Mouse Break Free Feature

1#include <SDL.h>
2#include <iostream>
3#include <cmath>
4
5class BreakFreeDetector {
6  const double VelocityThreshold{1000.0};
7  const Uint32 TimeWindow{200};// milliseconds
8
9  double TotalVelocity{0.0};
10  Uint32 LastResetTime{0};
11
12public:
13  bool CheckBreakFree(int DeltaX, int DeltaY) {
14    Uint32 CurrentTime{SDL_GetTicks()};
15
16    // Reset if outside time window
17    if (CurrentTime - LastResetTime > TimeWindow) {
18      TotalVelocity = 0.0;
19      LastResetTime = CurrentTime;
20    }
21
22    // Add current velocity to total
23    double Velocity{
24      std::sqrt(DeltaX * DeltaX + DeltaY * DeltaY)
25    };
26    TotalVelocity += Velocity;
27
28    // Check if break free threshold reached
29    return TotalVelocity > VelocityThreshold;
30  }
31};
32
33int main(int argc, char** argv) {
34  SDL_Init(SDL_INIT_VIDEO);
35  SDL_Window* Window{SDL_CreateWindow(
36    "Break Free Example",
37    100, 100, 800, 600,
38    SDL_WINDOW_MOUSE_GRABBED
39  )};
40
41  BreakFreeDetector Detector;
42  bool quit{false};
43  SDL_Event E;
44
45  while (!quit) {
46    while (SDL_PollEvent(&E)) {
47      if (E.type == SDL_QUIT) {
48        quit = true;
49      } else if (E.type == SDL_MOUSEMOTION) {
50        if (Detector.CheckBreakFree(
51          E.motion.xrel, E.motion.yrel
52        )) {
53          SDL_SetWindowMouseGrab(Window, SDL_FALSE);
54          std::cout << "Mouse broke free!\n";
55        }
56      }
57    }
58  }
59
60  SDL_DestroyWindow(Window);
61  SDL_Quit();
62  return 0;
63}

1#include <SDL.h>
2#include <cmath>
3#include <vector>
4
5class AdvancedBreakFreeDetector {
6  struct Movement {
7    double Velocity;
8    Uint32 Timestamp;
9  };
10
11  const double VelocityThreshold{800.0};
12  const Uint32 TimeWindow{300};// milliseconds
13  const size_t MinMovements{5};
14
15  std::vector<Movement> RecentMovements;
16
17  double CalculateIntensity() {
18    double TotalIntensity{0.0};
19    Uint32 CurrentTime{SDL_GetTicks()};
20
21    // Remove old movements
22    while (!RecentMovements.empty() &&
23      CurrentTime - RecentMovements[0].Timestamp
24        > TimeWindow) {
25      RecentMovements.erase(
26        RecentMovements.begin());
27    }
28
29    // Calculate intensity from recent movements
30    for (const auto& Move : RecentMovements) {
31      TotalIntensity += Move.Velocity;
32    }
33
34    return TotalIntensity;
35  }
36
37public:
38  bool CheckBreakFree(int DeltaX, int DeltaY) {
39    // Record new movement
40    Movement NewMove{
41      std::sqrt(DeltaX * DeltaX + DeltaY * DeltaY),
42      SDL_GetTicks()
43    };
44    RecentMovements.push_back(NewMove);
45
46    // Only check for break free if we have
47    // enough movements
48    if (RecentMovements.size() < MinMovements) {
49      return false;
50    }
51
52    return CalculateIntensity() > VelocityThreshold;
53  }
54};