AoE4 Generated Map Function: Draw Box

drawBox.lua

--draws a box starting from top left coordinates and expands down and to the right
--copy and paste code to preview at https://aoe4.app/

--rowCoord is the top left row of where your box draw begins
--colCoord is the top left col of where your box draw begins
--rowSize how far down do you want to draw your box
--colSize how far across do you want to draw your box
--pickedTerrain the terrainType e.g. tt_lake_shallow
function drawBox(rowCoord, colCoord, rowSize, colSize, pickedTerrain)
    
    --checks to see if coords exist in table
    --used to prevent out of bounds areas from being set
    local function isInTable(searchTable, row, col)
        if (searchTable[row] ~= nil and searchTable[col] ~= nil) then
            result = true
        else
            result = false
        end
        return result
    end
    
    drawRowSize = rowCoord + rowSize - 1
    drawColSize = colCoord + colSize - 1
    
    for row = rowCoord, drawRowSize do
        for col = colCoord, drawColSize do
            if (isInTable(terrainLayoutResult, row, col)) then
                terrainLayoutResult[row][col].terrainType = pickedTerrain
            end
        end
    end
end

--example
drawBox(mapQuarterSize, mapQuarterSize, mapHalfSize, mapHalfSize, tt_lake_shallow)