From 4bbfeae42a1245b1b84e8847787d7643e6a6f2cf Mon Sep 17 00:00:00 2001
From: Kelly Rauchenberger <fefferburbia@gmail.com>
Date: Thu, 10 May 2018 19:27:59 -0400
Subject: 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.
---
 src/systems/automating.cpp | 99 ++++++++++++++++++++++++++--------------------
 1 file changed, 57 insertions(+), 42 deletions(-)

(limited to 'src/systems/automating.cpp')

diff --git a/src/systems/automating.cpp b/src/systems/automating.cpp
index 61b97d9..6cec3bf 100644
--- a/src/systems/automating.cpp
+++ b/src/systems/automating.cpp
@@ -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);
 }
-- 
cgit 1.4.1