diff --git a/lib/graph.c b/lib/graph.c
new file mode 100644
index 0000000..8856668
--- /dev/null
+++ b/lib/graph.c
@@ -0,0 +1,58 @@
+#include "types.h"
+#include "vga.h"
+#include "video.h"
+#include "graph.h"
+#include "math.h"                                        
+
+/******************************************************************************/
+
+/* Affiche une ligne entre les points spécifiés */
+
+void line(u32 x1, u32 y1, u32 x2, u32 y2, u8 color)
+{
+  s32 dx,dy,sdx,sdy;
+  u32 i,dxabs,dyabs,x,y,px,py;
+
+  dx=x2-x1;      /*  distance horizontale de la line */
+  dy=y2-y1;      /* distance verticale de la line **/
+  dxabs=abs(dx);
+  dyabs=abs(dy);
+  sdx=sgn(dx);
+  sdy=sgn(dy);
+  x=dyabs>>1;
+  y=dxabs>>1;
+  px=x1;
+  py=y1;
+  
+  writepxl(px,py,color);
+
+  if (dxabs>=dyabs) /* la ligne est plus horizontale que verticale */
+  {
+    for(i=0;i<dxabs;i++)
+    {
+      y+=dyabs;
+      if (y>=dxabs)
+      {
+        y-=dxabs;
+        py+=sdy;
+      }
+      px+=sdx;
+      writepxl(px,py,color);
+    }
+  }
+  else /* la ligne est plus verticale que horizontale */
+  {
+    for(i=0;i<dyabs;i++)
+    {
+      x+=dxabs;
+      if (x>=dyabs)
+      {
+        x-=dyabs;
+        px+=sdx;
+      }
+      py+=sdy;
+      writepxl(px,py,color);
+    }
+  }
+}
+