Custom Mouse Focus Regions

1#include <SDL.h>
2#include <iostream>
3
4// Helper function to create a shape mask
5SDL_Surface* CreateShapeMask(
6  int width, int height) {
7  SDL_Surface* Mask = SDL_CreateRGBSurface(
8    0, width, height, 32, 0xFF000000,
9    0x00FF0000, 0x0000FF00, 0x000000FF);
10
11  // Make the surface fully transparent
12  SDL_FillRect(Mask, nullptr, 0x00000000);
13
14  // Create a rectangular active region in the center
15  SDL_Rect ActiveRegion = {
16    width / 4, height / 4, width / 2,
17    height / 2};
18  SDL_FillRect(Mask, &ActiveRegion, 0xFFFFFFFF);
19
20  return Mask;
21}
22
23int main(int argc, char** argv) {
24  if (SDL_Init(SDL_INIT_VIDEO) != 0) {
25    std::cerr << "Failed to initialize SDL: "
26      << SDL_GetError() << "\n";
27    return -1;
28  }
29
30  SDL_Window* Window = SDL_CreateShapedWindow(
31    "Shaped Window", 100, 100, 400,
32    300, SDL_WINDOW_SHOWN);
33
34  if (!Window) {
35    std::cerr
36      << "Failed to create shaped window: "
37      << SDL_GetError() << "\n";
38    SDL_Quit();
39    return -1;
40  }
41
42  // Create and apply the shape mask
43  SDL_Surface* ShapeMask = CreateShapeMask(
44    400, 300);
45
46  // Define the shape mode
47  SDL_WindowShapeMode ShapeMode;
48  ShapeMode.mode = ShapeModeBinarizeAlpha;
49  ShapeMode.parameters.binarizationCutoff = 128;
50
51  if (SDL_SetWindowShape(Window, ShapeMask,
52                         &ShapeMode) != 0) {
53    std::cerr << "Failed to set window shape: "
54      << SDL_GetError() << "\n";
55    SDL_FreeSurface(ShapeMask);
56    SDL_DestroyWindow(Window);
57    SDL_Quit();
58    return -1;
59  }
60
61  SDL_Event E;
62  bool Running = true;
63
64  while (Running) {
65    while (SDL_PollEvent(&E)) {
66      if (E.type == SDL_QUIT) {
67        Running = false;
68      } else if (
69        E.type == SDL_WINDOWEVENT) {
70        if (E.window.event ==
71          SDL_WINDOWEVENT_ENTER) {
72          std::cout <<
73            "Mouse entered active region\n";
74        } else if (E.window.event ==
75          SDL_WINDOWEVENT_LEAVE) {
76          std::cout <<
77            "Mouse left active region\n";
78        }
79      }
80    }
81
82    SDL_Window* FocusedWindow =
83      SDL_GetMouseFocus();
84    if (FocusedWindow == Window) {
85      // Mouse is over an active part of window
86    }
87  }
88
89  SDL_FreeSurface(ShapeMask);
90  SDL_DestroyWindow(Window);
91  SDL_Quit();
92  return 0;
93}

1#include <SDL.h>
2#include <iostream>
3#include <vector>
4#include "Window.h"
5
6struct FocusRegion {
7  SDL_Rect Bounds;
8  std::string Name;
9};
10
11bool IsPointInRect(
12  int x, int y, const SDL_Rect& rect
13) {
14  return x >= rect.x &&
15    x < rect.x + rect.w &&
16    y >= rect.y &&
17    y < rect.y + rect.h;
18}
19
20int main(int argc, char** argv) {
21  SDL_Init(SDL_INIT_VIDEO);
22  Window GameWindow;
23
24  std::vector<FocusRegion> ActiveRegions{
25    {{10, 10, 100, 100}, "Top Left"},
26    {{200, 10, 100, 100}, "Top Right"},
27    {{100, 100, 200, 100}, "Center"}};
28
29  SDL_Event E;
30  while (true) {
31    while (SDL_PollEvent(&E)) {
32      if (E.type == SDL_MOUSEMOTION) {
33        int MouseX, MouseY;
34        SDL_GetMouseState(&MouseX, &MouseY);
35
36        for (const auto& Region :
37             ActiveRegions) {
38          if (IsPointInRect(MouseX, MouseY,
39                            Region.Bounds)) {
40            std::cout << "Mouse in region: " <<
41              Region.Name << "\n";
42          }
43        }
44      }
45    }
46    GameWindow.Update();
47  }
48
49  SDL_Quit();
50  return 0;
51}