San Vicente map MapGazer – getting started


Download MapGazer

Getting started

Using marks:
   Mark properties

Using icons

Using transparency

General settings

Getting maps

Using map tools

Go to location

Coordinate formats

GPX files

Elevation data

Aspect ratio

Keyboard shortcuts

Command line


Working with maps

MapGazer should first start with a default ‘Globe’ map displayed; if not, select the Map → Open map menu item (or press the ‘m’ or Ctrl-O key).  This will open a dialog which will allow you to choose a folder containing a map.  MapGazer reads and saves maps in the simple MGMaps format; for information on downloading maps in this format, see Getting maps.

To change the map position, you can:

  • left click on the map and drag the map (dragging also works if you have a touch screen)
  • use the keyboard arrow keys
  • select Map → Go to location (or right-click on the map and choose Go to location on the pop-up menu, or press the ‘g’ key) and enter a latitude and longitude or UTM coordinate (please see the Go to location dialog for details).

Every map has one or more zoom levels, or layers, which can present a view of the map at a different scale. Zoom level 0 is the least detailed (it can show almost the entire globe as one small image) whereas (for example) 1:25,000 topographical maps are typically presented at zoom level 15 or 16.

The scale at a given zoom level differs from the one above or below it by a factor of two (a Scale bar indicates the actual scale).  If part of the map is not available at the current selected level, MapGazer will try and use data from the next available lower (less-detailed) level, if any, to supply context.

To change the zoom level when viewing a map, you can:

  • move the cursor over the map and spin the scroll wheel forward (to zoom in) or back (to zoom out); this will keep the point under the cursor at the same position in the window
  • if you have a touch screen, the ‘pinch’ and ‘expand’ gestures should also zoom in or zoom out, centred on a point between your fingertips (you can also drag the map by touch)
  • right-click on the map and choose Zoom in or Zoom out on the pop-up menu, which will similarly keep the point clicked on static while zooming
  • use the Map → Zoom in or Map → Zoom out menu items, which will keep the centre of the view fixed
  • use the ‘i’ or ‘o’ keys to zoom in or out while keeping the centre of the view fixed.

Only the zoom levels that are included in the map data are displayed as read.  Empty layers will show a compressed version of the next-highest zoom level (if available) or an enlarged version of a lower-zoom level (if any).  Three ‘over-zoom’ levels are provided (where MapGazer enlarges the most detailed level so it is easier to read on higher-resolution displays).  Similarly, one ‘under-zoom’ layer can be displayed, which compresses the least-detailed layer of the map.  For example, if a map has only (say) Layer 8, then MapGazer will create views for layers 7 through 11 using that data.

To change the displayed map, select the Map → Change map menu item (or press the ‘m’ or Ctrl-O key); this will open a dialog which will allow you to choose a folder containing a map (MapGazer includes three sample maps).  If possible (that is, if the map covers the area currently viewed and has a layer at the same zoom level) the viewpoint and zoom level will not be changed, so you will see the same geography at the same zoom.

If the current viewpoint (the point displayed at the centre of the window) is on the new map but the current zoom is not available, the closest exact zoom level will be used.  If the current viewpoint is not on the new map then the centre of the new map will be shown.

To see an aerial view of the same location, select the Map → Browse satellite view menu item.  This will start a new session of your default browser to view the same geography, at the same zoom, using Google Maps (this will only work if you have an internet connection); a ‘pushpin’ is added at the centre of the MapGazer view.  This can also be requested by right-clicking on the map and selecting the option from the pop-up menu; in this case the satellite view will be centred on the point clicked and the’pushpin’ will be there too.

To overlay a second map over the base map, select the Map → Add overlay map menu item.  You can then vary its transparency using the Map → Map transparencies dialog (or press the ‘t’ key), or you can simply press the ‘+’ or ‘−’ keys.  Overlaying maps lets you see (for example) how geological information relates to topographic, or see street map information along with topography. For more details, please see Using transparency.

An active overlay map can be changed using Map → Change overlay map or removed using Map → Remove overlay map.  The overlay map options are also available from the map pop-up menu.

To save the current map view as an image, use Window → Snapshot current view ... (or press the ‘s’ key).  This will save the current view; if saved as .jpg this will include the position of the view centre and (if known) its elevation.

To copy the location at the cursor (the latitude and longitude, and the elevation if known), right-click on the map and select Copy location to clipboard from the map pop-up menu.

To copy map details to the clipboard, right-click on the map and select the Map details item on the pop-up menu; this will display a dialog with the strings that can be copied (map name, zoom levels, position clicked, etc.) MapGazer assumes that the bounds of a map are the bounds of the map layer with the most data (this may not be the maximum zoom level, which might have less coverage).

To construct new maps by copying, merging, or compressing layers from existing maps, see Using map tools.

To find the centre of the displayed map, select the Map → Go to map centre menu item (or press the ‘c’ key); this will find the centre of a mid-detailed zoom level of the map and adjust the view so that point is shown at the centre of the view. 

To lighten the base map (so things drawn over it are easier to see), see Using transparency.

The MapGazer package includes the Globe map (also used as the ‘fallback’ map when scrolling outside the bounds of other maps) and also a small but more detailed sample map together with a corresponding geological map and also elevation data.  To get more maps there are more sample maps on the MapGazer website, or you can download maps from online map servers. For the sample maps and some suggestions for download tools, please see Getting maps.

Working with marks (tracks, routes, waypoints, images, areas, and scales)

Marks are extra information that can be drawn on a map; they are often created by a GPS (Global Positioning System) device or smartphone application.  All marks can be loaded from or saved to GPX (Global Positions eXchange format) files.  The types of marks are:

  • track – a recording of a where the device has been (e.g., the path taken for a walk).  MapGazer lets you view tracks and also trim them to remove unwanted start and end points.

    For details and screenshots, please see Using Tracks.

  • route – typically a plan for a journey; it has a start point and an end point and often has intermediate route waypoints. MapGazer lets you view, create, and edit routes; you can also change the icon and other properties of route waypoints.

    For details and screenshots, please see Using Routes.

  • waypoint – a single site of interest, either recorded during a journey or created in some other manner.  MapGazer lets you view, create, and edit waypoints; you can also change the icon and colour used to indicate a waypoint.

    For details and screenshots, please see Using Waypoints.

  • image – an image that has a specific geographic place and size (defined by a South West point and a North East point).  Images cover the same map area whatever the selected zoom, so can be used to overlay drone or satellite images, cave surveys and other graphics, etc., onto a map.  MapGazer lets you change the shape and size of images.

    For details and a screenshot, please see Using Images.

  • area – a description of an area (a ‘rectangle’ defined by a South West point and a North East point), used for creating images from maps (of any size) or for saving subsets of a map.  MapGazer lets you view, create, and edit areas.

    For details and a screenshot, please see Using Areas.

  • scale – a visual indication of the scale of a map.  MapGazer lets you view, create, and modify scales.

    For details and a screenshot, please see Using Scales.

All marks all have associated status which will be shown (unless turned off using the Settings menu item) at the top left of the screen.  Marks also have associated properties, including a name, colour, and web link (URL, Universal Resource Locator) – MapGazer lets you edit these.

Right-click on any mark for a pop-up menu of actions that can be carried out on the mark, including inspecting details (such as the length of a track or route – most details can be copied to the clipboard), browsing its link, editing its properties (name, colour, icon, link URL, etc.), allowing it to be dragged, moving between marks of the same type, saving it to a GPX file, etc.

To load a GPX file, drag the the file from File Explorer to a MapGazer window or icon.  Alternatively, use the Marks → Load marks from GPX file menu item (or press the ‘L’ key); this will open a dialog which you can use to select the GPX file to open. Any tracks, routes, etc., in the loaded file will then immediately be marked on the map (you may have to zoom or change the map, or move it, for the marks to be in view, but MapGazer will attempt to centre the map on newly-loaded geographical marks).  Depending on the source of the GPX file, marks may have a default colour or may have a colour selected at the time they were created.

If you associate MapGazer with the file extension .gpx then opening a file with that extension will start MapGazer and load that GPX file.

Marks loaded from a GPX file are initially ‘locked in position’ to prevent accidental relocation.  Use the mark’s pop-up menu and select Allow dragging to unlock a mark.

By default, marks are drawn ‘solid’ (opaque) on the map.  You can change that so the map shows through – see Using transparency.

To save all marks to a GPX file, use the Marks → Save marks to GPX file menu item (or press the ‘s’ key).

To find the nearest geographical mark, use Mark → Go to nearest mark.

To delete (clear) all marks, use the Marks → Delete all marks menu item (you will be asked to confirm if any have been changed but not saved).

Windows and window options

A map view is a window on the screen which displays a map.  You can have more than one window open and each window can display any available map (with overlay maps) at any available zoom.  This lets you compare maps, or view the same map (or marks on a map) at different places or zoom levels.

To add a new view window, select the Window → New window (view) menu item, or press the ‘v’ key.  You can add multiple windows and close (delete) them in any order; the application will keep running until you close all open windows.

To save the current view as an image, use Window → Save current view as image....

To set a specific window aspect ratio, select Window → Change aspect ratio; for details, see the Aspect Ratio page.

The window options (also under the Window menu item) let you change the appearance of the window.  For example, to increase the amount of the window used for the map you can choose not to show the menu bar and/or title bar (the menu bar can be turned back on by right-clicking on the map to get a pop-up menu).

You can also maximize or minimize the window from the menu, or request that it be made full-screen (you can also use the Esc (Escape) key for this).  When full-screen, only the map is shown (to then restore it to a normal window press the Esc (Escape) key or right-click on the map for the pop-up menu and choose Restore).  Similarly, you can choose Full Screen from that pop-up menu at other times).

Settings, Help, etc.

The Settings menu lets you change settings that apply to all windows, including the units to use for measurements, the format used for Latitude and Longitude, the status information to be displayed, the option of using a precision ‘crosshair’ cursor, and diagnostic settings.

For details, please see General settings.

The Help menu items let you view these help pages locally or browse the MapGazer web pages (these are the same as the local pages). The About MapGazer menu item confirms the version and origin of the application.

MapGazer may be started from the command line, or a script, to load specified GPX files, etc.  It can also be started by clicking on a .gpx file. For more details, please see the Command line help page.

MapGazer and these web pages were written by Mike Cowlishaw; Please send me any corrections, suggestions, etc.
All content Copyright © Mike Cowlishaw, 2014–2022, except where marked otherwise.  All rights reserved. The pages here, and the MapGazer program, are for non-commercial use only. Privacy policy: the Speleotrove website records no personal information and sets no ‘cookies’. However, statistics, etc. might be recorded by the web hosting service.

This page was last updated on 2022-02-23 by mfc.