triapi

function drawLine(x1, y1, x2, y2)
        local pixs = {}
        if nColour then
                        term.setBackgroundColor( nColour )
                end

                x1 = math.floor(x1)
                y1 = math.floor(y1)
                x2 = math.floor(x2)
                y2 = math.floor(y2)

                if x1 == x2 and y1 == y2 then
                        if pixs[x1] == nil then pixs[x1] = {} end
                        pixs[x1][y1] = true
                        return pixs
                end

                local minX = math.min( x1, x2 )
                if minX == x1 then
                        minY = y1
                        maxX = x2
                        maxY = y2
                else
                        minY = y2
                        maxX = x1
                        maxY = y1
                end

                local xDiff = maxX - minX
                local yDiff = maxY - minY

                if xDiff > math.abs(yDiff) then
                        local y = minY
                        local dy = yDiff / xDiff
                        for x=minX,maxX do
                                if pixs[x] == nil then pixs[x] = {} end
                                pixs[x][math.floor(y + 0.5)] = true
                                y = y + dy
                        end
                else
                        local x = minX
                        local dx = xDiff / yDiff
                        if maxY >= minY then
                                for y=minY,maxY do
                                        if pixs[math.floor(x+0.5)] == nil then pixs[math.floor(x+0.5)] = {} end
                                        pixs[math.floor(x+0.5)][y] = true
                                        x = x + dx
                                end
                        else
                                for y=minY,maxY,-1 do
                                        if pixs[math.floor(x+0.5)] == nil then pixs[math.floor(x+0.5)] = {} end
                                        pixs[math.floor(x+0.5)][y] = true
                                        x = x - dx
                                end
                        end
                end
                return pixs
end

function getTriangle(p1, p2, p3)
    local tab1 = drawLine(p1[1], p1[2], p2[1], p2[2])
    local tab2 = drawLine(p1[1], p1[2], p3[1], p3[2])
    local tab3 = drawLine(p2[1], p2[2], p3[1], p3[2])
    local tabs = {tab1, tab2, tab3}
    local triangle = {}
    for i=1,#tabs do
        local tab = tabs[i]
        for x,v in pairs(tab) do
            if v ~= nil then
                if triangle[x] == nil then triangle[x] = {} end
                for y,r in pairs(v) do
                    triangle[x][y] = r
                end
            end
        end
    end
    return triangle
end

local function getSize(tab)
    local size = 0
    for i,v in pairs(tab) do size = size + 1 end
    return size
end

local function getLastIndex(tab)
    local index = 1
    for i,v in pairs(tab) do
        if type(i) == "number" then
            if tonumber(i) > index then index = tonumber(i) end
        end
    end

    return index
end

local w,h = term.getSize()

function fillTriangle(tri)
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    local minX, maxX = nil
    local minys = {}
    local ntri = {}
    for x,v in pairs(tri) do
        if minX == nil then
            minX = x
        elseif x < minX then
            minX = x
        end

        if maxX == nil then
            maxX = x
        elseif x > maxX then
            maxX = x
        end

        if v ~= nil then
            if ntri[x] == nil then ntri[x] = {} end
            local minY = nil
            for y,r in pairs(v) do
                ntri[x][y] = r
                if minY == nil then
                    minY = y
                elseif y < minY then
                    minY = y
                end
            end
            if minY ~= nil then
                minys[x] = minY
            end
        end
    end

    if minX ~= nil and maxX ~= nil then
        for x=minX, maxX do
            if minys[x] ~= nil then
                local y = minys[x]
                if tri[x] ~= nil then
                    if ntri[x] == nil then ntri[x] = {} end
                    if getSize(tri[x]) > 1 then
                        local lasti = getLastIndex(tri[x])
                        for iy=y,lasti do
                            ntri[x][iy] = true
                        end
                    end
                end
            end
        end
    end
    return ntri
end

function fillSquare(p1, p2, p3, p4)
    local tri1 = fillTriangle(getTriangle(p1, p2, p3))
    local tri2 = fillTriangle(getTriangle(p1, p4, p3))
    local tris = {tri1, tri2}
    local square = {}
    for i=1,#tris do
        local tri = tris[i]
        for x,v in pairs(tri) do
            if v ~= nil then
                if square[x] == nil then square[x] = {} end
                for y,r in pairs(v) do
                    square[x][y] = true
                end
            end
        end
    end
    return square
end

function drawShape(shape, color, textcolor, text)
    for xt,v in pairs(shape) do
        if v ~= nil and type(v) == "table" then
            for yt,r in pairs(v) do
                if type(r) == "boolean" and type(yt) == "number" then
                    term.setCursorPos(xt, yt)
                    term.setBackgroundColor(color)
                    term.setTextColor(textcolor)
                    term.write(text)
                end
            end
        end
    end
end