feat: implement minimal camera movement

developer239 · Dec 3, 2023 · d8c4c28 · d8c4c28
1 parent ceaf19c
commit d8c4c28
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Showing 4 changed files with 47 additions and 43 deletions.
diff --git a/src/apps/day3/src/strategies/ECSStrategy.h b/src/apps/day3/src/strategies/ECSStrategy.h
@@ -49,8 +49,8 @@ class MinimalLoopStrategy : public Core::IStrategy {
     ECS::Registry::Instance().AddComponent<CameraComponent>(
         cameraEntity,
         Vec2(0, 0),
-        window.GetWidth() / 2,
-        window.GetHeight() / 2
+        window.GetWidth() + 100,
+        window.GetHeight() + 100
     );
 
     // Puzzle related entities
@@ -172,9 +172,8 @@ class MinimalLoopStrategy : public Core::IStrategy {
         renderer,
         cameraEntity
     );
-    ECS::Registry::Instance().GetSystem<RenderTextSystem>().Render(renderer);
+    ECS::Registry::Instance().GetSystem<RenderTextSystem>().Render(renderer, cameraEntity);
 
-    ECS::Registry::Instance().GetSystem<RenderCollidersSystem>().Render(renderer
-    );
+    ECS::Registry::Instance().GetSystem<RenderCollidersSystem>().Render(renderer, cameraEntity);
   }
 };
diff --git a/src/apps/day3/src/systems/RenderColliderSystem.h b/src/apps/day3/src/systems/RenderColliderSystem.h
@@ -16,15 +16,25 @@ class RenderCollidersSystem : public ECS::System {
     RequireComponent<RigidBodyComponent>();
   }
 
-  void Render(Core::Renderer& renderer) {
+  void Render(Core::Renderer& renderer, ECS::Entity cameraEntity) {
     const int borderWidth = 5;
+    auto& camera =
+        ECS::Registry::Instance().GetComponent<CameraComponent>(cameraEntity);
 
     for (auto entity : GetSystemEntities()) {
       auto& boxCollider =
           ECS::Registry::Instance().GetComponent<BoxColliderComponent>(entity);
       auto& rigidBody =
           ECS::Registry::Instance().GetComponent<RigidBodyComponent>(entity);
 
+      // Calculate the position of the collider relative to the camera
+      int relativeX = static_cast<int>(
+          rigidBody.position.x + boxCollider.offset.x - camera.position.x
+      );
+      int relativeY = static_cast<int>(
+          rigidBody.position.y + boxCollider.offset.y - camera.position.y
+      );
+
       SDL_SetRenderDrawColor(
           renderer.Get().get(),
           boxCollider.color.r,
@@ -35,14 +45,20 @@ class RenderCollidersSystem : public ECS::System {
 
       for (int i = 0; i < borderWidth; ++i) {
         SDL_Rect colliderRect = {
-            static_cast<int>(rigidBody.position.x + boxCollider.offset.x - i),
-            static_cast<int>(rigidBody.position.y + boxCollider.offset.y - i),
+            relativeX - i,
+            relativeY - i,
             boxCollider.width + i * 2,
             boxCollider.height + i * 2};
         SDL_RenderDrawRect(renderer.Get().get(), &colliderRect);
       }
     }
 
-    SDL_SetRenderDrawColor(renderer.Get().get(), 0, 0, 0, 255);
+    SDL_SetRenderDrawColor(
+        renderer.Get().get(),
+        0,
+        0,
+        0,
+        255
+    );  // Reset render color
   }
 };
diff --git a/src/apps/day3/src/systems/RenderRigidBodiesSystem.h b/src/apps/day3/src/systems/RenderRigidBodiesSystem.h
@@ -11,26 +11,21 @@ class RenderRigidBodiesSystem : public ECS::System {
   RenderRigidBodiesSystem() { RequireComponent<RigidBodyComponent>(); }
 
   void Render(Core::Renderer& renderer, ECS::Entity cameraEntity) {
-    auto& camera =
-        ECS::Registry::Instance().GetComponent<CameraComponent>(cameraEntity);
+    auto& camera = ECS::Registry::Instance().GetComponent<CameraComponent>(cameraEntity);
 
     for (auto entity : GetSystemEntities()) {
-      auto rigidBodyComponent =
-          ECS::Registry::Instance().GetComponent<RigidBodyComponent>(entity);
-
-      if (IsEntityInView(rigidBodyComponent, camera)) {
-        SDL_Rect rect = {
-            (int)rigidBodyComponent.position.x,
-            (int)rigidBodyComponent.position.y,
-            (int)rigidBodyComponent.width,
-            (int)rigidBodyComponent.height};
-        SDL_SetRenderDrawColor(
-            renderer.Get().get(),
-            rigidBodyComponent.color.r,
-            rigidBodyComponent.color.g,
-            rigidBodyComponent.color.b,
-            rigidBodyComponent.color.a
-        );
+      auto& rigidBodyComponent = ECS::Registry::Instance().GetComponent<RigidBodyComponent>(entity);
+
+      // Calculate the position of the rigid body relative to the camera
+      int relativeX = static_cast<int>(rigidBodyComponent.position.x - camera.position.x);
+      int relativeY = static_cast<int>(rigidBodyComponent.position.y - camera.position.y);
+
+      // Check if the entity is within the camera's view before rendering
+      if (relativeX + rigidBodyComponent.width > 0 && relativeX < camera.width &&
+          relativeY + rigidBodyComponent.height > 0 && relativeY < camera.height) {
+
+        SDL_Rect rect = { relativeX, relativeY, rigidBodyComponent.width, rigidBodyComponent.height };
+        SDL_SetRenderDrawColor(renderer.Get().get(), rigidBodyComponent.color.r, rigidBodyComponent.color.g, rigidBodyComponent.color.b, rigidBodyComponent.color.a);
         SDL_RenderFillRect(renderer.Get().get(), &rect);
       }
     }

diff --git a/src/apps/day3/src/systems/RenderTextSystem.h b/src/apps/day3/src/systems/RenderTextSystem.h
@@ -13,37 +13,31 @@ class RenderTextSystem : public ECS::System {
     RequireComponent<RigidBodyComponent>();
   }
 
-  void Render(Core::Renderer& renderer) {
+  void Render(Core::Renderer& renderer, ECS::Entity cameraEntity) {
+    auto& camera = ECS::Registry::Instance().GetComponent<CameraComponent>(cameraEntity);
+
     for (auto entity : GetSystemEntities()) {
       const auto& textLabel = ECS::Registry::Instance().GetComponent<TextComponent>(entity);
       const auto& rigidBody = ECS::Registry::Instance().GetComponent<RigidBodyComponent>(entity);
 
       TTF_Font* font = Core::AssetStore::Instance().GetFont(textLabel.fontId).get();
-      if (!font) {
-        continue;
-      }
+      if (!font) continue;
 
       SDL_Surface* surface = TTF_RenderText_Blended(font, textLabel.text.c_str(), textLabel.color);
-      if (!surface) {
-        continue;
-      }
+      if (!surface) continue;
 
       SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer.Get().get(), surface);
       SDL_FreeSurface(surface);
-      if (!texture) {
-        continue;
-      }
+      if (!texture) continue;
 
       int textWidth = 0, textHeight = 0;
       SDL_QueryTexture(texture, nullptr, nullptr, &textWidth, &textHeight);
 
-      // Center
-
-      int xPosition = static_cast<int>(rigidBody.position.x + (rigidBody.width - textWidth) / 2);
-      int yPosition = static_cast<int>(rigidBody.position.y + (rigidBody.height - textHeight) / 2);
-
-      SDL_Rect dstRect = { xPosition, yPosition, textWidth, textHeight };
+      // Calculate text position relative to the camera
+      int relativeX = rigidBody.position.x + (rigidBody.width - textWidth) / 2 - camera.position.x;
+      int relativeY = rigidBody.position.y + (rigidBody.height - textHeight) / 2 - camera.position.y;
 
+      SDL_Rect dstRect = { relativeX, relativeY, textWidth, textHeight };
       SDL_RenderCopy(renderer.Get().get(), texture, nullptr, &dstRect);
 
       SDL_DestroyTexture(texture);