added built-in timer around Scene::render() call

git-svn-id: svn://anubis/fart/trunk@195 7f9b0f55-74a9-4bce-be96-3c2cd072584d

.todo

@@ -1,4 +1,3 @@
 FART To-Do List
 ===============
 - Test subtractions of subtractions
-- Add built-in timing around Scene::render()

main/fart.cc

@@ -4,6 +4,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <getopt.h>
+#include <sys/time.h>               /* gettimeofday() */
 #include <string>
 #include <map>
 #include "Scene.h"
@@ -77,5 +78,17 @@ int main(int argc, char * argv[])
 
     Scene scene(scene_options, argv[optind]);
 
+    struct timeval before, after;
+    gettimeofday(&before, NULL);        /* start timing */
+
     scene.render();
+
+    gettimeofday(&after, NULL);         /* stop timing */
+
+    double time_before = before.tv_sec + before.tv_usec / 1000000.0;
+    double time_after = after.tv_sec + after.tv_usec / 1000000.0;
+    double diff = time_after - time_before;
+    cout << "Elapsed time: " << diff << " seconds." << endl;
+
+    return 0;
 }