The distinction between SDL_WINDOW_MOUSE_GRABBED
and SDL_WINDOW_INPUT_GRABBED
is important but subtle. Let's break down the differences and see when to use each.
SDL_WINDOW_MOUSE_GRABBED
only affects mouse input:
Here's an example of mouse-only grabbing:
#include <SDL.h>
#include <iostream>
void PrintGrabState(SDL_Window* Window) {
bool MouseGrabbed{
SDL_GetWindowMouseGrab(Window) == SDL_TRUE};
bool InputGrabbed{
SDL_GetWindowKeyboardGrab(Window) == SDL_TRUE};
std::cout << "Mouse Grabbed: "
<< (MouseGrabbed ? "Yes" : "No") << "\n";
std::cout << "Keyboard Grabbed: "
<< (InputGrabbed ? "Yes" : "No") << "\n";
}
int main(int argc, char** argv) {
SDL_Init(SDL_INIT_VIDEO);
SDL_Window* Window{SDL_CreateWindow(
"Mouse Grab Example",
100, 100, 800, 600,
SDL_WINDOW_MOUSE_GRABBED
)};
std::cout << "Initial State:\n";
PrintGrabState(Window);
SDL_DestroyWindow(Window);
SDL_Quit();
return 0;
}
Initial State:
Mouse Grabbed: Yes
Keyboard Grabbed: No
SDL_WINDOW_INPUT_GRABBED
is more comprehensive:
Here's an example showing the difference:
#include <SDL.h>
#include <iostream>
#include "PrintGrabState.h"
int main(int argc, char** argv) {
SDL_Init(SDL_INIT_VIDEO);
// Create two windows to demonstrate
// the difference
SDL_Window* MouseWindow{SDL_CreateWindow(
"Mouse Grabbed Window",
100, 100, 400, 300,
SDL_WINDOW_MOUSE_GRABBED
)};
SDL_Window* InputWindow{SDL_CreateWindow(
"Input Grabbed Window",
500, 100, 400, 300,
SDL_WINDOW_INPUT_GRABBED
)};
// Print state for both windows
std::cout << "Mouse Grabbed Window:\n";
PrintGrabState(MouseWindow);
std::cout << "\nInput Grabbed Window:\n";
PrintGrabState(InputWindow);
SDL_DestroyWindow(MouseWindow);
SDL_DestroyWindow(InputWindow);
SDL_Quit();
return 0;
}
In modern applications:
SDL_WINDOW_MOUSE_GRABBED
for most use casesSDL_WINDOW_INPUT_GRABBED
only when you need to capture all inputAnswers to questions are automatically generated and may not have been reviewed.
Implement mouse constraints in SDL2 to control cursor movement using window grabs and rectangular bounds