diff --git a/dwss.cc b/dwss.cc
index e1b6593..fa8790b 100644
--- a/dwss.cc
+++ b/dwss.cc
@@ -10,6 +10,12 @@
 
 #include "GnomeScreensaver.h"
 
+using namespace std;
+
+#define MAX_ASPECT (16.0/9.0*1.02)
+
+static int n_monitors = 1;
+
 static bool expose (GnomeScreensaver & gs)
 {
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
@@ -31,6 +37,11 @@ static bool expose (GnomeScreensaver & gs)
 
 static bool configure (GnomeScreensaver & gs, int width, int height)
 {
+    for (n_monitors = 1;
+         (double)width/(double)n_monitors/(double)height > MAX_ASPECT;
+         n_monitors++)
+        ;
+
     glViewport(0, 0, width, height);
 
     glMatrixMode(GL_PROJECTION);
diff --git a/modes/Mode.h b/modes/Mode.h
new file mode 100644
index 0000000..4cfc95a
--- /dev/null
+++ b/modes/Mode.h
@@ -0,0 +1,17 @@
+
+#ifndef MODE_H
+#define MODE_H
+
+#include "GnomeScreensaver.h"
+
+class Mode
+{
+    public:
+        virtual bool expose (GnomeScreensaver & gs) = 0;
+        virtual bool configure (GnomeScreensaver & gs, int width,
+                int height) = 0;
+        virtual bool update (GnomeScreensaver & gs) = 0;
+};
+
+#endif /* MODE_H */
+