Very basic ECS

1 files changed, 115 insertions, 0 deletions

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+#include "simulation.h"
+
+#include "consts.h"
+#include "level.h"
+
+void Simulation::tick(
+  double dt,
+  const Uint8* keystate)
+{
+  for (id_type id : active_)
+  {
+    Entity& entity = entities_.at(id);
+
+    // Control
+    if (entity.player &&
+        !entity.moving)
+    {
+      if (keystate[SDL_SCANCODE_LEFT] &&
+          entity.gridPos.x() > 0 &&
+          level_.getTileset().canPlayerMoveTo(
+            level_.at(entity.gridPos - vec2s { 1, 0 })))
+      {
+        entity.moving = true;
+        entity.destPos = entity.gridPos - vec2s { 1, 0 };
+      }
+      else if (keystate[SDL_SCANCODE_UP] &&
+          entity.gridPos.y() > 0 &&
+          level_.getTileset().canPlayerMoveTo(
+            level_.at(entity.gridPos - vec2s { 0, 1 })))
+      {
+        entity.moving = true;
+        entity.destPos = entity.gridPos - vec2s { 0, 1 };
+      } else if (keystate[SDL_SCANCODE_RIGHT] &&
+          entity.gridPos.x() < (level_.getSize().w() - 1) &&
+          level_.getTileset().canPlayerMoveTo(
+            level_.at(entity.gridPos + vec2s { 1, 0 })))
+      {
+        entity.moving = true;
+        entity.destPos = entity.gridPos + vec2s { 1, 0 };
+      }
+      else if (keystate[SDL_SCANCODE_DOWN] &&
+          entity.gridPos.y() < (level_.getSize().h() - 1) &&
+          level_.getTileset().canPlayerMoveTo(
+            level_.at(entity.gridPos + vec2s { 0, 1 })))
+      {
+        entity.moving = true;
+        entity.destPos = entity.gridPos + vec2s { 0, 1 };
+      }
+
+      if (entity.moving)
+      {
+        entity.movementTween = 0.0;
+      }
+    }
+
+
+
+
+    // Collision
+
+
+
+
+    // Movement
+    if (entity.moving)
+    {
+      entity.movementTween += entity.speed * dt;
+
+      if (entity.movementTween >= 1.0)
+      {
+        entity.moving = false;
+        entity.gridPos = entity.destPos;
+      }
+    }
+
+    if (entity.moving)
+    {
+      entity.pos.x() =
+        TILE_SIZE.x() * entity.destPos.x() * entity.movementTween +
+        TILE_SIZE.x() * entity.gridPos.x() * (1.0 - entity.movementTween);
+
+      entity.pos.y() =
+        TILE_SIZE.y() * entity.destPos.y() * entity.movementTween +
+        TILE_SIZE.y() * entity.gridPos.y() * (1.0 - entity.movementTween);
+    } else {
+      entity.pos = TILE_SIZE * entity.gridPos;
+    }
+  }
+}
+
+Simulation::id_type Simulation::emplaceEntity()
+{
+  id_type nextId;
+
+  if (!available_.empty())
+  {
+    nextId = available_.front();
+    available_.pop_front();
+
+    entities_.at(nextId) = Entity();
+  } else {
+    nextId = entities_.size();
+    entities_.emplace_back();
+  }
+
+  active_.insert(nextId);
+
+  return nextId;
+}
+
+void Simulation::deleteEntity(id_type id)
+{
+  available_.push_back(id);
+  active_.erase(id);
+}