Thuban.Model.data import SHAPETYPE_ARC, SHAPETYPE_POINT
from Thuban.Model.label import ALIGN_CENTER, ALIGN_TOP, ALIGN_BOTTOM, \
     ALIGN_LEFT, ALIGN_RIGHT

import Thuban.Model.resource

if Thuban.Model.resource.has_gdal_support():
    from gdalwarp import ProjectRasterFile


#
#       Renderer Extensions
#
# The renderer extensions provide a way to render layer types defined in
# Thuban extensions. The renderer extensions are stored as a list with
# (layer_class, draw_function) pairs. If the renderer has to draw a
# non-builtin layer type, i.e. a layer that is not a subclass of Layer
# or RasterLayer, it iterates through that list, tests whether the layer
# to be drawn is an instance of layer_class and if so calls
# draw_function with the renderer and the layer as arguments. Since
# drawing is done incrementally, the draw_function should return an
# iterable. The easiest way is to simply implement the draw_function as
# a generator and to yield in suitable places, or to return the empty
# tuple.
#
# New renderer extensions should be added with add_renderer_extension().
# If necessary the extensions list can be reset with
# init_renderer_extensions().

_renderer_extensions = []

def add_renderer_extension(layer_class, function):
    """Add a renderer extension for the layer class layer_class

    When an instance of layer_class is to be drawn by the renderer the
    renderer will call function with the renderer and the layer_class
    instance as arguments. Since drawing is done incrementally, the
    function should return an iterable. The easiest way is to simply
    implement the draw_function as a generator and to yield True in
    suitable places, or to return the empty tuple if it's not possible
    to do the rendering incrementally.
    """
    _renderer_extensions.append((layer_class, function))

def init_renderer_extensions():
    """(Re)initialize the list of renderer extensions

    Calling this function outside of the test suite is probably not
    useful.
    """
    del _renderer_extensions[:]

def proj_params_to_str(proj):
    "Build a string suitable for GDAL describing the given projection"
    str = ""
    if proj is not None:
        for p in proj.GetAllParameters():
            str += "+" + p + " "
    return str

#
#       Base Renderer
#

class BaseRenderer:

    """Basic Renderer Infrastructure for Thuban Maps

    This class can't be used directly to render because it doesn't know
    anything about real DCs such as how to create pens or brushes. That
    functionality has to be provided by derived classes. The reason for
    this is that it makes the BaseRenderer completely independend of wx
    and thus it's quite easy to write test cases for it.
    """
    # If true the render honors the visibility flag of the layers
    honor_visibility = 1

    # Transparent brushes and pens. Derived classes should define these
    # as appropriate.
    TRANSPARENT_PEN = None
    TRANSPARENT_BRUSH = None

    def __init__(self, dc, map, scale, offset, region = None,
                 resolution = 72.0, honor_visibility = None):
        """Inititalize the renderer.

        dc -- the device context to render on.

        scale, offset -- the scale factor and translation to convert
                between projected coordinates and the DC coordinates

        region -- The region to draw as a (x, y, width, height) tuple in
                  the map's coordinate system. Default is None meaning
                  to draw everything.

        resolution -- the assumed resolution of the DC. Used to convert
                absolute lengths like font sizes to DC coordinates. The
                default is 72.0. If given, this parameter must be
                provided as a keyword argument.

        honor_visibility -- boolean. If true, honor the visibility flag
                of the layers, otherwise draw all layers. If None (the
                default), use the renderer's default. If given, this
                parameter must be provided as a keyword argument.
        """
        # resolution in pixel/inch
        self.dc = dc
        self.map = map
        self.scale = scale
        self.offset = offset
        self.region = region
        if honor_visibility is not None:
            self.honor_visibility = honor_visibility
        # store the resolution in pixel/point because it's more useful
        # later.
        self.resolution = resolution / 72.0

    def tools_for_property(self, prop):
        """Return a suitable pen and brush for the property

        This method must be implemented in derived classes. The return
        value should be a tuple (pen, brush).
        """
        raise NotImplementedError

    def render_map(self):
        """Render the map onto the DC.

        Both map and DC are the ones the renderer was instantiated with.

        This method is just a front-end for render_map_incrementally
        which does all rendering in one go. It also calls the dc's
        BeginDrawing and EndDrawing methods before and after calling
        render_map_incrementally.
        """

        self.dc.BeginDrawing()
        try:
            for cont in self.render_map_incrementally():
                pass
        finally:
            self.dc.EndDrawing()

    def render_map_incrementally(self):
        """Render the map incrementally.

        Return an iterator whose next method should be called until it
        returns False. After returning False it will raise StopIteration
        so that you could also use it in a for loop (implementation
        detail: this method is implemented as a generator).

        Iterate through all layers and draw them. Layers containing
        vector data are drawn with the draw_shape_layer method, raster
        layers are drawn with draw_raster_layer. The label layer is
        drawn last with draw_label_layer.

        During execution of this method, the map is bound to self.map so
        that methods especially in derived classes have access to the
        map if necessary.
        """

        for layer in self.map.Layers():
            # if honor_visibility is true, only draw visible layers,
            # otherwise draw all layers
            if not self.honor_visibility or layer.Visible():
                if isinstance(layer, Layer):
                    for i in self.draw_shape_layer_incrementally(layer):
                        yield True
                elif isinstance(layer, RasterLayer) \
                    and Thuban.Model.resource.has_gdal_support():
                    self.draw_raster_layer(layer)
                    yield True
                else:
                    # look it up in the renderer extensions
                    for cls, func in _renderer_extensions:
                        if isinstance(layer, cls):
                            for i in func(self, layer):
                                yield True
                            break
                    else:
                        # No renderer found. Print a message about it
                        print >>sys.stderr, ("Drawing layer %r not supported"
                                             % layer)
            yield True

        self.draw_label_layer(self.map.LabelLayer())
        yield False

    def draw_shape_layer_incrementally(self, layer):
        """Draw the shape layer layer onto the map incrementally.

        This method is a generator which yields True after every 500
        shapes.
        """
        scale = self.scale
        offx, offy = self.offset

        map_proj = self.map.projection
        layer_proj = layer.projection

        brush = self.TRANSPARENT_BRUSH
        pen   = self.TRANSPARENT_PEN

        old_prop = None
        old_group = None
        lc = layer.GetClassification()
        field = layer.GetClassificationColumn()
        defaultGroup = lc.GetDefaultGroup()
        table = layer.ShapeStore().Table()

        if lc.GetNumGroups() == 0:
            # There's only the default group, so we can pretend that
            # there is no field to classifiy on which makes things
            # faster since we don't need the attribute information at
            # all.
            field = None

        # Determine which render function to use.
        useraw, draw_func, draw_func_param = self.low_level_renderer(layer)

        #
        # Iterate through all shapes that have to be drawn.
        #

        # Count the shapes drawn so that we can yield every few hundred
        # shapes
        count = 0

        # Cache the tools (pens and brushes) for the classification
        # groups. This is a mapping from the group's ids to the a tuple
        # (pen, brush)
        tool_cache = {}

        for shape in self.layer_shapes(layer):
            count += 1
            if field is None:
                group = defaultGroup
            else:
                value = table.ReadValue(shape.ShapeID(), field)
                group = lc.FindGroup(value)

            if not group.IsVisible():
                continue

            try:
                pen, brush = tool_cache[id(group)]
            except KeyError:
                pen, brush = tool_cache[id(group)] \
                             = self.tools_for_property(group.GetProperties())

            if useraw:
                data = shape.RawData()
            else:
                data = shape.Points()
            if draw_func == self.draw_point_shape:
                 draw_func(draw_func_param, data, pen, brush,
                           size = group.GetProperties().GetSize())
            else:
                 draw_func(draw_func_param, data, pen, brush)
            if count % 500 == 0:
                yield True

    def layer_shapes(self, layer):
        """Return an iterable over the shapes to be drawn from the given layer.

        The default implementation simply returns all ids in the layer.
        Override in derived classes to be more precise.
        """
        return layer.ShapeStore().AllShapes()

    def low_level_renderer(self, layer):
        """Return the low-level renderer for the layer for draw_shape_layer

        The low level renderer to be returned by this method is a tuple
        (useraw, func, param) where useraw is a boolean indicating
        whether the function uses the raw shape data, func is a callable
        object and param is passed as the first parameter to func. The
        draw_shape_layer method will call func like this:

            func(param, shapedata, pen, brush)

        where shapedata is the return value of the RawData method of the
        shape object if useraw is true or the return value of the Points
        method if it's false. pen and brush are the pen and brush to use
        to draw the shape on the dc.

        The default implementation returns one of
        self.draw_polygon_shape, self.draw_arc_shape or
        self.draw_point_shape as func and layer as param. None of the
        method use the raw shape data. Derived classes can override this
        method to return more efficient low level renderers.
        """
        shapetype = layer.ShapeType()
        if shapetype == SHAPETYPE_POINT:
            func = self.draw_point_shape
        elif shapetype == SHAPETYPE_ARC:
            func = self.draw_arc_shape
        else:
            func = self.draw_polygon_shape
        return False, func, layer

    def make_point(self, x, y):
        """Convert (x, y) to a point object.

        Derived classes must override this method.
        """
        raise NotImplementedError

    def projected_points(self, layer, points):
        """Return the projected coordinates of the points taken from layer.

        Transform all the points in the list of lists of coordinate
        pairs in points.

        The transformation applies the inverse of the layer's projection
        if any, then the map's projection if any and finally applies
        self.scale and self.offset.

        The returned list has the same structure as the one returned the
        shape's Points method.
        """
        proj = self.map.GetProjection()
        if proj is not None:
            forward = proj.Forward
        else:
            forward = None
        proj = layer.GetProjection()
        if proj is not None:
            inverse = proj.Inverse
        else:
            inverse = None
        result = []
        scale = self.scale
        offx, offy = self.offset
        make_point = self.make_point

        for part in points:
            result.append([])
            for x, y in part:
                if inverse:
                    x, y = inverse(x, y)
                if forward:
                    x, y = forward(x, y)
                result[-1].append(make_point(x * scale + offx,
                                             -y * scale + offy))
        return result

    def draw_polygon_shape(self, layer, points, pen, brush):
        """Draw a polygon shape from layer with the given brush and pen

        The shape is given by points argument which is a the return
        value of the shape's Points() method. The coordinates in the
        DC's coordinate system are determined with
        self.projected_points.

        For a description of the algorithm look in wxproj.cpp.
        """
        points = self.projected_points(layer, points)

        if brush is not self.TRANSPARENT_BRUSH:
            polygon = []
            for part in points:
                polygon.extend(part)

            # missing back vertices for correct filling.
            insert_index = len(polygon)
            for part in points[:-1]:
                polygon.insert(insert_index, part[0])

            self.dc.SetBrush(brush)
            self.dc.SetPen(self.TRANSPARENT_PEN)
            self.dc.DrawPolygon(polygon)

        if pen is not self.TRANSPARENT_PEN:
            # At last draw the boundarys of the simple polygons
            self.dc.SetBrush(self.TRANSPARENT_BRUSH)
            self.dc.SetPen(pen)
            for part in points:
                self.dc.DrawLines(part)

    def draw_arc_shape(self, layer, points, pen, brush):
        """Draw an arc shape from layer with the given brush and pen

        The shape is given by points argument which is a the return
        value of the shape's Points() method. The coordinates in the
        DC's coordinate system are determined with
        self.projected_points.
        """
        points = self.projected_points(layer, points)
        self.dc.SetBrush(brush)
        self.dc.SetPen(pen)
        for part in points:
            self.dc.DrawLines(part)

    def draw_point_shape(self, layer, points, pen, brush, size = 5):
        """Draw a point shape from layer with the given brush and pen

        The shape is given by points argument which is a the return
        value of the shape's Points() method. The coordinates in the
        DC's coordinate system are determined with
        self.projected_points.

        The point is drawn as a circle centered on the point.
        """
        points = self.projected_points(layer, points)
        if not points:
            return

        radius = int(round(self.resolution * size))
        self.dc.SetBrush(brush)
        self.dc.SetPen(pen)
        for part in points:
            for p in part:
                self.dc.DrawEllipse(p.x - radius, p.y - radius,
                                    2 * radius, 2 * radius)

    def draw_raster_layer(self, layer):
        """Draw the raster layer

        This implementation does the projection and scaling of the data
        as required by the layer's and map's projections and the scale
        and offset of the renderer and then hands the transformed data
        to self.draw_raster_data() which has to be implemented in
        derived classes.
        """
        offx, offy = self.offset
        width, height = self.dc.GetSizeTuple()

        in_proj  = proj_params_to_str(layer.GetProjection())
        out_proj = proj_params_to_str(self.map.GetProjection())

        # True  -- warp the image to the size of the whole screen
        # False -- only use the bound box of the layer (currently inaccurate)
        if True: 
        #if False: 
            pmin = [0,height]
            pmax = [width, 0]
        else:
            bb = layer.LatLongBoundingBox()
            bb = [[[bb[0], bb[1]], [bb[2], bb[3]],],]
            pmin, pmax = self.projected_points(layer, bb)[0]

        #print bb
        #print pmin, pmax

        fmin = [max(0, min(pmin[0], pmax[0])) - offx, 
                offy - min(height, max(pmin[1], pmax[1]))]

        fmax = [min(width, max(pmin[0], pmax[0])) - offx, 
                offy - max(0, min(pmin[1], pmax[1]))]

        xmin = fmin[0]/self.scale
        ymin = fmin[1]/self.scale
        xmax = fmax[0]/self.scale
        ymax = fmax[1]/self.scale

        width  = int(min(width,  round(fmax[0] - fmin[0] + 1)))
        height = int(min(height, round(fmax[1] - fmin[1] + 1)))

        try:
            project_params = (layer.GetImageFilename(), in_proj, out_proj, 
                              (xmin, ymin, xmax, ymax), "", (width, height),
                              layer.UseMask())

            data = (width, height, apply(ProjectRasterFile, project_params))

        except (IOError, AttributeError, ValueError):
            # Why does this catch AttributeError and ValueError?
            # FIXME: The exception should be communicated to the user
            # better.
            traceback.print_exc()
        else:
            self.draw_raster_data(fmin[0]+offx, offy-fmax[1], data, "RAW")
            data = None

    def draw_raster_data(self, x, y, data, format="BMP"):
        """Draw the raster image in data onto the DC with the top
        left corner at (x,y)

        The raster image data is a tuple of the form
            (width, height, (image_data, mask_data))
        
        holding the image width, height, image data, and mask data.
        mask_data may be None if a mask should not be used. Both kinds 
        of data are assumed to be in the format specified in format.

        The format parameter is a string with the name of the format.
        The following format names should be used:

          'RAW'  -- an array of RGB values (len=3*width*height)
          'BMP'  -- Windows Bitmap
          'JPEG' -- JPEG Image

        The default format is 'BMP'.

        This method has to be implemented by derived classes. The
        implementation in the derived class should try to support at
        least the formats specified above and may support more.
        """
        raise NotImplementedError

    def label_font(self):
        """Return the font object for the label layer"""
        raise NotImplementedError

    def draw_label_layer(self, layer):
        """Draw the label layer

        All labels are draw in the font returned by self.label_font().
        """
        scale = self.scale
        offx, offy = self.offset

        self.dc.SetFont(self.label_font())

        map_proj = self.map.projection
        if map_proj is not None:
            forward = map_proj.Forward
        else:
            forward = None

        for label in layer.Labels():
            x = label.x
            y = label.y
            text = label.text
            if forward:
                x, y = forward(x, y)
            x = int(round(x * scale + offx))
            y = int(round(-y * scale + offy))
            width, height = self.dc.GetTextExtent(text)
            if label.halign == ALIGN_LEFT:
                # nothing to be done
                pass
            elif label.halign == ALIGN_RIGHT:
                x = x - width
            elif label.halign == ALIGN_CENTER:
                x = x - width/2
            if label.valign == ALIGN_TOP:
                # nothing to be done
                pass
            elif label.valign == ALIGN_BOTTOM:
                y = y - height
            elif label.valign == ALIGN_CENTER:
                y = y - height/2
            self.dc.DrawText(text, x, y)
1	bh	2224	# Copyright (c) 2001, 2002, 2003, 2004 by Intevation GmbH
2	bh	1554	# Authors:
3			# Bernhard Herzog <[email protected]>
4			# Jonathan Coles <[email protected]>
5			# Frank Koormann <[email protected]>
6			#
7			# This program is free software under the GPL (>=v2)
8			# Read the file COPYING coming with Thuban for details.
9
10			"""Basic rendering logic for Thuban maps
11
12			The code in this module is completely independend of wx so that it can
13			be tested reasonably easily and it could make it easier to write non-wx
14			renderers.
15			"""
16
17	bh	1866	from __future__ import generators
18
19	bh	1554	__version__ = "$Revision$"
20			# $Source$
21			# $Id$
22
23	bh	1926	import sys
24	bh	1554	import traceback
25
26			from Thuban.Model.layer import Layer, RasterLayer
27			from Thuban.Model.data import SHAPETYPE_ARC, SHAPETYPE_POINT
28			from Thuban.Model.label import ALIGN_CENTER, ALIGN_TOP, ALIGN_BOTTOM, \
29			ALIGN_LEFT, ALIGN_RIGHT
30
31			import Thuban.Model.resource
32
33			if Thuban.Model.resource.has_gdal_support():
34			from gdalwarp import ProjectRasterFile
35
36
37	bh	1926	#
38			# Renderer Extensions
39			#
40			# The renderer extensions provide a way to render layer types defined in
41			# Thuban extensions. The renderer extensions are stored as a list with
42			# (layer_class, draw_function) pairs. If the renderer has to draw a
43			# non-builtin layer type, i.e. a layer that is not a subclass of Layer
44			# or RasterLayer, it iterates through that list, tests whether the layer
45	bh	2224	# to be drawn is an instance of layer_class and if so calls
46	bh	1926	# draw_function with the renderer and the layer as arguments. Since
47			# drawing is done incrementally, the draw_function should return an
48			# iterable. The easiest way is to simply implement the draw_function as
49			# a generator and to yield in suitable places, or to return the empty
50			# tuple.
51			#
52			# New renderer extensions should be added with add_renderer_extension().
53			# If necessary the extensions list can be reset with
54			# init_renderer_extensions().
55
56			_renderer_extensions = []
57
58			def add_renderer_extension(layer_class, function):
59			"""Add a renderer extension for the layer class layer_class
60
61			When an instance of layer_class is to be drawn by the renderer the
62			renderer will call function with the renderer and the layer_class
63			instance as arguments. Since drawing is done incrementally, the
64			function should return an iterable. The easiest way is to simply
65			implement the draw_function as a generator and to yield True in
66			suitable places, or to return the empty tuple if it's not possible
67	bh	2224	to do the rendering incrementally.
68	bh	1926	"""
69			_renderer_extensions.append((layer_class, function))
70
71			def init_renderer_extensions():
72			"""(Re)initialize the list of renderer extensions
73
74			Calling this function outside of the test suite is probably not
75			useful.
76			"""
77			del _renderer_extensions[:]
78
79	jonathan	2537	def proj_params_to_str(proj):
80			"Build a string suitable for GDAL describing the given projection"
81			str = ""
82			if proj is not None:
83			for p in proj.GetAllParameters():
84			str += "+" + p + " "
85			return str
86	bh	1926
87			#
88			# Base Renderer
89			#
90
91	bh	1554	class BaseRenderer:
92
93			"""Basic Renderer Infrastructure for Thuban Maps
94
95			This class can't be used directly to render because it doesn't know
96			anything about real DCs such as how to create pens or brushes. That
97			functionality has to be provided by derived classes. The reason for
98			this is that it makes the BaseRenderer completely independend of wx
99			and thus it's quite easy to write test cases for it.
100			"""
101			# If true the render honors the visibility flag of the layers
102			honor_visibility = 1
103
104			# Transparent brushes and pens. Derived classes should define these
105			# as appropriate.
106			TRANSPARENT_PEN = None
107			TRANSPARENT_BRUSH = None
108
109	bh	1866	def __init__(self, dc, map, scale, offset, region = None,
110			resolution = 72.0, honor_visibility = None):
111	bh	1554	"""Inititalize the renderer.
112
113			dc -- the device context to render on.
114
115			scale, offset -- the scale factor and translation to convert
116			between projected coordinates and the DC coordinates
117
118	bh	1866	region -- The region to draw as a (x, y, width, height) tuple in
119			the map's coordinate system. Default is None meaning
120			to draw everything.
121
122	bh	1554	resolution -- the assumed resolution of the DC. Used to convert
123			absolute lengths like font sizes to DC coordinates. The
124	bh	1866	default is 72.0. If given, this parameter must be
125			provided as a keyword argument.
126	bh	1554
127			honor_visibility -- boolean. If true, honor the visibility flag
128			of the layers, otherwise draw all layers. If None (the
129	bh	1866	default), use the renderer's default. If given, this
130			parameter must be provided as a keyword argument.
131	bh	1554	"""
132			# resolution in pixel/inch
133			self.dc = dc
134	bh	1866	self.map = map
135	bh	1554	self.scale = scale
136			self.offset = offset
137	bh	1866	self.region = region
138	bh	1554	if honor_visibility is not None:
139			self.honor_visibility = honor_visibility
140			# store the resolution in pixel/point because it's more useful
141			# later.
142			self.resolution = resolution / 72.0
143
144			def tools_for_property(self, prop):
145			"""Return a suitable pen and brush for the property
146
147			This method must be implemented in derived classes. The return
148			value should be a tuple (pen, brush).
149			"""
150			raise NotImplementedError
151
152	bh	1866	def render_map(self):
153			"""Render the map onto the DC.
154	bh	1554
155	bh	1866	Both map and DC are the ones the renderer was instantiated with.
156
157			This method is just a front-end for render_map_incrementally
158			which does all rendering in one go. It also calls the dc's
159			BeginDrawing and EndDrawing methods before and after calling
160			render_map_incrementally.
161			"""
162
163			self.dc.BeginDrawing()
164			try:
165			for cont in self.render_map_incrementally():
166			pass
167			finally:
168			self.dc.EndDrawing()
169
170			def render_map_incrementally(self):
171			"""Render the map incrementally.
172
173			Return an iterator whose next method should be called until it
174			returns False. After returning False it will raise StopIteration
175			so that you could also use it in a for loop (implementation
176			detail: this method is implemented as a generator).
177
178	bh	1554	Iterate through all layers and draw them. Layers containing
179			vector data are drawn with the draw_shape_layer method, raster
180			layers are drawn with draw_raster_layer. The label layer is
181			drawn last with draw_label_layer.
182
183			During execution of this method, the map is bound to self.map so
184			that methods especially in derived classes have access to the
185			map if necessary.
186			"""
187
188	bh	1866	for layer in self.map.Layers():
189			# if honor_visibility is true, only draw visible layers,
190			# otherwise draw all layers
191			if not self.honor_visibility or layer.Visible():
192	bh	2278	if isinstance(layer, Layer):
193	jonathan	2537	for i in self.draw_shape_layer_incrementally(layer):
194			yield True
195	bh	1866	elif isinstance(layer, RasterLayer) \
196			and Thuban.Model.resource.has_gdal_support():
197			self.draw_raster_layer(layer)
198			yield True
199	bh	1926	else:
200			# look it up in the renderer extensions
201			for cls, func in _renderer_extensions:
202			if isinstance(layer, cls):
203			for i in func(self, layer):
204			yield True
205			break
206			else:
207			# No renderer found. Print a message about it
208			print >>sys.stderr, ("Drawing layer %r not supported"
209			% layer)
210			yield True
211	bh	1554
212	bh	1866	self.draw_label_layer(self.map.LabelLayer())
213			yield False
214	bh	1554
215	bh	1866	def draw_shape_layer_incrementally(self, layer):
216			"""Draw the shape layer layer onto the map incrementally.
217	bh	1554
218	bh	1866	This method is a generator which yields True after every 500
219			shapes.
220	bh	1554	"""
221			scale = self.scale
222			offx, offy = self.offset
223
224			map_proj = self.map.projection
225			layer_proj = layer.projection
226
227			brush = self.TRANSPARENT_BRUSH
228			pen = self.TRANSPARENT_PEN
229
230			old_prop = None
231			old_group = None
232			lc = layer.GetClassification()
233			field = layer.GetClassificationColumn()
234			defaultGroup = lc.GetDefaultGroup()
235			table = layer.ShapeStore().Table()
236
237	bh	1879	if lc.GetNumGroups() == 0:
238			# There's only the default group, so we can pretend that
239			# there is no field to classifiy on which makes things
240			# faster since we don't need the attribute information at
241			# all.
242			field = None
243
244	bh	1554	# Determine which render function to use.
245	bh	1591	useraw, draw_func, draw_func_param = self.low_level_renderer(layer)
246	bh	1554
247	bh	1914	#
248	bh	1554	# Iterate through all shapes that have to be drawn.
249	bh	1914	#
250
251			# Count the shapes drawn so that we can yield every few hundred
252			# shapes
253	bh	1866	count = 0
254	bh	1914
255			# Cache the tools (pens and brushes) for the classification
256			# groups. This is a mapping from the group's ids to the a tuple
257			# (pen, brush)
258			tool_cache = {}
259
260	bh	1593	for shape in self.layer_shapes(layer):
261	bh	1866	count += 1
262	bh	1554	if field is None:
263			group = defaultGroup
264			else:
265	bh	1918	value = table.ReadValue(shape.ShapeID(), field)
266	bh	1914	group = lc.FindGroup(value)
267	bh	1554
268			if not group.IsVisible():
269			continue
270
271	bh	1914	try:
272			pen, brush = tool_cache[id(group)]
273			except KeyError:
274			pen, brush = tool_cache[id(group)] \
275			= self.tools_for_property(group.GetProperties())
276	bh	1554
277	bh	1591	if useraw:
278			data = shape.RawData()
279			else:
280			data = shape.Points()
281	jan	2377	if draw_func == self.draw_point_shape:
282			draw_func(draw_func_param, data, pen, brush,
283			size = group.GetProperties().GetSize())
284			else:
285			draw_func(draw_func_param, data, pen, brush)
286	bh	1866	if count % 500 == 0:
287			yield True
288	bh	1554
289	bh	1593	def layer_shapes(self, layer):
290			"""Return an iterable over the shapes to be drawn from the given layer.
291	bh	1554
292			The default implementation simply returns all ids in the layer.
293			Override in derived classes to be more precise.
294			"""
295	bh	1593	return layer.ShapeStore().AllShapes()
296	bh	1554
297			def low_level_renderer(self, layer):
298			"""Return the low-level renderer for the layer for draw_shape_layer
299
300			The low level renderer to be returned by this method is a tuple
301	bh	1591	(useraw, func, param) where useraw is a boolean indicating
302			whether the function uses the raw shape data, func is a callable
303			object and param is passed as the first parameter to func. The
304			draw_shape_layer method will call func like this:
305	bh	1554
306	bh	1591	func(param, shapedata, pen, brush)
307	bh	1554
308	bh	1591	where shapedata is the return value of the RawData method of the
309			shape object if useraw is true or the return value of the Points
310			method if it's false. pen and brush are the pen and brush to use
311			to draw the shape on the dc.
312	bh	1554
313			The default implementation returns one of
314			self.draw_polygon_shape, self.draw_arc_shape or
315	bh	1591	self.draw_point_shape as func and layer as param. None of the
316			method use the raw shape data. Derived classes can override this
317			method to return more efficient low level renderers.
318	bh	1554	"""
319			shapetype = layer.ShapeType()
320			if shapetype == SHAPETYPE_POINT:
321			func = self.draw_point_shape
322			elif shapetype == SHAPETYPE_ARC:
323			func = self.draw_arc_shape
324			else:
325			func = self.draw_polygon_shape
326	bh	1591	return False, func, layer
327	bh	1554
328			def make_point(self, x, y):
329			"""Convert (x, y) to a point object.
330
331			Derived classes must override this method.
332			"""
333			raise NotImplementedError
334
335	bh	1591	def projected_points(self, layer, points):
336			"""Return the projected coordinates of the points taken from layer.
337	bh	1554
338	bh	1591	Transform all the points in the list of lists of coordinate
339			pairs in points.
340	bh	1554
341			The transformation applies the inverse of the layer's projection
342			if any, then the map's projection if any and finally applies
343			self.scale and self.offset.
344
345			The returned list has the same structure as the one returned the
346			shape's Points method.
347			"""
348			proj = self.map.GetProjection()
349			if proj is not None:
350			forward = proj.Forward
351			else:
352			forward = None
353			proj = layer.GetProjection()
354			if proj is not None:
355			inverse = proj.Inverse
356			else:
357			inverse = None
358	bh	1591	result = []
359	bh	1554	scale = self.scale
360			offx, offy = self.offset
361			make_point = self.make_point
362	jonathan	2537
363	bh	1591	for part in points:
364			result.append([])
365	bh	1554	for x, y in part:
366			if inverse:
367			x, y = inverse(x, y)
368			if forward:
369			x, y = forward(x, y)
370	bh	1591	result[-1].append(make_point(x * scale + offx,
371	bh	1554	-y * scale + offy))
372	bh	1591	return result
373	bh	1554
374	bh	1591	def draw_polygon_shape(self, layer, points, pen, brush):
375			"""Draw a polygon shape from layer with the given brush and pen
376	bh	1554
377	bh	1591	The shape is given by points argument which is a the return
378			value of the shape's Points() method. The coordinates in the
379			DC's coordinate system are determined with
380	bh	1554	self.projected_points.
381	bernhard	2413
382			For a description of the algorithm look in wxproj.cpp.
383	bh	1554	"""
384	bh	1591	points = self.projected_points(layer, points)
385	bh	1554
386			if brush is not self.TRANSPARENT_BRUSH:
387			polygon = []
388			for part in points:
389			polygon.extend(part)
390
391	bernhard	2413	# missing back vertices for correct filling.
392	bh	1554	insert_index = len(polygon)
393			for part in points[:-1]:
394			polygon.insert(insert_index, part[0])
395
396			self.dc.SetBrush(brush)
397			self.dc.SetPen(self.TRANSPARENT_PEN)
398			self.dc.DrawPolygon(polygon)
399
400			if pen is not self.TRANSPARENT_PEN:
401			# At last draw the boundarys of the simple polygons
402			self.dc.SetBrush(self.TRANSPARENT_BRUSH)
403			self.dc.SetPen(pen)
404			for part in points:
405			self.dc.DrawLines(part)
406
407	bh	1591	def draw_arc_shape(self, layer, points, pen, brush):
408			"""Draw an arc shape from layer with the given brush and pen
409	bh	1554
410	bh	1591	The shape is given by points argument which is a the return
411			value of the shape's Points() method. The coordinates in the
412			DC's coordinate system are determined with
413	bh	1554	self.projected_points.
414			"""
415	bh	1591	points = self.projected_points(layer, points)
416	bh	1554	self.dc.SetBrush(brush)
417			self.dc.SetPen(pen)
418			for part in points:
419			self.dc.DrawLines(part)
420
421	jan	2377	def draw_point_shape(self, layer, points, pen, brush, size = 5):
422	bh	1591	"""Draw a point shape from layer with the given brush and pen
423	bh	1554
424	bh	1591	The shape is given by points argument which is a the return
425			value of the shape's Points() method. The coordinates in the
426			DC's coordinate system are determined with
427	bh	1554	self.projected_points.
428
429			The point is drawn as a circle centered on the point.
430			"""
431	bh	1591	points = self.projected_points(layer, points)
432	bh	1554	if not points:
433			return
434
435	jan	2377	radius = int(round(self.resolution * size))
436	bh	1554	self.dc.SetBrush(brush)
437			self.dc.SetPen(pen)
438			for part in points:
439			for p in part:
440			self.dc.DrawEllipse(p.x - radius, p.y - radius,
441			2 * radius, 2 * radius)
442
443			def draw_raster_layer(self, layer):
444			"""Draw the raster layer
445
446			This implementation does the projection and scaling of the data
447			as required by the layer's and map's projections and the scale
448			and offset of the renderer and then hands the transformed data
449			to self.draw_raster_data() which has to be implemented in
450			derived classes.
451			"""
452			offx, offy = self.offset
453			width, height = self.dc.GetSizeTuple()
454
455	jonathan	2537	in_proj = proj_params_to_str(layer.GetProjection())
456			out_proj = proj_params_to_str(self.map.GetProjection())
457	bh	1554
458	jonathan	2537	# True -- warp the image to the size of the whole screen
459			# False -- only use the bound box of the layer (currently inaccurate)
460			if True:
461	jonathan	2551	#if False:
462	jonathan	2537	pmin = [0,height]
463			pmax = [width, 0]
464			else:
465			bb = layer.LatLongBoundingBox()
466			bb = [[[bb[0], bb[1]], [bb[2], bb[3]],],]
467			pmin, pmax = self.projected_points(layer, bb)[0]
468	bh	1554
469	jonathan	2551	#print bb
470			#print pmin, pmax
471	bh	1554
472	jonathan	2551	fmin = [max(0, min(pmin[0], pmax[0])) - offx,
473			offy - min(height, max(pmin[1], pmax[1]))]
474
475			fmax = [min(width, max(pmin[0], pmax[0])) - offx,
476			offy - max(0, min(pmin[1], pmax[1]))]
477
478	jonathan	2537	xmin = fmin[0]/self.scale
479			ymin = fmin[1]/self.scale
480			xmax = fmax[0]/self.scale
481			ymax = fmax[1]/self.scale
482
483			width = int(min(width, round(fmax[0] - fmin[0] + 1)))
484			height = int(min(height, round(fmax[1] - fmin[1] + 1)))
485
486	bh	1554	try:
487	jonathan	2551	project_params = (layer.GetImageFilename(), in_proj, out_proj,
488			(xmin, ymin, xmax, ymax), "", (width, height),
489			layer.UseMask())
490
491			data = (width, height, apply(ProjectRasterFile, project_params))
492
493	bh	1554	except (IOError, AttributeError, ValueError):
494			# Why does this catch AttributeError and ValueError?
495			# FIXME: The exception should be communicated to the user
496			# better.
497			traceback.print_exc()
498			else:
499	jonathan	2551	self.draw_raster_data(fmin[0]+offx, offy-fmax[1], data, "RAW")
500	jonathan	2537	data = None
501	bh	1554
502	jonathan	2551	def draw_raster_data(self, x, y, data, format="BMP"):
503	jonathan	2537	"""Draw the raster image in data onto the DC with the top
504			left corner at (x,y)
505	bh	1554
506	jonathan	2551	The raster image data is a tuple of the form
507			(width, height, (image_data, mask_data))
508
509			holding the image width, height, image data, and mask data.
510			mask_data may be None if a mask should not be used. Both kinds
511			of data are assumed to be in the format specified in format.
512	bh	1554
513	bh	1926	The format parameter is a string with the name of the format.
514			The following format names should be used:
515
516	jonathan	2537	'RAW' -- an array of RGB values (len=3widthheight)
517			'BMP' -- Windows Bitmap
518			'JPEG' -- JPEG Image
519	bh	1926
520	jonathan	2537	The default format is 'BMP'.
521	bh	1926
522			This method has to be implemented by derived classes. The
523			implementation in the derived class should try to support at
524			least the formats specified above and may support more.
525	bh	1554	"""
526			raise NotImplementedError
527
528			def label_font(self):
529			"""Return the font object for the label layer"""
530			raise NotImplementedError
531
532			def draw_label_layer(self, layer):
533			"""Draw the label layer
534
535			All labels are draw in the font returned by self.label_font().
536			"""
537			scale = self.scale
538			offx, offy = self.offset
539
540			self.dc.SetFont(self.label_font())
541
542			map_proj = self.map.projection
543			if map_proj is not None:
544			forward = map_proj.Forward
545			else:
546			forward = None
547
548			for label in layer.Labels():
549			x = label.x
550			y = label.y
551			text = label.text
552			if forward:
553			x, y = forward(x, y)
554	bh	1935	x = int(round(x * scale + offx))
555			y = int(round(-y * scale + offy))
556	bh	1554	width, height = self.dc.GetTextExtent(text)
557			if label.halign == ALIGN_LEFT:
558			# nothing to be done
559			pass
560			elif label.halign == ALIGN_RIGHT:
561			x = x - width
562			elif label.halign == ALIGN_CENTER:
563			x = x - width/2
564			if label.valign == ALIGN_TOP:
565			# nothing to be done
566			pass
567			elif label.valign == ALIGN_BOTTOM:
568			y = y - height
569			elif label.valign == ALIGN_CENTER:
570			y = y - height/2
571			self.dc.DrawText(text, x, y)
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision