7 files changed, 81 insertions, 19 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 58161830..3640dc85 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,29 +14,33 @@ set(YAGE_VERSION
 set(CMAKE_CXX_STANDARD 14)
 
 # set the test sources
-set(YAGE_SOURCE_DIR ${CMAKE_SOURCE_DIR}/src)
-set(YAGE_TEST_DIR ${CMAKE_SOURCE_DIR}/test)
+set(YAGE_SOURCE_DIR ${PROJECT_SOURCE_DIR}/src)
+set(YAGE_TEST_DIR ${PROJECT_SOURCE_DIR}/test)
 
 # add include directory
-set(YAGE_INCLUDE_DIR ${CMAKE_SOURCE_DIR}/include/YAGE)
+set(YAGE_INCLUDE_DIR ${PROJECT_SOURCE_DIR}/include/YAGE)
 
 # set binary directory
-set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/bin)
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR}/bin)
 
 # add sources to library
 set(YAGE_SOURCES
+  ${PROJECT_SOURCE_DIR}/src/body.cpp
   ${PROJECT_SOURCE_DIR}/src/camera2d.cpp
   ${PROJECT_SOURCE_DIR}/src/glslprogram.cpp
   ${PROJECT_SOURCE_DIR}/src/imageloader.cpp
   ${PROJECT_SOURCE_DIR}/src/inputmanager.cpp
   ${PROJECT_SOURCE_DIR}/src/iomanager.cpp
   ${PROJECT_SOURCE_DIR}/src/picopng.cpp
+  ${PROJECT_SOURCE_DIR}/src/rectanglecollider.cpp
   ${PROJECT_SOURCE_DIR}/src/resourcemanager.cpp
+  ${PROJECT_SOURCE_DIR}/src/rigidbody.cpp
+  ${PROJECT_SOURCE_DIR}/src/spritebatch.cpp  
   ${PROJECT_SOURCE_DIR}/src/sprite.cpp
-  ${PROJECT_SOURCE_DIR}/src/spritebatch.cpp
   ${PROJECT_SOURCE_DIR}/src/texturecache.cpp
   ${PROJECT_SOURCE_DIR}/src/window.cpp)
 
+
 # find libraries
 find_package(OpenGL REQUIRED)
 find_package(GLEW REQUIRED)
diff --git a/include/YAGE/Physics/body.hpp b/include/YAGE/Physics/body.hpp
index 170ef491..c781e1d4 100644
--- a/include/YAGE/Physics/body.hpp
+++ b/include/YAGE/Physics/body.hpp
@@ -1,5 +1,5 @@
-#ifndef YAGE_BODDY_HPP
-#define YAGE_BODDY_HPP
+#ifndef YAGE_BODY_HPP
+#define YAGE_BODY_HPP
 
 #include <glm/glm.hpp>
 
@@ -11,6 +11,10 @@ class Body
 protected:
 	// current force acting on object
 	glm::vec2 force_;
+
+	// current acceleration
+	glm::vec2 acceleration_=glm::vec2(0.f, 0.f);
+	
 	// current velocity of the object
 	glm::vec2 velocity_;
 
@@ -24,16 +28,17 @@ protected:
 	bool gravity_;
     
 public:
-	virtual ~Body() {}
+	virtual ~Body();
 
 	// apply force to the object and update the velocity
 	virtual void applyForce(const glm::vec2 &force)=0;
+	virtual void update()=0;
+
+	float xPosition() const;
+	float yPosition() const;
 protected:
 	// protected constructor to initialize member variables
-	Body(const glm::vec2 &center_of_mass, double mass, const glm::vec2 &force, const glm::vec2 &velocity, bool gravity) :
-		force_(force), velocity_(velocity), center_of_mass_(center_of_mass),
-		mass_(mass), gravity_(gravity)
-	{}
+	Body(const glm::vec2 &center_of_mass, double mass, const glm::vec2 &force, const glm::vec2 &velocity, bool gravity);
 };
 
 } // yage
diff --git a/include/YAGE/Physics/rigidbody.hpp b/include/YAGE/Physics/rigidbody.hpp
index 56f089ed..bf729828 100644
--- a/include/YAGE/Physics/rigidbody.hpp
+++ b/include/YAGE/Physics/rigidbody.hpp
@@ -1,7 +1,7 @@
 #ifndef YAGE_RIGID_BODY_HPP
 #define YAGE_RIGID_BODY_HPP
 
-#include "Physics/body.hpp"
+#include "body.hpp"
 
 namespace yage
 {
@@ -17,6 +17,7 @@ public:
 
 	// apply a force to the rigid body
 	virtual void applyForce(const glm::vec2 &force);
+	virtual void update();
 };
 
 } // yage
diff --git a/src/body.cpp b/src/body.cpp
new file mode 100644
index 00000000..fb6c40e7
--- /dev/null
+++ b/src/body.cpp
@@ -0,0 +1,24 @@
+#include "Physics/body.hpp"
+
+namespace yage
+{
+
+Body::~Body()
+{}
+
+Body::Body(const glm::vec2 &center_of_mass, double mass, const glm::vec2 &force, const glm::vec2 &velocity, bool gravity) :
+	force_(force), velocity_(velocity), center_of_mass_(center_of_mass),
+	mass_(mass), gravity_(gravity)
+{}
+
+float Body::xPosition() const
+{
+	return center_of_mass_.x;
+}
+
+float Body::yPosition() const
+{
+	return center_of_mass_.y;
+}
+
+} // yage
diff --git a/src/body.cpps b/src/body.cpps
new file mode 100644
index 00000000..3cacc0b9
--- /dev/null
+++ b/src/body.cpps
@@ -0,0 +1 @@
+12
+\ No newline at end of file
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
diff --git a/test/rigid_body_test.cpp b/test/rigid_body_test.cpp
index b0b1d1d6..39488599 100644
--- a/test/rigid_body_test.cpp
+++ b/test/rigid_body_test.cpp
@@ -1,6 +1,19 @@
 #include "Physics/rigidbody.hpp"
 
+#include <iostream>
+
 int main(int, char**)
 {
-	
+	yage::RigidBody body(glm::vec2(0.f, 0.f), 1, glm::vec2(0.f, 9.81f));
+	for(int i=0; i<60*3; ++i)
+	{
+		body.update();
+		std::cout<<"position: "<<body.xPosition()<<", "<<body.yPosition()<<"\n";
+	}
+
+	double ideal_position=0.5*9.81*3*3;
+
+	if(body.yPosition()>ideal_position*0.95 && body.yPosition()<ideal_position*1.05)
+		return 0;
+	return 1;
 }