Added camera behaviour with spring behaviour

assets/game_assets/blueprints/camera.json

@@ -5,5 +5,16 @@
     "fov": 50.0,
     "near": 0.05,
     "far": 80.0
+  },
+  "Viewtarget": {
+    "offset": {
+      "x": 0.0,
+      "y": 10.0,
+      "z": 1.0
+    }
+  },
+  "Spring": {
+    "spring_constant": 20.0,
+    "mass":  1.0
   }
 }

src/gameplay/camera_system.cpp

+#include "camera_system.hpp"
+
+#include <mirrage/ecs/components/transform_comp.hpp>
+
+namespace phase_shifter::gameplay {
+
+	Camera_system::Camera_system(mirrage::ecs::Entity_manager& entity_manager) 
+		: _entity_manager(entity_manager)
+	{
+		_entity_manager.register_component_type<Viewtarget_comp>();
+		_entity_manager.register_component_type<Spring_comp>();
+	}
+
+	void Camera_system::update(mirrage::util::Time dt)
+	{ 
+		for (auto&& [camera, viewtarget, spring] : _entity_manager.list<mirrage::ecs::Entity_facet, Viewtarget_comp, Spring_comp>()) {
+			auto& target_facet = _entity_manager.get(viewtarget.target);
+
+			if(target_facet.is_some()) {
+				auto& target_transform = target_facet.get_or_throw().get<mirrage::ecs::components::Transform_comp>();
+
+				if(target_transform.is_some()) {
+					auto&     target_position  = target_transform.get_or_throw().position;
+					glm::vec3 offset           = viewtarget.offset;
+					glm::vec3 dest_pos         = {target_position.x + offset.x,
+                                          target_position.y + offset.y,
+                                          target_position.z + offset.z};
+					float     damping_constant = 2 * sqrtf(spring.spring_constant);
+					glm::vec3 damping_force    = -damping_constant * spring.velocity;
+
+					camera.process([&](mirrage::ecs::components::Transform_comp& transform) {
+						glm::vec3 spring_force = spring.spring_constant * (dest_pos - transform.position);
+						glm::vec3 acceleration = (spring_force + damping_force) / spring.mass;
+						spring.velocity        += dt.value() * acceleration;
+						transform.position     += dt.value() * spring.velocity;
+						transform.direction(-offset);
+					});
+				}
+			}
+		}
+	}
+}
\ No newline at end of file

src/gameplay/camera_system.hpp

+#pragma once
+
+#include <mirrage/utils/units.hpp>
+#include <mirrage/ecs/entity_manager.hpp>
+
+#include "viewtarget_comp.hpp"
+#include "spring_comp.hpp"
+
+namespace phase_shifter::gameplay {
+
+	class Camera_system {
+	  public:
+		Camera_system(mirrage::ecs::Entity_manager& entity_manager);
+		void update(mirrage::util::Time dt);
+
+	  private:
+		mirrage::ecs::Entity_manager& _entity_manager;
+	};
+}
\ No newline at end of file

src/gameplay/spring_comp.hpp

+#pragma once
+
+#include <mirrage/ecs/ecs.hpp>
+#include <mirrage/utils/sf2_glm.hpp>
+
+namespace phase_shifter::gameplay {
+
+	struct Spring_comp : public mirrage::ecs::Component<Spring_comp> {
+		static constexpr const char* name() { return "Spring"; }
+		using Component::Component;
+
+		glm::vec3 velocity = {0.f, 0.f, 0.f};
+
+		float spring_constant = 1.f;
+		float mass            = 1.f;
+	};
+
+	sf2_structDef(Spring_comp, spring_constant);
+}
\ No newline at end of file

src/gameplay/viewtarget_comp.hpp

+#pragma once
+
+#include <mirrage/ecs/ecs.hpp>
+#include <mirrage/utils/sf2_glm.hpp>
+
+namespace phase_shifter::gameplay {
+	
+	struct Viewtarget_comp : public mirrage::ecs::Component<Viewtarget_comp> {
+		static constexpr const char* name() { return "Viewtarget"; }
+		using Component::Component;
+
+		mirrage::ecs::Entity_handle target;
+
+		glm::vec3 offset = {0.f, 10.f, 1.f};
+	};
+
+	sf2_structDef(Viewtarget_comp, offset);
+}
\ No newline at end of file

src/meta_system.cpp

@@ -4,6 +4,7 @@
 #include "game_engine.hpp"
 #include "gameplay/beat_system.hpp"
 #include "gameplay/movement_system.hpp"
+#include "gameplay/camera_system.hpp"
 #include "helper/attachment_system.hpp"
 #include "input/input_system.hpp"
 #include "ui/hud_system.hpp"
@@ -28,6 +29,7 @@ namespace phase_shifter {
 	  , _model_loading(std::make_unique<renderer::Loading_system>(_entities, engine.assets()))
 	  , _beat_system(std::make_unique<gameplay::Beat_system>())
 	  , _movement_system(std::make_unique<gameplay::Movement_system>(_entities, *_beat_system))
+	  , _camera_system(std::make_unique<gameplay::Camera_system>(_entities))
 	  , _input_system(std::make_unique<input::Input_system>(engine.bus(), _entities))
 	  , _attachment_system(std::make_unique<helper::Attachment_system>(_entities))
 	  , _hud_system(std::make_unique<ui::Hud_system>(engine.gui(), _entities))
@@ -79,17 +81,6 @@ namespace phase_shifter {
 		auto cam_azimuth   = 0.0f;
 		auto cam_dir       = glm::quat(glm::vec3(
                 (cam_elevation - 2.f) * glm::pi<float>() / 2.f, glm::pi<float>() * cam_azimuth, 0.f));
-		entities()
-		        .entity_builder("camera")
-		        .rotation(cam_dir)
-		        .position(glm::rotate(cam_dir, glm::vec3(0, 0, -1)) * 8.f)
-		        .post_create([=](ecs::Entity_facet entity) {
-			        entity.process<Transform_comp>([&](auto& transform) {
-				        transform.position = transform.direction() * -10.f;
-				        transform.look_at({0, 0, 0});
-			        });
-		        })
-		        .create();
 
 		auto sun_elevation = 0.05f * glm::pi<float>();
 		auto sun_azimuth   = 0.7f;
@@ -101,7 +92,20 @@ namespace phase_shifter {
 		        .position(glm::rotate(sun_dir, glm::vec3(0, 0, 1)) * 40.f)
 		        .create();
 
-		entities().entity_builder("player").position({0, 1, 0}).create();
+		mirrage::ecs::Entity_facet player = entities().entity_builder("player").position({0, 1, 0}).create();
+		auto                       playerhandle = player.handle();
+		mirrage::ecs::Entity_facet camera = entities()
+		        .entity_builder("camera")
+		        .rotation(cam_dir)
+		        .position(glm::rotate(cam_dir, glm::vec3(0, 0, -1)) * 8.f)
+		        .post_create([=](ecs::Entity_facet entity) {
+			        entity.process<Transform_comp>([&](auto& transform) {
+				        transform.position = transform.direction() * -10.f;
+				        transform.look_at({0, 0, 0});
+			        });
+				    entity.process([=](gameplay::Viewtarget_comp& viewtarget) { viewtarget.target = playerhandle; });
+		        })
+		        .create();
 
 		entities()
 		        .entity_builder("cube")
@@ -127,6 +131,7 @@ namespace phase_shifter {
 		_beat_system->update(dt);
 		_input_system->update(dt);
 		_movement_system->update(dt);
+		_camera_system->update(dt);
 
 		_attachment_system->update(dt);
 

src/meta_system.hpp

@@ -22,6 +22,7 @@ namespace phase_shifter {
 	namespace gameplay {
 		class Beat_system;
 		class Movement_system;
+		class Camera_system;
 	} // namespace gameplay
 	namespace helper {
 		class Attachment_system;
@@ -60,6 +61,7 @@ namespace phase_shifter {
 		std::unique_ptr<input::Input_system>       _input_system;
 		std::unique_ptr<helper::Attachment_system> _attachment_system;
 		std::unique_ptr<ui::Hud_system>            _hud_system;
+		std::unique_ptr<gameplay::Camera_system>   _camera_system;
 		// TODO: add systems here
 
 		mirrage::util::Console_command_container _commands;