Adding files

1 files changed, 19 insertions, 5 deletions

diff --git a/src/rigidbody.cpp b/src/rigidbody.cpp
index 4d774937..d8b963de 100644
--- a/src/rigidbody.cpp
+++ b/src/rigidbody.cpp
@@ -9,15 +9,29 @@ RigidBody::RigidBody(const glm::vec2 &center_of_mass, double mass, const glm::ve
 
 void RigidBody::applyForce(const glm::vec2 &force)
 {
+	force_+=force;
+}
+
+void RigidBody::update()
+{
 	// set the time_step for 60fps
 	double time_step=1.0/60.0;
-	
-	// a=F/m
-	glm::vec2 acceleration((force_.x+force.x)/mass_, (force_.y+force.y)/mass_); // = a(t0)
 
-	glm::vec2 intermediate_velocity=acceleration+glm::vec2(acceleration.x*time_step/2, acceleration.y*time_step/2);
+	// set the last acceleration
+	glm::vec2 last_acceleration=acceleration_;
+
+	// update the position of the body
+	center_of_mass_.x+=velocity_.x*time_step+(0.5*last_acceleration.x*time_step*time_step);
+	center_of_mass_.y+=velocity_.y*time_step+(0.5*last_acceleration.y*time_step*time_step);
+
+	// update the acceleration
+	acceleration_=glm::vec2(force_.x/mass_, force_.y/mass_);
+	glm::vec2 avg_acceleration=glm::vec2((acceleration_.x+last_acceleration.x)/2,
+	                                     (acceleration_.y+last_acceleration.y)/2);
 
-	velocity_=acceleration+glm::vec2(intermediate_velocity.x*time_step, intermediate_velocity.y*time_step);
+	// update the velocity of the body
+	velocity_.x+=avg_acceleration.x*time_step;
+	velocity_.y+=avg_acceleration.y*time_step;
 }
 
 } // yage