replace it with support for rendering to a cairo context rather than
a cairo surface.
When rendering to a surface a show_page is done, when rendering to a
context it is not so that multiple renders can be done, possibly with
modified scaling and/or translation.
Example:
>>> from mapnik import *
>>> im = Image(200,200)
>> save_to_file('test.png',im) # Guess image type from file extension
>> save_to_file('test.png,'jpeg',im) # Explicitly save as JPEG
- libxml2 support
- strict error handling while parsing XML map files
- implemented save_map()
- removed some duplicate defaults
- all symbolizers with icons share a common base class now
Shield symbolizer is now a subclass of text symbolizer.
Some small improvements to text rendering.
Fixed up placement finder for horizontal placement.
Cleaned up placement finder.
fs = m.query_map_point(x,y) # Map (screen) coordinates
for feature in fs:
print feature
TODO: provide interface to feature in Python, at the moment only __str__ implemented which dumps attributes
to be rendered. This allows for a large extent (larger than can be
rendered into a single image in memory) to be rendered out as tiles.
Since the full extent is used for the placement calculations text
crossing tile boundaries will be consistent.
This method is a little inefficient when a large number of labels need
placed, an improved method would be to cache these placements between
tiles, but the attached is a start.
c++ users should simple call the render method with a start X and Y
coordinate specified,
for (int TileX = 0;TileX < 5;++TileX)
{
for(int TileY = 0;TileY < 5; ++TileY)
{
int TileSize=250;
int StartX = TileX*TileSize;
int StartY = TileY*TileSize;
Image32 buf(TileSize,TileSize);
agg_renderer<Image32> ren(m,buf,StartX,StartY);
ren.apply();
char name[324];
sprintf(name,"tile_%d_%d.png",TileX,TileY);
ImageUtils::save_to_file(name,"png",buf);
}
}
python users should call render_tile_to_file
for y in range(tile_count_y):
for x in range(tile_count_x):
if not os.path.exists("tiles/%d/%d/" % (map_scale, y)):
os.makedirs("tiles/%d/%d/" % (map_scale, y))
render_tile_to_file(m, x*tile_size, y*tile_size, tile_size, tile_size,
'tiles/%d/%d/%d.png' % (map_scale,y,x), 'png')
