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Constrain the mouse position before it's used to generate mouse deltas

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Also clamp the mouse position to the maximum of *max and the last mouse position

Fixes https://github.com/libsdl-org/SDL/issues/7221#issuecomment-1426054481
This commit is contained in:
Sam Lantinga 2023-02-10 09:08:12 -08:00
parent 144390f8fc
commit b55bb02723
1 changed files with 49 additions and 41 deletions
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90
src/events/SDL_mouse.c
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@ -443,6 +443,47 @@ static void GetScaledMouseDeltas(SDL_Mouse *mouse, float *x, float *y)
}
}
static void ConstrainMousePosition(SDL_Mouse *mouse, SDL_Window *window, float *x, float *y)
{
/* make sure that the pointers find themselves inside the windows,
unless we have the mouse captured. */
if (window && !(window->flags & SDL_WINDOW_MOUSE_CAPTURE)) {
int x_min = 0, x_max = window->w - 1;
int y_min = 0, y_max = window->h - 1;
const SDL_Rect *confine = SDL_GetWindowMouseRect(window);
if (confine) {
SDL_Rect window_rect;
SDL_Rect mouse_rect;
window_rect.x = 0;
window_rect.y = 0;
window_rect.w = x_max + 1;
window_rect.h = y_max + 1;
if (SDL_GetRectIntersection(confine, &window_rect, &mouse_rect)) {
x_min = mouse_rect.x;
y_min = mouse_rect.y;
x_max = x_min + mouse_rect.w - 1;
y_max = y_min + mouse_rect.h - 1;
}
}
if (*x >= (float)(x_max + 1)) {
*x = SDL_max((float)x_max, mouse->last_x);
}
if (*x < (float)x_min) {
*x = (float)x_min;
}
if (*y >= (float)(y_max + 1)) {
*y = SDL_max((float)y_max, mouse->last_y);
}
if (*y < (float)y_min) {
*y = (float)y_min;
}
}
}
static int SDL_PrivateSendMouseMotion(Uint64 timestamp, SDL_Window *window, SDL_MouseID mouseID, int relative, float x, float y)
{
SDL_Mouse *mouse = SDL_GetMouse();
@ -498,9 +539,14 @@ static int SDL_PrivateSendMouseMotion(Uint64 timestamp, SDL_Window *window, SDL_
yrel = y;
x = (mouse->last_x + xrel);
y = (mouse->last_y + yrel);
} else if (mouse->has_position) {
xrel = x - mouse->last_x;
yrel = y - mouse->last_y;
ConstrainMousePosition(mouse, window, &x, &y);
} else {
ConstrainMousePosition(mouse, window, &x, &y);
if (mouse->has_position) {
xrel = x - mouse->last_x;
yrel = y - mouse->last_y;
}
}
/* Ignore relative motion when first positioning the mouse */
@ -530,44 +576,6 @@ static int SDL_PrivateSendMouseMotion(Uint64 timestamp, SDL_Window *window, SDL_
mouse->y += yrel;
}
/* make sure that the pointers find themselves inside the windows,
unless we have the mouse captured. */
if (window && !(window->flags & SDL_WINDOW_MOUSE_CAPTURE)) {
int x_min = 0, x_max = window->w - 1;
int y_min = 0, y_max = window->h - 1;
const SDL_Rect *confine = SDL_GetWindowMouseRect(window);
if (confine) {
SDL_Rect window_rect;
SDL_Rect mouse_rect;
window_rect.x = 0;
window_rect.y = 0;
window_rect.w = x_max + 1;
window_rect.h = y_max + 1;
if (SDL_GetRectIntersection(confine, &window_rect, &mouse_rect)) {
x_min = mouse_rect.x;
y_min = mouse_rect.y;
x_max = x_min + mouse_rect.w - 1;
y_max = y_min + mouse_rect.h - 1;
}
}
if (mouse->x >= (float)(x_max + 1)) {
mouse->x = (float)x_max;
}
if (mouse->x < (float)x_min) {
mouse->x = (float)x_min;
}
if (mouse->y >= (float)(y_max + 1)) {
mouse->y = (float)y_max;
}
if (mouse->y < (float)y_min) {
mouse->y = (float)y_min;
}
}
mouse->xdelta += xrel;
mouse->ydelta += yrel;