Skip to content

Commit

Permalink
wayland: Use the integer buffer scale event when applicable
Browse files Browse the repository at this point in the history 
wl_compositor v6 introduces the preferred buffer scale event, which serves a similar function to the fractional scale protocol, but deals in integer scale factors. Listen to this event when the wl_compositor version is >= 6 and the fractional scale protocol is not present to set the scale factor for surfaces.
  • Loading branch information
@Kontrabant
Kontrabant committed Apr 10, 2023
1 parent 05b701f commit 8162d66
Show file tree
Hide file tree
Showing 2 changed files with 66 additions and 43 deletions.
8 changes: 7 additions & 1 deletion src/video/wayland/SDL_waylandvideo.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,12 @@

#define WAYLANDVID_DRIVER_NAME "wayland"

#if SDL_WAYLAND_CHECK_VERSION(1, 22, 0)
#define SDL_WL_COMPOSITOR_VERSION 6
#else
#define SDL_WL_COMPOSITOR_VERSION 4
#endif

#if SDL_WAYLAND_CHECK_VERSION(1, 20, 0)
#define SDL_WL_OUTPUT_VERSION 4
#else
Expand Down Expand Up @@ -792,7 +798,7 @@ static void display_handle_global(void *data, struct wl_registry *registry, uint
/*printf("WAYLAND INTERFACE: %s\n", interface);*/

if (SDL_strcmp(interface, "wl_compositor") == 0) {
d->compositor = wl_registry_bind(d->registry, id, &wl_compositor_interface, SDL_min(4, version));
d->compositor = wl_registry_bind(d->registry, id, &wl_compositor_interface, SDL_min(SDL_WL_COMPOSITOR_VERSION, version));
} else if (SDL_strcmp(interface, "wl_output") == 0) {
Wayland_add_display(d, id, SDL_min(version, SDL_WL_OUTPUT_VERSION));
} else if (SDL_strcmp(interface, "wl_seat") == 0) {
Expand Down
101 changes: 59 additions & 42 deletions src/video/wayland/SDL_waylandwindow.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -968,33 +968,48 @@ static const struct qt_extended_surface_listener extended_surface_listener = {
};
#endif /* SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH */

static void update_scale_factor(SDL_WindowData *window)
static void Wayland_HandlePreferredScaleChanged(SDL_WindowData *window_data, float factor)
{
float old_factor = window->windowed_scale_factor;
float new_factor;
int i;
const float old_factor = window_data->windowed_scale_factor;

if (!(window->sdlwindow->flags & SDL_WINDOW_ALLOW_HIGHDPI)) {
if (!(window_data->sdlwindow->flags & SDL_WINDOW_ALLOW_HIGHDPI)) {
/* Scale will always be 1, just ignore this */
return;
}

if (!FloatEqual(factor, old_factor)) {
window_data->windowed_scale_factor = factor;
ConfigureWindowGeometry(window_data->sdlwindow);
}
}

static void Wayland_MaybeUpdateScaleFactor(SDL_WindowData *window)
{
float factor;
int i;

/* If the fractional scale protocol is present or the core protocol supports the
* preferred buffer scale event, the compositor will tell explicitly the application
* what scale it wants via these events, so don't try to determine the scale factor
* from which displays the surface has entered.
*/
if (window->fractional_scale || wl_surface_get_version(window->surface) >= WL_SURFACE_PREFERRED_BUFFER_SCALE_SINCE_VERSION) {
return;
}

if (window->num_outputs != 0) {
/* Check every display's factor, use the highest */
new_factor = 0.0f;
factor = 0.0f;
for (i = 0; i < window->num_outputs; i++) {
SDL_DisplayData *driverdata = window->outputs[i];
new_factor = SDL_max(new_factor, driverdata->scale_factor);
factor = SDL_max(factor, driverdata->scale_factor);
}
} else {
/* No monitor (somehow)? Just fall back. */
new_factor = old_factor;
factor = window->windowed_scale_factor;
}

if (!FloatEqual(new_factor, old_factor)) {
window->windowed_scale_factor = new_factor;
ConfigureWindowGeometry(window->sdlwindow);
}
Wayland_HandlePreferredScaleChanged(window, factor);
}

/* While we can't get window position from the compositor, we do at least know
Expand Down Expand Up @@ -1060,10 +1075,7 @@ static void handle_surface_enter(void *data, struct wl_surface *surface,

/* Update the scale factor after the move so that fullscreen outputs are updated. */
Wayland_move_window(window->sdlwindow, driverdata);

if (!window->fractional_scale) {
update_scale_factor(window);
}
Wayland_MaybeUpdateScaleFactor(window);
}

static void handle_surface_leave(void *data, struct wl_surface *surface,
Expand Down Expand Up @@ -1100,14 +1112,42 @@ static void handle_surface_leave(void *data, struct wl_surface *surface,
window->outputs[window->num_outputs - 1]);
}

if (!window->fractional_scale) {
update_scale_factor(window);
Wayland_MaybeUpdateScaleFactor(window);
}

static void handle_preferred_buffer_scale(void *data, struct wl_surface *wl_surface, int32_t factor)
{
SDL_WindowData *wind = data;

/* The spec is unclear on how this interacts with the fractional scaling protocol,
* so, for now, assume that the fractional scaling protocol takes priority and
* only listen to this event if the fractional scaling protocol is not present.
*/
if (!wind->fractional_scale) {
Wayland_HandlePreferredScaleChanged(data, (float)factor);
}
}

static void handle_preferred_buffer_transform(void *data, struct wl_surface *wl_surface, uint32_t transform)
{
/* Nothing to do here. */
}

static const struct wl_surface_listener surface_listener = {
handle_surface_enter,
handle_surface_leave
handle_surface_leave,
handle_preferred_buffer_scale,
handle_preferred_buffer_transform
};

static void handle_preferred_fractional_scale(void *data, struct wp_fractional_scale_v1 *wp_fractional_scale_v1, uint32_t scale)
{
const float factor = scale / 120.; /* 120 is a magic number defined in the spec as a common denominator */
Wayland_HandlePreferredScaleChanged(data, factor);
}

static const struct wp_fractional_scale_v1_listener fractional_scale_listener = {
handle_preferred_fractional_scale
};

static void SetKeyboardFocus(SDL_Window *window)
Expand Down Expand Up @@ -1605,29 +1645,6 @@ int Wayland_FlashWindow(_THIS, SDL_Window *window, SDL_FlashOperation operation)
return 0;
}

static void handle_preferred_scale_changed(void *data,
struct wp_fractional_scale_v1 *wp_fractional_scale_v1,
uint preferred_scale)
{
SDL_WindowData *window = data;
float old_factor = window->windowed_scale_factor;
float new_factor = preferred_scale / 120.; /* 120 is a magic number defined in the spec as a common denominator*/

if (!(window->sdlwindow->flags & SDL_WINDOW_ALLOW_HIGHDPI)) {
/* Scale will always be 1, just ignore this */
return;
}

if (!FloatEqual(new_factor, old_factor)) {
window->windowed_scale_factor = new_factor;
ConfigureWindowGeometry(window->sdlwindow);
}
}

static const struct wp_fractional_scale_v1_listener fractional_scale_listener = {
handle_preferred_scale_changed
};

#ifdef SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH
static void SDLCALL QtExtendedSurface_OnHintChanged(void *userdata, const char *name,
const char *oldValue, const char *newValue)
Expand Down

0 comments on commit 8162d66

Please sign in to comment.