Index: apps/plugins/spacerocks.c
===================================================================
--- apps/plugins/spacerocks.c	(revision 23917)
+++ apps/plugins/spacerocks.c	(working copy)
@@ -527,6 +527,7 @@
 struct Asteroid
 {
     struct Point position;
+    struct Point rotation;
     struct Point vertices[NUM_ASTEROID_VERTICES];
     bool exists;
     int explode_countdown;
@@ -539,6 +540,7 @@
 struct Ship
 {
     struct Point position;
+    struct Point rotation;
     struct Point vertices[NUM_SHIP_VERTICES];
     bool exists;
     int explode_countdown;
@@ -637,20 +639,40 @@
 
 /* Rotate polygon */
 static void rotate_polygon(struct Point* vertices, int num_vertices,
-                           int cos, int sin)
+                           struct Point* rotation, int cos, int sin)
 {
     struct Point* point;
     int n;
     long temp_x, temp_y;
 
+    temp_x = rotation->x;
+    temp_y = rotation->y;
+    rotation->x = (temp_x*cos - temp_y*sin)/SIN_COS_SCALE;
+    rotation->y = (temp_y*cos + temp_x*sin)/SIN_COS_SCALE;
+    /* lame method to normalize vector.
+     * this is not accurate but maybe enough. */
+#define MIN_SCALE   (SCALE-5)
+#define MAX_SCALE   (SCALE+5)
+    temp_x = rotation->x*rotation->x + rotation->y*rotation->y;
+    if (temp_x <= MIN_SCALE*MIN_SCALE)
+    {
+        rotation->x = rotation->x*SCALE/MIN_SCALE;
+        rotation->y = rotation->y*SCALE/MIN_SCALE;
+    }
+    else if (temp_x >= MAX_SCALE*MAX_SCALE)
+    {
+        rotation->x = rotation->x*SCALE/MAX_SCALE;
+        rotation->y = rotation->y*SCALE/MAX_SCALE;
+    }
+#undef  MIN_SCALE
+#undef  MAX_SCALE
+
     point = vertices;
     n = num_vertices;
     while (n--)
     {
-        temp_x = point->x;
-        temp_y = point->y;
-        point->x = temp_x*cos/SIN_COS_SCALE - temp_y*sin/SIN_COS_SCALE;
-        point->y = temp_y*cos/SIN_COS_SCALE + temp_x*sin/SIN_COS_SCALE;
+        point->x = (point->dx*rotation->x - point->dy*rotation->y)/SCALE;
+        point->y = (point->dy*rotation->x + point->dx*rotation->y)/SCALE;
         point++;
     }
 }
@@ -849,6 +871,7 @@
 static void rotate_asteroid(struct Asteroid* asteroid)
 {
     rotate_polygon(asteroid->vertices, NUM_ASTEROID_VERTICES,
+                   &asteroid->rotation,
                    asteroid->speed_cos, asteroid->speed_sin);
 }
 
@@ -908,6 +931,9 @@
         point->y = asteroid_vertices[n+1];
         point->x *= asteroid->radius/20;
         point->y *= asteroid->radius/20;
+        /* use dx and dy as a master copy for ratation */
+        point->dx = point->x;
+        point->dy = point->y;
         point++;
     }
 
@@ -937,6 +963,9 @@
     asteroid->position.dx *= SCALE/10;
     asteroid->position.dy *= SCALE/10;
 
+    asteroid->rotation.x = SCALE;
+    asteroid->rotation.y = 0;
+
     /* Now rotate the asteroid a bit, so they all look a bit different */
     for(n = (rb->rand()%30)+2; n--; )
         rotate_asteroid(asteroid);
@@ -1044,6 +1073,8 @@
     ship.position.y = CENTER_LCD_Y * SCALE;
     ship.position.dx = 0;
     ship.position.dy = 0;
+    ship.rotation.x = SCALE;
+    ship.rotation.y = 0;
     ship.exists = true;
     ship.explode_countdown = 0;
     ship.invulnerable_time = INVULNERABLE_TIME;
@@ -1056,6 +1087,9 @@
         point->y = ship_vertices[n+1];
         point->x *= SCALE;
         point->y *= SCALE;
+        /* use dx and dy as a master copy for ratation */
+        point->dx = point->x;
+        point->dy = point->y;
         /* grab a copy of the ships points for the lives display: */
         lives_point->x = point->x;
         lives_point->y = point->y;
@@ -1129,7 +1163,8 @@
 {
     if (ship.exists)
     {
-        rotate_polygon(ship.vertices, NUM_SHIP_VERTICES, cos, sin);
+        rotate_polygon(ship.vertices, NUM_SHIP_VERTICES,
+                       &ship.rotation, cos, sin);
     }
 }