Factored distance calculation into separate utility class

drawutils.cpp

@@ -1,5 +1,6 @@
 #include "drawutils.h"
 #include <cmath>
+#include "mathutils.h"
 
 SDL_Surface* DrawUtils::load(string file)
 {
@@ -58,15 +59,12 @@ void DrawUtils::draw_line(SDL_Surface* dest, Sint16 x1, Sint16 y1, Sint16 x2, Si
 
     SDL_Rect pen;
 
-    dx = static_cast<float>(x2-x1);
-    dy = static_cast<float>(y2-y1);
-
-    len = sqrt(dx*dx + dy*dy);
+    len = MathUtils::distance(x1,y1,x2,y2);
 
     // changing dx and dy's meanings. Now they represent the amount we move
     // each step in our drawing loop
-    dx /= len;
-    dy /= len;
+    dx = static_cast<float>(x2-x1) / len;
+    dy = static_cast<float>(y2-y1) / len;
 
     int j = static_cast<int>(len);