fixed bug in QuadraticSolver, cheap lighting working

git-svn-id: svn://anubis/fart/trunk@45 7f9b0f55-74a9-4bce-be96-3c2cd072584d

shapes/Sphere.cc

@@ -1,6 +1,7 @@
 
 #include "Sphere.h"
 #include "util/Solver.h"
+#include <math.h>
 #include <iostream>
 using namespace std;
 
@@ -22,14 +23,11 @@ Solver::Result Sphere::intersect(const Ray & ray)
                            + ray.getOrigin()[2] * ray.getOrigin()[2]
                            - m_radius2);
     Solver::Result quadSolutions = solver.solve();
-    int resIdx = 0;
     for (int i = 0; i < quadSolutions.numResults; i++)
     {
         if (quadSolutions.results[i] >= 0.0)
         {
-            res.results[resIdx] = quadSolutions.results[i];
-            resIdx++;
-            res.numResults = resIdx;
+            res.results[res.numResults++] = quadSolutions.results[i];
         }
     }
     return res;