display both f64 and Fractional based polygons

@@ -21,6 +21,7 @@
 use std::convert::{TryFrom, TryInto, Into};
 use std::f64::consts::PI as FPI;
 use std::fmt::Display;
+use std::marker::Send;
 use std::num::TryFromIntError;
 use std::ops::{Add,Sub,Neg,Mul,Div};
 use std::sync::mpsc;
@@ -309,66 +310,34 @@ fn _line() {
     println!("{:>14} : {}", pg, pg.plot());
 }
 
-fn main() {
-    common_fractional();
-    println!();
-    continuous();
-    println!();
-    sqrt();
-    println!();
-    pi();
-    println!();
-    _sin();
-    println!();
-    _cos();
-    println!();
-    _tan();
-    println!();
-    _vector1();
-    println!();
-    _vector2();
-    println!();
-    _transform1();
-    println!();
-    _transform2();
-    println!();
-    _line();
+fn _democanvas<T>( xcb         :&XcbEasel
+                 , title       :&'static str
+                 , tx          :mpsc::Sender<i32>
+                 , tetrahedron :Polyeder<T>
+                 , cube        :Polyeder<T> )
+    where T: 'static + Add<Output = T> + Sub<Output = T> + Neg<Output = T>
+           + Mul<Output = T> + Div<Output = T>
+           + Copy + Trig + Send + From<i32> {
 
-    let xcb = XcbEasel::new().unwrap();
     let mut canvas = xcb.canvas(151, 151).unwrap();
+    let camera = Camera::<T>::new(&canvas, 45); // the orig. view angle
+                                                // was 50.
 
-    canvas.set_title("Something...");
+    canvas.set_title(title);
     canvas.init_events();
+    canvas.start_events(tx.clone());
 
-    let (tx, rx) = mpsc::channel();
-
-    let tetrahedron = Polyeder::tetrahedron(60.0);
-    let        cube = Polyeder::cube(60.0);
-    let      camera = Camera::<f64>::new(&canvas, 45); // the orig. view angle
-                                                       // was 50.
-    /*
-    let tetrahedron = Polyeder::tetrahedron(Fractional(60,1));
-    let        cube = Polyeder::cube(Fractional(60,1));
-    let      camera = Camera::<Fractional>::new(&canvas, 45);
-    */
-
-    canvas.start_events(tx);
-
-    let     start = Instant::now();
-    let     step  = Duration::from_millis(25);
-    let mut last  = Instant::now();
     thread::spawn(move || {
+        let     start = Instant::now();
+        let     step  = Duration::from_millis(25);
+        let mut last  = Instant::now();
+
+        let t :TMatrix<T> = translate(Vector(0.into(), 0.into(), 150.into()));
+
         loop {
             let deg = ((start.elapsed() / 25).as_millis() % 360) as i32;
 
-            let t = translate(Vector(0.0, 0.0, 150.0));
-            let rz :TMatrix<f64> = rotate_z(deg);
-            /*
-            let t = translate(Vector( Fractional(0,1)
-                                    , Fractional(0,1)
-                                    , Fractional(150,1) ));
-            let rz :TMatrix<Fractional> = rotate_z(deg);
-            */
+            let  rz :TMatrix<T> = rotate_z(deg);
 
             let rot1 = TMatrix::combine(vec!(rz, rotate_x(-deg*2), t));
             let rot2 = TMatrix::combine(vec!(rz, rotate_y(-deg*2), t));
@@ -388,7 +357,7 @@ fn main() {
             let f      = (passed.as_nanos() / step.as_nanos()) as u32;
 
             if f > 1 {
-                println!("!!! Detected frame drop");
+                println!("{} !!! Detected frame drop", title);
             }
 
             last = last + step*(f + 1);
@@ -399,6 +368,42 @@ fn main() {
             thread::sleep(last - Instant::now());
         }
     });
+}
+
+fn main() {
+    common_fractional();
+    println!();
+    continuous();
+    println!();
+    sqrt();
+    println!();
+    pi();
+    println!();
+    _sin();
+    println!();
+    _cos();
+    println!();
+    _tan();
+    println!();
+    _vector1();
+    println!();
+    _vector2();
+    println!();
+    _transform1();
+    println!();
+    _transform2();
+    println!();
+    _line();
+
+    let xcb = XcbEasel::new().unwrap();
+    let (tx, rx) = mpsc::channel();
+
+    _democanvas( &xcb, "Something...(f64)", tx.clone()
+               , Polyeder::tetrahedron(60.0)
+               , Polyeder::cube(60.0) );
+    _democanvas( &xcb, "Something...(Fractional)", tx.clone()
+               , Polyeder::tetrahedron(Fractional(60,1))
+               , Polyeder::cube(Fractional(60,1)) );
 
     for x in rx {
         match x {