rm shader, tutorial uses new viewer refactor

tutorial/103_Events/main.cpp

@@ -1,5 +1,5 @@
 #include <igl/readOFF.h>
-#include <igl/viewer/Viewer.h>
+#include <igl/opengl/glfw/Viewer.h>
 #include <iostream>
 #include "tutorial_shared_path.h"
 
@@ -7,7 +7,7 @@ Eigen::MatrixXd V1,V2;
 Eigen::MatrixXi F1,F2;
 
 // This function is called every time a keyboard button is pressed
-bool key_down(igl::viewer::Viewer& viewer, unsigned char key, int modifier)
+bool key_down(igl::opengl::glfw::Viewer& viewer, unsigned char key, int modifier)
 {
   std::cout<<"Key: "<<key<<" "<<(unsigned int)key<<std::endl;
   if (key == '1')
@@ -41,7 +41,7 @@ int main(int argc, char *argv[])
 2 Switch to fertility mesh
     )";
 
-  igl::viewer::Viewer viewer;
+  igl::opengl::glfw::Viewer viewer;
   // Register a keyboard callback that allows to switch between
   // the two loaded meshes
   viewer.callback_key_down = &key_down;