Is point in triangle

gistfile1.txt

function setup()
    A={}
    n=10000
    for i=1,n do
        A[i]=vec2(math.random(0,WIDTH),math.random(0,HEIGHT))
    end
    v1,v2,v3=vec2(445,30),vec2(150,500),vec2(600,600)
    parameter.integer("Method",1,4,1)
    methods={IsPointInTriangleBary,IsPointInTrianglePara,IsPointInTriangleDot,IsPointInTriangleDot2}
    local n1=vec2(v2.y-v1.y,v1.x-v2.x)
    local n2=vec2(v1.y-v3.y,v3.x-v1.x)
    for j=1,4 do
        f=methods[j]
        t=os.time()
        for i=1,n do
            a=f(A[i],v1,v2,v3,n1,n2)
        end
        print(j,os.time()-t,(os.time()-t)*60/n)
    end
end

function draw()
    --[
    background(150)
    strokeWidth(2) stroke(0)
    line(v1.x,v1.y,v2.x,v2.y)
    line(v1.x,v1.y,v3.x,v3.y)
    line(v3.x,v3.y,v2.x,v2.y)
    f=methods[Method]
    local n1=vec2(v2.y-v1.y,v1.x-v2.x)
    local n2=vec2(v1.y-v3.y,v3.x-v1.x)
    for i=1,1000 do
        if f(A[i],v1,v2,v3,n1,n2) then fill(0,0,255) else fill(255,0,0) end
        ellipse(A[i].x,A[i].y,10)
    end
    --]]
end

function IsPointInTriangleBary(p,p1,p2,p3)
    local x,y,x1,y1,x2,y2,x3,y3=p.x,p.y,p1.x,p1.y,p2.x,p2.y,p3.x,p3.y
    local d=((y2 - y3)*(x1 - x3) + (x3 - x2)*(y1 - y3))
    local a = ((y2 - y3)*(x - x3) + (x3 - x2)*(y - y3)) / d
    if a<0 or a>1 then return false end
    local b = ((y3 - y1)*(x - x3) + (x1 - x3)*(y - y3)) / d
    if b<0 or b>1 then return false end
    local c = 1 - a - b
    if c<0 or c>1 then return false else return true end
end

function IsPointInTrianglePara(p,p1,p2,p3)
    local x,y,x1,y1,x2,y2,x3,y3=p.x,p.y,p1.x,p1.y,p2.x,p2.y,p3.x,p3.y
    local d=(x1*(y2 - y3) + y1*(x3 - x2) + x2*y3 - y2*x3)
    t1 = (x*(y3 - y1) + y*(x1 - x3) - x1*y3 + y1*x3) / d
    if t1<0 or t1>1 then return false end
    t2 = (x*(y2 - y1) + y*(x1 - x2) - x1*y2 + y1*x2) / -d
    if t2<0 or t2>1 then return false end
    if t1 + t2 <= 1 then return true else return false end
end

function IsPointInTriangleDot(p,p1,p2,p3)
    local x,y,x1,y1,x2,y2,x3,y3=p.x,p.y,p1.x,p1.y,p2.x,p2.y,p3.x,p3.y
    local side= function(x1, y1, x2, y2, x, y)
                 return (y2 - y1)*(x - x1) + (-x2 + x1)*(y - y1)>=0
             end
    if not side(x1, y1, x2, y2, x, y) then return false end
    if not side(x2, y2, x3, y3, x, y) then return false end
    if not side(x3, y3, x1, y1, x, y) then return false end
    return true
end

function IsPointInTriangleDot2(p,p1,p2,p3,n1,n2) --p1 must be camera position, p2 is left far end
    local a=p-p1
    if n1:dot(a)<0 or n2:dot(a)<0 then return false else return true end
end