Implement perlin noise

perlin.h

@@ -0,0 +1,63 @@
+#ifndef PERLIN_H
+#define PERLIN_H
+
+#include "rayTracer.h"
+
+class perlin {
+    public: 
+        perlin() {
+            randFloat = new double[pointCount];
+            for (int i = 0; i < pointCount; i++) {
+                randFloat[i] = randomDouble();
+            }
+
+            permX = perlinGeneratePerm();
+            permY = perlinGeneratePerm();
+            permZ = perlinGeneratePerm();
+        }
+
+        ~perlin() {
+            delete[] randFloat;
+            delete[] permX;
+            delete[] permY;
+            delete[] permZ;
+        }
+
+        double noise(const point3& p) const {
+            auto i = int(4 * p.x()) & 255;
+            auto j = int(4 * p.y()) & 255;
+            auto k = int(4 * p.z()) & 255;
+
+            return randFloat[permX[i] ^ permY[j] ^ permZ[k]];
+        }
+
+    private: 
+        static const int pointCount = 256;
+        double* randFloat;
+        int* permX;
+        int* permY;
+        int* permZ;
+
+        static int* perlinGeneratePerm(void) {
+            auto p = new int[pointCount];
+
+            for (int i = 0; i < pointCount; i++) {
+                p[i] = i;
+            }
+
+            permute(p, pointCount);
+
+            return p;
+        }
+
+        static void permute(int* p, int n) {
+            for (int i = n - 1; i > 0; i--) {
+                int target = randomInt(0, i);
+                int tmp = p[i];
+                p[i] = p[target];
+                p[target] = tmp;
+            }
+        }
+};
+
+#endif