function setup()
    --this block assumes we are looking at it top down, ie using OpenGL defaults
    blockTop=MakeBlock(20,30,50,nil,readImage("Platformer Art:Block Brick"))
    --now make another block that will look exactly the same if viewed from the front
    --we need to swap the y and z values, after changing the sign of the z values first
    --I'm lazy, so first I'll just make an exact copy of the first block
    --this saves me having to copy texture positions etc, all I need to do is modify the vertex positions
    blockFront=MakeBlock(20,30,50,color(255,0,0),readImage("Platformer Art:Block Brick"))
    blockFront:setColors(color(255,255,0)) --give it a tint so we see when it is used
    --this is how you modify vertex positions in a mesh, first get a reference to them
    local vec=blockFront:buffer("position")
    for i=1,blockFront.size do
        local v=vec[i]
        vec[i]=vec3(vec[i].x,-vec[i].z,vec[i].y) --swap y,z, change sign of z
    end
    camDistance=200 --camera settings
    camHeight=50
    camX=-50
    View=1 --we'll swap between the two views every couple of seconds
    lastSwapTime=0
end

function draw()
    background(0)
    fill(255) fontSize(18)
    if View==1 then text("Top down view",WIDTH/2,600) else text("Front view",WIDTH/2,600) end
    text("Adjusted",WIDTH/2,200)
    text("Not adjusted",WIDTH/2+200,200)
    perspective()
    if View==1 then --top down
        camera(camX,camHeight,camDistance,0,0,0,0,1,0)
        blockTop:draw()
    else --front facing
        camera(camX,-camDistance,camHeight,0,0,0,0,0,1)
        blockFront:draw()
    end
    --draw blockTop to the side as well
    translate(50,0,0)
    blockTop:draw()
    if ElapsedTime>lastSwapTime+2then
        View=3-View
        lastSwapTime=ElapsedTime
    end
end

function MakeBlock(w,h,d,c,tex) --width,height,depth, colour,texture
    local m=mesh()
    --define the 8 corners of the block ,centred on (0,0,0)
    local fbl=vec3(-w/2,-h/2,d/2) --front bottom left
    local fbr=vec3(w/2,-h/2,d/2) --front bottom right
    local ftr=vec3(w/2,h/2,d/2) --front top right
    local ftl=vec3(-w/2,h/2,d/2) --front top left
    local bbl=vec3(-w/2,-h/2,-d/2) --back bottom left (as viewed from the front)
    local bbr=vec3(w/2,-h/2,-d/2) --back bottom right
    local btr=vec3(w/2,h/2,-d/2) --back top right
    local btl=vec3(-w/2,h/2,-d/2) --back top left
    --now create the 6 faces of the block, each is two triangles with 3 vertices (arranged anticlockwise)
    --so that is 36 vertices
    --for each face, I'm going to start at bottom left, then bottom right, then top right, and for the second
    --triangle, top right, top left, then bottom left
    local v={
        fbl,fbr,ftr, ftr,ftl,fbl, --front face
        bbl,fbl,ftl, ftl,btl,bbl, --left face
        fbr,bbr,btr, btr,ftr,fbr, --right face
        ftl,ftr,btr, btr,btl,ftl, --top face
        bbl,bbr,fbr, fbr,fbl,bbl, --bottom face
        bbr,bbl,btl, btl,btr,bbr --back face
    }
    m.vertices=v
    local t={}
    if tex then
        --add texture positions, we will use the same image for each face so we only need 4 corner positions
        local bl,br,tr,tl=vec2(0,0),vec2(1,0),vec2(1,1),vec2(0,1)
        for i=1,6 do --use a loop to add texture positions for each face, as they are the same for each face
            t[#t+1],t[#t+2],t[#t+3],t[#t+4],t[#t+5],t[#t+6]=bl,br,tr,tr,tl,bl
        end
        m.texCoords=t
        m.texture=tex
        m:setColors(color(255))
    else m:setColors(c)
    end

    return m,v,t,c
end