Creating Scrolling Terrain - Page 5

The Terrain Controller Movie Clip

There is an object on the main timeline called "terrain controller". This object -- you guessed it -- controls all the terrain. That is, it decides when to duplicate terrain and where to put it. Each terrain piece then automatically lives out its little life scrolling down the screen, then disappearing, all by itself.

Comment: the marker will tell us when to draw the next row of terrain
If (GetProperty("../marker",_y)<%gt%>45)
    Go to and Play ("draw_next")
End If

The marker simply moves itself down the screen exactly as a terrain piece does....
Since all the terrain pieces are exact squares, 50 pixels wide, and /:tmov is "5", once the maker is beyond 45 we reset it to zero (that happens later in the terrain controller). It is essentially just another terrain piece, but with no graphics. I should have done this with variables for tidyness' sake. It should have read "If Marker's Y position is greater than (50-/:tmov) Then..." but it does not. The majority of the code in this piece is tidy, but this is something that could be cleaned up.

Here is all the "marker" does to move itself...

Set Property ("", Y Position) = GetProperty("",_y)+/:tmov