Add acceleration and deceleration to MovementComponent

include/simpleengine/components/movement/movement_component.h

@@ -16,11 +16,15 @@ namespace simpleengine {
 
     class MovementComponent : public Component {
     public:
-        MovementComponent(Entity& owning_entity, float movement_speed);
+        MovementComponent(Entity& owning_entity, float max_velocity, float acceleration = 7, float deceleration = 2.5);
 
+        void Move(const float &delta_time, const float& dir_x, const float& dir_y);
         void Update(const float &delta_time) override;
     private:
-        float movement_speed;
+        float max_velocity;
+        sf::Vector2f velocity;
+        float acceleration;
+        float deceleration;
     };
 }
 

include/simpleengine/entity.h

@@ -25,7 +25,9 @@ namespace simpleengine {
         virtual ~Entity() = default;
         Entity(const Entity& entity) = delete;
 
-        virtual void Move(const float& delta_time, const float& x, const float& y) {};
+        virtual void Move(const float& delta_time, const float& dir_x, const float& dir_y) {};
+        virtual void Move(const float& delta_time, const sf::Vector2f& offset) {};
+        virtual void Move(const sf::Vector2f& offset) {};
         virtual void Update(const float& delta_time) = 0;
         virtual void Render(sf::RenderTarget* target) = 0;
 

include/simpleengine/events/entity_event.h

@@ -27,7 +27,7 @@ namespace simpleengine {
             entity->Update(delta_time);
 
             if (entity->IsGettingDestroyed()) {
-                entity->DestroyLater();
+                quit = true;
             }
         }
 

src/components/movement/movement_component.cpp

@@ -5,29 +5,133 @@
 //
 
 #include "components/movement/movement_component.h"
-
-#include <utility>
 #include "entity.h"
 
-simpleengine::MovementComponent::MovementComponent(Entity& owning_entity, float movement_speed) :
-    Component(owning_entity), movement_speed(movement_speed) {
+#include <algorithm>
+#include <iostream>
 
+simpleengine::MovementComponent::MovementComponent(Entity& owning_entity, float max_velocity, float acceleration, float deceleration) :
+    Component(owning_entity), max_velocity(max_velocity), acceleration(acceleration), deceleration(deceleration) {
+
+}
+
+void simpleengine::MovementComponent::Move(const float &delta_time, const float& dir_x, const float& dir_y) {
+    // Acceleration
+    velocity.x += acceleration * dir_x;
+    // Limit the horizontal velocity
+    if (velocity.x > 0) { // Right
+        velocity.x = std::min(velocity.x, max_velocity);
+    } else if (velocity.x < 0) { // Left
+        velocity.x = std::max(velocity.x, -max_velocity);
+    }
+
+    velocity.y += acceleration * dir_y;
+    // Limit the vertical velocity
+    if (velocity.y > 0) { // Up
+        velocity.y = std::min(velocity.y, max_velocity);
+    } else if (velocity.y < 0) { // Down
+        velocity.y = std::max(velocity.y, -max_velocity);
+    }
+
+    // Limit total velocity
+    float y_sq = velocity.y * velocity.y;
+    float x_sq = velocity.x * velocity.x;
+    float abs_sq = y_sq + x_sq;
+    if (abs_sq > max_velocity * max_velocity) {
+        float abs = sqrt(abs_sq);
+        velocity.x *= max_velocity / abs;
+        velocity.y *= max_velocity / abs;
+    }
+
+    owning_entity.Move(velocity * delta_time);
 }
 
 void simpleengine::MovementComponent::Update(const float &delta_time) {
+    sf::Vector2f direction;
     if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) {
-        owning_entity.Move(delta_time, -1, 0);
+        direction.x = -1;
     }
 
     if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) {
-        owning_entity.Move(delta_time, 0, -1);
+        direction.y = -1;
     }
 
     if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) {
-        owning_entity.Move(delta_time, 1, 0);
+        direction.x = 1;
     }
 
     if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) {
-        owning_entity.Move(delta_time, 0, 1);
+        direction.y = 1;
+    }
+
+    //std::cout << "Speed: " << velocity.x << ", " << velocity.y << std::endl;
+
+    // If we're not moving from deceleration or player input, then reset velocity.
+    bool no_movement = true;
+
+    if (direction.y != 0 || direction.x == 0) {
+        if (velocity.y > 0) {
+            if (velocity.y > max_velocity) {
+                velocity.y = max_velocity;
+            }
+
+            velocity.y -= deceleration;
+            if (velocity.y < 0) {
+                velocity.y = 0;
+            }
+
+            owning_entity.Move(velocity * delta_time);
+            no_movement = false;
+        } else if (velocity.y < 0) {
+            if (velocity.y < -max_velocity) {
+                velocity.y = -max_velocity;
+            }
+
+            velocity.y += deceleration;
+            if (velocity.y > 0) {
+                velocity.y = 0;
+            }
+
+            owning_entity.Move(velocity * delta_time);
+            no_movement = false;
+        }
+    }
+
+    if (direction.x != 0 || direction.y == 0) {
+        if (velocity.x > 0) {
+            if (velocity.x > max_velocity) {
+                velocity.x = max_velocity;
+            }
+
+            velocity.x -= deceleration;
+            if (velocity.x < 0) {
+                velocity.x = 0;
+            }
+
+            owning_entity.Move(velocity * delta_time);
+            no_movement = false;
+        } else if (velocity.x < 0) {
+            if (velocity.x < -max_velocity) {
+                velocity.x = -max_velocity;
+            }
+
+            velocity.x += deceleration;
+            if (velocity.x > 0) {
+                velocity.x = 0;
+            }
+
+            owning_entity.Move(velocity * delta_time);
+            no_movement = false;
+
+        }
+    }
+
+    if (direction.x != 0 || direction.y != 0) {
+        Move(delta_time, direction.x, direction.y);
+        no_movement = false;
+    }
+
+    if (no_movement) {
+        velocity = sf::Vector2f();
     }
 }