Started integrating Lua as a scripting engine

Currently moving platforms are able to have their movement controlled by a script rather than by XML, which is probably a better implementation and scales better to other things. The scripts, instead of using the components as state, use the stack as state. In this way, they pretend to be multithreaded. For instance, the moving platform calls moveRight and then moveLeft. Both of those functions internally make calls that say to wait until the next tick. When the AutomatingSystem ticks, it continues execution of all scripts (sequentially, of course) until they ask for the next tick again. This is implemented using coroutines.

3 files changed, 68 insertions, 187 deletions

@@ -2,13 +2,24 @@
 #include "game.h"
 #include "components/automatable.h"
 #include "components/ponderable.h"
-#include "systems/pondering.h"
+#include "components/realizable.h"
+#include "systems/realizing.h"
+#include "vector.h"
+
+struct script_entity {
+  using id_type = EntityManager::id_type;
+
+  id_type id;
+
+  script_entity(id_type id) : id(id)
+  {
+  }
+};
 
 void AutomatingSystem::tick(double dt)
 {
   auto entities = game_.getEntityManager().getEntitiesWithComponents<
-    AutomatableComponent,
-    PonderableComponent>();
+    AutomatableComponent>();
 
   for (id_type entity : entities)
   {
@@ -20,43 +31,7 @@ void AutomatingSystem::tick(double dt)
       continue;
     }
 
-    if (automatable.behaviorRunning &&
-        (automatable.remaining <= 0.0))
-    {
-      automatable.currentAction++;
-      automatable.actionRunning = false;
-
-      if (automatable.currentAction ==
-            automatable.behaviors[automatable.currentBehavior].size())
-      {
-        automatable.behaviorRunning = false;
-      }
-    }
-
-    if (!automatable.behaviorRunning)
-    {
-      automatable.currentBehavior = automatable.behaviorDist(game_.getRng());
-      automatable.currentAction = 0;
-      automatable.behaviorRunning = true;
-    }
-
-    AutomatableComponent::Action& curAction =
-      automatable.behaviors
-        [automatable.currentBehavior]
-          [automatable.currentAction];
-
-    if (!automatable.actionRunning)
-    {
-      automatable.remaining = curAction.dur;
-      automatable.actionRunning = true;
-    }
-
-    auto& ponderable = game_.getEntityManager().
-      getComponent<PonderableComponent>(entity);
-
-    ponderable.vel = curAction.speed;
-
-    automatable.remaining -= dt;
+    (*automatable.behavior)(dt);
   }
 }
 
@@ -65,6 +40,46 @@ void AutomatingSystem::initPrototype(id_type prototype)
   auto& automatable = game_.getEntityManager().
     getComponent<AutomatableComponent>(prototype);
 
-  automatable.behaviorRunning = false;
-  automatable.actionRunning = false;
+  auto& realizable = game_.getEntityManager().
+    getComponent<RealizableComponent>(
+      game_.getSystemManager().getSystem<RealizingSystem>().getSingleton());
+  automatable.behavior.reset();
+  automatable.runner = std::unique_ptr<sol::thread>(new sol::thread(sol::thread::create(realizable.scriptEngine.lua_state())));
+  automatable.behavior = std::unique_ptr<sol::coroutine>(new sol::coroutine(automatable.runner->state()["run"]));
+  (*automatable.behavior)(script_entity(prototype));
+}
+
+void AutomatingSystem::initScriptEngine(sol::state& scriptEngine)
+{
+  scriptEngine.open_libraries(sol::lib::base, sol::lib::coroutine);
+  scriptEngine.new_usertype<vec2d>(
+    "vec2d",
+    sol::constructors<vec2d(), vec2d(double, double)>(),
+    "x", sol::property(
+      [] (vec2d& v) -> double { return v.x(); },
+      [] (vec2d& v, double x) { v.x() = x; }),
+    "y", sol::property(
+      [] (vec2d& v) -> double { return v.y(); },
+      [] (vec2d& v, double y) { v.y() = y; }));
+
+  scriptEngine.new_usertype<vec2i>(
+    "vec2i",
+    sol::constructors<vec2i(), vec2i(int, int)>(),
+    "x", [] (vec2i& v) -> int& { return v.x(); },
+    "y", [] (vec2i& v) -> int& { return v.y(); });
+
+  scriptEngine.new_usertype<script_entity>(
+    "entity",
+    sol::constructors<script_entity(id_type)>(),
+    "id", &script_entity::id,
+    "ponderable",
+      [&] (script_entity& entity) -> PonderableComponent& {
+        return game_.getEntityManager().
+          getComponent<PonderableComponent>(entity.id);
+      });
+
+  scriptEngine.new_usertype<PonderableComponent>(
+    "ponderable",
+    "vel", &PonderableComponent::vel,
+    "accel", &PonderableComponent::accel);
 }
@@ -2,6 +2,7 @@
 #define AUTOMATING_H_E6E5D76E
 
 #include "system.h"
+#include <sol.hpp>
 
 class AutomatingSystem : public System {
 public:
@@ -14,6 +15,8 @@ public:
 
   void initPrototype(id_type prototype);
 
+  void initScriptEngine(sol::state& scriptEngine);
+
 };
 
 #endif /* end of include guard: AUTOMATING_H_E6E5D76E */
@@ -29,92 +29,6 @@ inline xmlChar* getProp(xmlNodePtr node, const char* attr)
   return key;
 }
 
-void parseAI(
-  xmlNodePtr node,
-  std::vector<AutomatableComponent::Action>& behavior,
-  const std::map<std::string, int>& items)
-{
-  xmlChar* key = nullptr;
-
-  if (!xmlStrcmp(
-    node->name,
-    reinterpret_cast<const xmlChar*>("switch")))
-  {
-    key = getProp(node, "item");
-    std::string switchItem = reinterpret_cast<char*>(key);
-    xmlFree(key);
-
-    for (xmlNodePtr switchNode = node->xmlChildrenNode;
-         switchNode != nullptr;
-         switchNode = switchNode->next)
-    {
-      if (!xmlStrcmp(
-        switchNode->name,
-        reinterpret_cast<const xmlChar*>("case")))
-      {
-        key = getProp(switchNode, "value");
-        int caseValue = atoi(reinterpret_cast<char*>(key));
-        xmlFree(key);
-
-        if (items.at(switchItem) == caseValue)
-        {
-          for (xmlNodePtr caseNode = switchNode->xmlChildrenNode;
-               caseNode != nullptr;
-               caseNode = caseNode->next)
-          {
-            parseAI(
-              caseNode,
-              behavior,
-              items);
-          }
-        }
-      }
-    }
-  } else if (!xmlStrcmp(
-    node->name,
-    reinterpret_cast<const xmlChar*>("move")))
-  {
-    key = getProp(node, "direction");
-    std::string direction = reinterpret_cast<char*>(key);
-    xmlFree(key);
-
-    key = getProp(node, "length-var");
-    std::string lengthVar = reinterpret_cast<char*>(key);
-    xmlFree(key);
-
-    key = getProp(node, "speed-var");
-    std::string speedVar = reinterpret_cast<char*>(key);
-    xmlFree(key);
-
-    double length = items.at(lengthVar);
-    double speed = items.at(speedVar);
-
-    AutomatableComponent::Action action;
-
-    if (direction == "left")
-    {
-      action.speed.x() = -speed;
-      action.speed.y() = 0;
-    } else if (direction == "right")
-    {
-      action.speed.x() = speed;
-      action.speed.y() = 0;
-    } else if (direction == "up")
-    {
-      action.speed.x() = 0;
-      action.speed.y() = -speed;
-    } else if (direction == "down")
-    {
-      action.speed.x() = 0;
-      action.speed.y() = speed;
-    }
-
-    action.dur = length / speed;
-
-    behavior.push_back(std::move(action));
-  }
-}
-
 // TODO: neither the XML doc nor any of the emplaced entities are properly
 // destroyed if this method throws an exception.
 EntityManager::id_type RealizingSystem::initSingleton(
@@ -126,6 +40,9 @@ EntityManager::id_type RealizingSystem::initSingleton(
   auto& realizable = game_.getEntityManager().
     emplaceComponent<RealizableComponent>(world);
 
+  game_.getSystemManager().getSystem<AutomatingSystem>().
+    initScriptEngine(realizable.scriptEngine);
+
   realizable.worldFile = worldFile;
   realizable.prototypeFile = prototypeFile;
 
@@ -299,68 +216,14 @@ EntityManager::id_type RealizingSystem::initSingleton(
           game_.getSystemManager().getSystem<PonderingSystem>().
             initializeBody(mapObject, PonderableComponent::Type::vacuumed);
 
-          // Look for any object configuration.
-          std::map<std::string, int> items;
-
-          for (xmlNodePtr objectNode = mapNode->xmlChildrenNode;
-            objectNode != nullptr;
-            objectNode = objectNode->next)
+          if (prototypeId == "movplat")
           {
-            if (!xmlStrcmp(
-              objectNode->name,
-              reinterpret_cast<const xmlChar*>("item")))
-            {
-              key = getProp(objectNode, "id");
-              std::string itemName = reinterpret_cast<char*>(key);
-              xmlFree(key);
-
-              key = xmlNodeGetContent(objectNode);
-              int itemVal = atoi(reinterpret_cast<char*>(key));
-              xmlFree(key);
-
-              items[itemName] = itemVal;
-            }
-          }
+            auto& automatable = game_.getEntityManager().
+              emplaceComponent<AutomatableComponent>(mapObject);
 
-          // Add any AI behaviors.
-          std::vector<double> behaviorWeights;
 
-          for (xmlNodePtr protoSubNode = prototypeNode->xmlChildrenNode;
-            protoSubNode != nullptr;
-            protoSubNode = protoSubNode->next)
-          {
-            if (!xmlStrcmp(
-              protoSubNode->name,
-              reinterpret_cast<const xmlChar*>("ai")))
-            {
-              if (!game_.getEntityManager().
-                hasComponent<AutomatableComponent>(mapObject))
-              {
-                game_.getEntityManager().
-                  emplaceComponent<AutomatableComponent>(mapObject);
-              }
-
-              auto& automatable = game_.getEntityManager().
-                getComponent<AutomatableComponent>(mapObject);
-
-              key = getProp(protoSubNode, "chance");
-              behaviorWeights.push_back(atof(reinterpret_cast<char*>(key)));
-              xmlFree(key);
-
-              std::vector<AutomatableComponent::Action> behavior;
-
-              for (xmlNodePtr aiNode = protoSubNode->xmlChildrenNode;
-                aiNode != nullptr;
-                aiNode = aiNode->next)
-              {
-                parseAI(
-                  aiNode,
-                  behavior,
-                  items);
-              }
-
-              automatable.behaviors.push_back(std::move(behavior));
-            }
+            realizable.scriptEngine.script_file(
+              "res/platform.lua");//,
           }
 
           mappable.objects.push_back(mapObject);