Implemented map rendering and basic collision

Only wall and platform collision currently works, and map edges are not currently implemented.

15 files changed, 825 insertions, 31 deletions

@@ -0,0 +1,146 @@
+#ifndef MAPPABLE_H_0B0316FB
+#define MAPPABLE_H_0B0316FB
+
+#include <map>
+#include "component.h"
+#include "renderer.h"
+#include "map.h"
+
+class MappableComponent : public Component {
+public:
+
+  class Boundary {
+  public:
+
+    enum class Type {
+      wall,
+      wrap,
+      teleport,
+      reverse,
+      platform,
+      danger
+    };
+
+    Boundary(
+      double axis,
+      double lower,
+      double upper,
+      Type type) :
+        axis_(axis),
+        lower_(lower),
+        upper_(upper),
+        type_(type)
+    {
+    }
+
+    inline double getAxis() const
+    {
+      return axis_;
+    }
+
+    inline double getLower() const
+    {
+      return lower_;
+    }
+
+    inline double getUpper() const
+    {
+      return upper_;
+    }
+
+    inline Type getType() const
+    {
+      return type_;
+    }
+
+  private:
+
+    double axis_;
+    double lower_;
+    double upper_;
+    Type type_;
+  };
+
+  MappableComponent(
+    Texture tileset,
+    Texture font) :
+      tileset_(std::move(tileset)),
+      font_(std::move(font))
+  {
+  }
+
+  using asc_boundaries_type =
+    std::multimap<
+      double,
+      Boundary,
+      std::less<double>>;
+
+  using desc_boundaries_type =
+    std::multimap<
+      double,
+      Boundary,
+      std::greater<double>>;
+
+  inline size_t getMapId() const
+  {
+    return mapId_;
+  }
+
+  inline void setMapId(size_t v)
+  {
+    mapId_ = v;
+  }
+
+  inline desc_boundaries_type& getLeftBoundaries()
+  {
+    return leftBoundaries_;
+  }
+
+  inline asc_boundaries_type& getRightBoundaries()
+  {
+    return rightBoundaries_;
+  }
+
+  inline desc_boundaries_type& getUpBoundaries()
+  {
+    return upBoundaries_;
+  }
+
+  inline asc_boundaries_type& getDownBoundaries()
+  {
+    return downBoundaries_;
+  }
+
+  inline const Texture& getTileset() const
+  {
+    return tileset_;
+  }
+
+  inline void setTileset(Texture v)
+  {
+    tileset_ = std::move(v);
+  }
+
+  inline const Texture& getFont() const
+  {
+    return font_;
+  }
+
+  inline void setFont(Texture v)
+  {
+    font_ = std::move(v);
+  }
+
+private:
+
+  size_t mapId_ = -1;
+
+  desc_boundaries_type leftBoundaries_;
+  asc_boundaries_type rightBoundaries_;
+  desc_boundaries_type upBoundaries_;
+  asc_boundaries_type downBoundaries_;
+  Texture tileset_;
+  Texture font_;
+};
+
+#endif /* end of include guard: MAPPABLE_H_0B0316FB */
@@ -6,13 +6,27 @@
 class PonderableComponent : public Component {
 public:
 
-  enum class state {
+  enum class Type {
+    vacuumed,
+    freefalling
+  };
+
+  enum class State {
     grounded,
     jumping,
     falling,
     dropping
   };
 
+  PonderableComponent(Type type) : type_(type)
+  {
+  }
+
+  inline Type getType() const
+  {
+    return type_;
+  }
+
   inline double getVelocityX() const
   {
     return velX_;
@@ -53,12 +67,12 @@ public:
     accelY_ = v;
   }
 
-  inline state getState() const
+  inline State getState() const
   {
     return state_;
   }
 
-  inline void setState(state arg)
+  inline void setState(State arg)
   {
     state_ = arg;
   }
@@ -69,7 +83,8 @@ private:
   double velY_ = 0.0;
   double accelX_ = 0.0;
   double accelY_ = 0.0;
-  state state_ = state::grounded;
+  Type type_ = Type::vacuumed;
+  State state_ = State::grounded;
 };
 
 #endif /* end of include guard: TANGIBLE_H_746DB3EE */
@@ -7,6 +7,9 @@ const int GAME_WIDTH = 320;
 const int GAME_HEIGHT = 200;
 const int MAP_WIDTH = GAME_WIDTH/TILE_WIDTH;
 const int MAP_HEIGHT = GAME_HEIGHT/TILE_HEIGHT - 1;
+const int WALL_GAP = 6;
+const int TILESET_COLS = 8;
+const int FONT_COLS = 16;
 
 const int FRAMES_PER_SECOND = 60;
 const double SECONDS_PER_FRAME = 1.0 / FRAMES_PER_SECOND;
@@ -2,10 +2,10 @@
 #define DIRECTION_H_9C49EAFD
 
 enum class Direction {
-  Left,
-  Right,
-  Up,
-  Down
+  left,
+  right,
+  up,
+  down
 };
 
 #endif /* end of include guard: DIRECTION_H_9C49EAFD */
@@ -106,7 +106,7 @@ public:
   {
     if ((entity >= entities.size()) || slotAvailable[entity])
     {
-      throw std::invalid_argument("Cannot delete non-existent entity");
+      throw std::invalid_argument("Cannot get non-existent entity");
     }
 
     EntityData& data = entities[entity];
@@ -138,7 +138,7 @@ public:
   {
     if ((entity >= entities.size()) || slotAvailable[entity])
     {
-      throw std::invalid_argument("Cannot delete non-existent entity");
+      throw std::invalid_argument("Cannot get non-existent entity");
     }
 
     EntityData& data = entities[entity];
@@ -167,7 +167,7 @@ public:
   {
     if ((entity >= entities.size()) || slotAvailable[entity])
     {
-      throw std::invalid_argument("Cannot delete non-existent entity");
+      throw std::invalid_argument("Cannot get non-existent entity");
     }
 
     EntityData& data = entities[entity];
@@ -181,6 +181,20 @@ public:
     return *dynamic_cast<T*>(data.components[componentType].get());
   }
 
+  template <class T>
+  bool hasComponent(id_type entity)
+  {
+    if ((entity >= entities.size()) || slotAvailable[entity])
+    {
+      throw std::invalid_argument("Cannot get non-existent entity");
+    }
+
+    EntityData& data = entities[entity];
+    std::type_index componentType = typeid(T);
+
+    return data.components.count(componentType);
+  }
+
   template <class... R>
   std::set<id_type> getEntitiesWithComponents()
   {
@@ -8,6 +8,7 @@
 #include "systems/controlling.h"
 #include "systems/pondering.h"
 #include "systems/animating.h"
+#include "systems/mapping.h"
 #include "animation.h"
 #include "renderer.h"
 #include "consts.h"
@@ -26,10 +27,14 @@ void key_callback(GLFWwindow* window, int key, int, int action, int)
   game.systemManager_.input(key, action);
 }
 
-Game::Game(GLFWwindow* window) : window_(window)
+Game::Game(
+  GLFWwindow* window) :
+    window_(window),
+    world_("res/maps.xml")
 {
   systemManager_.emplaceSystem<ControllingSystem>(*this);
   systemManager_.emplaceSystem<PonderingSystem>(*this);
+  systemManager_.emplaceSystem<MappingSystem>(*this);
   systemManager_.emplaceSystem<AnimatingSystem>(*this);
 
   int player = entityManager_.emplaceEntity();
@@ -49,11 +54,16 @@ Game::Game(GLFWwindow* window) : window_(window)
     player,
     203, 44, 10, 12);
 
+  systemManager_.getSystem<PonderingSystem>().initializeBody(
+    player,
+    PonderableComponent::Type::freefalling);
+
   entityManager_.emplaceComponent<DroppableComponent>(player);
-  entityManager_.emplaceComponent<PonderableComponent>(player);
   entityManager_.emplaceComponent<ControllableComponent>(player);
   entityManager_.emplaceComponent<OrientableComponent>(player);
 
+  systemManager_.getSystem<MappingSystem>().loadMap(world_.getStartingMapId());
+
   glfwSwapInterval(1);
   glfwSetWindowUserPointer(window_, this);
   glfwSetKeyCallback(window_, key_callback);
@@ -4,6 +4,7 @@
 #include "renderer.h"
 #include "entity_manager.h"
 #include "system_manager.h"
+#include "world.h"
 
 class Game {
 public:
@@ -22,6 +23,11 @@ public:
     return systemManager_;
   }
 
+  inline const World& getWorld()
+  {
+    return world_;
+  }
+
   friend void key_callback(
     GLFWwindow* window,
     int key,
@@ -31,9 +37,10 @@ public:
 
 private:
 
+  GLFWwindow* const window_;
   EntityManager entityManager_;
   SystemManager systemManager_;
-  GLFWwindow* const window_;
+  World world_;
   bool shouldQuit_ = false;
 };
 
@@ -0,0 +1,45 @@
+#ifndef MAP_H_74055FC0
+#define MAP_H_74055FC0
+
+#include <vector>
+#include <string>
+#include <list>
+#include <stdexcept>
+#include <map>
+
+class Map {
+public:
+
+  Map(
+    int id,
+    std::vector<int> tiles,
+    std::string title) :
+      id_(id),
+      tiles_(std::move(tiles)),
+      title_(std::move(title))
+  {
+  }
+
+  inline size_t getId() const
+  {
+    return id_;
+  }
+
+  inline const std::vector<int>& getTiles() const
+  {
+    return tiles_;
+  }
+
+  inline const std::string& getTitle() const
+  {
+    return title_;
+  }
+
+private:
+
+  int id_;
+  std::vector<int> tiles_;
+  std::string title_;
+};
+
+#endif /* end of include guard: MAP_H_74055FC0 */
@@ -123,7 +123,7 @@ void ControllingSystem::walkLeft(id_type entity)
 
   auto& animating = game_.getSystemManager().getSystem<AnimatingSystem>();
 
-  if (ponderable.getState() == PonderableComponent::state::grounded)
+  if (ponderable.getState() == PonderableComponent::State::grounded)
   {
     animating.startAnimation(entity, "walkingLeft");
   } else {
@@ -141,7 +141,7 @@ void ControllingSystem::walkRight(id_type entity)
 
   auto& animating = game_.getSystemManager().getSystem<AnimatingSystem>();
 
-  if (ponderable.getState() == PonderableComponent::state::grounded)
+  if (ponderable.getState() == PonderableComponent::State::grounded)
   {
     animating.startAnimation(entity, "walkingRight");
   } else {
@@ -156,7 +156,7 @@ void ControllingSystem::stopWalking(id_type entity)
 
   ponderable.setVelocityX(0);
 
-  if (ponderable.getState() == PonderableComponent::state::grounded)
+  if (ponderable.getState() == PonderableComponent::State::grounded)
   {
     auto& animating = game_.getSystemManager().getSystem<AnimatingSystem>();
 
@@ -173,13 +173,13 @@ void ControllingSystem::jump(id_type entity)
 {
   auto& ponderable = game_.getEntityManager().getComponent<PonderableComponent>(entity);
 
-  if (ponderable.getState() == PonderableComponent::state::grounded)
+  if (ponderable.getState() == PonderableComponent::State::grounded)
   {
     playSound("res/Randomize87.wav", 0.25);
 
     ponderable.setVelocityY(JUMP_VELOCITY(TILE_HEIGHT*4.5, 0.3));
     ponderable.setAccelY(JUMP_GRAVITY(TILE_HEIGHT*4.5, 0.3));
-    ponderable.setState(PonderableComponent::state::jumping);
+    ponderable.setState(PonderableComponent::State::jumping);
   }
 }
 
@@ -187,10 +187,10 @@ void ControllingSystem::stopJumping(id_type entity)
 {
   auto& ponderable = game_.getEntityManager().getComponent<PonderableComponent>(entity);
 
-  if (ponderable.getState() == PonderableComponent::state::jumping)
+  if (ponderable.getState() == PonderableComponent::State::jumping)
   {
     ponderable.setAccelY(JUMP_GRAVITY(TILE_HEIGHT*3.5, 0.233));
-    ponderable.setState(PonderableComponent::state::falling);
+    ponderable.setState(PonderableComponent::State::falling);
   }
 }
 
@@ -199,12 +199,12 @@ void ControllingSystem::drop(id_type entity, bool start)
   auto& droppable = game_.getEntityManager().getComponent<DroppableComponent>(entity);
   auto& ponderable = game_.getEntityManager().getComponent<PonderableComponent>(entity);
 
-  if (start && (ponderable.getState() == PonderableComponent::state::grounded))
+  if (start && (ponderable.getState() == PonderableComponent::State::grounded))
   {
-    ponderable.setState(PonderableComponent::state::dropping);
-  } else if ((!start) && (ponderable.getState() == PonderableComponent::state::dropping))
+    ponderable.setState(PonderableComponent::State::dropping);
+  } else if ((!start) && (ponderable.getState() == PonderableComponent::State::dropping))
   {
-    ponderable.setState(PonderableComponent::state::grounded);
+    ponderable.setState(PonderableComponent::State::grounded);
   }
   droppable.setDroppable(start);
 }
@@ -0,0 +1,143 @@
+#include "mapping.h"
+#include "components/mappable.h"
+#include "game.h"
+#include "consts.h"
+
+#include <iostream>
+
+template <typename Storage>
+inline void addBoundary(
+  Storage& boundaries,
+  int axis,
+  int lower,
+  int upper,
+  MappableComponent::Boundary::Type type)
+{
+  boundaries.emplace(std::piecewise_construct,
+    std::tie(axis),
+    std::tie(axis, lower, upper, type));
+}
+
+void MappingSystem::render(Texture& texture)
+{
+  auto entities = game_.getEntityManager().getEntitiesWithComponents<
+    MappableComponent>();
+
+  for (id_type entity : entities)
+  {
+    auto& mappable = game_.getEntityManager().
+      getComponent<MappableComponent>(entity);
+
+    const Map& map = game_.getWorld().getMap(mappable.getMapId());
+
+    for (int i = 0; i < MAP_WIDTH * MAP_HEIGHT; i++)
+    {
+      int x = i % MAP_WIDTH;
+      int y = i / MAP_WIDTH;
+      int tile = map.getTiles()[i];
+
+      if (tile > 0)
+      {
+        Rectangle dst {
+          x * TILE_WIDTH,
+          y * TILE_HEIGHT,
+          TILE_WIDTH,
+          TILE_HEIGHT};
+
+        Rectangle src {
+          (tile % TILESET_COLS) * TILE_WIDTH,
+          (tile / TILESET_COLS) * TILE_HEIGHT,
+          TILE_WIDTH,
+          TILE_HEIGHT};
+
+        texture.blit(mappable.getTileset(), std::move(src), std::move(dst));
+      }
+    }
+
+    int startX = ((GAME_WIDTH / TILE_WIDTH) / 2) - (map.getTitle().size() / 2);
+    for (size_t i = 0; i < map.getTitle().size(); i++)
+    {
+      Rectangle src {
+        (map.getTitle()[i] % FONT_COLS) * TILE_WIDTH,
+        (map.getTitle()[i] / FONT_COLS) * TILE_HEIGHT,
+        TILE_WIDTH,
+        TILE_HEIGHT};
+
+      Rectangle dst {
+        (startX + static_cast<int>(i)) * TILE_WIDTH,
+        24 * TILE_HEIGHT,
+        TILE_WIDTH,
+        TILE_HEIGHT};
+
+      texture.blit(mappable.getFont(), std::move(src), std::move(dst));
+    }
+  }
+}
+
+void MappingSystem::loadMap(size_t mapId)
+{
+  id_type mapEntity = game_.getEntityManager().emplaceEntity();
+
+  auto& mappable = game_.getEntityManager().
+    emplaceComponent<MappableComponent>(mapEntity,
+      Texture("res/tiles.png"),
+      Texture("res/font.bmp"));
+
+  mappable.setMapId(mapId);
+
+  const Map& map = game_.getWorld().getMap(mappable.getMapId());
+
+  for (size_t i = 0; i < MAP_WIDTH * MAP_HEIGHT; i++)
+  {
+    size_t x = i % MAP_WIDTH;
+    size_t y = i / MAP_WIDTH;
+    int tile = map.getTiles()[i];
+
+    if ((tile >= 5) && (tile <= 7))
+    {
+      addBoundary(
+        mappable.getDownBoundaries(),
+        y * TILE_HEIGHT,
+        x * TILE_WIDTH,
+        (x + 1) * TILE_WIDTH,
+        MappableComponent::Boundary::Type::platform);
+    } else if ((tile > 0) && (tile < 28))
+    {
+      addBoundary(
+        mappable.getRightBoundaries(),
+        x * TILE_WIDTH,
+        y * TILE_HEIGHT,
+        (y+1) * TILE_HEIGHT,
+        MappableComponent::Boundary::Type::wall);
+
+      addBoundary(
+        mappable.getLeftBoundaries(),
+        (x+1) * TILE_WIDTH,
+        y * TILE_HEIGHT,
+        (y+1) * TILE_HEIGHT,
+        MappableComponent::Boundary::Type::wall);
+
+      addBoundary(
+        mappable.getDownBoundaries(),
+        y * TILE_HEIGHT,
+        x * TILE_WIDTH,
+        (x+1) * TILE_WIDTH,
+        MappableComponent::Boundary::Type::wall);
+
+      addBoundary(
+        mappable.getUpBoundaries(),
+        (y+1) * TILE_HEIGHT,
+        x * TILE_WIDTH,
+        (x+1) * TILE_WIDTH,
+        MappableComponent::Boundary::Type::wall);
+    } else if (tile == 42)
+    {
+      addBoundary(
+        mappable.getDownBoundaries(),
+        y * TILE_HEIGHT,
+        x * TILE_WIDTH,
+        (x+1) * TILE_WIDTH,
+        MappableComponent::Boundary::Type::danger);
+    }
+  }
+}
@@ -0,0 +1,19 @@
+#ifndef MAPPING_H_33FC2294
+#define MAPPING_H_33FC2294
+
+#include "system.h"
+
+class MappingSystem : public System {
+public:
+
+  MappingSystem(Game& game) : System(game)
+  {
+  }
+
+  void render(Texture& texture);
+
+  void loadMap(size_t mapId);
+
+};
+
+#endif /* end of include guard: MAPPING_H_33FC2294 */
@@ -2,6 +2,8 @@
 #include "game.h"
 #include "components/ponderable.h"
 #include "components/transformable.h"
+#include "components/droppable.h"
+#include "consts.h"
 
 void PonderingSystem::tick(double dt)
 {
@@ -9,17 +11,251 @@ void PonderingSystem::tick(double dt)
     PonderableComponent,
     TransformableComponent>();
 
+  auto maps = game_.getEntityManager().getEntitiesWithComponents<
+    MappableComponent>();
+
   for (id_type entity : entities)
   {
-    auto& transformable = game_.getEntityManager().getComponent<TransformableComponent>(entity);
-    auto& ponderable = game_.getEntityManager().getComponent<PonderableComponent>(entity);
+    auto& transformable = game_.getEntityManager().
+      getComponent<TransformableComponent>(entity);
+
+    auto& ponderable = game_.getEntityManager().
+      getComponent<PonderableComponent>(entity);
 
     // Accelerate
-    ponderable.setVelocityX(ponderable.getVelocityX() + ponderable.getAccelX() * dt);
-    ponderable.setVelocityY(ponderable.getVelocityY() + ponderable.getAccelY() * dt);
+    ponderable.setVelocityX(
+      ponderable.getVelocityX() + ponderable.getAccelX() * dt);
+
+    ponderable.setVelocityY(
+      ponderable.getVelocityY() + ponderable.getAccelY() * dt);
+
+    const double oldX = transformable.getX();
+    const double oldY = transformable.getY();
+    const double oldRight = oldX + transformable.getW();
+    const double oldBottom = oldY + transformable.getH();
+
+    double newX = oldX + ponderable.getVelocityX() * dt;
+    double newY = oldY + ponderable.getVelocityY() * dt;
+
+    if (ponderable.getVelocityY() > 0.0)
+    {
+      ponderable.setState(PonderableComponent::State::falling);
+    }
+
+    for (id_type mapEntity : maps)
+    {
+      auto& mappable = game_.getEntityManager().
+        getComponent<MappableComponent>(mapEntity);
+
+      if (newX < oldX)
+      {
+        for (auto it = mappable.getLeftBoundaries().lower_bound(oldX);
+          (it != std::end(mappable.getLeftBoundaries())) && (it->first >= newX);
+          it++)
+        {
+          if ((oldBottom > it->second.getLower())
+            && (oldY < it->second.getUpper()))
+          {
+            // We have a collision!
+            processCollision(
+              entity,
+              Direction::left,
+              newX,
+              newY,
+              it->first,
+              it->second.getType());
+
+            break;
+          }
+        }
+      } else if (newX > oldX)
+      {
+        for (auto it = mappable.getRightBoundaries().lower_bound(oldRight);
+          (it != std::end(mappable.getRightBoundaries()))
+            && (it->first <= (newX + transformable.getW()));
+          it++)
+        {
+          if ((oldBottom > it->second.getLower())
+            && (oldY < it->second.getUpper()))
+          {
+            // We have a collision!
+            processCollision(
+              entity,
+              Direction::right,
+              newX,
+              newY,
+              it->first,
+              it->second.getType());
+
+            break;
+          }
+        }
+      }
+
+      if (newY < oldY)
+      {
+        for (auto it = mappable.getUpBoundaries().lower_bound(oldY);
+          (it != std::end(mappable.getUpBoundaries())) && (it->first >= newY);
+          it++)
+        {
+          if ((oldRight > it->second.getLower())
+            && (oldX < it->second.getUpper()))
+          {
+            // We have a collision!
+            processCollision(
+              entity,
+              Direction::up,
+              newX,
+              newY,
+              it->first,
+              it->second.getType());
+
+            break;
+          }
+        }
+      } else if (newY > oldY)
+      {
+        for (auto it = mappable.getDownBoundaries().lower_bound(oldBottom);
+          (it != std::end(mappable.getDownBoundaries()))
+            && (it->first <= (newY + transformable.getH()));
+          it++)
+        {
+          if ((oldRight > it->second.getLower())
+            && (oldX < it->second.getUpper()))
+          {
+            // We have a collision!
+            processCollision(
+              entity,
+              Direction::down,
+              newX,
+              newY,
+              it->first,
+              it->second.getType());
+
+            break;
+          }
+        }
+      }
+    }
 
     // Move
-    transformable.setX(transformable.getX() + ponderable.getVelocityX() * dt);
-    transformable.setY(transformable.getY() + ponderable.getVelocityY() * dt);
+    transformable.setX(newX);
+    transformable.setY(newY);
+  }
+}
+
+void PonderingSystem::initializeBody(
+  id_type entity,
+  PonderableComponent::Type type)
+{
+  auto& ponderable = game_.getEntityManager().
+    emplaceComponent<PonderableComponent>(entity, type);
+
+  if (type == PonderableComponent::Type::freefalling)
+  {
+    ponderable.setAccelY(JUMP_GRAVITY(TILE_HEIGHT*3.5, 0.233));
+    ponderable.setState(PonderableComponent::State::falling);
+  }
+}
+
+void PonderingSystem::processCollision(
+  id_type entity,
+  Direction dir,
+  double& newX,
+  double& newY,
+  int axis,
+  MappableComponent::Boundary::Type type)
+{
+  auto& ponderable = game_.getEntityManager().
+    getComponent<PonderableComponent>(entity);
+
+  auto& transformable = game_.getEntityManager().
+    getComponent<TransformableComponent>(entity);
+
+  switch (type)
+  {
+    case MappableComponent::Boundary::Type::wall:
+    {
+      switch (dir)
+      {
+        case Direction::left:
+        {
+          newX = axis;
+          ponderable.setVelocityX(0.0);
+
+          break;
+        }
+
+        case Direction::right:
+        {
+          newX = axis - transformable.getW();
+          ponderable.setVelocityX(0.0);
+
+          break;
+        }
+
+        case Direction::up:
+        {
+          newY = axis;
+          ponderable.setVelocityY(0.0);
+
+          break;
+        }
+
+        case Direction::down:
+        {
+          newY = axis - transformable.getH();
+          ponderable.setVelocityY(0.0);
+
+          if (ponderable.getState() == PonderableComponent::State::falling)
+          {
+            ponderable.setState(PonderableComponent::State::grounded);
+          }
+
+          break;
+        }
+      }
+
+      break;
+    }
+
+    case MappableComponent::Boundary::Type::platform:
+    {
+      if (game_.getEntityManager().hasComponent<DroppableComponent>(entity))
+      {
+        auto& droppable = game_.getEntityManager().
+          getComponent<DroppableComponent>(entity);
+
+        if (droppable.isDroppable())
+        {
+          droppable.setDroppable(false);
+        } else {
+          newY = axis - transformable.getH();
+          ponderable.setVelocityY(0.0);
+
+          if (ponderable.getState() == PonderableComponent::State::falling)
+          {
+            ponderable.setState(PonderableComponent::State::grounded);
+          }
+        }
+      } else {
+        newY = axis - transformable.getH();
+        ponderable.setVelocityY(0.0);
+
+        if (ponderable.getState() == PonderableComponent::State::falling)
+        {
+          ponderable.setState(PonderableComponent::State::grounded);
+        }
+      }
+
+      break;
+    }
+
+    default:
+    {
+      // Not yet implemented.
+
+      break;
+    }
   }
 }
@@ -2,6 +2,9 @@
 #define PONDERING_H_F2530E0E
 
 #include "system.h"
+#include "components/mappable.h"
+#include "components/ponderable.h"
+#include "direction.h"
 
 class PonderingSystem : public System {
 public:
@@ -11,6 +14,19 @@ public:
   }
 
   void tick(double dt);
+
+  void initializeBody(id_type entity, PonderableComponent::Type type);
+
+private:
+
+  void processCollision(
+    id_type entity,
+    Direction dir,
+    double& newX,
+    double& newY,
+    int axis,
+    MappableComponent::Boundary::Type type);
+
 };
 
 #endif /* end of include guard: PONDERING_H_F2530E0E */
@@ -0,0 +1,99 @@
+#include "world.h"
+#include <libxml/parser.h>
+#include <stdexcept>
+#include <cstring>
+#include "consts.h"
+
+inline xmlChar* getProp(xmlNodePtr node, const char* attr)
+{
+  xmlChar* key = xmlGetProp(node, reinterpret_cast<const xmlChar*>(attr));
+  if (key == nullptr)
+  {
+    throw std::invalid_argument("Error parsing world file");
+  }
+
+  return key;
+}
+
+World::World(std::string filename)
+{
+  xmlDocPtr doc = xmlParseFile(filename.c_str());
+  if (doc == nullptr)
+  {
+    throw std::invalid_argument("Cannot find world file");
+  }
+
+  xmlNodePtr top = xmlDocGetRootElement(doc);
+  if (top == nullptr)
+  {
+    throw std::invalid_argument("Error parsing world file");
+  }
+
+  if (xmlStrcmp(top->name, reinterpret_cast<const xmlChar*>("world")))
+  {
+    throw std::invalid_argument("Error parsing world file");
+  }
+
+  xmlChar* key = nullptr;
+
+  key = getProp(top, "startx");
+  startX_ = atoi(reinterpret_cast<char*>(key));
+  xmlFree(key);
+
+  key = getProp(top, "starty");
+  startY_ = atoi(reinterpret_cast<char*>(key));
+  xmlFree(key);
+
+  key = getProp(top, "startmap");
+  startMap_ = atoi(reinterpret_cast<char*>(key));
+  xmlFree(key);
+
+  for (xmlNodePtr node = top->xmlChildrenNode;
+    node != nullptr;
+    node = node->next)
+  {
+    if (!xmlStrcmp(node->name, reinterpret_cast<const xmlChar*>("map")))
+    {
+      key = getProp(node, "id");
+      size_t mapId = atoi(reinterpret_cast<char*>(key));
+      xmlFree(key);
+
+      key = getProp(node, "title");
+      std::string mapTitle(reinterpret_cast<char*>(key));
+      xmlFree(key);
+
+      std::vector<int> mapTiles;
+
+      for (xmlNodePtr mapNode = node->xmlChildrenNode;
+        mapNode != nullptr;
+        mapNode = mapNode->next)
+      {
+        if (!xmlStrcmp(
+          mapNode->name,
+          reinterpret_cast<const xmlChar*>("environment")))
+        {
+          key = xmlNodeGetContent(mapNode);
+
+          mapTiles.clear();
+          mapTiles.push_back(atoi(strtok(reinterpret_cast<char*>(key), ",\n")));
+          for (size_t i = 1; i < (MAP_WIDTH * MAP_HEIGHT); i++)
+          {
+            mapTiles.push_back(atoi(strtok(nullptr, ",\n")));
+          }
+
+          xmlFree(key);
+        }
+      }
+
+      maps_.emplace(
+        std::piecewise_construct,
+        std::forward_as_tuple(mapId),
+        std::forward_as_tuple(
+          mapId,
+          std::move(mapTiles),
+          std::move(mapTitle)));
+    }
+  }
+
+  xmlFreeDoc(doc);
+}
@@ -0,0 +1,41 @@
+#ifndef WORLD_H_153C698B
+#define WORLD_H_153C698B
+
+#include <map>
+#include <string>
+#include "map.h"
+
+class World {
+public:
+
+  explicit World(std::string filename);
+
+  inline const Map& getMap(size_t id) const
+  {
+    return maps_.at(id);
+  }
+
+  inline size_t getStartingMapId() const
+  {
+    return startMap_;
+  }
+
+  inline int getStartingX() const
+  {
+    return startX_;
+  }
+
+  inline int getStartingY() const
+  {
+    return startY_;
+  }
+
+private:
+
+  std::map<size_t, Map> maps_;
+  size_t startMap_;
+  int startX_;
+  int startY_;
+};
+
+#endif /* end of include guard: WORLD_H_153C698B */