moved all sources into src directory

src/Color.cpp

@@ -0,0 +1,83 @@
+//
+// 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 {
+        double hi = hsb.h / 60;
+        int i = static_cast<int>(hi);
+        double f = hi - i;
+        double p = hsb.b * (1.0 - hsb.s);
+        double q = hsb.b * (1.0 - (hsb.s * f));
+        double t = hsb.b * (1.0 - (hsb.s * (1.0 -f)));
+        switch (i) {
+            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:
+            default:
+                _rgb.r = hsb.b;
+                _rgb.g = p;
+                _rgb.b = q;
+                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 (delta < 0.00001) {
+        hsb.h = 0;
+        hsb.s = 0;
+        hsb.b = rgb_max;
+        return hsb;
+    }
+    if (_rgb.r >= rgb_max) { // between yellow and magenta
+        hsb.h = (_rgb.g - _rgb.b) / delta;
+    } else if (_rgb.g >= rgb_max) { //  between cyan and yellow
+        hsb.h = 2.0 + (_rgb.b - _rgb.r) / delta;
+    } else { // between magenta and cyan
+        hsb.h = 4.0 + (_rgb.r - _rgb.g) / delta;
+    }
+    hsb.h *= 60;
+    hsb.s = rgb_max > 0.0 ? delta / rgb_max : 0;
+    hsb.b = rgb_max;
+    return hsb;
+}

src/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_

src/ScreensaverPlugin.cpp

@@ -0,0 +1,64 @@
+//
+// ScreensaverPlugin.cpp
+// tmp
+//
+// Created by Bob Polis at 2020-10-26
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#include "ScreensaverPlugin.hpp"
+
+void ScreensaverPlugin::setup(cairo_t* context, const cairo_rectangle_t& rect) {
+    _c = context;
+    _r = rect;
+    make_black();
+}
+
+int ScreensaverPlugin::fps() const {
+    return 30;
+}
+
+void ScreensaverPlugin::make_black() {
+    cairo_set_source_rgb(_c, 0, 0, 0);
+    cairo_rectangle(_c, 0, 0, _r.width, _r.height);
+    cairo_fill(_c);
+}
+
+cairo_rectangle_t ScreensaverPlugin::random_rect() {
+    cairo_rectangle_t rect;
+    double v1, v2;
+    v1 = random_x();
+    v2 = random_x();
+    if (v1 < v2) {
+        rect.x = v1;
+        rect.width = v2 - v1;
+    } else {
+        rect.x = v2;
+        rect.width = v1 - v2;
+    }
+    v1 = random_y();
+    v2 = random_y();
+    if (v1 < v2) {
+        rect.y = v1;
+        rect.height = v2 - v1;
+    } else {
+        rect.y = v2;
+        rect.height = v1 - v2;
+    }
+    return rect;
+}
+
+double ScreensaverPlugin::random_x() {
+    std::uniform_real_distribution<double> dist {0, _r.width};
+    return dist(_eng);
+}
+
+double ScreensaverPlugin::random_y() {
+    std::uniform_real_distribution<double> dist {0, _r.height};
+    return dist(_eng);
+}
+
+double ScreensaverPlugin::random01() {
+    std::uniform_real_distribution<double> dist {};
+    return dist(_eng);
+}

src/ScreensaverPlugin.hpp

@@ -0,0 +1,38 @@
+//
+// ScreensaverPlugin.hpp
+// screensaver
+//
+// Created by Bob Polis at 2020-10-26
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#ifndef _ScreensaverPlugin_H_
+#define _ScreensaverPlugin_H_
+
+#include <cairo/cairo.h>
+#include <random>
+
+class ScreensaverPlugin {
+    public:
+        ScreensaverPlugin() = default;
+        virtual ~ScreensaverPlugin() = default;
+
+        virtual void setup(cairo_t* context, const cairo_rectangle_t& rect);
+        virtual int fps() const;
+
+        virtual void draw_frame() = 0;
+
+    protected:
+        cairo_t* _c {nullptr};
+        cairo_rectangle_t _r {};
+        std::random_device _dev {};
+        std::default_random_engine _eng {_dev()};
+
+        void make_black();
+        cairo_rectangle_t random_rect();
+        double random_x();
+        double random_y();
+        double random01();
+};
+
+#endif // _ScreensaverPlugin_H_