diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8a58964..3636658 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,10 +2,8 @@ cmake_minimum_required(VERSION 3.10)
 
 project(snoopy)
 
-file(GLOB snoopy_src
-    "src/*.h"
-    "src/*.cpp"
-)
+include_directories("include")
+file(GLOB SOURCES "src/*.cpp")
 
-add_executable(snoopy ${snoopy_src})
+add_executable(snoopy ${SOURCES})
 
diff --git a/include/camera.h b/include/camera.h
new file mode 100644
index 0000000..0f68329
--- /dev/null
+++ b/include/camera.h
@@ -0,0 +1,52 @@
+#pragma once
+
+#include "rtweekend.h"
+#include "image.h"
+
+class camera
+{
+    public:
+        camera(
+            point3  lookfrom,
+            point3  lookat,
+            vec3    vup,
+            double  vfov,   // vertical field of view in degrees
+            double  aspect_ratio,
+            double  aperture,
+            double  focus_dist)
+        {
+            auto theta = degrees_to_radians(vfov);
+            auto h = tan(theta/2);
+            auto viewport_height = 2.0 * h;
+            auto viewport_width = aspect_ratio * viewport_height;
+
+            w_ = unit_vector(lookfrom - lookat);
+            u_ = unit_vector(cross(vup, w_));
+            v_ = cross(w_, u_);
+
+            origin_ = lookfrom;
+            horizontal_ = focus_dist * viewport_width * u_;
+            vertical_ = focus_dist * viewport_height * v_;
+            lower_left_corner_ = origin_ - horizontal_/2 - vertical_/2 - focus_dist * w_;
+
+            lens_radius_ = aperture / 2;
+        }
+
+        ray get_ray(double s, double t) const 
+        {
+            vec3 rd = lens_radius_ * random_in_unit_disk();
+            vec3 offset = (u_ * rd.x()) + (v_ * rd.y());
+
+            return ray(
+                origin_ + offset,
+                lower_left_corner_ + s*horizontal_ + t*vertical_ - origin_ - offset);
+        }
+
+    private:
+        point3  origin_;
+        point3  lower_left_corner_;
+        vec3    horizontal_;
+        vec3    vertical_;
+        vec3    u_, v_, w_;
+        double  lens_radius_;
+};
diff --git a/src/colour.h b/include/colour.h
similarity index 100%
rename from src/colour.h
rename to include/colour.h
diff --git a/src/error.h b/include/error.h
similarity index 100%
rename from src/error.h
rename to include/error.h
diff --git a/include/foo.h b/include/foo.h
new file mode 100644
index 0000000..604782e
--- /dev/null
+++ b/include/foo.h
@@ -0,0 +1 @@
+#include <iostream>
diff --git a/src/hittable.h b/include/hittable.h
similarity index 100%
rename from src/hittable.h
rename to include/hittable.h
diff --git a/src/hittable_list.h b/include/hittable_list.h
similarity index 100%
rename from src/hittable_list.h
rename to include/hittable_list.h
diff --git a/src/image.h b/include/image.h
similarity index 100%
rename from src/image.h
rename to include/image.h
diff --git a/src/material.h b/include/material.h
similarity index 100%
rename from src/material.h
rename to include/material.h
diff --git a/src/rtweekend.h b/include/math.h
similarity index 71%
rename from src/rtweekend.h
rename to include/math.h
index e79e95a..0a27e02 100644
--- a/src/rtweekend.h
+++ b/include/math.h
@@ -1,22 +1,10 @@
 #pragma once
 
 #include <cmath>
-#include <cstdlib>
-#include <limits>
-#include <memory>
-
-// usings
-
-using std::shared_ptr;
-using std::make_shared;
-using std::sqrt;
-
-// constants
 
 const double infinity = std::numeric_limits<double>::infinity();
 const double pi = 3.1415926535897932385;
 
-// utility functions
 inline double degrees_to_radians(double degrees)
 {
     return degrees * pi / 180;
@@ -40,9 +28,3 @@ inline double clamp(double x, double min, double max)
     if (x > max) return max;
     return x;
 }
-
-// common headers
-
-#include "error.h"
-#include "ray.h"
-#include "vec3.h"
diff --git a/src/ray.h b/include/ray.h
similarity index 100%
rename from src/ray.h
rename to include/ray.h
diff --git a/include/rtweekend.h b/include/rtweekend.h
new file mode 100644
index 0000000..e5ae6a2
--- /dev/null
+++ b/include/rtweekend.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <cmath>
+#include <cstdlib>
+#include <limits>
+#include <memory>
+
+// usings
+
+using std::shared_ptr;
+using std::make_shared;
+using std::sqrt;
+
+// common headers
+
+#include "error.h"
+#include "ray.h"
+#include "vec3.h"
diff --git a/src/scene.h b/include/scene.h
similarity index 99%
rename from src/scene.h
rename to include/scene.h
index 33acf32..45a5131 100644
--- a/src/scene.h
+++ b/include/scene.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "math.h"
 #include "sphere.h"
 #include "colour.h"
 #include "material.h"
diff --git a/src/sphere.h b/include/sphere.h
similarity index 100%
rename from src/sphere.h
rename to include/sphere.h
diff --git a/src/vec3.h b/include/vec3.h
similarity index 69%
rename from src/vec3.h
rename to include/vec3.h
index d76dcff..a7ac81f 100755
--- a/src/vec3.h
+++ b/include/vec3.h
@@ -1,9 +1,8 @@
 #pragma once
 
-#include <cmath>
 #include <iostream>
 
-#include "rtweekend.h"
+#include "math.h"
 
 class vec3
 {
@@ -129,57 +128,3 @@ inline vec3 unit_vector(vec3 v)
     return v / v.length();
 }
 
-vec3 random_in_unit_sphere()
-{
-    while (true)
-    {
-        auto p = vec3::random(-1,1);
-        if (p.length_squared() >= 1) continue;
-        return p;
-    }
-}
-
-vec3 random_unit_vector()
-{
-    auto a = random_double(0, 2*pi);
-    auto z = random_double(-1,1);
-    auto r = sqrt(1 - z*z);
-    return vec3(r*cos(a), r*sin(a), z);
-}
-
-vec3 random_in_hemisphere(const vec3& normal)
-{
-    vec3 in_unit_sphere = random_in_unit_sphere();
-    if (dot(in_unit_sphere, normal) > 0.0)
-    {
-        return in_unit_sphere;
-    }
-    else
-    {
-        return -in_unit_sphere;
-    }
-}
-
-vec3 random_in_unit_disk()
-{
-    while(true)
-    {
-        auto p = vec3(random_double(-1,1), random_double(-1,1), 0);
-        if (p.length_squared() >= 1) continue;
-        return p;
-    }
-}
-
-vec3 reflect(const vec3& v, const vec3& n)
-{
-    return v - 2*dot(v,n)*n;
-}
-
-vec3 refract(const vec3& uv, const vec3& n, double etai_over_etat)
-{
-    auto cos_theta = dot(-uv, n);
-    vec3 r_out_parallel = etai_over_etat * (uv + cos_theta*n);
-    vec3 r_out_perp = -sqrt(1.0 - r_out_parallel.length_squared()) * n;
-
-    return r_out_parallel + r_out_perp;
-}
diff --git a/src/camera.cpp b/src/camera.cpp
new file mode 100644
index 0000000..b29fa37
--- /dev/null
+++ b/src/camera.cpp
@@ -0,0 +1,37 @@
+#include "camera.h"
+
+camera::camera(
+    point3  lookfrom,
+    point3  lookat,
+    vec3    vup,
+    double  vfov,   // vertical field of view in degrees
+    double  aspect_ratio,
+    double  aperture,
+    double  focus_dist)
+{
+    auto theta = degrees_to_radians(vfov);
+    auto h = tan(theta/2);
+    auto viewport_height = 2.0 * h;
+    auto viewport_width = aspect_ratio * viewport_height;
+
+    w_ = unit_vector(lookfrom - lookat);
+    u_ = unit_vector(cross(vup, w_));
+    v_ = cross(w_, u_);
+
+    origin_ = lookfrom;
+    horizontal_ = focus_dist * viewport_width * u_;
+    vertical_ = focus_dist * viewport_height * v_;
+    lower_left_corner_ = origin_ - horizontal_/2 - vertical_/2 - focus_dist * w_;
+
+    lens_radius_ = aperture / 2;
+}
+
+ray camera::get_ray(double s, double t) const
+{
+    vec3 rd = lens_radius_ * random_in_unit_disk();
+    vec3 offset = (u_ * rd.x()) + (v_ * rd.y());
+
+    return ray(
+        origin_ + offset,
+        lower_left_corner_ + s*horizontal_ + t*vertical_ - origin_ - offset);
+}
diff --git a/src/camera.h b/src/camera.h
index 0f68329..f8b423f 100644
--- a/src/camera.h
+++ b/src/camera.h
@@ -1,52 +1,29 @@
 #pragma once
 
-#include "rtweekend.h"
+#include "math.h"
+#include "vec3.h"
+#include "ray.h"
 #include "image.h"
 
 class camera
 {
-    public:
-        camera(
-            point3  lookfrom,
-            point3  lookat,
-            vec3    vup,
-            double  vfov,   // vertical field of view in degrees
-            double  aspect_ratio,
-            double  aperture,
-            double  focus_dist)
-        {
-            auto theta = degrees_to_radians(vfov);
-            auto h = tan(theta/2);
-            auto viewport_height = 2.0 * h;
-            auto viewport_width = aspect_ratio * viewport_height;
+public:
+    camera(
+        point3  lookfrom,
+        point3  lookat,
+        vec3    vup,
+        double  vfov,   // vertical field of view in degrees
+        double  aspect_ratio,
+        double  aperture,
+        double  focus_dist);
 
-            w_ = unit_vector(lookfrom - lookat);
-            u_ = unit_vector(cross(vup, w_));
-            v_ = cross(w_, u_);
+    ray get_ray(double s, double t) const; 
 
-            origin_ = lookfrom;
-            horizontal_ = focus_dist * viewport_width * u_;
-            vertical_ = focus_dist * viewport_height * v_;
-            lower_left_corner_ = origin_ - horizontal_/2 - vertical_/2 - focus_dist * w_;
-
-            lens_radius_ = aperture / 2;
-        }
-
-        ray get_ray(double s, double t) const 
-        {
-            vec3 rd = lens_radius_ * random_in_unit_disk();
-            vec3 offset = (u_ * rd.x()) + (v_ * rd.y());
-
-            return ray(
-                origin_ + offset,
-                lower_left_corner_ + s*horizontal_ + t*vertical_ - origin_ - offset);
-        }
-
-    private:
-        point3  origin_;
-        point3  lower_left_corner_;
-        vec3    horizontal_;
-        vec3    vertical_;
-        vec3    u_, v_, w_;
-        double  lens_radius_;
+private:
+    point3  origin_;
+    point3  lower_left_corner_;
+    vec3    horizontal_;
+    vec3    vertical_;
+    vec3    u_, v_, w_;
+    double  lens_radius_;
 };
diff --git a/src/foo.cpp b/src/foo.cpp
new file mode 100644
index 0000000..f4de601
--- /dev/null
+++ b/src/foo.cpp
@@ -0,0 +1 @@
+#include "foo.h"
diff --git a/src/math.cpp b/src/math.cpp
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/math.cpp
@@ -0,0 +1 @@
+
diff --git a/src/vec3.cpp b/src/vec3.cpp
new file mode 100644
index 0000000..eb73211
--- /dev/null
+++ b/src/vec3.cpp
@@ -0,0 +1,57 @@
+#include "vec3.h"
+
+vec3 random_unit_vector()
+{
+    auto a = random_double(0, 2*pi);
+    auto z = random_double(-1,1);
+    auto r = sqrt(1 - z*z);
+    return vec3(r*cos(a), r*sin(a), z);
+}
+
+vec3 reflect(const vec3& v, const vec3& n)
+{
+    return v - 2*dot(v,n)*n;
+}
+
+vec3 refract(const vec3& uv, const vec3& n, double etai_over_etat)
+{
+    auto cos_theta = dot(-uv, n);
+    vec3 r_out_parallel = etai_over_etat * (uv + cos_theta*n);
+    vec3 r_out_perp = -sqrt(1.0 - r_out_parallel.length_squared()) * n;
+
+    return r_out_parallel + r_out_perp;
+}
+
+vec3 random_in_unit_disk()
+{
+    while(true)
+    {
+        auto p = vec3(random_double(-1,1), random_double(-1,1), 0);
+        if (p.length_squared() >= 1) continue;
+        return p;
+    }
+}
+
+vec3 random_in_unit_sphere()
+{
+    while (true)
+    {
+        auto p = vec3::random(-1,1);
+        if (p.length_squared() >= 1) continue;
+        return p;
+    }
+}
+
+vec3 random_in_hemisphere(const vec3& normal)
+{
+    vec3 in_unit_sphere = random_in_unit_sphere();
+    if (dot(in_unit_sphere, normal) > 0.0)
+    {
+        return in_unit_sphere;
+    }
+    else
+    {
+        return -in_unit_sphere;
+    }
+}
+