Files
DeeJanuz--frametop/screens/compositor.c
T
Patrick McDavidandClaude Opus 5.5 6fb168a8b8 Lazy susan: Meta+Alt+Tab spins the panels around you
- ft-screens "spin next|prev|<degrees>": every unpinned screen and
  floating window turns together about a vertical axis through your
  head (0.3 s, eased), so the next panel on the right or left comes to
  straight ahead; the arrangement stays as it is. Taps during a spin
  add to it, from where the panels are headed; grabbing a panel or
  placing it (ft-layout, ft-floatd) takes it out of the spin
- when a spin settles, the panel in front gets the pointer (recenter),
  typing (as after a click), and KWin's active window: its floating
  window, or the top window on a screen (ft-floatd "front N", the KWin
  script's activate-output). KWin's outputs follow the screens'
  new places (ft-layout scale), as after a move
- the input relay: spin_next and spin_prev actions, Meta+Alt+Tab and
  Meta+Alt+Shift+Tab by default; Frametop Input Settings lists them.
  Not Meta+Tab: that's Cmd+Tab on a Mac reached through a remote
  desktop like RustDesk, and the relay would take the Mac's app
  switcher. Meta+Alt+Tab (Cmd+Option+Tab) is unused on macOS,
  Windows, and KDE

Used on the Frame (SteamOS 0.3.0 build 20260922) with one screen and
three or four floating windows, through RustDesk to a Mac.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-03 10:17:22 -06:00

767 lines
35 KiB
C

// ft-screens: a minimal Wayland compositor that hosts the nested KWin and shows each of
// its screens as its own SteamVR panel. It replaces gamescope for Frametop:
// - KWin (nested Wayland backend) opens one window per screen. We send each window its
// size (xdg_toplevel configure), and KWin resizes that screen to match, so every
// screen has its own resolution and shape (ultrawide, portrait, 4K...). gamescope
// never sized its windows and drew them all into one canvas of at most 1920x1080.
// - KWin renders into DMA-BUFs and hands them to us (linux-dmabuf). We draw nothing:
// each buffer goes to SteamVR as the panel's texture (vr.cpp, ImportDmabuf).
// - Pointer input from the panels (controller lasers, the 3D mouse) goes to KWin through
// our seat, as if we were a normal desktop. KWin's nested backend adds our surface
// coordinates to its output's logical position without undoing its own scale, and its
// buffers are in pixels, so a panel position in pixels is divided by the screen's KWin
// scale first ("scale <screen> <s>", from ft-layout).
//
// Usage: ft-screens [--socket NAME] [--control NAME] [--no-vr] [--screen WxH@METRES]...
// [--spares N] [-- COMMAND ARGS...]
// --socket Wayland socket name in $XDG_RUNTIME_DIR (default ft-screens-0)
// --control the control socket's abstract name (default ft_screens)
// --no-vr run without SteamVR, for tests next to the running desktop: no panels, no
// input, and nothing sent to the input relay. Commands still work, and
// "toplevels" shows what KWin opened.
// --screen one per screen, in KWin's order (default: 3440x1440@2.4)
// --spares KWin's outputs after the screens: spares for floating windows (ft-floatd
// turns them on and sizes them; see docs/floating-windows.md)
// COMMAND run with WAYLAND_DISPLAY set to our socket (e.g. the Frametop session)
// Runs in the dev container (wlroots 0.20); KWin connects from the host.
#define _GNU_SOURCE
#include <drm_fourcc.h>
#include <linux/input-event-codes.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <wayland-server-core.h>
#include <xkbcommon/xkbcommon.h>
#define WLR_USE_UNSTABLE
#include <wlr/interfaces/wlr_keyboard.h>
#include <wlr/render/dmabuf.h>
#include <wlr/render/drm_format_set.h>
#include <wlr/types/wlr_buffer.h>
#include <wlr/types/wlr_compositor.h>
#include <wlr/types/wlr_data_device.h>
#include <wlr/types/wlr_keyboard.h>
#include <wlr/types/wlr_linux_dmabuf_v1.h>
#include <wlr/types/wlr_seat.h>
#include <wlr/types/wlr_shm.h>
#include <wlr/types/wlr_subcompositor.h>
#include <wlr/types/wlr_xdg_decoration_v1.h>
#include <wlr/types/wlr_xdg_shell.h>
#include <wlr/util/log.h>
#include "vr.h"
#define MAX_SCREENS 24 // screens and spare outputs
struct config {
int width, height;
double metres;
};
struct server;
// One KWin window = one screen.
struct screen {
struct server *server;
int index;
struct wlr_xdg_toplevel *toplevel;
struct wlr_buffer *held; // on the panel now; unlocked when the next one arrives
bool frame_pending; // a commit waits for its frame callback
unsigned commits; // buffers committed, and the last one's size ("toplevels")
int buffer_width, buffer_height;
struct wlr_xdg_toplevel_decoration_v1 *decoration; // answered on the first commit
struct wl_listener commit, destroy, decoration_destroy, set_title;
};
// Per client buffer: forget its import when it goes away.
struct tracked_buffer {
struct wlr_buffer *buffer;
struct wl_listener destroy;
struct wl_list link;
};
struct server {
struct wl_display *display;
struct wl_event_loop *loop;
struct wlr_seat *seat;
struct wlr_keyboard keyboard;
struct wlr_xdg_shell *xdg_shell;
struct wlr_xdg_decoration_manager_v1 *decoration;
struct wl_listener new_toplevel, new_decoration;
struct screen *screens[MAX_SCREENS];
struct config config[MAX_SCREENS];
double scale[MAX_SCREENS]; // KWin's scale for each screen (panel pixels per logical unit)
int n_config, n_screens; // n_config: the screens; the outputs after them are spares
int spares;
struct wl_list buffers; // tracked_buffer
struct wl_event_source *tick;
struct screen *pointer_focus;
pid_t child;
// Where typing goes: the screens after a click on one, Steam after a click on another
// panel. The input relay grabs the keyboards while it's the screens (see keys_update).
bool keys_clicked; // the last click was on a screen
bool keys_desktop; // ...and the screens are showing: typing goes to the desktop
int relay_fd; // unbound, so the relay can't reply into our control socket
uint32_t relay_sent; // when the relay last heard from us (ms)
unsigned ticks;
// Our keyboard ("vrkeyboard" commands from the input relay; see keyboard_command).
int kb_screen; // the screen it's open for, -1 closed
bool kb_auto; // opened for a focused text field (not by a button)
unsigned kb_close_at; // ticks: close it then (a text field lost focus), 0 not
bool vr; // connected to SteamVR (not --no-vr)
};
static uint32_t now_ms(void) {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return (uint32_t)(ts.tv_sec * 1000 + ts.tv_nsec / 1000000);
}
// ---------------------------------------------------------------- buffers
static void buffer_destroyed(struct wl_listener *l, void *data) {
struct tracked_buffer *t = wl_container_of(l, t, destroy);
ft_vr_forget(t->buffer);
wl_list_remove(&t->destroy.link);
wl_list_remove(&t->link);
free(t);
}
static void track_buffer(struct server *s, struct wlr_buffer *buffer) {
struct tracked_buffer *t;
wl_list_for_each(t, &s->buffers, link) if (t->buffer == buffer) return;
t = calloc(1, sizeof *t);
t->buffer = buffer;
t->destroy.notify = buffer_destroyed;
wl_signal_add(&buffer->events.destroy, &t->destroy);
wl_list_insert(&s->buffers, &t->link);
}
// ---------------------------------------------------------------- screens
static void screen_commit(struct wl_listener *l, void *data) {
struct screen *sc = wl_container_of(l, sc, commit);
struct wlr_xdg_surface *xdg = sc->toplevel->base;
if (xdg->initial_commit) {
// First commit: tell KWin the size of this screen.
const struct config spare = {640, 480, 0.5}; // until ft-floatd sizes it
const struct config *c = sc->index < sc->server->n_config ? &sc->server->config[sc->index] : &spare;
wlr_xdg_toplevel_set_size(sc->toplevel, c->width, c->height);
wlr_xdg_toplevel_set_activated(sc->toplevel, true);
if (sc->decoration)
wlr_xdg_toplevel_decoration_v1_set_mode(sc->decoration, WLR_XDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
return;
}
struct wlr_buffer *buffer = xdg->surface->current.buffer;
static int logged;
if (logged < 6) {
++logged;
wlr_log(WLR_INFO, "screen %d: commit, buffer %p (%dx%d), mapped %d", sc->index + 1, (void *)buffer,
buffer ? buffer->width : 0, buffer ? buffer->height : 0, xdg->surface->mapped);
}
if (!buffer) return;
sc->frame_pending = true;
++sc->commits;
sc->buffer_width = buffer->width, sc->buffer_height = buffer->height;
if (buffer == sc->held) return;
struct wlr_dmabuf_attributes a;
if (!wlr_buffer_get_dmabuf(buffer, &a)) {
static bool warned;
if (!warned) wlr_log(WLR_ERROR, "screen %d: not a DMA-BUF (shm?); skipped", sc->index + 1);
warned = true;
return;
}
struct ft_dmabuf b = {.width = a.width, .height = a.height, .format = a.format, .modifier = a.modifier,
.n_planes = a.n_planes};
for (int i = 0; i < a.n_planes && i < 4; ++i) {
b.offset[i] = a.offset[i];
b.stride[i] = a.stride[i];
b.fd[i] = a.fd[i];
}
track_buffer(sc->server, buffer);
if (!ft_vr_screen_present(sc->index, buffer, &b)) return;
// Keep this buffer until the next frame replaces it, so SteamVR never samples a
// buffer KWin is drawing into; then let KWin have the previous one back.
wlr_buffer_lock(buffer);
if (sc->held) wlr_buffer_unlock(sc->held);
sc->held = buffer;
}
static void screen_destroy(struct wl_listener *l, void *data) {
struct screen *sc = wl_container_of(l, sc, destroy);
wlr_log(WLR_INFO, "screen %d closed", sc->index + 1);
if (sc->held) wlr_buffer_unlock(sc->held);
ft_vr_screen_destroy(sc->index);
if (sc->server->pointer_focus == sc) sc->server->pointer_focus = NULL;
if (sc->decoration) wl_list_remove(&sc->decoration_destroy.link);
sc->server->screens[sc->index] = NULL;
wl_list_remove(&sc->commit.link);
wl_list_remove(&sc->destroy.link);
wl_list_remove(&sc->set_title.link);
free(sc);
}
// KWin titles each window "KDE Wayland Compositor <output name>", with "- Output disabled"
// after it while that output is off.
static void screen_title(struct wl_listener *l, void *data) {
struct screen *sc = wl_container_of(l, sc, set_title);
const char *title = sc->toplevel->title ? sc->toplevel->title : "";
wlr_log(WLR_INFO, "screen %d: \"%s\"", sc->index + 1, title);
if (sc->index >= sc->server->n_config) ft_vr_float_output(sc->index, !strstr(title, "Output disabled"));
}
static void new_toplevel(struct wl_listener *l, void *data) {
struct server *s = wl_container_of(l, s, new_toplevel);
struct wlr_xdg_toplevel *toplevel = data;
int index = 0;
while (index < MAX_SCREENS && s->screens[index]) ++index;
if (index == MAX_SCREENS) {
wlr_log(WLR_ERROR, "more than %d screens; ignoring one", MAX_SCREENS);
return;
}
struct screen *sc = calloc(1, sizeof *sc);
sc->server = s;
sc->index = index;
sc->toplevel = toplevel;
s->screens[index] = sc;
if (index >= s->n_config) {
wlr_log(WLR_INFO, "screen %d: KWin window, a spare output (floating window %d)", index + 1,
index - s->n_config + 1);
ft_vr_float_create(index, index - s->n_config + 1);
} else {
const struct config *c = &s->config[index];
wlr_log(WLR_INFO, "screen %d: KWin window, %dx%d, %.2f m wide", index + 1, c->width, c->height, c->metres);
ft_vr_screen_create(index, c->metres, s->n_config);
}
sc->commit.notify = screen_commit;
wl_signal_add(&toplevel->base->surface->events.commit, &sc->commit);
sc->destroy.notify = screen_destroy;
wl_signal_add(&toplevel->events.destroy, &sc->destroy);
sc->set_title.notify = screen_title;
wl_signal_add(&toplevel->events.set_title, &sc->set_title);
}
// KWin asks for server-side decorations for its screens; we draw none. It asks before its
// first commit, when a configure isn't allowed yet, so the answer waits for that commit.
static void decoration_destroyed(struct wl_listener *l, void *data) {
struct screen *sc = wl_container_of(l, sc, decoration_destroy);
wl_list_remove(&sc->decoration_destroy.link);
sc->decoration = NULL;
}
static void new_decoration(struct wl_listener *l, void *data) {
struct server *s = wl_container_of(l, s, new_decoration);
struct wlr_xdg_toplevel_decoration_v1 *d = data;
for (int i = 0; i < MAX_SCREENS; ++i) {
struct screen *sc = s->screens[i];
if (!sc || sc->toplevel != d->toplevel) continue;
sc->decoration = d;
sc->decoration_destroy.notify = decoration_destroyed;
wl_signal_add(&d->events.destroy, &sc->decoration_destroy);
if (d->toplevel->base->initialized)
wlr_xdg_toplevel_decoration_v1_set_mode(d, WLR_XDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
}
}
// ---------------------------------------------------------------- input from the panels
static void panel_key(struct server *s, uint32_t code, bool pressed);
static void handle_vr_event(const struct ft_event *e, void *data) {
struct server *s = data;
if (e->type == FT_QUIT) {
wl_display_terminate(s->display);
return;
}
if (e->type == FT_KEY) {
panel_key(s, e->key, e->pressed);
return;
}
if (e->type == FT_KEYBOARD_CLOSED) {
if (s->kb_screen >= 0) wlr_log(WLR_INFO, "keyboard closed");
s->kb_screen = -1;
s->kb_close_at = 0;
return;
}
if (e->screen < 0 || e->screen >= MAX_SCREENS || !s->screens[e->screen]) return;
struct screen *sc = s->screens[e->screen];
struct wlr_surface *surface = sc->toplevel->base->surface;
if (e->type == FT_FRONT) {
// A spin brought this panel to the front: typing goes to it, as after a click there,
// and ft-floatd makes its window (or the top one on a screen) KWin's active window.
wlr_seat_keyboard_notify_enter(s->seat, surface, NULL, 0, NULL);
s->keys_clicked = true;
char msg[32];
snprintf(msg, sizeof msg, "front %d", e->screen + 1);
struct sockaddr_un addr = {.sun_family = AF_UNIX};
const char name[] = "frametop_float";
memcpy(addr.sun_path + 1, name, sizeof name - 1);
sendto(s->relay_fd, msg, strlen(msg), MSG_DONTWAIT, (struct sockaddr *)&addr,
offsetof(struct sockaddr_un, sun_path) + 1 + sizeof name - 1);
return;
}
const uint32_t t = now_ms();
const double x = e->x / s->scale[e->screen], y = e->y / s->scale[e->screen]; // KWin's units
switch (e->type) {
case FT_MOTION:
case FT_BUTTON:
if (s->pointer_focus != sc) {
// KWin's nested backend ignores the position in wl_pointer.enter, and wlroots
// drops a motion to the position it entered at, so KWin would keep its old
// pointer until the next move: a press right after crossing onto another
// screen landed where the pointer had been. Entering one unit off makes the
// motion below go through.
wlr_seat_pointer_notify_enter(s->seat, surface, x + 1, y);
s->pointer_focus = sc;
}
wlr_seat_pointer_notify_motion(s->seat, t, x, y);
if (e->type == FT_BUTTON) {
wlr_seat_pointer_notify_button(s->seat, t, e->button,
e->pressed ? WL_POINTER_BUTTON_STATE_PRESSED
: WL_POINTER_BUTTON_STATE_RELEASED);
if (e->pressed) {
wlr_seat_keyboard_notify_enter(s->seat, surface, NULL, 0, NULL);
s->keys_clicked = true;
}
}
break;
case FT_SCROLL:
if (s->pointer_focus != sc) break;
if (sc->index >= s->n_config && e->dy != 0 &&
(wlr_keyboard_get_modifiers(&s->keyboard) & WLR_MODIFIER_LOGO)) {
// Meta+scroll on a floating window: its scale, bigger or smaller (ft-floatd).
char msg[48];
snprintf(msg, sizeof msg, "scale %d %d", sc->index + 1, e->dy < 0 ? 1 : -1);
struct sockaddr_un addr = {.sun_family = AF_UNIX};
const char name[] = "frametop_float";
memcpy(addr.sun_path + 1, name, sizeof name - 1);
sendto(s->relay_fd, msg, strlen(msg), MSG_DONTWAIT, (struct sockaddr *)&addr,
offsetof(struct sockaddr_un, sun_path) + 1 + sizeof name - 1);
break;
}
if (e->dy != 0)
wlr_seat_pointer_notify_axis(s->seat, t, WL_POINTER_AXIS_VERTICAL_SCROLL, e->dy * 15,
(int32_t)(e->dy * 120), WL_POINTER_AXIS_SOURCE_WHEEL,
WL_POINTER_AXIS_RELATIVE_DIRECTION_IDENTICAL);
if (e->dx != 0)
wlr_seat_pointer_notify_axis(s->seat, t, WL_POINTER_AXIS_HORIZONTAL_SCROLL, e->dx * 15,
(int32_t)(e->dx * 120), WL_POINTER_AXIS_SOURCE_WHEEL,
WL_POINTER_AXIS_RELATIVE_DIRECTION_IDENTICAL);
break;
case FT_LEAVE:
if (s->pointer_focus == sc) {
wlr_seat_pointer_notify_clear_focus(s->seat);
s->pointer_focus = NULL;
}
break;
default:
break;
}
wlr_seat_pointer_notify_frame(s->seat);
}
// Tell the input relay where typing goes, on a change and every second: while it's the
// desktop, the relay grabs pass-through keyboards so SteamVR (and the Steam app with
// gamescope's focus) doesn't get the keys too. Without word from us for a few seconds,
// the relay gives the keyboards back, so a closed desktop doesn't keep them.
static void keys_update(struct server *s) {
if (!s->vr) return; // a test instance leaves the running desktop's keyboards alone
const bool desktop = s->keys_clicked && ft_vr_screens_shown();
const uint32_t t = now_ms();
if (desktop == s->keys_desktop && t - s->relay_sent < 1000) return;
if (desktop != s->keys_desktop) wlr_log(WLR_INFO, "typing goes to %s", desktop ? "the desktop" : "Steam");
s->keys_desktop = desktop;
s->relay_sent = t;
struct sockaddr_un addr = {.sun_family = AF_UNIX};
const char name[] = "frametop_relay";
memcpy(addr.sun_path + 1, name, sizeof name - 1);
const char *msg = desktop ? "keyboard desktop" : "keyboard steam";
sendto(s->relay_fd, msg, strlen(msg), MSG_DONTWAIT, (struct sockaddr *)&addr,
offsetof(struct sockaddr_un, sun_path) + 1 + sizeof name - 1);
}
// Every ~11 ms (90 Hz): SteamVR events, and frame callbacks for screens that committed.
static int tick(void *data) {
struct server *s = data;
ft_vr_poll(handle_vr_event, s);
if (++s->ticks % 9 == 0) keys_update(s);
if (s->kb_close_at && s->ticks >= s->kb_close_at) {
s->kb_close_at = 0;
if (s->kb_screen >= 0) {
ft_vr_keyboard_hide();
s->kb_screen = -1;
}
}
struct timespec now;
clock_gettime(CLOCK_MONOTONIC, &now);
for (int i = 0; i < MAX_SCREENS; ++i) {
struct screen *sc = s->screens[i];
if (sc && sc->frame_pending) {
sc->frame_pending = false;
wlr_surface_send_frame_done(sc->toplevel->base->surface, &now);
}
}
wl_event_source_timer_update(s->tick, 11);
return 0;
}
static int child_exited(int sig, void *data) {
struct server *s = data;
int status;
pid_t pid;
while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
if (pid == s->child) {
wlr_log(WLR_INFO, "session exited");
wl_display_terminate(s->display);
}
return 0;
}
static bool key_held(const struct wlr_keyboard *kb, uint32_t code) {
for (size_t i = 0; i < kb->num_keycodes; i++)
if (kb->keycodes[i] == code) return true;
return false;
}
// One key to the focused screen, through the seat's keyboard so its xkb state and
// modifiers stay right.
static void send_key(struct server *s, uint32_t code, int pressed) {
struct wlr_keyboard_key_event ev = {
.time_msec = now_ms(), .keycode = code, .update_state = true,
.state = pressed ? WL_KEYBOARD_KEY_STATE_PRESSED : WL_KEYBOARD_KEY_STATE_RELEASED};
wlr_keyboard_notify_key(&s->keyboard, &ev);
wlr_seat_keyboard_notify_modifiers(s->seat, &s->keyboard.modifiers);
wlr_seat_keyboard_notify_key(s->seat, ev.time_msec, code, ev.state);
}
// Keys from the input relay (physical keyboards): "key <evdev code> <1 press|0 release>".
// They go to the screen KWin has keyboard focus on (the last one clicked), while typing
// goes to the desktop (keys_update). The release of a key the desktop got the press for
// always goes through, or the key stays held there (a modifier held as typing moves to
// Steam would otherwise modify every key typed after it).
static void handle_key(struct server *s, uint32_t code, int value, char *reply, int size) {
if (value == 2) return (void)snprintf(reply, size, "ok repeat ignored"); // KWin repeats itself
if (value || !key_held(&s->keyboard, code)) {
if (!s->seat->keyboard_state.focused_surface) return (void)snprintf(reply, size, "ok no focus");
if (!s->keys_desktop) return (void)snprintf(reply, size, "ok typing goes to Steam");
}
send_key(s, code, value);
snprintf(reply, size, "ok");
}
// Our keyboard (keyboard.cpp). The input relay sends "vrkeyboard show" when a text field
// on the desktop gets focus (and its setting allows), "vrkeyboard hide" when it loses it,
// and "vrkeyboard toggle" for a mapped button; ft-layout sends "vrkeyboard close" when it
// resets the layout. It opens for the screen KWin has keyboard focus on. A hide closes only a keyboard a text field opened, and waits a moment, so
// moving between text fields doesn't close and reopen it.
static int focused_screen(struct server *s) {
struct wlr_surface *focus = s->seat->keyboard_state.focused_surface;
for (int i = 0; i < MAX_SCREENS; ++i)
if (s->screens[i] && s->screens[i]->toplevel->base->surface == focus) return i;
if (s->pointer_focus) return s->pointer_focus->index;
for (int i = 0; i < MAX_SCREENS; ++i)
if (s->screens[i]) return i;
return -1;
}
static void keyboard_command(struct server *s, const char *what, char *reply, int size) {
const bool open = s->kb_screen >= 0;
if (strcmp(what, "hide") == 0) {
if (open && s->kb_auto && !s->kb_close_at) s->kb_close_at = s->ticks + 30; // ~1/3 s
return (void)snprintf(reply, size, "ok");
}
if (strcmp(what, "close") == 0) { // however it opened, now (ft-layout apply: a reset)
if (open) wlr_log(WLR_INFO, "keyboard closed (reset)");
ft_vr_keyboard_hide();
s->kb_screen = -1;
s->kb_close_at = 0;
return (void)snprintf(reply, size, "ok");
}
const bool toggle = strcmp(what, "toggle") == 0;
if (!toggle && strcmp(what, "show") != 0) return (void)snprintf(reply, size, "error show|hide|toggle|close");
s->kb_close_at = 0;
if (open && toggle) {
ft_vr_keyboard_hide();
s->kb_screen = -1;
return (void)snprintf(reply, size, "ok closed");
}
if (open) return (void)snprintf(reply, size, "ok open");
if (!ft_vr_screens_shown()) return (void)snprintf(reply, size, "ok screens hidden");
const int screen = focused_screen(s);
if (screen < 0 || !ft_vr_keyboard_show(screen)) return (void)snprintf(reply, size, "error not shown");
wlr_log(WLR_INFO, "keyboard open for screen %d (%s)", screen + 1, toggle ? "button" : "text field");
s->kb_screen = screen;
s->kb_auto = !toggle;
snprintf(reply, size, "ok opened");
}
// A key from our keyboard, for the focused screen. Its release always goes through, so
// no key stays held.
static void panel_key(struct server *s, uint32_t code, bool pressed) {
if (pressed ? s->seat->keyboard_state.focused_surface != NULL : key_held(&s->keyboard, code))
send_key(s, code, pressed);
}
// Control socket: abstract datagram @ft_screens. Here: "size <screen> <w> <h>" (a new
// resolution, live), "scale <screen> <s>" (KWin's scale for it, from ft-layout),
// "toplevels" (-> "ok <count>" and a line per KWin window: "<screen> <w>x<h> <commits>
// <title>"), "input <screen> move|down|up|leave [x y [left|right|middle]]" (pointer input
// as if from that panel, x and y in its pixels; for tests, mostly with --no-vr),
// "key <code> <value>", "vrkeyboard show|hide|toggle|close" (our keyboard, from the input
// relay), and "click <overlay key>" (from the pointer helper: a mouse click landed on
// that panel, "-" for none); the rest is in vr.cpp (ft_vr_command).
static int control_readable(int fd, uint32_t mask, void *data) {
struct server *s = data;
char buf[512], reply[2048];
struct sockaddr_un from;
socklen_t len = sizeof from;
ssize_t n;
while ((n = recvfrom(fd, buf, sizeof buf - 1, MSG_DONTWAIT, (struct sockaddr *)&from, &len)) > 0) {
buf[n] = 0;
unsigned code;
int value, index, w, h;
double scale;
if (sscanf(buf, "size %d %d %d", &index, &w, &h) == 3) {
// A new resolution for a screen, live: KWin resizes the screen to match. (KWin makes
// it this size times its scale; ft-floatd sends spares' sizes divided by theirs.)
const int min_w = index - 1 < s->n_config ? 320 : 64, min_h = index - 1 < s->n_config ? 200 : 64;
if (index < 1 || index > MAX_SCREENS || !s->screens[index - 1] || w < min_w || h < min_h || w > 16384 ||
h > 16384) {
snprintf(reply, sizeof reply, "error bad screen or size");
} else {
// A screen's size is even: KWin's nested backend gives a scaled screen a whole
// buffer scale (1.5 -> 2), and a buffer that isn't a multiple of it is a protocol
// error that disconnects KWin. (ft-floatd rounds spares' sizes for their scale.)
if (index - 1 < s->n_config) w += w & 1, h += h & 1;
if (index - 1 < s->n_config) s->config[index - 1].width = w, s->config[index - 1].height = h;
wlr_xdg_toplevel_set_size(s->screens[index - 1]->toplevel, w, h);
snprintf(reply, sizeof reply, "ok");
}
} else if (sscanf(buf, "scale %d %lf", &index, &scale) == 2) {
if (index < 1 || index > MAX_SCREENS || !(scale >= 0.25 && scale <= 8)) {
snprintf(reply, sizeof reply, "error bad screen or scale");
} else {
if (s->scale[index - 1] != scale) wlr_log(WLR_INFO, "screen %d: KWin scale %g", index, scale);
s->scale[index - 1] = scale;
snprintf(reply, sizeof reply, "ok");
}
} else if (sscanf(buf, "key %u %d", &code, &value) == 2) {
handle_key(s, code, value, reply, sizeof reply);
len = sizeof from;
continue; // no reply: keys are fire-and-forget
} else if (strncmp(buf, "vrkeyboard ", 11) == 0) {
keyboard_command(s, buf + 11, reply, sizeof reply);
} else if (strncmp(buf, "input ", 6) == 0) {
char what[8] = "", button[8] = "left";
double x = 0, y = 0;
const int got = sscanf(buf, "input %d %7s %lf %lf %7s", &index, what, &x, &y, button);
struct ft_event e = {.screen = index - 1, .x = x, .y = y, .button = BTN_LEFT};
if (strcmp(button, "right") == 0) e.button = BTN_RIGHT;
else if (strcmp(button, "middle") == 0) e.button = BTN_MIDDLE;
if (got >= 2 && strcmp(what, "leave") == 0) e.type = FT_LEAVE;
else if (got >= 4 && strcmp(what, "move") == 0) e.type = FT_MOTION;
else if (got >= 4 && (strcmp(what, "down") == 0 || strcmp(what, "up") == 0))
e.type = FT_BUTTON, e.pressed = what[0] == 'd';
else index = 0;
if (index < 1 || index > MAX_SCREENS || !s->screens[index - 1]) {
snprintf(reply, sizeof reply, "error input <screen> move|down|up|leave [x y [button]]");
} else {
handle_vr_event(&e, s);
snprintf(reply, sizeof reply, "ok");
}
} else if (strcmp(buf, "toplevels") == 0) {
int n = 0, at = 0;
for (int i = 0; i < MAX_SCREENS; ++i) n += s->screens[i] != NULL;
at = snprintf(reply, sizeof reply, "ok %d", n);
for (int i = 0; i < MAX_SCREENS && at < (int)sizeof reply; ++i) {
const struct screen *sc = s->screens[i];
if (!sc) continue;
at += snprintf(reply + at, sizeof reply - at, "\n%d %dx%d %u %s", i + 1, sc->buffer_width,
sc->buffer_height, sc->commits, sc->toplevel->title ? sc->toplevel->title : "");
}
} else if (strncmp(buf, "click ", 6) == 0) {
// A click on another panel takes typing to Steam. Our own panels (the screens,
// their controls) leave it: a click on a screen arrives as a panel event.
if (strcmp(buf + 6, "-") != 0 && strncmp(buf + 6, "frametop.", 9) != 0) s->keys_clicked = false;
len = sizeof from;
continue;
} else {
ft_vr_command(buf, reply, sizeof reply);
}
if (len > offsetof(struct sockaddr_un, sun_path))
sendto(fd, reply, strlen(reply), MSG_DONTWAIT, (struct sockaddr *)&from, len);
len = sizeof from;
}
return 0;
}
static int open_control_socket(const char *name) {
int fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
struct sockaddr_un addr = {.sun_family = AF_UNIX};
const size_t len = strlen(name);
if (len == 0 || len >= sizeof addr.sun_path - 1) {
wlr_log(WLR_ERROR, "bad control socket name");
close(fd);
return -1;
}
memcpy(addr.sun_path + 1, name, len);
if (bind(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + 1 + len) != 0) {
wlr_log(WLR_ERROR, "can't bind @%s (another ft-screens running?)", name);
close(fd);
return -1;
}
return fd;
}
static int stop(int sig, void *data) {
wl_display_terminate(((struct server *)data)->display);
return 0;
}
// ---------------------------------------------------------------- setup
static void keyboard_led(struct wlr_keyboard *kb, uint32_t leds) {}
static const struct wlr_keyboard_impl keyboard_impl = {.name = "ft-screens-keyboard", .led_update = keyboard_led};
static bool setup_dmabuf(struct server *s) {
struct stat st;
const char *node = "/dev/dri/renderD128";
if (stat(node, &st) != 0) {
wlr_log(WLR_ERROR, "no %s", node);
return false;
}
struct wlr_linux_dmabuf_feedback_v1 fb = {.main_device = st.st_rdev};
wl_array_init(&fb.tranches);
struct wlr_linux_dmabuf_feedback_v1_tranche *tr = wlr_linux_dmabuf_feedback_add_tranche(&fb);
tr->target_device = st.st_rdev;
const uint32_t formats[] = {DRM_FORMAT_XRGB8888, DRM_FORMAT_ARGB8888};
for (size_t f = 0; f < 2; ++f) {
uint64_t mods[64];
const int n = ft_vr_modifiers(formats[f], mods, 64);
for (int i = 0; i < n; ++i) wlr_drm_format_set_add(&tr->formats, formats[f], mods[i]);
wlr_log(WLR_INFO, "dmabuf: format 0x%x, %d modifiers SteamVR can import", formats[f], n);
}
struct wlr_linux_dmabuf_v1 *dmabuf = wlr_linux_dmabuf_v1_create(s->display, 4, &fb);
wlr_linux_dmabuf_feedback_v1_finish(&fb);
return dmabuf != NULL;
}
int main(int argc, char **argv) {
struct server s = {0};
for (int i = 0; i < MAX_SCREENS; ++i) s.scale[i] = 1;
s.kb_screen = -1;
const char *socket_name = "ft-screens-0", *control_name = "ft_screens";
char **command = NULL;
s.vr = true;
for (int i = 1; i < argc; ++i) {
if (strcmp(argv[i], "--socket") == 0 && i + 1 < argc) {
socket_name = argv[++i];
} else if (strcmp(argv[i], "--control") == 0 && i + 1 < argc) {
control_name = argv[++i];
} else if (strcmp(argv[i], "--spares") == 0 && i + 1 < argc) {
s.spares = atoi(argv[++i]);
} else if (strcmp(argv[i], "--no-vr") == 0) {
s.vr = false;
} else if (strcmp(argv[i], "--screen") == 0 && i + 1 < argc && s.n_config < MAX_SCREENS) {
struct config *c = &s.config[s.n_config];
c->metres = 0;
if (sscanf(argv[++i], "%dx%d@%lf", &c->width, &c->height, &c->metres) < 2) {
fprintf(stderr, "bad --screen %s (want WxH@METRES)\n", argv[i]);
return 2;
}
if (c->metres <= 0) c->metres = 1.5 * c->width / 1920.0;
++s.n_config;
} else if (strcmp(argv[i], "--") == 0) {
command = &argv[i + 1];
break;
} else {
fprintf(stderr,
"usage: %s [--socket NAME] [--control NAME] [--no-vr] [--screen WxH@METRES]... "
"[--spares N] [-- COMMAND ARGS...]\n",
argv[0]);
return 2;
}
}
if (s.n_config == 0) s.config[s.n_config++] = (struct config){3440, 1440, 2.4};
setvbuf(stdout, NULL, _IOLBF, 0); // vr.cpp prints to stdout; keep it in order with the log
wlr_log_init(WLR_INFO, NULL);
if (s.vr && !ft_vr_init()) return 1;
if (!s.vr) wlr_log(WLR_INFO, "--no-vr: running without SteamVR");
s.display = wl_display_create();
s.loop = wl_display_get_event_loop(s.display);
wl_list_init(&s.buffers);
wlr_compositor_create(s.display, 6, NULL);
wlr_subcompositor_create(s.display);
const uint32_t shm_formats[] = {DRM_FORMAT_ARGB8888, DRM_FORMAT_XRGB8888}; // wlroots wants DRM codes
wlr_shm_create(s.display, 1, shm_formats, 2);
if (!setup_dmabuf(&s)) return 1;
wlr_data_device_manager_create(s.display);
s.xdg_shell = wlr_xdg_shell_create(s.display, 3);
s.new_toplevel.notify = new_toplevel;
wl_signal_add(&s.xdg_shell->events.new_toplevel, &s.new_toplevel);
s.decoration = wlr_xdg_decoration_manager_v1_create(s.display);
s.new_decoration.notify = new_decoration;
wl_signal_add(&s.decoration->events.new_toplevel_decoration, &s.new_decoration);
s.seat = wlr_seat_create(s.display, "seat0");
wlr_keyboard_init(&s.keyboard, &keyboard_impl, "ft-screens-keyboard");
struct xkb_context *xkb = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
struct xkb_keymap *keymap = xkb_keymap_new_from_names(xkb, NULL, XKB_KEYMAP_COMPILE_NO_FLAGS);
wlr_keyboard_set_keymap(&s.keyboard, keymap);
xkb_keymap_unref(keymap);
xkb_context_unref(xkb);
wlr_seat_set_keyboard(s.seat, &s.keyboard);
wlr_seat_set_capabilities(s.seat, WL_SEAT_CAPABILITY_POINTER | WL_SEAT_CAPABILITY_KEYBOARD);
if (wl_display_add_socket(s.display, socket_name) != 0) {
wlr_log(WLR_ERROR, "can't create socket %s (another ft-screens?)", socket_name);
return 1;
}
char path[256];
snprintf(path, sizeof path, "%s/%s", getenv("XDG_RUNTIME_DIR") ? getenv("XDG_RUNTIME_DIR") : "/tmp", socket_name);
wlr_log(WLR_INFO, "listening on %s; %d screen(s) configured, %d spare(s)", path, s.n_config, s.spares);
const int control = open_control_socket(control_name);
if (control < 0) return 1;
s.relay_fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
wl_event_loop_add_fd(s.loop, control, WL_EVENT_READABLE, control_readable, &s);
s.tick = wl_event_loop_add_timer(s.loop, tick, &s);
wl_event_source_timer_update(s.tick, 11);
wl_event_loop_add_signal(s.loop, SIGINT, stop, &s);
wl_event_loop_add_signal(s.loop, SIGTERM, stop, &s);
wl_event_loop_add_signal(s.loop, SIGCHLD, child_exited, &s);
if (command && command[0]) {
s.child = fork();
if (s.child == 0) {
setenv("WAYLAND_DISPLAY", path, 1);
execvp(command[0], command);
perror(command[0]);
_exit(127);
}
}
wl_display_run(s.display);
wlr_log(WLR_INFO, "stopping");
if (s.child > 0) kill(s.child, SIGTERM);
wl_display_destroy_clients(s.display);
// wlroots asserts that nothing still listens to its globals when they go.
wl_list_remove(&s.new_toplevel.link);
wl_list_remove(&s.new_decoration.link);
ft_vr_shutdown();
wl_display_destroy(s.display);
return 0;
}