forked from MTSR/mapserver
57 lines
1.4 KiB
Go
57 lines
1.4 KiB
Go
package coords
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import (
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"math"
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)
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type TileCoords struct {
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X int `json:"x"`
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Y int `json:"y"`
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Zoom int `json:"zoom"`
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LayerId int `json:"layerid"`
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}
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type TileQuadrants struct {
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UpperLeft, UpperRight, LowerLeft, LowerRight *TileCoords
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}
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func NewTileCoords(x, y, zoom int, layerId int) *TileCoords {
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return &TileCoords{X: x, Y: y, Zoom: zoom, LayerId: layerId}
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}
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func (tc *TileCoords) ZoomOut(n int) *TileCoords {
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var nc *TileCoords = tc
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for i := 0; i < n; i++ {
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nc = nc.GetZoomedOutTile()
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}
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return nc
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}
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func (tc *TileCoords) GetZoomedOutTile() *TileCoords {
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return &TileCoords{
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X: int(math.Floor(float64(tc.X) / 2.0)),
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Y: int(math.Floor(float64(tc.Y) / 2.0)),
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Zoom: tc.Zoom - 1,
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LayerId: tc.LayerId}
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}
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func (tc *TileCoords) GetZoomedQuadrantsFromTile() TileQuadrants {
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nextZoom := tc.Zoom + 1
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nextZoomX := tc.X * 2
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nextZoomY := tc.Y * 2
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upperLeft := &TileCoords{X: nextZoomX, Y: nextZoomY, Zoom: nextZoom, LayerId: tc.LayerId}
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upperRight := &TileCoords{X: nextZoomX + 1, Y: nextZoomY, Zoom: nextZoom, LayerId: tc.LayerId}
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lowerLeft := &TileCoords{X: nextZoomX, Y: nextZoomY + 1, Zoom: nextZoom, LayerId: tc.LayerId}
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lowerRight := &TileCoords{X: nextZoomX + 1, Y: nextZoomY + 1, Zoom: nextZoom, LayerId: tc.LayerId}
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return TileQuadrants{
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UpperLeft: upperLeft,
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UpperRight: upperRight,
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LowerLeft: lowerLeft,
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LowerRight: lowerRight,
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}
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}
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