Added colors and display coordinate abstraction

Author: stevenewald

CMakeLists.txt

@@ -19,6 +19,7 @@ add_library(
     fractal-generator_lib OBJECT
     source/lib.cpp
     source/graphics/basic_display.cpp
+    source/graphics/color_conversions.cpp
 )
 
 target_include_directories(

source/config.hpp

@@ -1,7 +1,9 @@
 #pragma once
 
+#include <cstddef>
+
 namespace fractal {
-constexpr auto WINDOW_WIDTH = 800UZ;
-constexpr auto WINDOW_HEIGHT = 600UZ;
-constexpr auto FRAME_RATE{60UZ};
+constexpr std::size_t WINDOW_WIDTH = 800UZ;
+constexpr std::size_t WINDOW_HEIGHT = 600UZ;
+constexpr std::size_t FRAME_RATE = 60UZ;
 } // namespace fractal

source/coordinates.hpp

@@ -0,0 +1,65 @@
+#pragma once
+
+#include <complex>
+
+namespace fractal {
+using display_coordinate = std::pair<uint16_t, uint16_t>;
+using complex_coordinate = std::complex<float>;
+
+struct display_domain {
+    display_coordinate start_coordinate;
+    display_coordinate end_coordinate;
+
+    class DisplayCoordinateIterator {
+        display_coordinate current_coordinate_;
+        display_coordinate end_coordinate_;
+
+    public:
+        explicit DisplayCoordinateIterator(const display_domain& domain) :
+            current_coordinate_{domain.start_coordinate},
+            end_coordinate_{domain.end_coordinate}
+        {}
+
+        const display_coordinate& operator*() const { return current_coordinate_; }
+
+        DisplayCoordinateIterator& operator++()
+        {
+            if (current_coordinate_.first == end_coordinate_.first) [[unlikely]] {
+                current_coordinate_.first = 0;
+                current_coordinate_.second++;
+            }
+            else {
+                current_coordinate_.first++;
+            }
+            return *this;
+        }
+
+        bool operator==(const DisplayCoordinateIterator&) const = default;
+    };
+
+    DisplayCoordinateIterator begin() const { return DisplayCoordinateIterator{*this}; }
+
+    DisplayCoordinateIterator end() const
+    {
+        return DisplayCoordinateIterator{
+            display_domain{end_coordinate, end_coordinate}
+        };
+    }
+};
+
+struct complex_domain {
+    complex_coordinate start_coordinate;
+    complex_coordinate end_coordinate;
+};
+
+inline float real_domain_size(const complex_domain& domain)
+{
+    return domain.end_coordinate.real() - domain.start_coordinate.real();
+}
+
+inline float imaginary_domain_size(const complex_domain& domain)
+{
+    return domain.end_coordinate.imag() - domain.start_coordinate.imag();
+}
+
+} // namespace fractal

source/graphics/basic_display.cpp

@@ -1,13 +1,27 @@
 #include "basic_display.hpp"
 
+#include "graphics/color_conversions.hpp"
+
 #include <fmt/format.h>
 #include <SFML/Graphics.hpp>
 #include <SFML/Graphics/RectangleShape.hpp>
 
+#include <cmath>
+
 namespace fractal {
-void BasicDisplay::set_pixel(std::size_t x_pos, std::size_t y_pos, uint8_t value)
+void BasicDisplay::set_pixel(display_coordinate coordinate, uint16_t value)
+{
+    pixels_.at(coordinate.first).at(coordinate.second) = value;
+}
+
+std::tuple<int, int, int> interpolateColor(
+    float t, std::tuple<int, int, int> color1, std::tuple<int, int, int> color2
+)
 {
-    pixels_.at(x_pos).at(y_pos) = value;
+    int r = std::get<0>(color1) + t * (std::get<0>(color2) - std::get<0>(color1));
+    int g = std::get<1>(color1) + t * (std::get<1>(color2) - std::get<1>(color1));
+    int b = std::get<2>(color1) + t * (std::get<2>(color2) - std::get<2>(color1));
+    return {r, g, b};
 }
 
 void BasicDisplay::display_window()
@@ -20,10 +34,12 @@ void BasicDisplay::display_window()
     image.create(WINDOW_WIDTH, WINDOW_HEIGHT);
     for (std::size_t x_pos = 0; x_pos < WINDOW_WIDTH; ++x_pos) {
         for (std::size_t y_pos = 0; y_pos < WINDOW_HEIGHT; ++y_pos) {
-            std::uint8_t pixel_value = pixels_.at(x_pos).at(y_pos);
+            std::uint16_t pixel_value = pixels_.at(x_pos).at(y_pos);
+            auto tuple = number_to_rgb(pixel_value);
+
             image.setPixel(
                 static_cast<unsigned int>(x_pos), static_cast<unsigned int>(y_pos),
-                sf::Color(pixel_value, pixel_value, pixel_value)
+                sf::Color(std::get<0>(tuple), std::get<1>(tuple), std::get<2>(tuple))
             );
         }
     }

source/graphics/basic_display.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "config.hpp"
+#include "coordinates.hpp"
 
 #include <SFML/System/Vector2.hpp>
 
@@ -12,7 +13,7 @@
 
 namespace fractal {
 class BasicDisplay {
-    std::array<std::array<uint8_t, WINDOW_HEIGHT>, WINDOW_WIDTH> pixels_{};
+    std::array<std::array<uint16_t, WINDOW_HEIGHT>, WINDOW_WIDTH> pixels_{};
     std::function<void(sf::Vector2f, sf::Vector2f)> on_resize_;
 
 public:
@@ -22,7 +23,7 @@ class BasicDisplay {
     ) : on_resize_(std::move(on_resize))
     {}
 
-    void set_pixel(std::size_t x_pos, std::size_t y_pos, std::uint8_t value);
+    void set_pixel(display_coordinate coordinate, uint16_t value);
     void display_window();
 };
 } // namespace fractal

source/graphics/color_conversions.cpp

@@ -0,0 +1,68 @@
+#include "color_conversions.hpp"
+
+#include <cmath>
+
+namespace fractal {
+std::tuple<uint16_t, uint16_t, uint16_t>
+hsv_to_rgb(float hue, float saturation, float value)
+{
+    float chroma = value * saturation;
+    float hue_prime = hue / 60.0f;
+    float uint16_termediate =
+        chroma * (1 - static_cast<float>(std::fabs(std::fmod(hue_prime, 2) - 1)));
+    float red_temp = 0.0f;
+    float green_temp = 0.0f;
+    float blue_temp = 0.0f;
+
+    if (0 <= hue_prime && hue_prime < 1) {
+        red_temp = chroma;
+        green_temp = uint16_termediate;
+        blue_temp = 0;
+    }
+    else if (1 <= hue_prime && hue_prime < 2) {
+        red_temp = uint16_termediate;
+        green_temp = chroma;
+        blue_temp = 0;
+    }
+    else if (2 <= hue_prime && hue_prime < 3) {
+        red_temp = 0;
+        green_temp = chroma;
+        blue_temp = uint16_termediate;
+    }
+    else if (3 <= hue_prime && hue_prime < 4) {
+        red_temp = 0;
+        green_temp = uint16_termediate;
+        blue_temp = chroma;
+    }
+    else if (4 <= hue_prime && hue_prime < 5) {
+        red_temp = uint16_termediate;
+        green_temp = 0;
+        blue_temp = chroma;
+    }
+    else if (5 <= hue_prime && hue_prime < 6) {
+        red_temp = chroma;
+        green_temp = 0;
+        blue_temp = uint16_termediate;
+    }
+
+    float match_value = value - chroma;
+    float red = red_temp + match_value;
+    float green = green_temp + match_value;
+    float blue = blue_temp + match_value;
+
+    auto red_int = static_cast<uint16_t>(red * 255);
+    auto green_int = static_cast<uint16_t>(green * 255);
+    auto blue_int = static_cast<uint16_t>(blue * 255);
+
+    return {red_int, green_int, blue_int};
+}
+
+std::tuple<uint16_t, uint16_t, uint16_t> number_to_rgb(uint16_t number)
+{
+    float hue = (static_cast<float>(number) / 65535.0f) * 360.0f;
+    float saturation = 1.0f;
+    float value = 1.0f;
+
+    return hsv_to_rgb(hue, saturation, value);
+}
+} // namespace fractal

source/graphics/color_conversions.hpp

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstdint>
+
+#include <tuple>
+
+namespace fractal {
+std::tuple<uint16_t, uint16_t, uint16_t>
+hsv_to_rgb(float hue, float saturation, float value);
+
+std::tuple<uint16_t, uint16_t, uint16_t> number_to_rgb(uint16_t number);
+} // namespace fractal

source/graphics/display_to_complex.hpp

@@ -0,0 +1,59 @@
+#pragma once
+
+#include "coordinates.hpp"
+
+#include <complex>
+
+namespace fractal {
+class DisplayToComplexCoordinates {
+    float real_scaling_factor_;
+    float imaginary_scaling_factor_;
+    complex_coordinate complex_domain_start_;
+
+    static float real_scaling_factor(
+        const display_coordinate& display_top_right,
+        const complex_domain& complex_domain
+    )
+    {
+        float real_d_size = real_domain_size(complex_domain);
+        return real_d_size / static_cast<float>(display_top_right.first);
+    }
+
+    static float imaginary_scaling_factor(
+        const display_coordinate& display_top_right,
+        const complex_domain& complex_domain
+    )
+    {
+        float imaginary_d_size = imaginary_domain_size(complex_domain);
+        return imaginary_d_size / static_cast<float>(display_top_right.second);
+    }
+
+    static complex_coordinate to_complex(display_coordinate coordinate)
+    {
+        return {
+            static_cast<float>(coordinate.first), static_cast<float>(coordinate.second)
+        };
+    }
+
+public:
+    DisplayToComplexCoordinates(
+        display_coordinate display_top_right, const complex_domain& complex_domain
+    ) :
+        real_scaling_factor_(real_scaling_factor(display_top_right, complex_domain)),
+        imaginary_scaling_factor_(
+            imaginary_scaling_factor(display_top_right, complex_domain)
+        ),
+        complex_domain_start_(complex_domain.start_coordinate)
+    {}
+
+    complex_coordinate to_complex_projection(display_coordinate display_coord)
+    {
+        std::complex<float> raw_complex_coord = to_complex(display_coord);
+        std::complex offset = {
+            real_scaling_factor_ * raw_complex_coord.real(),
+            imaginary_scaling_factor_ * raw_complex_coord.imag()
+        };
+        return complex_domain_start_ + offset;
+    }
+};
+} // namespace fractal