ray_triangle

FUNCTION ray_triangle(RayPos REF AS Vec3, RayDir REF AS Vec3, Tri_Vert REF AS Vec3[])
    e1 AS Vec3 : e1 = v3Sub(Tri_Vert[1], Tri_Vert[0])
    e2 AS Vec3 : e2 = v3Sub(Tri_Vert[2], Tri_Vert[0])
    pv AS Vec3 : pv = v3Crs(RayDir, e2)
    tv AS Vec3

    d AS FLOAT : d = v3Dot(e1, pv)

    IF d > 0.0
        tv = v3Sub(RayPos, Tri_Vert[0])
    ELSE
        tv = v3Sub(Tri_Vert[0], RayPos)
        d = -d
    ENDIF

    u AS FLOAT : u = v3Dot(tv, pv)

    IF u < 0 OR u > d THEN EXITFUNCTION 0

    v AS FLOAT : v = v3Dot(RayDir, v3Crs(tv, e1))

    IF v < 0 OR u + v > d THEN EXITFUNCTION 0
ENDFUNCTION 1