add rear cam on mobile

public/sketch.js

@@ -14,10 +14,23 @@ let messages_list = []
 let timerWaiting;
 let waiting = false;
 
+let active_rearcam = false;
+let camConfig = "user";
+let isOnMobile;
+let camIsON = false;
+
+function isMobileDevice() {
+    return (typeof window.orientation !== "undefined") || (navigator.userAgent.indexOf('IEMobile') !== -1);
+}
+
 //-----------------------------------------------------
 //-----------------------------------------------------
 
 function preload(){
+
+    isOnMobile = isMobileDevice()
+    console.log("is on mobile ? " + isOnMobile)
+    
     // Socket events handlers
     socket = io();
     // client-side
@@ -100,9 +113,69 @@ function setup() {
     // Buttons 
     start_capture_button=createButton("turn on cam")
     start_capture_button.mousePressed(() => {
-        capture = createCapture(VIDEO);
+        camIsON = true;
+        if(!active_rearcam){
+            camConfig = "user"
+        } else {
+            camConfig = {
+                exact: "environment"
+            }
+        }
+        let constraints = {
+            audio: false,
+            video: {
+              facingMode:  camConfig
+            }    
+          };
+        capture = createCapture(constraints);
         capture.hide();
     })
+
+    if(isOnMobile){
+        checkbox_rearcam = createCheckbox("switch to rear cam");
+        checkbox_rearcam.parent("checkbox-rear");
+    
+        checkbox_rearcam.mousePressed( () => {
+            if(active_rearcam == false){
+                active_rearcam = true;
+            } else {
+            active_rearcam = false
+            }
+            
+            if(camIsON){
+                if(capture){
+                    capture.remove()
+                    capture = undefined
+                  }
+            
+                  if(active_rearcam == true){
+                    let new_constraints = {
+                          audio: false,
+                          video: {
+                            facingMode:  {
+                              exact: "environment"
+                            }
+                          }    
+                        };
+                    capture = createCapture(new_constraints)
+                    capture.hide()
+                  } else {
+                    let new_constraints = {
+                          audio: false,
+                          video: {
+                            facingMode:  "user"
+                          }    
+                          //video: {
+                            //facingMode: "user"
+                          //} 
+                        };
+                    capture = createCapture(new_constraints)
+                    capture.hide()
+                  }
+                }
+            })
+          
+    }
     
     start_button = createButton('start live vision');
     start_button.mousePressed(() => {
@@ -124,6 +197,7 @@ function setup() {
         if(capture){
             capture.remove();
             capture = undefined
+            camIsON = false;
         }
         console.log("live is OFF")
         //redraw()