Commit c11bdeeb6975e00ecf7d7be0d13b47669a50abf9
2022-06-21T13:28:14
wayland: Round fractional backbuffer sizes halfway away from zero Use SDL_lroundf() to round fractional backbuffer sizes halfway away from zero, as this is the rounding method recommended by the forthcoming Wayland fractional scaling protocol.
diff --git a/src/video/wayland/SDL_waylandwindow.c b/src/video/wayland/SDL_waylandwindow.c
index cfd835b..8ca0842 100644
--- a/src/video/wayland/SDL_waylandwindow.c
+++ b/src/video/wayland/SDL_waylandwindow.c
@@ -184,8 +184,9 @@ GetBufferSize(SDL_Window *window, int *width, int *height)
if (FullscreenModeEmulation(window)) {
GetFullScreenDimensions(window, NULL, NULL, &buf_width, &buf_height);
} else if (NeedViewport(window)) {
- buf_width = (int)SDL_ceil(window->w * data->scale_factor);
- buf_height = (int)SDL_ceil(window->h * data->scale_factor);
+ /* Round fractional backbuffer sizes halfway away from zero. */
+ buf_width = (int)SDL_lroundf(window->w * data->scale_factor);
+ buf_height = (int)SDL_lroundf(window->h * data->scale_factor);
} else {
/*
* Integer scaled windowed or fullscreen with no viewport
@@ -1897,8 +1898,8 @@ int Wayland_CreateWindow(_THIS, SDL_Window *window)
}
#endif /* SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH */
- data->drawable_width = SDL_ceilf(window->w * data->scale_factor);
- data->drawable_height = SDL_ceilf(window->h * data->scale_factor);
+ data->drawable_width = SDL_lroundf(window->w * data->scale_factor);
+ data->drawable_height = SDL_lroundf(window->h * data->scale_factor);
if (window->flags & SDL_WINDOW_OPENGL) {
data->egl_window = WAYLAND_wl_egl_window_create(data->surface, data->drawable_width, data->drawable_height);