Since I started practicing for my first marathon, I had the problem that I never knew the distance of my usual training tracks. I needed a tool for easily measuring these distances on a map. And that's what MaDiCal was designed to do.
Given a GIF image of a map that you loaded you can:
At first, you want to load a new map image by selecting File->New map.
Press and hold left mouse button while moving the mouse to grab and move the map around in the window.
Set a node of a track at the current map position by pressing the right mouse button. The nodes will be connected by straight lines in the order you place them. To remove the last node of the track press the middle mouse button anywhere on the map. The current length of the track is displayed in the lower right corner of the window.
Well, just use the right mouse button to set the points that will be connected by straight lines. Smooth curves are not supported and are not of much use either. The straight line sections work fine for me.
If you want MaDiCal to remember the current track for later use, select Action->Remember Track from the menu. Then you will be requested to enter a name for this track. You can later show this track by simply selecting it from the Tracks menu.
To let MaDiCal to forget a remembered track, select it from the Tracks menu and then select Action->Forget track.
Note: Only tracks that are remembered and thus listed in the Tracks menu will be saved with the map.
Hint: The tracks menu is a tear-off menu; this means that if you click on the first entry that looks like a separator, the menu detaches and becomes a window where you can select the tracks from.
Select the track from the Tracks menu and invoke Action->Forget track. This will leave the track shown in the map. Now you can just remember it again with the new name using Action->Remember track.
Once the image is loaded, you should define the scale. This part is most important and should be done very accurate. When you select Action->Redefine scale a dialog pops up where you should enter a distance of the map image in pixels and the according real distance. Select the unit you want and enter the correct distance.
If there is a track defined when you open the scale dialog, then the track distance in pixels will be inserted in the pixels entry field. Most maps have a scale drawn in a corner. If you define a track along it you only have to set the scale distance in the scale dialog and you're done.
If you have selected a unit other than pixels and change units, the value will be changed accordingly. That's useful if you know the map scale in another unit than the one you'd like to use.
The menu button Action->Clear track removes the currently shown track from the display. It does not delete the track if it was remembered. But you cannot get a cleared track back if it wasn't remembered.