Why not adopt me?
NAME
Imager::Bing::MapLayer::Utils - utility functions for map layer modules
DESCRIPTION
This module contains utility functions for Imager::Bing::MapLayer.
EXPORTS
By default, none. Constants and functions must be included in the usage line explicitly.
CONSTANTS
$TILE_WIDTH
$TILE_HEIGHT
The width and height of individual tiles.
$MIN_ZOOM_LEVEL
$MIN_ZOOM_LEVEL
The minimum and maximum zoom levels supported by these modules.
Note that $MAX_ZOOM_LEVEL can actually be as high as 23, but that causes bit overflows for calculations on 32-bit integers. We also
don't want to generate tiles beyond level 18, since the amount of tiles required is so large that we run out of memory (and we also don't need it, since Bing switches to a street view mode).
When the tiles are not saved in memory, then we can generate higher resolutions. However, Bing doesn't seem to support zoom levels higher than 19 at this time.
FUNCTIONS
width_at_level
my $width = width_at_level( $level );Returns the width of a zoom level.
latlon_to_pixel
my ($pixel_x, $pixel_y) = latlon_to_pixel( $level, $latitude, $longitude );Converts latitude and longitude to pixel coodinates on a specific zoom level.
pixel_to_tile_coords
my ($tile_x, $tile_y) = pixel_to_tile_coords( $pixel_x, $pixel_y );Converts pixel coordinates to map tile coordinates.
tile_coords_to_pixel_origin
my ($origin_x, $origin_y) = tile_coords_to_pixel_origin( $tile_x, $tile_y );Returns the top-left pixel coordinates from tile coordinates.
tile_coords_to_quad_key
my $quad_key = tile_coords_to_quad_key( $level, $tile_x, $tile_y );Returns the quadrant key ("quad key") for a given tile at a given level.
quad_key_to_tile_coords
my ($tile_x, $tile_y, $level) = quad_key_to_tile_coords( $quad_key );Returns the tile coordinates and level from the quad key.
get_ground_resolution
$meters_per_pixel = get_ground_resolution( $level, $latitude );This returns the distance on the ground that's represented by a single pixel.
get_map_scale
TODO
bounding_box
my ($left, $top, $right, $bottom) = bounding_box( %args );This parses the arguments given to Imager::Draw methods to calculate a bounding box.
optimize_points
my @points2 = @{ optimize_points( \@points ) };This function takes a reference to a list of points and returns another reference to a list of points, without adjacent duplicate points. This reduces the number of points to plot for complex polylines on lower zoom levels.