diff --git a/graphics.c b/graphics.c
index 00286ab..cb73350 100644
--- a/graphics.c
+++ b/graphics.c
@@ -19,27 +19,27 @@ typedef struct Canvas {
 void clear();
 void render(Canvas* c);
 void line(Canvas* c, uint start_x, uint start_y, uint end_x, uint end_y);
-void dot(Canvas* c, uint x, uint y);
+void dot(Canvas* c, const uint x, const uint y);
 
 
 /*
  * main
  */
-int main(){
-	char *data = malloc(40*40);
-	Canvas c = {40, 40, data};
-	memset(c.data, OFF, c.x * c.y);
-
-	//line(&c, 1, 1, 8, 8);
-	//line(&c, 8, 8, 1, 1);
-	//line(&c, 0, 5, 8, 8);
-	line(&c, 8, 8, 35, 39);
-
-
-	render(&c);
-
-	return 0;
-}
+//int main(){
+//	char *data = malloc(40*40);
+//	Canvas c = {40, 40, data};
+//	memset(c.data, OFF, c.x * c.y);
+//
+//	//line(&c, 1, 1, 8, 8);
+//	//line(&c, 8, 8, 1, 1);
+//	//line(&c, 0, 5, 8, 8);
+//	line(&c, 8, 8, 35, 39);
+//
+//
+//	render(&c);
+//
+//	return 0;
+//}
 
 
 
@@ -71,7 +71,7 @@ void render(Canvas* c){
 /*
  * Sets pixel at x,y to ON
  */
-void dot(Canvas* c, uint x, uint y){	
+void dot(Canvas* c, const uint x, const uint y){
 	c->data[ y*(c->x) + x] = ON;
 }
 
diff --git a/graphics.h b/graphics.h
new file mode 100644
index 0000000..607fa87
--- /dev/null
+++ b/graphics.h
@@ -0,0 +1,16 @@
+
+#ifndef GRAPHICS_H_
+#define GRAPHICS_H_
+
+typedef struct Canvas {
+	int x;
+	int y;
+	char* data;
+} Canvas;
+
+void clear();
+void render(Canvas*);
+void line(Canvas*, unsigned int, unsigned int, unsigned int, unsigned int);
+void dot(Canvas*, const unsigned int, const unsigned int);
+
+#endif
diff --git a/physics.c b/physics.c
new file mode 100644
index 0000000..0bc8afc
--- /dev/null
+++ b/physics.c
@@ -0,0 +1,64 @@
+
+
+#include "graphics.h"
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct Point{
+	uint x;
+	uint y;
+	uint px;
+	uint py;
+	uint fx;
+	uint fy;
+} Point;
+
+typedef struct Link {
+	Point* a;
+	Point* b;
+	double length;
+} Link;
+
+
+
+void draw_link(Canvas* c, Link* l){
+	line(&c, l->a->x, l->a->y, l->b->x, l->b->y);
+}
+
+void update_point(Point* p){
+	uint tempx = p->x;
+	uint tempy = p->y;
+	p->x += (p->x - p->px) + fx;
+	p->y += (p->y - p->py) + fy;
+	p->px = tempx;
+	p->py = tempy;
+}
+
+
+int main(){
+	char *data = malloc(40*40);
+	Canvas c = {40, 40, data};
+	memset(c.data, '.', c.x * c.y);
+
+
+	Point a = {10, 10, 10, 10, 0, 5};
+	Point b = {20, 10, 10, 10, 0, 5};
+	Link l_ab = {&a, &b, 10};
+
+	//line(&c, 1, 1, 8, 8);
+	//line(&c, 8, 8, 1, 1);
+	//line(&c, 0, 5, 8, 8);
+	
+	for(int i=0; i<100; i++){
+		draw_link(&c, &l_ab);
+		update_point(&a);
+		update_point(&b);
+	}
+
+
+	render(&c);
+
+	return 0;
+}
+
+