Love2d rendering

local tShapes={}
local tOrigin={400,1}
local nTimeElapsed=0
local nSecCount=0
local tTemplates={}
local shape_mt={}

local function rotatePoint(x,y,rad)
    local ang=math.atan2(y,x)+rad
    local len=(x^2+y^2)^0.5
    return math.cos(ang)*len,math.sin(ang)*len
end

shape_mt.__index=function(self,index)
    return shape_mt[index]
end
local tAxis={{"x","y"},{"x","z"},{"z","y"}}
shape_mt.rotate=function(self,tDegs,tOrigins)
    self.rotated=self.rotated or {}
    tOrigins=tOrigins or {}
    local sIndex
    for k,v in pairs(self.nodes) do sIndex=k break end
    tOrigins.x,tOrigins.y,tOrigins.z=tOrigins.x or self.nodes[sIndex].x,tOrigins.y or self.nodes[sIndex].y,tOrigins.z or self.nodes[sIndex].z
    for num,nDeg in pairs(tDegs) do
        self.rotated[num]=(self.rotated[num]+nDeg)%360
        local axis1=tAxis[num][1]
        local axis2=tAxis[num][2]
        for _,tNode in pairs(self.nodes) do
            local rotatedx,rotatedy=rotatePoint(tNode[axis1]-tOrigins[axis1],tNode[axis2]-tOrigins[axis2],math.rad(nDeg))
            tNode[axis1]=rotatedx+tOrigins[axis1]
            tNode[axis2]=rotatedy+tOrigins[axis2]
        end
    end
end
tTemplates.rectangle=function(x1,y1,z1,x2,y2,z2)
    local ref=#tShapes+1
    tShapes[ref]=setmetatable({rotated={0,0,0},nodes={
    bo={x=x1,y=y1,z=z1,links={{"bx",colors={255,0,0}},{"bz",colors={255,0,0}},"ro"}},
    bx={x=x2,y=y1,z=z1},
    bz={x=x1,y=y1,z=z2},
    ro={x=x1,y=y2,z=z1},
    rx={x=x2,y=y2,z=z1,links={"bx",{"ro",colors={0,0,255}},{"rb",colors={0,0,255}}}},
    rz={x=x1,y=y2,z=z2,links={"bz",{"ro",colors={0,0,255}},{"rb",colors={0,0,255}}}},
    rb={x=x2,y=y2,z=z2},
    bb={x=x2,y=y1,z=z2,links={{"bx",colors={255,0,0}},{"bz",colors={255,0,0}},"rb"}},
    center={x=(x2-x1)/2+x1,y=(y2-y1)/2+y1,z=(z2-z1)/2+z1},
    }},shape_mt)
    return tShapes[ref],ref
end

local myRec=tTemplates.rectangle(30,30,30,90,60,60)
local rec2=tTemplates.rectangle(0,30,0,20,40,20)
rec2:rotate({5,0,0},rec2.nodes.center)

local function convert(x,y,z)
    local c=math.cos(math.rad(30))
    local s=math.sin(math.rad(30))
    return z*c-x*c,y+z*s+x*s
end

function love.load()
    love.graphics.setBackgroundColor(0,0,0)
end

local rotated=0
function love.update(nTime)
    rotated=(rotated)%216+1
    --rec2:rotate({5,0,4},rec2.nodes.center)
    rec2:rotate({5,0,4},{})
    myRec:rotate(rotated>144 and {0,0,5} or rotated>72 and {0,5,0} or {5,0,0},myRec.nodes.center)
    myRec:rotate({1,0,0},{x=60,y=250,z=45})
    nTimeElapsed=nTimeElapsed+nTime
end

function love.draw()
    love.graphics.setColor(255,255,255)
    love.graphics.print(table.concat(rec2.rotated,","),0,0)
    local x1,y1=convert(60,250,45)
    local x2,y2=convert(myRec.nodes.center.x,myRec.nodes.center.y,myRec.nodes.center.z)
    love.graphics.line(tOrigin[1]+x1,tOrigin[2]+y1,tOrigin[1]+x2,tOrigin[2]+y2)
    for _,tShape in pairs(tShapes) do
        for _,tNode in pairs(tShape.nodes) do
            local nodeX,nodeY
            if tNode.z then
                nodeX,nodeY=convert(tNode.x,tNode.y,tNode.z)
            else
                nodeX,nodeY=tNode.x,tNode.y
            end
            for _,nLink in pairs(tNode.links or {}) do
                local colors={255,0,255}
                if type(nLink)=="table" then
                    colors=nLink.colors
                    nLink=nLink[1]
                end
                local tLink=tShape.nodes[nLink]
                local linkX,linkY
                if tLink.z then
                    linkX,linkY=convert(tLink.x,tLink.y,tLink.z)
                else
                    linkX,linkY=tLink.x,tLink.y
                end
                love.graphics.setColor(unpack(colors))
                love.graphics.line(tOrigin[1]+nodeX,tOrigin[2]+nodeY,tOrigin[1]+linkX,tOrigin[2]+linkY)
            end
        end
    end
end