libs/Threading/Naca_sweep.scad

// Naca4_sweep.scad - sweep library
// Code: Rudolf Huttary, Berlin 
// June 2015
// commercial use prohibited

use <Naca4.scad>

//example1(); 
//rotate([80, 180, 130])
example(); 

// sweep from NACA1480 to NACA6480 (len = 230 mm, winding y,z = 80°
// sweeps generates a single polyhedron from multiple datasets
module example()
{
  N = 40; 
  sweep(gen_dat(N=5, dz=1,N=N)); 
  
  // specific generator function
  function gen_dat(M=10,dz=.1,N=10) = [for (i=[1:dz:M])   
    let( L = length(i))
    let( af = vec3D(
        airfoil_data([.1,.5,thickness(i)], L=length(i), N = N)))
    T_(-L/2, 0, (i+1)*2, af)];  // translate airfoil
  
  function thickness(i) = .5*sin(i*i)+.1; 
  function length(i) = (60+sin(12*(i-3))*30); 
}

module help()
{
  echo(str("\n\nList of signatures in lib:\n=================\n", 
  "sweep(dat, convexity = 5, showslices = false, plaincaps = true)  // dat - vec of vec2, with vec1 = airfoil_data\n", 
  "function vec3D(v, z=0)  // expand vec2 to vec3",
  "function rot(w=0, p) // rotate vec2",
  "function T_(x=0, y=0, z=0, v) // translates vec of vec3\n", 
  "function R_(x=0, y=0, z=0, v) // rotates vec of vec3\n", 
  "function Rx_(x=0, v) // x-rotates vec of vec3\n", 
  "function Ry_(y=0, v) // y-rotates vec of vec3\n", 
  "function Rz_(z=0, v) // z-rotates vec of vec3\n", 
  "function T_(x=0, y=0, z=0, v) // translates vec of vec3\n", 
  "function Tx_(x=0, v) // x-translates vec of vec3\n", 
  "function Ry_(y=0, v) // y-translates vec of vec3\n", 
  "function Rz_(z=0, v) // z-translates vec of vec3\n", 
  "function S_(x=0, y=0, z=0, v) // scales vec of vec3\n", 
  "function Sx_(x=0, v) // x-translates vec of vec3\n", 
  "function Sy_(x=0, v) // y-translates vec of vec3\n", 
  "function Sz_(x=0, v) // z-translates vec of vec3\n", 
  "=================\n")); 
}


// generate polyhedron from multiple airfoil_datasets
// dat - vec of vec1, with vec1 = simple polygon like airfoil_data, > 3 points per dataset expected
module sweep(dat, convexity = 5, showslices = false, plaincaps = true) 
{
  n = len(dat);     // # datasets
  l = len(dat[0]);  // points per dataset 
  if(l<=3) 
    echo("ERROR: sweep() expects more than 3 points per dataset"); 
  else
  {
    if(n==1) 
      polyhedron(points = dat[0], faces = [count(l-1, 0)]);
    else{
    first = plaincaps?[count(l-1, 0)]: 
            faces_polygon(l, true);  // triangulate first dataset
    last = plaincaps?[count((n-1)*l,(n)*l-1)]: 
            faces_shift((n-2)*l, faces_polygon(l, false)); // triangulate last dataset
    if (showslices)
      for(i=[0:n-1])
        sweep([dat[i]]); 
    else
      if (n<2)  // this case is also used recursively for showslices
        polyhedron(points = flat(), faces  = last, convexity = 5); 
      else
      {
        polyhedron(points = flat(), 
                   faces  = concat(first, last, faces_sweep(l,n)), convexity = 5); 
      }
    }
  }
  function count(a, b) = let(st = (a<b?1:-1))[for (i=[a:st:b]) i]; 
  function faces_shift(d, dat) = [for (i=[0:len(dat)-1]) dat[i] + [d, d, d]]; 
  function flat() = [for (i=[0:n-1], j=[0:l-1]) dat[i][j]]; 
}

function del(A, n) = [for(i=[0:len(A)-1]) if (n!=i)A[i]]; 

//// composition stuff for polyhedron
  function faces_sweep(l, n=1) = let(M = n*l) 
      concat([[0,l,l-1]],   // first face
      [for (i=[0:l*(n-1)-2], j = [0,1])
        j==0? [i, i+1, (i+l)] : [i+1, (i+l+1), i+l]], 
      [[n*l-1, (n-1)*l-1, (n-1)*l]]) // last face
      ;
    
  function faces_polygon(l, first = true) = let(odd = (l%2==1), d=first?0:l)
    let(res = odd?concat([[d,d+1,d+l-1]],
      [for (i=[1:(l-3)/2], j=[0,1])(j==0)?[d+i,d+i+1,d+l-i]:[d+i+1,d+l-i-1, d+l-i]]):
      [for (i=[0:(l-4)/2], j=[0,1])(j==0)?[d+i,d+i+1,d+l-i-1]:[d+i+1,d+l-i-2, d+l-i-1]])
    first?facerev(res):res;
    
  function facerev(dat) = [for (i=[0:len(dat)-1]) [dat[i][0],dat[i][2],dat[i][1]]]; 


//// vector and vector set operation stuff ///////////////////////
//// Expand 2D vector into 3D
function vec3D(v, z=0) = [for(i = [0:len(v)-1]) 
  len(v[i])==2?[v[i][0], v[i][1], z]:v[i]+[0, 0, z]]; 

// Translation - 1D, 2D, 3D point vector //////////////////////////
// vector along all axes
function T_(x=0, y=0, z=0, v) = let(x_ = (len(x)==3)?x:[x, y, z])
  [for (i=[0:len(v)-1]) T__(x_[0], x_[1], x_[2], p=v[i])]; 
/// vector along one axis
function Tx_(x=0, v) = T_(x=x, v=v); 
function Ty_(y=0, v) = T_(y=y, v=v); 
function Tz_(z=0, v) = T_(z=z, v=v); 
/// point along all axes 1D, 2D, 3D allowed
function T__(x=0, y=0, z=0, p) = len(p)==3?p+[x, y, z]:len(p)==2?p+[x, y]:p+x; 

//// Rotation - 2D, 3D point vector ///////////////////////////////////
// vector around all axes 
function R_(x=0, y=0, z=0, v) =             // 2D vectors allowed 
  let(x_ = (len(x)==3)?x:[x, y, z])
  len(v[0])==3?Rx_(x_[0], Ry_(x_[1], Rz_(x_[2], v))):
  [for(i = [0:len(v)-1]) rot(x_[2], v[i])];  
// vector around one axis
function Rx_(w, A) = A*[[1, 0, 0], [0, cos(w), sin(w)], [0, -sin(w), cos(w)]]; 
function Ry_(w, A) = A*[[cos(w), 0, sin(w)], [0, 1, 0], [-sin(w), 0, cos(w)]]; 
function Rz_(w, A) = A*[[cos(w), sin(w), 0], [-sin(w), cos(w), 0], [0, 0, 1]]; 


//// Scale - 2D, 3D point vector ///////////////////////////////////
// vector along all axes 
function S_(x=1, y=1, z=1, v) = 
  [for (i=[0:len(v)-1]) S__(x,y,z, v[i])]; 
// vector along one axis
function Sx_(x=0, v) = S_(x=x, v=v); 
function Sy_(y=0, v) = S_(y=y, v=v); 
function Sz_(z=0, v) = S_(z=z, v=v); 
// single point in 2D
function S__(x=1, y=1, z=1, p) = 
  len(p)==3?[p[0]*x, p[1]*y, p[2]*z]:len(p)==2?[p[0]*x+p[1]*y]:[p[0]*x];