Handling SDL Relative Mode Failure

1#include <SDL.h>
2#include <iostream>
3#include "Window.h"
4
5class MouseController {
6 public:
7  bool EnableRelativeMode() {
8    if (SDL_SetRelativeMouseMode(SDL_TRUE) < 0) {
9      std::cerr << "Failed to enable relative mode: "
10        << SDL_GetError() << '\n';
11      return false;
12    }
13    IsRelative = true;
14    return true;
15  }
16
17  void HandleFailure() {
18    // Fall back to normal mouse mode
19    SDL_SetRelativeMouseMode(SDL_FALSE);
20    IsRelative = false;
21
22    // Notify the user
23    std::cout << "Using standard mouse mode\n";
24  }
25
26  void Update(SDL_MouseMotionEvent& E) {
27    if (IsRelative) {
28      HandleRelativeMotion(E);
29    } else {
30      HandleAbsoluteMotion(E);
31    }
32  }
33
34 private:
35  void HandleRelativeMotion(SDL_MouseMotionEvent& E) {
36    // Process relative motion
37    std::cout << "Relative motion: " << E.xrel
38      << ", " << E.yrel << '\n';
39  }
40
41  void HandleAbsoluteMotion(SDL_MouseMotionEvent& E) {
42    // Process absolute motion
43    std::cout << "Absolute position: " << E.x
44      << ", " << E.y << '\n';
45  }
46
47  bool IsRelative{false};
48};
49
50int main() {
51  SDL_Init(SDL_INIT_VIDEO);
52  Window GameWindow;
53  MouseController Mouse;
54
55  if (!Mouse.EnableRelativeMode()) {
56    Mouse.HandleFailure();
57  }
58
59  SDL_Event E;
60  while (true) {
61    while (SDL_PollEvent(&E)) {
62      if (E.type == SDL_MOUSEMOTION) {
63        Mouse.Update(E.motion);
64      } else if (E.type == SDL_QUIT) {
65        SDL_Quit();
66        return 0;
67      }
68    }
69    GameWindow.Update();
70    GameWindow.Render();
71  }
72}