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')
bool hit_test(double x, double y, double tol);
2. added image_view(unsigned x, unsigned y, unsigned width, unsigned height)
allowing to select region from image data e.g (in Python):
im = Image(2048,2048)
view = im.view(0,0,256,256)
save_to_file(filename,type, view)
3. changed envelope method to return vy value in datasource classes
4. features_at_point impl for shape and postgis plug-ins
rendering them as labels when using the text or shield symbolisers
(blame my horrible datasets)
* correctly recognise the Postgis "text" data type (it was in
postgisfs.cpp just not postgis.cpp) - my initial workaround to the
above was "SELECT trim(from label) AS label ..." which failed
miserably because it returned a text data type.
Thanks to Robert Coup for the patch!
2. added extra parameter 'estimate_extent'. By default, exact extent will be calulated e.g :
select extent(geom) from table_name;
Sometimes it is more practical (faster!) to use estimated extent
select estimated_extent('table_name','geom');
but it is somewhere around 95% accurate.
Usage:
....
params["estimate_extent"]="true";
....
f = feature(id);
f["name"] = "what is my name?";
boost.put(f,"area",123123.4325);
2. simplified and corrected value class and operators
3. updated input plug-ins to work with new features
4. add text_symbolizer (getting there:)
5. template version of agg_renderer
6. attribute_collector how accepts rules
(to collect attribute names for text labels)
