From b8bafb47004dd00e4ddf55cd6903ef500157ea37 Mon Sep 17 00:00:00 2001
From: Allanis <allanis@saracraft.net>
Date: Wed, 10 Jul 2013 19:30:58 +0100
Subject: [PATCH] [Add] More planet functions for ai: ai.getrndplanet() and
 ai.getlandplanet().

---
 scripts/ai/empire.lua   |  2 +-
 scripts/ai/merchant.lua |  2 +-
 scripts/ai/scout.lua    | 27 +++++++++++++++------------
 src/ai.c                | 21 ++++++++++++++++++++-
 4 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/scripts/ai/empire.lua b/scripts/ai/empire.lua
index 9cddf38..a0a41bf 100644
--- a/scripts/ai/empire.lua
+++ b/scripts/ai/empire.lua
@@ -12,7 +12,7 @@ function control()
    ai.hostile(enemy)
   ai.pushtask(0, "attack", enemy)
  elseif task == "none" then
-  planet = ai.rndplanet()
+  planet = ai.landplanet()
   -- Planet needs to exist..
   if planet == nil then
    ai.pushtask(0, "hyperspace")
diff --git a/scripts/ai/merchant.lua b/scripts/ai/merchant.lua
index 0a9e765..73fb294 100644
--- a/scripts/ai/merchant.lua
+++ b/scripts/ai/merchant.lua
@@ -13,7 +13,7 @@ function control()
    ai.hyperspace()
   end
  elseif task == "none" then
-    planet = ai.rndplanet()
+    planet = ai.landplanet()
   -- Planet must exist.
   if planet == nil then
    ai.pushtask(0, "hyperspace")
diff --git a/scripts/ai/scout.lua b/scripts/ai/scout.lua
index f9f013b..471081b 100644
--- a/scripts/ai/scout.lua
+++ b/scripts/ai/scout.lua
@@ -16,43 +16,46 @@ function control()
     -- There is an enemy.
     if enemy ~= 0 then
       -- Make hostile to the enemy (mainly for player).
-      if ai.dist(enemy) < enemy_dist then
+      if ai.dist(enemy) < enemy_dist or ai.haslockon() then
         ai.pushtask(0, "runaway", enemy)
+        return
       end
+    end
 
-      -- No enemy.
-    else
-      -- Nothing to do so check if we are too far from the planet.
-      -- (If there is one).
-      planet = ai.rndplanet()
+    -- Nothing to do so check if we are too far from the planet.
+    -- (If there is one).
+    planet = ai.rndplanet()
 
-      if planet ~= nil then
-        if ai.dist(planet) > planet_dist then
-          ai.pushtask(0, "approach", planet)
-        end
+    if planet ~= nil then
+      if ai.dist(planet) > planet_dist then
+        ai.pushtask(0, "approach", planet)
+        return
       end
     end
 
     -- Go idle if no task.
     if task == "none" then
       ai.pushtask(0, "idle")
+      return
     end
 
     -- Check if we are near enough.
   elseif task == "approach" then
     planet = ai.target()
 
-    if ai.dist(planet) < planet_dist then
+    if ai.dist(planet) < planet_dist + ai.minbrakedist() then
       ai.poptask()
       ai.pushtask(0, "idle")
+      return
     end
 
     -- Check if we need to run more.
   elseif task == "runaway" then
     enemy = ai.targetid()
 
-    if ai.dist(enemy) > enemy_dist then
+    if ai.dist(enemy) > enemy_dist and ai.haslockon() == false then
       ai.poptask()
+      return
     end
   end
 end
diff --git a/src/ai.c b/src/ai.c
index 16d4e42..25492b6 100644
--- a/src/ai.c
+++ b/src/ai.c
@@ -120,6 +120,7 @@ static int ai_face(lua_State* L);               /* face(number/pointer) */
 static int ai_brake(lua_State* L);              /* Brake() */
 static int ai_getnearestplanet(lua_State* L);   /* pointer getnearestplanet() */
 static int ai_getrndplanet(lua_State* L);       /* pointer getrndplanet() */
+static int ai_getlandplanet(lua_State* L);      /* pointer getlandplanet() */
 static int ai_hyperspace(lua_State* L);         /* [number] hyperspace() */
 static int ai_stop(lua_State* L);               /* stop() */
 /* Combat. */
@@ -169,6 +170,7 @@ static const luaL_Reg ai_methods[] = {
   { "cargofree",            ai_cargofree        },
   { "nearestplanet",        ai_getnearestplanet },
   { "rndplanet",            ai_getrndplanet     },
+  { "landplanet",           ai_getlandplanet    },
   /* Movement. */
   { "accel",                ai_accel            },
   { "turn",                 ai_turn             },
@@ -771,15 +773,32 @@ static int ai_getnearestplanet(lua_State* L) {
   return 1;
 }
 
-/* Return a random friendly planet's position to the pilot. */
+/* Return a random planet's position to the pilot. */
 static int ai_getrndplanet(lua_State* L) {
+  Vec2 v;
+  int p;
+
   if(cur_system->nplanets == 0) return 0; /* No planets. */
 
+  /* Get a random planet. */
+  p = RNG(0, cur_system->nplanets-1);
+
+  /* Copy the data into a vector. */
+  vectcpy(&v, &cur_system->planets[p].pos);
+  lua_pushlightuserdata(L, &v);
+
+  return 1;
+}
+
+/* Return a random friendly planet's position to the pilot. */
+static int ai_getlandplanet(lua_State* L) {
   Planet** planets;
   int nplanets, i;
   Vec2 v;
   planets = malloc(sizeof(Planet*) * cur_system->nplanets);
 
+  if(cur_system->nplanets == 0) return 0; /* No planets. */
+
   for(nplanets = 0, i = 0; i < cur_system->nplanets; i++)
     if(planet_hasService(&cur_system->planets[i], PLANET_SERVICE_BASIC) &&
        !areEnemies(cur_pilot->faction, cur_system->planets[i].faction))