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Drawing maps with Lua.
Updated Sun, 17 Jan 2016 12:43:55 +0000 by Wuzzy

Drawing maps with Lua (OUTDATED)


Starting in 0.9.18 it is possible to reliably use drawn map mode to draw maps with scripts. A simple example is given below. Note that Drawn maps use an area of 4096x2048. The examples below are static, but obviously this could be used for a random map variation - for example, simulating the Cave map by doing the fill below, then drawing random tunnels using circles that shift their course smoothly.


First, a couple of convenience functions for drawing to the map. PointsBuffer = '' -- A string to accumulate points in function AddPoint(x, y, width, erase) PointsBuffer = PointsBuffer .. string.char(band(x,0xff00) / 256 , band(x,0xff) , band(y,0xff00) / 256 , band(y,0xff)) if width then width = bor(width,0x80) if erase then width = bor(width,0x40) end PointsBuffer = PointsBuffer .. string.char(width) else PointsBuffer = PointsBuffer .. string.char(0) end if #PointsBuffer > 245 then ParseCommand('draw '..PointsBuffer) PointsBuffer = '' end end function FlushPoints() if #PointsBuffer > 0 then ParseCommand('draw '..PointsBuffer) PointsBuffer = '' end end AddPoint? takes an x and y location for the point, a width (indicates the start of a new line) and erase (whether the line is erasing from the map). The width calculation is described in DrawnMapFormat.

FlushPoints? writes out any values from PointsBuffer? that have not already been sent to the engine. It would be called at the end of a drawing session.

A simple example below.

function onGameInit() MapGen = 2 TemplateFilter = 0 AddPoint(100,100,10) AddPoint(2000,2000) AddPoint(2000,100,10) AddPoint(100,2000) AddPoint(1000,1000,63,true) AddPoint(1000,1000,20) for i = 63,2,-4 do AddPoint(2000,1000,i) AddPoint(2000,1000,i-2,true) end for i = 1,2000,50 do AddPoint(i+2000,2000,1) AddPoint(4000,2000-i) end AddPoint(2000,2000,1) AddPoint(4000,2000) AddPoint(4000,0,1) AddPoint(4000,2000) FlushPoints() end The first set of AddPoints? draws a large X and erases the centre. The following loop draws a set of nested points, alternating erasure and fill, which results in a set of concentric circles. The 2nd loop draws a web of lines and frames it using some final AddPoints.

screenshot here

Another brief example. for i = 200,2000,600 do AddPoint(1,i,63) AddPoint(4000,i) end for i = 500,3500,1000 do AddPoint(i,1000,63,true) end FlushPoints() This one fills the map with solid land, and draws 4 circular erased points in it.

screenshot here