1 files changed, 65 insertions, 0 deletions

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+#include "physics_body.h"
+#include "game.h"
+
+void PhysicsBodyComponent::receive(Game&, Entity&, const Message& msg)
+{
+  if (msg.type == Message::Type::walkLeft)
+  {
+    velocity.first = -90;
+  } else if (msg.type == Message::Type::walkRight)
+  {
+    velocity.first = 90;
+  } else if (msg.type == Message::Type::stopWalking)
+  {
+    velocity.first = 0.0;
+  } else if (msg.type == Message::Type::stopMovingHorizontally)
+  {
+    velocity.first = 0.0;
+  } else if (msg.type == Message::Type::stopMovingVertically)
+  {
+    velocity.second = 0.0;
+  }
+}
+
+void PhysicsBodyComponent::tick(Game&, Entity& entity, double dt)
+{
+  // Accelerate
+  velocity.first += accel.first * dt;
+  velocity.second += accel.second * dt;
+  
+  // Terminal velocity
+#define TERMINAL_VELOCITY_X (2 * TILE_WIDTH * FRAMES_PER_SECOND)
+#define TERMINAL_VELOCITY_Y (2 * TILE_HEIGHT * FRAMES_PER_SECOND)
+  if (velocity.first < -TERMINAL_VELOCITY_X) velocity.first = -TERMINAL_VELOCITY_X;
+  if (velocity.first > TERMINAL_VELOCITY_X) velocity.first = TERMINAL_VELOCITY_X;
+  if (velocity.second < -TERMINAL_VELOCITY_Y) velocity.second = -TERMINAL_VELOCITY_Y;
+  if (velocity.second > TERMINAL_VELOCITY_Y) velocity.second = TERMINAL_VELOCITY_Y;
+  
+  // Do the movement
+  entity.position.first += velocity.first * dt;
+  entity.position.second += velocity.second * dt;
+}
+
+void PhysicsBodyComponent::detectCollision(Game& game, Entity& entity, Entity& collider, std::pair<double, double> old_position)
+{
+  // If already colliding, do nothing!
+  if ((old_position.first + collider.size.first > entity.position.first)
+    && (old_position.first < entity.position.first + entity.size.first)
+    && (old_position.second + collider.size.second > entity.position.second)
+    && (old_position.second < entity.position.second + entity.size.second))
+  {
+    return;
+  }
+  
+  // If newly colliding, SHOCK AND HORROR!
+  if ((collider.position.first + collider.size.first > entity.position.first)
+    && (collider.position.first < entity.position.first + entity.size.first)
+    && (collider.position.second + collider.size.second > entity.position.second)
+    && (collider.position.second < entity.position.second + entity.size.second))
+  {
+    Message msg(Message::Type::collision);
+    msg.collisionEntity = &collider;
+    
+    entity.send(game, msg);
+  }
+}