Initial commit

colour.h

@@ -0,0 +1,35 @@
+#ifndef COLOUR_H
+#define COLOUR_H
+
+#include "interval.h"
+#include "vec3.h"
+
+using colour = vec3;
+
+inline double linearToGamma(double linearComponent) {
+    if (linearComponent > 0) return sqrt(linearComponent);
+
+    return 0;
+}
+
+void writeColour(std::ostream& out, const colour& pixelColour) {
+    auto r = pixelColour.x();
+    auto g = pixelColour.y();
+    auto b = pixelColour.z();
+
+    // Apply a linear to gamma transform for gamma 2. 
+    r = linearToGamma(r);
+    g = linearToGamma(g);
+    b = linearToGamma(b);
+
+    // Translate the [0, 1] component values to the byte range [0, 255].
+    static const interval intensity(0.000, 0.999);
+    int rbyte = int(255 * intensity.clamp(r));
+    int gbyte = int(255 * intensity.clamp(g));
+    int bbyte = int(255 * intensity.clamp(b));
+
+    // Write out the pixel colour components. 
+    out << rbyte << ' ' << gbyte << ' ' << bbyte << '\n';
+}
+
+#endif