Create a Brightness Settings Slider

1#include <SDL.h>
2#include <iostream>
3
4class BrightnessControl {
5  SDL_Window* Window;
6  float CurrentBrightness{1.0f};
7  float MinBrightness{0.5f};
8  float MaxBrightness{2.0f};
9
10public:
11  BrightnessControl(SDL_Window* W) : Window{W} {
12    // Store initial brightness
13    CurrentBrightness = SDL_GetWindowBrightness(
14      Window);
15  }
16
17  // Convert 0-100 slider value to brightness
18  void SetFromSlider(int SliderValue) {
19    float Normalized{SliderValue / 100.0f};
20    float NewBrightness{
21      MinBrightness +
22      (MaxBrightness - MinBrightness) *
23      Normalized
24    };
25
26    SetBrightness(NewBrightness);
27  }
28
29  // Convert current brightness to 0-100 slider value
30  int GetSliderValue() const {
31    float Normalized{
32      (CurrentBrightness - MinBrightness) /
33      (MaxBrightness - MinBrightness)
34    };
35
36    return static_cast<int>(Normalized *
37      100.0f);
38  }
39
40  void SetBrightness(float NewBrightness) {
41    // Clamp to valid range
42    if (NewBrightness < MinBrightness) {
43      NewBrightness = MinBrightness;
44    }
45    if (NewBrightness > MaxBrightness) {
46      NewBrightness = MaxBrightness;
47    }
48
49    if (SDL_SetWindowBrightness(
50      Window, NewBrightness) < 0) {
51      std::cout << "Brightness error: "
52        << SDL_GetError() << '\n';
53      return;
54    }
55
56    CurrentBrightness = NewBrightness;
57  }
58
59  float GetBrightness() const {
60    return CurrentBrightness;
61  }
62};
63
64// Example usage in a settings menu
65int main() {
66  SDL_Init(SDL_INIT_VIDEO);
67
68  SDL_Window* Window{
69    SDL_CreateWindow(
70      "Brightness Demo",
71      SDL_WINDOWPOS_UNDEFINED,
72      SDL_WINDOWPOS_UNDEFINED,
73      800, 600,
74      SDL_WINDOW_SHOWN
75    )};
76
77  BrightnessControl Control{Window};
78
79  // Simulate user moving slider to 75%
80  Control.SetFromSlider(75);
81  std::cout << "Brightness set to: "
82    << Control.GetBrightness() << '\n';
83
84  // Get slider position for UI
85  std::cout << "Slider position: "
86    << Control.GetSliderValue() << '\n';
87
88  SDL_DestroyWindow(Window);
89  SDL_Quit();
90  return 0;
91}