Map This!/Old version

The application supports map tiles compatible with Google Maps' grid (see below for acquisition options).

Tips & tricksEdit

Here is a few things, not mention in the original README file:

  • you can generate maps with negative zoom value with some services, but check the preview to make sure the data is available for your area first.
  • you can delete some zoom levels to save space by deleting Nx folders inside your map's folder. You cannot wipeout the 1x (base) zoom folder though.
  • Negative zoom works (except for Google Map - which only goes down to 0). In my experience, Google Satellite goes to -3 (to -4 in Vegas), all Local.Live maps go to -2.
  • The Google Maps Download.exe will work on its own(icons and resources folders and config.txt should be in the same directory) (just compile a release version which will be marginally faster, or copy the one out of bin/Debug). I will not release "just the exe" since I think it's important for people to have the source and not just run some random application.

Ready Made MapsEdit Star Maps - with lat/lon Subways (New York, London, Moscow, and Toronto) - no lat/lon - Lithuanian maps (with mapViewer program) USGS topographic maps of US parks Various maps aligned and rendered with MapCruncher / topographic maps aligned and rendered with MapCruncher topographic maps of Canadian parks rendered with MapCruncher

Ready Made POI FilesEdit UK Speed Cameras (to be rehosted)


This has not yet been finalized or made it into a release version of Map This!, so just here for reference.

Credit goes to Juanito, who created the original FS draft, thanks.

#          __________
# 0-7     | GPSFSV01 |
# 	  |----------|
# 8	  |    X     |
# 	  |----------|
# 16      |    Y     |
# 	  |----------|
# 24      | basezoom |
# 	  |----------|
# 32      | filetype |
# 	  |----------|
# 40      | maxsize  |
# 	  |----------|
# 48      |   IDX0   |
# 	  |----------|
# 56      |   IDX1   |
# 	  |__________|
# 	       .
# 	       .
# 	       .
#          __________
# 	  | IDX N    | - points to GPSFSEOF 
# 	  |----------|
#         |   PNG0   |
# 	  |----------|
# ..      |   PNG1   |
# 	  |----------|
# 	       .
# 	       .
# 	       .
#          __________
# 	  | PNG N-1  | - last image
# 	  |----------|
#         | GPSFSEOF |
# 	  |__________|


48 bytes, all Int64's are signed

Format Value Description
char[8] GPSFSV01
Int64 x from coords.txt
Int64 y from coords.txt
Int64 basezoom from coords.txt
Int64 filetype 0 = png, 1 = jpg
Int64 maxsize (N) number of tiles (including missing)

Note: if x and/or y are negative it is interpreted as coords.txt is missing


8 * (N + 1) bytes, all Int64's are signed

Format Value Description
Int64 IDX0 points (including header byte (48) offset) to first image
Int64 IDX1 points (including header byte (48) offset) to second image
... ... ...
Int64 IDXN-1 points (including header byte (48) offset) to last (Nth) image
Int64 IDXN points to GPSFSOEF marker

Note from Pontomedon: in maps created with the GMDL (Global Map Download Tool) by in7ane ( IDXN actually doesn't point to the GPSFSEOF marker, but instead contains the negative size of the last image (As if there was a (missing) (N+1)th image)


  • Number of IDX entries is always fixed and equals to the max number of tiles for given map size.
  • This way any IDXn entry is completely defined as offset from the beginning of the file.
  • The IDX section cover the most distant zoom tiles first. Here is the example:




IDX.->4x015015 <last tile at this level>





Note from Pontomedon: This example is a bit confusing, since IDX0 actually points to 1x000000 which is the top left tile in the "most-zoomed-in" zoom-level.

The example should be like: A map with 4 levels (1x, 2x, 4x, 8x) (340 tiles)








IDX255->1x015015 <last tile at level 1x>

IDX256->2x000000 <first tile at level 2x>


IDX319->2x007007 <last tile at level 2x>

IDX320->4x000000 <fist tile at level 4x>


IDX335->4x003003 <last tile at level 4x>

IDX336->8x000000 <fist tile at level 8x>


IDX339->8x001001 <last tile at level 8x>


  • IDX offsets are relative to the beginning of the map file: IDX0 = [00100000] means that the PNG0 starts 100000 bytes from the beginning of the file.
  • If a tile is omitted - the corresponding index has a negative number. The absolute value of this entry should be equal to the file size of previous entry. Example:

IDX0 00010000 non-empty PNG 1K size

IDX1 00011000 non-empty PNG 3K size

IDX2 -0003000 empty file

IDX3 -0003000 empty file - don't really care what value is as long as it's negative

IDX4 00014000 non-empty file - size is determined by next index entry

5 File Span ChangeEdit

Changes from the previous format:

There are now 5 files (GPSFS, GPSFS1, GPSFS2, GPSFS3, and GPSFS4) - at this stage latter ones will be missing for a 4 tile map (this may cause problems in Map This! - test).

The IDX fields have been split into IDXfile and IDXidx both being int32's (other numerics stay int64) IDXfile is 0 to 4 IDXidx has the same logic as before EXCEPT it resets to 0 for each new file - so (1) if the next IDX is 0 use file.length instead (2) if you were using idx > 0 to identify existing tiles that needs to be >= 0 now (yes, took me ages to find in my own code).