Replace color with pbr-book inspired Spectrum class

7 files changed, 141 insertions, 40 deletions

diff --git a/src/core/common.hpp b/src/core/common.hpp
index fd219bf..a3e682e 100644
--- a/src/core/common.hpp
+++ b/src/core/common.hpp
@@ -1,6 +1,10 @@
 #ifndef COMMON_H
 #define COMMON_H
 
+#include <limits>
+
 #define ZERO_APPROX 1e-6
 
+#define INFINITY std::numeric_limits<double>::infinity()
+
 #endif
diff --git a/src/core/spectrum.cpp b/src/core/spectrum.cpp
new file mode 100644
index 0000000..d53cf49
--- /dev/null
+++ b/src/core/spectrum.cpp
@@ -0,0 +1,90 @@
+#include "spectrum.hpp"
+
+static double clamp(double v, double low = 0, double high = 0) {
+    if (v < low) {
+        return low;
+    } 
+    if (v > high) {
+        return high;
+    }
+    return v;
+}
+
+Spectrum::Spectrum(double v) {
+    c[0] = v;
+    c[1] = v;
+    c[2] = v;
+}
+
+Spectrum Spectrum::FromRGB(double r, double g, double b) {
+    Spectrum ret;
+    ret.c[0] = r;
+    ret.c[1] = g;
+    ret.c[2] = b;
+
+    return ret;
+}
+
+Spectrum &Spectrum::operator+=(const Spectrum &o) {
+    c[0] += o.c[0];
+    c[1] += o.c[1];
+    c[2] += o.c[2];
+
+    return *this;
+}
+
+Spectrum &Spectrum::operator*=(double o) {
+    c[0] *= o;
+    c[1] *= o;
+    c[2] *= o;
+
+    return *this;
+}
+
+Spectrum Spectrum::operator+(const Spectrum &o) const {
+    Spectrum ret = *this;
+
+    ret.c[0] += o.c[0];
+    ret.c[1] += o.c[1];
+    ret.c[2] += o.c[2];
+
+    return ret;
+}
+
+Spectrum Spectrum::operator-(const Spectrum &o) const {
+    Spectrum ret = *this;
+
+    ret.c[0] -= o.c[0];
+    ret.c[1] -= o.c[1];
+    ret.c[2] -= o.c[2];
+
+    return ret;
+}
+
+Spectrum Spectrum::operator*(const Spectrum &o) const {
+    Spectrum ret = *this;
+
+    ret.c[0] *= o.c[0];
+    ret.c[1] *= o.c[1];
+    ret.c[2] *= o.c[2];
+
+    return ret;
+}
+
+Spectrum Spectrum::operator/(const Spectrum &o) const {
+    Spectrum ret = *this;
+
+    ret.c[0] /= o.c[0];
+    ret.c[1] /= o.c[1];
+    ret.c[2] /= o.c[2];
+
+    return ret;
+}
+
+Spectrum Spectrum::clamp(double low, double high) const {
+    Spectrum ret;
+    ret.c[0] = ::clamp(c[0], low, high);
+    ret.c[1] = ::clamp(c[1], low, high);
+    ret.c[2] = ::clamp(c[2], low, high);
+    return ret;
+}
diff --git a/src/core/spectrum.hpp b/src/core/spectrum.hpp
new file mode 100644
index 0000000..de9355d
--- /dev/null
+++ b/src/core/spectrum.hpp
@@ -0,0 +1,29 @@
+#ifndef SPECTRUM_H
+#define SPECTRUM_H
+
+#include "core/common.hpp"
+
+// Contains a RGB spectrum value
+class Spectrum {
+public:
+    Spectrum(double v = 0);
+    static Spectrum FromRGB(double r, double g, double b);
+
+    Spectrum &operator+=(const Spectrum &o);
+    Spectrum &operator*=(double o);
+    Spectrum operator+(const Spectrum &o) const;
+    Spectrum operator-(const Spectrum &o) const;
+    Spectrum operator*(const Spectrum &o) const;
+    Spectrum operator/(const Spectrum &o) const;
+
+    Spectrum clamp(double low = 0, double high = INFINITY) const;
+
+    double R() const { return c[0]; }
+    double G() const { return c[1]; }
+    double B() const { return c[2]; }
+
+private:
+    double c[3];
+};
+
+#endif
diff --git a/src/object.cpp b/src/object.cpp
index 0f7332f..40e21b2 100644
--- a/src/object.cpp
+++ b/src/object.cpp
@@ -4,13 +4,7 @@
 #include <iostream>
 #include "core/common.hpp"
 
-void Color::clamp() {
-    if (m_x > 1) { m_x = 1; }
-    if (m_y > 1) { m_y = 1; }
-    if (m_z > 1) { m_z = 1; }
-}
-
-Material::Material(Color color, double defuse, double spectral, double spectral_pow, double emissive) {
+Material::Material(Spectrum color, double defuse, double spectral, double spectral_pow, double emissive) {
     m_color = color;
     m_defuse = defuse;
     m_emissive = emissive;
@@ -18,17 +12,17 @@ Material::Material(Color color, double defuse, double spectral, double spectral_
     m_spectral_pow = spectral_pow;
 }
 
-Color Material::reflect(const Vec3d &normal, const Vec3d &in, const Vec3d &out, const Color &incol) const {
+Spectrum Material::reflect(const Vec3d &normal, const Vec3d &in, const Vec3d &out, const Spectrum &incol) const {
     // Emissive
-    Color c = Vec3d(m_color) * m_emissive;
+    Spectrum c = m_color * m_emissive;
 
     // Defuse
-    c += (Vec3d(m_color) * Vec3d(incol)) * (in.dot(normal) * m_defuse);
+    c += (m_color * incol) * (in.dot(normal) * m_defuse);
 
     // Spectral
     if (m_spectral > 0) {
         auto R = normal * (2 * normal.dot(in)) - in;
-        c += Vec3d(incol) * pow(out.dot(R) * m_spectral, m_spectral_pow);
+        c += incol * pow(out.dot(R) * m_spectral, m_spectral_pow);
     }
 
     return c;
diff --git a/src/object.hpp b/src/object.hpp
index 1cfb254..1cfd10d 100644
--- a/src/object.hpp
+++ b/src/object.hpp
@@ -4,39 +4,23 @@
 #include <memory>
 #include "core/vector.hpp"
 #include "core/ray.hpp"
-
-class Color : public Vec3d {
-    public:
-        Color() {}
-        Color(const Vec3d &v) : Vec3d(v) {}
-        Color(double r, double g, double b) : Vec3d(r, g, b) {}
-
-        uint8_t r() { return m_x * 255; }
-        uint8_t g() { return m_y * 255; }
-        uint8_t b() { return m_z * 255; }
-
-        Color& operator+=(const Color& op) {
-            Vec3d::operator+=(op);
-            return *this;
-        }
-        void clamp();
-};
+#include "core/spectrum.hpp"
 
 // Implements phong BRDF 
 class Material {
     public:
-        Material(Color color, double defuse, double spectral=0, double spectral_pow=0, double emissive=0);
+        Material(Spectrum color, double defuse, double spectral=0, double spectral_pow=0, double emissive=0);
 
-        Color reflect(const Vec3d &normal, const Vec3d &in, const Vec3d &out, const Color &incol) const;
+        Spectrum reflect(const Vec3d &normal, const Vec3d &in, const Vec3d &out, const Spectrum &incol) const;
 
-        Color emits() const {
+        Spectrum emits() const {
             return m_color * m_emissive;
         }
 
         // Whether the material is reflective
         bool reflects() const { return m_defuse+m_spectral > 0; }
     private:
-        Color m_color;
+        Spectrum m_color;
         double m_defuse;
         double m_emissive;
         double m_spectral;
diff --git a/src/render.cpp b/src/render.cpp
index a81c6bb..286cbae 100644
--- a/src/render.cpp
+++ b/src/render.cpp
@@ -86,9 +86,9 @@ Ray Renderer::findray(double x, double y) const {
     return Ray(m_eye, dir, true);
 }
 
-Color Renderer::render(unsigned x, unsigned y, unsigned samples) {
+Spectrum Renderer::render(unsigned x, unsigned y, unsigned samples) {
 
-    Color sum(0, 0, 0);
+    Spectrum sum;
 
     for (unsigned i = 0; i < samples; i++) {
         auto r = findray(x + m_random(), y + m_random());
@@ -98,20 +98,20 @@ Color Renderer::render(unsigned x, unsigned y, unsigned samples) {
     if (samples < 2) {
         return sum;
     } else {
-        return Vec3d(sum) / (double)samples;
+        return sum / (double)samples;
     }
 }
 
-Color Renderer::pathtrace_sample(const Ray &r, unsigned hop) {
+Spectrum Renderer::pathtrace_sample(const Ray &r, unsigned hop) {
     if (hop >= m_maxhops) {
-        return Color(0, 0, 0);
+        return Spectrum();
     }
 
     double dist;
     auto res = cast_ray(r, 0, &dist);
 
     if (!res) {
-        return Color(0, 0, 0);
+        return Spectrum();
     }
 
     auto col = res->m_mat.emits();
diff --git a/src/render.hpp b/src/render.hpp
index 8102686..f8da98a 100644
--- a/src/render.hpp
+++ b/src/render.hpp
@@ -30,7 +30,7 @@ class Renderer {
     public:
     Renderer(const Scene &scn, Vec3d eye, Vec3d target, unsigned width, unsigned height, unsigned maxhops);
 
-    Color render(unsigned x, unsigned y, unsigned samples);
+    Spectrum render(unsigned x, unsigned y, unsigned samples);
 
     unsigned m_width, m_height;
     Sampler m_sampler;
@@ -39,7 +39,7 @@ class Renderer {
     void recalculate();
     Ray findray(double x, double y) const ;
 
-    Color pathtrace_sample(const Ray &r, unsigned hop);
+    Spectrum pathtrace_sample(const Ray &r, unsigned hop);
     // Will return first result less than chk_dist. 
     // This is ignored if chk_dist is 0.
     // If dist is non-null the resulting distance is written here.