triTest

local mon = peripheral.find("monitor")
local ar = peripheral.find("arController")
local oldTerm = term.redirect(mon)
mon.setTextScale(0.5)
mon.setCursorPos(1,1)
mon.clear()
term.setCursorPos(1,1)
term.clear()
ar.clear()

local function drawFlatBottomTriangleTex( arController,vec1,vec2,vec3,tex )
    local m1 = (vec2.x - vec1.x) / (vec2.y - vec1.y)
    local m2 = (vec3.x - vec1.x) / (vec3.y - vec1.y)

    local yStart = math.ceil(vec1.y-0.5)
    local yEnd =   math.ceil(vec3.y-0.5)-1

    local C = vec2 --Bottom left
    local B = vec1 --Top
    local A = vec3 --Bottom Right

    arController.drawString(A.u..", "..A.v ,A.x+100, A.y, 0xFF00FF)
    arController.drawString(B.u..", "..B.v ,B.x+100, B.y, 0xFF00FF)
    arController.drawString(C.u..", "..C.v ,C.x+100, C.y, 0xFF00FF)

    local tWidth = tex.size.x
    local tHeight = tex.size.y

    for y = yStart, yEnd do
        local px1 = m1 * (y + 0.5 - vec1.y) + vec1.x
        local px2 = m2 * (y + 0.5 - vec1.y) + vec1.x
        local xStart = math.ceil(px1 - 0.5)
        local xEnd =   math.ceil(px2 - 0.5)
        for x = xStart, xEnd do
            if y > 0 and x > 0 then

                local w1 =
                    ( (A.x*(C.y - A.y)) + ((y - A.y)*(C.x - A.x)) - (x*(C.y - A.y)) )
                    / ( ((B.y - A.y) * (C.x - A.x)) - ((B.x - A.x) * (C.y - A.y)) )

                local w2 = (y - A.y - (w1 * (B.y - A.y))) / (C.y - A.y)

                local w3 = 1-w1-w2

                print(w1,w2,w3)

                local u = (w1*A.u)+(w2*B.u)+(w3*C.u)
                local v = (w1*A.v)+(w2*B.v)+(w3*C.v)

                local tu = math.floor(u * tWidth)
                local tv = math.floor(v * tHeight)

                local color
                local colIndex = (tv*tWidth + tu)
                --local colIndex = ((y-(yStart-1))*tWidth + (x-(xStart-1)))
                if tex[ colIndex ] then
                    color = tex[ colIndex ] --Look up the pixel color in the image texture
                else
                    color = 0xFF00FF
                end

                arController.horizontalLine(x, x, y, color)
            end
        end
    end
end

local function getTex(fileName)
    local f, err = fs.open(fileName, "r")
    assert(f, err)
    local fileData = textutils.unserialize(f.readAll())
    f.close()
    return fileData
end

local shronk = getTex("shrekC")

local v1 = { x = 100, y = 100, z = 4, u = 0, v = 1, }

local v2 = { x = 100,  y = 200, z = 4, u = 0, v = 0, }

local v3 = { x = 200, y = 200, z = 4, u = 1, v = 0, }

drawFlatBottomTriangleTex(ar, v1 , v2, v3, shronk)