Declaration

TIESlippyMap = class(TIEVirtualBitmapProvider);

Description

Slippy Map is a term referring to the main openstreetmap.org map display, a web interface for browsing rendered OpenStreetMap data (from openstreetmap wiki).
For more detail: wiki.openstreetmap.org/wiki/Slippy_Map

TIESlippyMap is a virtual image provider for TIEBitmap objects. Selecting a position using Latitude and Longitude a map (an image) will be loaded and handled as TIEBitmap content.
Local caching is provided to speed up re-loading tiles and to support off-line jobs.

Demo

Example

ImageEnView1.IEBitmap.VirtualBitmapProvider := TIESlippyMap.Create();
with TIESlippyMap(ImageEnView1.IEBitmap.VirtualBitmapProvider) do
begin
  // move to London
  Latitude  := 51.503614574056016;
  Longitude := -0.12774750793460043;
  // location at bitmap center
  PointPosition := Point(ImageEnView1.IEBitmap.Width div 2, ImageEnView1.IEBitmap.Height div 2);
  // zoom
  Zoom := 14;
end;
ImageEnView1.Update();

// Save an image with pins drawn for GPS coordinates
const
  Pin_Width  = 40;
  Pin_Height = 40;
var
  i: integer;
  idx: integer;
  lat, lon: double;
  x, y: integer;
  fn: string;
begin
  // Prompt for a filename
  fn := ImageEnView1.IO.ExecuteSaveDialog();
  if fn = '' then
    exit;

  // Hide changes from view
  ImageEnView1.LockUpdate();
  try

    // Add pins as shape layers
    for i := 0 to ImageEnMView1.MultiSelectedImagesCount - 1 do
    begin
      idx := ImageEnMView1.MultiSelectedImages[i];
      lat := ImageEnMView1.MIO.Params[idx].EXIF_GPSLatitude;
      lon := ImageEnMView1.MIO.Params[idx].EXIF_GPSLongitude;
      x := map.LongitudeToBmpX(lon);
      y := map.LatitudeToBmpY(lat);

      ImageEnView1.LayersAdd( iesPinLeft, x, y - Pin_Height, Pin_Width, Pin_Height );
    end;

    // Save current image + layers to file
    ImageEnView1.LayersSaveMergedTo( fn );

    // Clean up
    ImageEnView1.LayersClear(False);

  finally
    // Reenable ImageEnView1
    ImageEnView1.UnlockUpdate();
  end;
end;

Methods and Properties

Constructor

Generic Rendering

TIEVirtualBitmapProvider rendering

Multithreading and Cache

Map Coordinates and Zooming

Coordinates Conversion

Other

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