added Color class

Color.cpp

@@ -0,0 +1,76 @@
+//
+// Color.cpp
+// screensaver
+//
+// Created by Bob Polis at 2020-10-27
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#include "Color.hpp"
+#include <algorithm>
+#include <cmath>
+
+Color::Color(const RGB& rgb) : _rgb {rgb} {}
+
+Color::Color(const HSB& hsb) {
+    if (hsb.s == 0) {
+        _rgb.r = _rgb.g = _rgb.b = hsb.b;
+    } else {
+        int hi = static_cast<int>(round(fabs(hsb.h / 60)));
+        double f = hsb.h / 60 - hi;
+        double p = hsb.b * (1 - hsb.s);
+        double q = hsb.b * (1 - f * hsb.s);
+        double t = hsb.b * (1- (1 - f) * hsb.s);
+        switch (hi) {
+            case 0:
+                _rgb.r = hsb.b;
+                _rgb.g = t;
+                _rgb.b = p;
+                break;
+            case 1:
+                _rgb.r = q;
+                _rgb.g = hsb.b;
+                _rgb.b = p;
+                break;
+            case 2:
+                _rgb.r = p;
+                _rgb.g = hsb.b;
+                _rgb.b = t;
+                break;
+            case 3:
+                _rgb.r = p;
+                _rgb.g = q;
+                _rgb.b = hsb.b;
+                break;
+            case 4:
+                _rgb.r = t;
+                _rgb.g = p;
+                _rgb.b = hsb.b;
+                break;
+            case 5:
+                _rgb.r = hsb.b;
+                _rgb.g = p;
+                _rgb.b = q;
+                break;
+            default:
+                break;
+        }
+    }
+}
+
+Color::operator HSB() const {
+    HSB hsb;
+    double rgb_max = std::max<double>({_rgb.r, _rgb.g, _rgb.b});
+    double rgb_min = std::min<double>({_rgb.r, _rgb.g, _rgb.b});
+    double delta = rgb_max - rgb_min;
+    if (_rgb.r > _rgb.g && _rgb.r > _rgb.b) { // red is max
+        hsb.h = ((_rgb.g - _rgb.b) / delta) * 60;
+    } else if (_rgb.g > _rgb.r && _rgb.g > _rgb.b) { // green is max
+        hsb.h = ((_rgb.b - _rgb.r) / delta) * 60;
+    } else { // blue is max
+        hsb.h = ((_rgb.r - _rgb.g) / delta) * 60;
+    }
+    hsb.s = delta / rgb_max;
+    hsb.b = rgb_max;
+    return hsb;
+}

Color.hpp

@@ -0,0 +1,36 @@
+//
+// Color.hpp
+// screensaver
+//
+// Created by Bob Polis at 2020-10-27
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#ifndef _Color_H_
+#define _Color_H_
+
+struct RGB {
+    double r;
+    double g;
+    double b;
+};
+
+struct HSB {
+    double h;
+    double s;
+    double b;
+};
+
+class Color {
+    public:
+        Color(const RGB& rgb);
+        Color(const HSB& hsb);
+
+        operator RGB() const { return _rgb; }
+        operator HSB() const;
+
+    private:
+        RGB _rgb;
+};
+
+#endif // _Color_H_