/// <summary>
/// Computes the list of all possible tiles to request
/// </summary>
/// <returns></returns>
public TileRef[] GetTileList()
{
var ranges = new TileSetRange[_maxZoomLevel + 1];
for (int z = 0; z < ranges.Length; z++)
{
//Allow floating point drift
var ll = WorldToTilePos(_ll.X, _ll.Y, z);
var ur = WorldToTilePos(_ur.X, _ur.Y, z);
if (_specificZoomLevels.Count == 0 || _specificZoomLevels.Contains(z))
{
var rows = Math.Abs(ur.X - ll.X) + 1;
var cols = Math.Abs(ur.Y - ll.Y) + 1;
ranges[z] = new TileSetRange(Math.Min(ll.X, ur.X), Math.Min(ll.Y, ur.Y), z, rows, cols);
}
else //This zoom level has been omitted
{
ranges[z] = new TileSetRange(z);
}
}
var capacity = ranges.Sum(g => g.Total);
var tiles = new TileRef[capacity];
var current = 0;
for (int z = 0; z < ranges.Length; z++)
{
var g = ranges[z];
for (int xi = 0; xi < g.Rows; xi++)
{
for (int yi = 0; yi < g.Cols; yi++)
{
int x = g.X + xi;
int y = g.Y + yi;
tiles[current] = new TileRef(string.Empty, x, y, z);
current++;
}
}
}
return(tiles);
}
/// <summary>
/// Computes the list of all possible tiles to request
/// </summary>
/// <returns></returns>
public TileRef[] GetTileList()
{
//Z goes from 0 to 19
var ranges = new TileSetRange[20];
for (int z = 0; z < ranges.Length; z++)
{
//Allow floating point drift
var ll = WorldToTilePos(_ll.X, _ll.Y, z);
var ur = WorldToTilePos(_ur.X, _ur.Y, z);
var rows = Math.Abs(ur.X - ll.X) + 1;
var cols = Math.Abs(ur.Y - ll.Y) + 1;
ranges[z] = new TileSetRange(Math.Min(ll.X, ur.X), Math.Min(ll.Y, ur.Y), z, rows, cols);
}
var capacity = ranges.Sum(g => g.Total);
var tiles = new TileRef[capacity];
var current = 0;
for (int z = 0; z < ranges.Length; z++)
{
var g = ranges[z];
for (int xi = 0; xi < g.Rows; xi++)
{
for (int yi = 0; yi < g.Cols; yi++)
{
int x = g.X + xi;
int y = g.Y + yi;
tiles[current] = new TileRef(string.Empty, x, y, z);
current++;
}
}
}
return(tiles);
}
static void DefaultExecutor(Action <TileRef> fetcher, TileRef tile) => fetcher(tile);
/// <summary>
/// Computes the list of all possible tiles to request
/// </summary>
/// <returns></returns>
public TileRef[] GetTileList()
{
var extents = _options.Extents;
var tileSet = _options.TileSet;
var maxScale = tileSet.GetMaxScale();
var metersPerUnit = _options.MetersPerUnit;
var widthM = Math.Abs(metersPerUnit * (extents.MaxX - extents.MinX));
var heightM = Math.Abs(metersPerUnit * (extents.MaxY - extents.MinY));
var scaleCount = tileSet.ScaleCount;
var groups = new List <TileGroupSet>();
for (var scaleIndex = scaleCount - 1; scaleIndex >= 0; scaleIndex--)
{
var rowTileOffset = 0;
var colTileOffset = 0;
var scale = tileSet.GetScaleAt(scaleIndex);
// This is the official method, and the only one MgCooker will ever use
// This is the algorithm proposed by the MapGuide team:
// http://www.nabble.com/Pre-Genererate--tiles-for-the-entire-map-at-all-pre-defined-zoom-scales-to6074037.html#a6078663
//
// Method description inline (in case nabble link disappears):
//
// The upper left corner of the extents of the map corresponds to tile (0,0). Then tile (1,0) is to the right of that and tile (0,1) is under tile (0,0).
// So assuming you know the extents of your map, you can calculate how many tiles it spans at the given scale, using the following
//
// number of tiles x = map width in meters / ( 0.079375 * map_scale)
// number of tiles y = map height in meters / ( 0.079375 * map_scale)
//
// where 0.079375 = [inch to meter] / image DPI * tile size = 0.0254 / 96 * 300.
//
// This assumes you know the scale factor that converts your map width and height to meters. You can get this from the coordinate system of the map if you don't know it, but it's much easier to just plug in the number into this equation.
//
// Also have in mind that you can also request tiles beyond the map extent (for example tile (-1, -1), however, there is probably no point to cache them unless you have valid data outside your initial map extents.
//The tile extent in meters
var tileMapWidth = ((INCH_TO_METER / _options.DPI * _options.TileWidth) * (scale));
var tileMapHeight = ((INCH_TO_METER / _options.DPI * _options.TileHeight) * (scale));
//Using this algorithm, yields a negative number of columns/rows, if the max scale is larger than the max extent of the map.
var rows = Math.Max(1, (int)Math.Ceiling((heightM / tileMapHeight)));
var cols = Math.Max(1, (int)Math.Ceiling((widthM / tileMapWidth)));
var ovExtents = _options.OverrideExtents;
if (ovExtents != null)
{
//The extent is overridden, so we need to adjust the start offsets
//and re-compute row/col span against the overridden extents
var offsetMapX = Math.Abs(metersPerUnit * (ovExtents.MinX - extents.MinX));
var offsetMapY = Math.Abs(metersPerUnit * (extents.MaxY - ovExtents.MaxY));
rowTileOffset = (int)Math.Floor(offsetMapY / tileMapHeight);
colTileOffset = (int)Math.Floor(offsetMapX / tileMapWidth);
//Re-compute rows/cols against override extent
widthM = Math.Abs(metersPerUnit * (ovExtents.MaxX - ovExtents.MinX));
heightM = Math.Abs(metersPerUnit * (ovExtents.MaxY - ovExtents.MinY));
rows = Math.Max(1, (int)Math.Ceiling((heightM / tileMapHeight)));
cols = Math.Max(1, (int)Math.Ceiling((widthM / tileMapWidth)));
}
//Collect the sub-totals for each group, so that we can then do one big array allocation with
//the grand total number of tile requests we are expecting to make at the end
foreach (var groupName in _options.GroupNames)
{
groups.Add(new TileGroupSet(groupName, rows, cols, scaleIndex, rowTileOffset, colTileOffset));
}
}
var capacity = groups.Sum(g => g.Total);
var tiles = new TileRef[capacity];
var current = 0;
foreach (var g in groups)
{
for (int r = 0; r < g.Rows; r++)
{
for (int c = 0; c < g.Cols; c++)
{
var row = r + g.RowTileOffset;
var col = c + g.ColTileOffset;
tiles[current] = new TileRef(g.GroupName, row, col, g.ScaleIndex);
current++;
}
}
}
return(tiles);
}
