1 files changed, 17 insertions, 4 deletions

diff --git a/src/wolff_ising.cpp b/src/wolff_ising.cpp
index f4073da..83b6448 100644
--- a/src/wolff_ising.cpp
+++ b/src/wolff_ising.cpp
@@ -1,6 +1,8 @@
 
 #include <getopt.h>
+#ifdef HAVE_GLUT
 #include <GL/glut.h>
+#endif
 
 // include your group and spin space
 #include <z2.h>
@@ -11,7 +13,7 @@
 
 int main(int argc, char *argv[]) {
 
-  count_t N = (count_t)1e7;
+  count_t N = (count_t)1e4;
 
   D_t D = 2;
   L_t L = 128;
@@ -20,10 +22,11 @@ int main(int argc, char *argv[]) {
 
   bool silent = false;
   bool draw = false;
+  unsigned int window_size = 512;
 
   int opt;
 
-  while ((opt = getopt(argc, argv, "N:D:L:T:H:sd")) != -1) {
+  while ((opt = getopt(argc, argv, "N:D:L:T:H:sdw:")) != -1) {
     switch (opt) {
     case 'N': // number of steps
       N = (count_t)atof(optarg);
@@ -44,8 +47,16 @@ int main(int argc, char *argv[]) {
       silent = true;
       break;
     case 'd':
+#ifdef HAVE_GLUT
       draw = true;
       break;
+#else
+      printf("You didn't compile this with the glut library installed!\n");
+      exit(EXIT_FAILURE);
+#endif
+    case 'w':
+      window_size = atoi(optarg);
+      break;
     default:
       exit(EXIT_FAILURE);
     }
@@ -95,11 +106,12 @@ int main(int argc, char *argv[]) {
   } else {
     // a more complex example: measure the average magnetization, and draw the spin configuration to the screen
 
+#ifdef HAVE_GLUT
     // initialize glut
     glutInit(&argc, argv);
     glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
-    glutInitWindowSize(L,L);
-    glutCreateWindow("null");
+    glutInitWindowSize(window_size, window_size);
+    glutCreateWindow("wolff");
     glClearColor(0.0,0.0,0.0,0.0);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
@@ -118,6 +130,7 @@ int main(int argc, char *argv[]) {
       }
       glFlush();
     };
+#endif
   }
 
   // run wolff for N cluster flips