Updates from book 3 complete progression

src/InOneWeekend/color.h

@@ -16,6 +16,7 @@
 
 using color = vec3;
 
+
 inline double linear_to_gamma(double linear_component)
 {
     if (linear_component > 0)
@@ -24,6 +25,7 @@ inline double linear_to_gamma(double linear_component)
     return 0;
 }
 
+
 void write_color(std::ostream& out, const color& pixel_color) {
     auto r = pixel_color.x();
     auto g = pixel_color.y();

src/InOneWeekend/rtweekend.h

@@ -21,11 +21,13 @@
 using std::make_shared;
 using std::shared_ptr;
 
+
 // Constants
 
 const double infinity = std::numeric_limits<double>::infinity();
 const double pi = 3.1415926535897932385;
 
+
 // Utility Functions
 
 inline double degrees_to_radians(double degrees) {
@@ -42,6 +44,7 @@ inline double random_double(double min, double max) {
     return min + (max-min)*random_double();
 }
 
+
 // Common Headers
 
 #include "color.h"

src/TheNextWeek/color.h

@@ -16,6 +16,7 @@
 
 using color = vec3;
 
+
 inline double linear_to_gamma(double linear_component)
 {
     if (linear_component > 0)
@@ -24,6 +25,7 @@ inline double linear_to_gamma(double linear_component)
     return 0;
 }
 
+
 void write_color(std::ostream& out, const color& pixel_color) {
     auto r = pixel_color.x();
     auto g = pixel_color.y();

src/TheNextWeek/quad.h

@@ -14,6 +14,7 @@
 #include "hittable.h"
 #include "hittable_list.h"
 
+
 class quad : public hittable {
   public:
     quad(const point3& Q, const vec3& u, const vec3& v, shared_ptr<material> mat)

src/TheNextWeek/rtweekend.h

@@ -21,11 +21,13 @@
 using std::make_shared;
 using std::shared_ptr;
 
+
 // Constants
 
 const double infinity = std::numeric_limits<double>::infinity();
 const double pi = 3.1415926535897932385;
 
+
 // Utility Functions
 
 inline double degrees_to_radians(double degrees) {
@@ -47,6 +49,7 @@ inline int random_int(int min, int max) {
     return int(random_double(min, max+1));
 }
 
+
 // Common Headers
 
 #include "color.h"

src/TheRestOfYourLife/camera.h

@@ -14,6 +14,7 @@
 #include "rtweekend.h"
 
 #include "hittable.h"
+#include "pdf.h"
 #include "material.h"
 
 
@@ -175,12 +176,13 @@ class camera {
         mixture_pdf p(light_ptr, srec.pdf_ptr);
 
         ray scattered = ray(rec.p, p.generate(), r.time());
-        auto pdf_val = p.value(scattered.direction());
+        auto pdf_value = p.value(scattered.direction());
 
         double scattering_pdf = rec.mat->scattering_pdf(r, rec, scattered);
 
         color sample_color = ray_color(scattered, depth-1, world, lights);
-        color color_from_scatter = (srec.attenuation * scattering_pdf * sample_color) / pdf_val;
+        color color_from_scatter =
+            (srec.attenuation * scattering_pdf * sample_color) / pdf_value;
 
         return color_from_emission + color_from_scatter;
     }

src/TheRestOfYourLife/color.h

@@ -16,6 +16,7 @@
 
 using color = vec3;
 
+
 inline double linear_to_gamma(double linear_component)
 {
     if (linear_component > 0)
@@ -24,6 +25,7 @@ inline double linear_to_gamma(double linear_component)
     return 0;
 }
 
+
 void write_color(std::ostream& out, const color& pixel_color) {
     auto r = pixel_color.x();
     auto g = pixel_color.y();

src/TheRestOfYourLife/cos_cubed.cc

@@ -13,7 +13,7 @@
 
 #include <iostream>
 #include <iomanip>
-#include <math.h>
+
 
 double f(double r2) {
     // auto x = std::cos(2*pi*r1) * 2 * std::sqrt(r2*(1-r2));
@@ -23,10 +23,12 @@ double f(double r2) {
     return cos_theta*cos_theta*cos_theta;
 }
 
+
 double pdf() {
     return 1.0 / (2.0*pi);
 }
 
+
 int main() {
     int N = 1000000;
 

src/TheRestOfYourLife/cos_density.cc

@@ -13,17 +13,19 @@
 
 #include <iostream>
 #include <iomanip>
-#include <math.h>
+
 
 double f(const vec3& d) {
     auto cos_theta = d.z();
     return cos_theta*cos_theta*cos_theta;
 }
 
+
 double pdf(const vec3& d) {
     return d.z() / pi;
 }
 
+
 int main() {
     int N = 1000000;
 

src/TheRestOfYourLife/estimate_halfway.cc

@@ -13,40 +13,42 @@
 #include <vector>
 #include <iostream>
 #include <iomanip>
-#include <math.h>
-#include <cmath>
-#include <stdlib.h>
+
 
 struct sample {
     double x;
     double p_x;
 };
 
+
 bool compare_by_x(const sample& a, const sample& b) {
     return a.x < b.x;
 }
 
+
 int main() {
     unsigned int N = 10000;
     double sum = 0.0;
 
-    // iterate through all of our samples
+    // Iterate through all of our samples.
+
     std::vector<sample> samples;
     for (unsigned int i = 0; i < N; i++) {
-        // Get the area under the curve
+        // Get the area under the curve.
         auto x = random_double(0, 2*pi);
         auto sin_x = std::sin(x);
         auto p_x = exp(-x / (2*pi)) * sin_x * sin_x;
         sum += p_x;
-        // store this sample
+
+        // Store this sample.
         sample this_sample = {x, p_x};
         samples.push_back(this_sample);
     }
 
-    // Sort the samples by x
+    // Sort the samples by x.
     std::sort(samples.begin(), samples.end(), compare_by_x);
 
-    // Find out the sample at which we have half of our area
+    // Find out the sample at which we have half of our area.
     double half_sum = sum / 2.0;
     double halfway_point = 0.0;
     double accum = 0.0;

src/TheRestOfYourLife/integrate_x_sq.cc

@@ -13,26 +13,31 @@
 
 #include <iostream>
 #include <iomanip>
-#include <math.h>
-#include <stdlib.h>
+
 
 double f(double d) {
     return 8.0 * std::pow(d, 1.0/3.0);
 }
 
+
 double pdf(double x) {
-        return (3.0/8.0) * x*x;
+    return (3.0/8.0) * x*x;
 }
 
+
 int main() {
     int N = 1;
-
     auto sum = 0.0;
+
     for (int i = 0; i < N; i++) {
-        auto x = f(random_double());
+        auto z = random_double();
+        if (z == 0.0)  // Ignore zero to avoid NaNs
+            continue;
+
+        auto x = f(z);
         sum += x*x / pdf(x);
     }
 
     std::cout << std::fixed << std::setprecision(12);
-    std::cout << "I = " << sum / N << '\n';
+    std::cout << "I = " << (sum / N) << '\n';
 }

src/TheRestOfYourLife/main.cc

@@ -12,8 +12,6 @@
 #include "rtweekend.h"
 
 #include "camera.h"
-#include "constant_medium.h"
-#include "hittable.h"
 #include "hittable_list.h"
 #include "material.h"
 #include "quad.h"

src/TheRestOfYourLife/onb.h

@@ -13,6 +13,7 @@
 
 #include "rtweekend.h"
 
+
 class onb {
   public:
     onb() {}

src/TheRestOfYourLife/pdf.h

@@ -26,35 +26,35 @@ class pdf {
 };
 
 
-class cosine_pdf : public pdf {
+class sphere_pdf : public pdf {
   public:
-    cosine_pdf(const vec3& w) { uvw.build_from_w(w); }
+    sphere_pdf() {}
 
     double value(const vec3& direction) const override {
-        auto cosine_theta = dot(unit_vector(direction), uvw.w());
-        return std::fmax(0, cosine_theta/pi);
+        return 1/ (4 * pi);
     }
 
     vec3 generate() const override {
-        return uvw.local(random_cosine_direction());
+        return random_unit_vector();
     }
-
-  private:
-    onb uvw;
 };
 
 
-class sphere_pdf : public pdf {
+class cosine_pdf : public pdf {
   public:
-    sphere_pdf() {}
+    cosine_pdf(const vec3& w) { uvw.build_from_w(w); }
 
     double value(const vec3& direction) const override {
-        return 1/ (4 * pi);
+        auto cosine_theta = dot(unit_vector(direction), uvw.w());
+        return std::fmax(0, cosine_theta/pi);
     }
 
     vec3 generate() const override {
-        return random_unit_vector();
+        return uvw.local(random_cosine_direction());
     }
+
+  private:
+    onb uvw;
 };
 
 

src/TheRestOfYourLife/pi.cc

@@ -13,10 +13,11 @@
 
 #include <iostream>
 #include <iomanip>
-#include <stdlib.h>
 
 
 int main() {
+    std::cout << std::fixed << std::setprecision(12);
+
     int inside_circle = 0;
     int inside_circle_stratified = 0;
     int sqrt_N = 1000;
@@ -25,21 +26,19 @@ int main() {
         for (int j = 0; j < sqrt_N; j++) {
             auto x = random_double(-1,1);
             auto y = random_double(-1,1);
-
             if (x*x + y*y < 1)
                 inside_circle++;
 
             x = 2*((i + random_double()) / sqrt_N) - 1;
             y = 2*((j + random_double()) / sqrt_N) - 1;
-
             if (x*x + y*y < 1)
                 inside_circle_stratified++;
         }
     }
 
-    std::cout << std::fixed << std::setprecision(12);
-    std::cout << "Regular    Estimate of Pi = "
-        << (4.0 * inside_circle) / (sqrt_N*sqrt_N) << '\n';
-    std::cout << "Stratified Estimate of Pi = "
+    std::cout
+        << "Regular    Estimate of Pi = "
+        << (4.0 * inside_circle) / (sqrt_N*sqrt_N) << '\n'
+        << "Stratified Estimate of Pi = "
         << (4.0 * inside_circle_stratified) / (sqrt_N*sqrt_N) << '\n';
 }

src/TheRestOfYourLife/quad.h

@@ -14,6 +14,7 @@
 #include "hittable.h"
 #include "hittable_list.h"
 
+
 class quad : public hittable {
   public:
     quad(const point3& Q, const vec3& u, const vec3& v, shared_ptr<material> mat)

src/TheRestOfYourLife/rtweekend.h

@@ -21,11 +21,13 @@
 using std::make_shared;
 using std::shared_ptr;
 
+
 // Constants
 
 const double infinity = std::numeric_limits<double>::infinity();
 const double pi = 3.1415926535897932385;
 
+
 // Utility Functions
 
 inline double degrees_to_radians(double degrees) {
@@ -47,6 +49,7 @@ inline int random_int(int min, int max) {
     return int(random_double(min, max+1));
 }
 
+
 // Common Headers
 
 #include "color.h"