tiles

Documentation

Index

• Variables
• func GeoToMercator(lon float64, lat float64) (x float64, y float64)
• func TileRange(zoom uint8, bounds [4]float64) (*TileID, *TileID)
• type EncodingConfig
  • func NewDefaultEncodingConfig() *EncodingConfig
  • func NewEncodingConfig(extent uint16, buffer uint16, precision uint8, simplification uint8, ...) *EncodingConfig
• type TileID
  • func GeoToTile(zoom uint8, x float64, y float64) *TileID
  • func NewTileID(zoom uint8, x uint32, y uint32) *TileID
  • func (t *TileID) GeoBounds() (float64, float64, float64, float64)
  • func (t *TileID) MercatorBounds() (float64, float64, float64, float64)
  • func (t *TileID) String() string

Variables

var CE float64 = 2.0 * ORIGIN

var DEG2RAD float64 = math.Pi / 180.0

var ORIGIN = RE * math.Pi

var RE float64 = 6378137.0

Functions

func GeoToMercator

func GeoToMercator(lon float64, lat float64) (x float64, y float64)

func TileRange

func TileRange(zoom uint8, bounds [4]float64) (*TileID, *TileID)

TileRange calculates the min tile x, min tile y, max tile x, max tile y tile range for Mercator coordinates xmin, ymin, xmax, ymax at a given zoom level. Assumes bounds have already been clipped to Mercator world bounds.

Types

type EncodingConfig

type EncodingConfig struct {
	Extent                uint16
	Buffer                uint16
	Precision             uint8
	Simplification        uint8
	SimplificationMaxZoom uint8
}

EncodingParams holds parameters used for encoding tiles

func NewDefaultEncodingConfig

func NewDefaultEncodingConfig() *EncodingConfig

func NewEncodingConfig

func NewEncodingConfig(extent uint16, buffer uint16, precision uint8, simplification uint8, simplificationMaxZoom uint8) *EncodingConfig

type TileID

type TileID struct {
	Zoom uint8
	X    uint32
	Y    uint32
}

WebMercator tile, numbered starting from upper left

func GeoToTile

func GeoToTile(zoom uint8, x float64, y float64) *TileID

GeoToTile calculates the tile x,y at zoom that contains longitude, latitude

func NewTileID

func NewTileID(zoom uint8, x uint32, y uint32) *TileID

func (*TileID) GeoBounds

func (t *TileID) GeoBounds() (float64, float64, float64, float64)

func (*TileID) MercatorBounds

func (t *TileID) MercatorBounds() (float64, float64, float64, float64)

func (*TileID) String

func (t *TileID) String() string