Basic diffuse mapping and gamma correction

vec3.hpp

@@ -1,8 +1,7 @@
 #ifndef VEC3_H
 #define VEC3_H
 
-#include <math.h>
-#include <stdio.h>
+#include "rtweekend.hpp"
 
 struct vec3 {
     /* Members */
@@ -65,6 +64,18 @@ struct vec3 {
     {
         return x*x + y*y + z*z;
     }
+
+    // Get a vec3 with random components in the range [0,1)
+    inline static vec3 random()
+    {
+        return vec3(random_double(), random_double(), random_double());
+    }
+
+    // Get a vec3 with random components in the range [min, max)
+    inline static vec3 random(double min, double max)
+    {
+        return vec3(random_double(min, max), random_double(min, max), random_double(min, max));
+    }
 };
 
 /* Type aliases */
@@ -135,4 +146,17 @@ inline vec3 normalize(const vec3 v)
     return v / v.length();
 }
 
+// Returns a vec3 of random components between [-1,1) that is inside a unit sphere
+vec3 random_in_unit_sphere()
+{
+    // Iterate until we find a vector with length < 1
+    while (true)
+    {
+        vec3 p = vec3::random(-1,1);
+        if (p.length_squared() >= 1)
+            continue;
+        return p;
+    }
+}
+
 #endif