Handling Small Movements

1#include <SDL.h>
2#include <cmath>
3#include "Window.h"
4
5class MotionFilter {
6public:
7  struct FilteredMotion {
8    float x;
9    float y;
10    bool SignificantMotion;
11  };
12
13  FilteredMotion Filter(int RawX, int RawY) {
14    // Convert to floating point for
15    // precise calculations
16    float X{static_cast<float>(RawX)};
17    float Y{static_cast<float>(RawY)};
18
19    // Calculate magnitude of movement
20    float Magnitude{std::sqrt(X * X + Y * Y)};
21
22    // Check if movement exceeds dead zone
23    bool IsSignificant{Magnitude > DeadZone};
24
25    if (!IsSignificant) {
26      return {0.0f, 0.0f, false};
27    }
28
29    // Apply scaling to significant movements
30    float Scale{
31      (Magnitude - DeadZone) / Magnitude};
32    return {X * Scale, Y * Scale, true};
33  }
34
35  void SetDeadZone(float NewDeadZone) {
36    DeadZone = NewDeadZone;
37  }
38
39private:
40  float DeadZone{2.0f};
41};
42
43class Camera {
44public:
45  void Update(SDL_MouseMotionEvent& E) {
46    auto Filtered{
47      Filter.Filter(E.xrel, E.yrel)};
48
49    if (Filtered.SignificantMotion) {
50      Rotation.x += Filtered.x * Sensitivity;
51      Rotation.y += Filtered.y * Sensitivity;
52
53      std::cout << "\nRaw input: "
54        << E.xrel << ", " << E.yrel
55        << "\nFiltered: " << Filtered.x << ", "
56        << Filtered.y
57        << "\nRotation: " << Rotation.x << ", "
58        << Rotation.y;
59    }
60  }
61
62private:
63  MotionFilter Filter;
64  SDL_FPoint Rotation{0.0f, 0.0f};
65  float Sensitivity{0.1f};
66};
67
68int main() {
69  SDL_Init(SDL_INIT_VIDEO);
70  Window GameWindow;
71  Camera Cam;
72  SDL_SetRelativeMouseMode(SDL_TRUE);
73
74  SDL_Event E;
75  while (true) {
76    while (SDL_PollEvent(&E)) {
77      if (E.type == SDL_MOUSEMOTION) {
78        Cam.Update(E.motion);
79      } else if (E.type == SDL_QUIT) {
80        SDL_Quit();
81        return 0;
82      }
83    }
84    GameWindow.Update();
85    GameWindow.Render();
86  }
87}