-// Seed the random number generater with time() so we don't see the
-// same sequence every time
-void sg_srandom_time(void);
+#define MT_N 624
+#define MT_M 397
+
+/**
+ * Structure to hold MT algorithm state to easily allow independant
+ * sets of random numbers with different seeds.
+ */
+struct {unsigned int array[MT_N]; int index; } typedef mt;
+
+/**
+ * Initialize a new MT state with a given seed.
+ */
+void mt_init(mt *mt, unsigned int seed);
+
+/**
+ * Generate a new 32-bit random number based on the given MT state.
+ */
+unsigned int mt_rand32( mt *mt);
+
+/**
+ * Generate a new random number between [0.0, 1.0) based
+ * on the given MT state.
+ */
+double mt_rand(mt *mt);
+
+/**
+ * Seed the random number generater with time() so we don't see the
+ * same sequence every time.
+ */
+void sg_srandom_time();
+
+/**
+ * Seed the random number generater with time() in 10 minute intervals
+ * so we get the same sequence within 10 minutes interval.
+ * This is useful for synchronizing two display systems.
+ */
+void sg_srandom_time_10();