Merge pull request #164 from ascent12/x11-backend

X11 backend

5 files changed, 345 insertions, 5 deletions

diff --git a/backend/backend.c b/backend/backend.c
index 88b9dfbc..ec309da4 100644
--- a/backend/backend.c
+++ b/backend/backend.c
@@ -10,6 +10,7 @@
 #include <wlr/backend/drm.h>
 #include <wlr/backend/libinput.h>
 #include <wlr/backend/wayland.h>
+#include <wlr/backend/x11.h>
 #include <wlr/backend/multi.h>
 #include <wlr/util/log.h>
 
@@ -77,9 +78,9 @@ struct wlr_backend *wlr_backend_autocreate(struct wl_display *display) {
 		}
 	}
 
-	if (getenv("DISPLAY")) {
-		wlr_log(L_ERROR, "X11 backend is not implemented"); // TODO
-		return NULL;
+	const char *x11_display = getenv("DISPLAY");
+	if (x11_display) {
+		return wlr_x11_backend_create(display, x11_display);
 	}
 
 	// Attempt DRM+libinput
diff --git a/backend/drm/drm.c b/backend/drm/drm.c
index 8e70e528..1a656172 100644
--- a/backend/drm/drm.c
+++ b/backend/drm/drm.c
@@ -182,7 +182,8 @@ bool wlr_drm_renderer_init(struct wlr_drm_renderer *renderer, int fd) {
 		return false;
 	}
 
-	if (!wlr_egl_init(&renderer->egl, EGL_PLATFORM_GBM_MESA, renderer->gbm)) {
+	if (!wlr_egl_init(&renderer->egl, EGL_PLATFORM_GBM_MESA,
+			GBM_FORMAT_ARGB8888, renderer->gbm)) {
 		gbm_device_destroy(renderer->gbm);
 		return false;
 	}
diff --git a/backend/meson.build b/backend/meson.build
index a3cb7b64..9e3b6fed 100644
--- a/backend/meson.build
+++ b/backend/meson.build
@@ -22,6 +22,7 @@ backend_files = files(
 	'wayland/registry.c',
 	'wayland/wl_seat.c',
 	'wayland/os-compatibility.c',
+	'x11/backend.c',
 )
 
 if systemd.found()
diff --git a/backend/wayland/backend.c b/backend/wayland/backend.c
index 264ce338..e57f3583 100644
--- a/backend/wayland/backend.c
+++ b/backend/wayland/backend.c
@@ -42,6 +42,7 @@ static bool wlr_wl_backend_start(struct wlr_backend *_backend) {
 	}
 
 	backend->started = true;
+
 	for (size_t i = 0; i < backend->requested_outputs; ++i) {
 		wlr_wl_output_create(&backend->backend);
 	}
@@ -145,7 +146,7 @@ struct wlr_backend *wlr_wl_backend_create(struct wl_display *display) {
 		return false;
 	}
 
-	wlr_egl_init(&backend->egl, EGL_PLATFORM_WAYLAND_EXT, backend->remote_display);
+	wlr_egl_init(&backend->egl, EGL_PLATFORM_WAYLAND_EXT, WL_SHM_FORMAT_ARGB8888, backend->remote_display);
 	wlr_egl_bind_display(&backend->egl, backend->local_display);
 
 	return &backend->backend;
diff --git a/backend/x11/backend.c b/backend/x11/backend.c
new file mode 100644
index 00000000..88c022d1
--- /dev/null
+++ b/backend/x11/backend.c
@@ -0,0 +1,336 @@
+#define _POSIX_C_SOURCE 199309L
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <EGL/egl.h>
+#include <wayland-server.h>
+#include <xcb/xcb.h>
+#include <xcb/glx.h>
+#include <X11/Xlib-xcb.h>
+#include <linux/input-event-codes.h>
+#include <wlr/backend/interface.h>
+#include <wlr/backend/x11.h>
+#include <wlr/egl.h>
+#include <wlr/interfaces/wlr_output.h>
+#include <wlr/interfaces/wlr_input_device.h>
+#include <wlr/interfaces/wlr_keyboard.h>
+#include <wlr/interfaces/wlr_pointer.h>
+#include <wlr/util/log.h>
+#include "backend/x11.h"
+
+static struct wlr_backend_impl backend_impl;
+static struct wlr_output_impl output_impl;
+
+static uint32_t xcb_button_to_wl(uint32_t button) {
+	switch (button) {
+	case XCB_BUTTON_INDEX_1: return BTN_LEFT;
+	case XCB_BUTTON_INDEX_2: return BTN_MIDDLE;
+	case XCB_BUTTON_INDEX_3: return BTN_RIGHT;
+	// XXX: I'm not sure the scroll-wheel direction is right
+	case XCB_BUTTON_INDEX_4: return BTN_GEAR_UP;
+	case XCB_BUTTON_INDEX_5: return BTN_GEAR_DOWN;
+	default: return 0;
+	}
+}
+
+static bool handle_x11_event(struct wlr_x11_backend *x11, xcb_generic_event_t *event) {
+	struct wlr_x11_output *output = &x11->output;
+
+	switch (event->response_type) {
+	case XCB_EXPOSE: {
+		wl_signal_emit(&output->wlr_output.events.frame, output);
+		break;
+	}
+	case XCB_KEY_PRESS:
+	case XCB_KEY_RELEASE: {
+		xcb_key_press_event_t *ev = (xcb_key_press_event_t *)event;
+		struct wlr_event_keyboard_key key = {
+			.time_sec = ev->time / 1000,
+			.time_usec = (ev->time % 1000) * 1000,
+			.keycode = ev->detail - 8,
+			.state = event->response_type == XCB_KEY_PRESS ?
+				WLR_KEY_PRESSED : WLR_KEY_RELEASED,
+		};
+
+		wl_signal_emit(&x11->keyboard.events.key, &key);
+		x11->time = ev->time;
+		break;
+	}
+	case XCB_BUTTON_PRESS:
+	case XCB_BUTTON_RELEASE: {
+		xcb_button_press_event_t *ev = (xcb_button_press_event_t *)event;
+		struct wlr_event_pointer_button button = {
+			.device = &x11->pointer_dev,
+			.time_sec = ev->time / 1000,
+			.time_usec = (ev->time % 1000) * 1000,
+			.button = xcb_button_to_wl(ev->detail),
+			.state = event->response_type == XCB_BUTTON_PRESS ?
+				WLR_BUTTON_PRESSED : WLR_BUTTON_RELEASED,
+		};
+
+		wl_signal_emit(&x11->pointer.events.button, &button);
+		x11->time = ev->time;
+		break;
+	}
+	case XCB_MOTION_NOTIFY: {
+		xcb_motion_notify_event_t *ev = (xcb_motion_notify_event_t *)event;
+		struct wlr_event_pointer_motion_absolute abs = {
+			.device = &x11->pointer_dev,
+			.time_sec = ev->time / 1000,
+			.time_usec = (ev->time % 1000) * 1000,
+			.x_mm = ev->event_x,
+			.y_mm = ev->event_y,
+			.width_mm = output->wlr_output.width,
+			.height_mm = output->wlr_output.height,
+		};
+
+		wl_signal_emit(&x11->pointer.events.motion_absolute, &abs);
+		x11->time = ev->time;
+		break;
+	}
+	case XCB_CONFIGURE_NOTIFY: {
+		xcb_configure_notify_event_t *ev = (xcb_configure_notify_event_t *)event;
+
+		output->wlr_output.width = ev->width;
+		output->wlr_output.height = ev->height;
+		wlr_output_update_matrix(&output->wlr_output);
+		wl_signal_emit(&output->wlr_output.events.resolution, output);
+
+		// Move the pointer to its new location
+		xcb_query_pointer_cookie_t cookie =
+			xcb_query_pointer(x11->xcb_conn, output->win);
+		xcb_query_pointer_reply_t *pointer =
+			xcb_query_pointer_reply(x11->xcb_conn, cookie, NULL);
+		if (!pointer) {
+			break;
+		}
+
+		struct wlr_event_pointer_motion_absolute abs = {
+			.device = &x11->pointer_dev,
+			.time_sec = x11->time / 1000,
+			.time_usec = (x11->time % 1000) * 1000,
+			.x_mm = pointer->root_x,
+			.y_mm = pointer->root_y,
+			.width_mm = output->wlr_output.width,
+			.height_mm = output->wlr_output.height,
+		};
+
+		wl_signal_emit(&x11->pointer.events.motion_absolute, &abs);
+		break;
+	}
+	case XCB_GLX_DELETE_QUERIES_ARB: {
+		wl_display_terminate(x11->wl_display);
+		return true;
+		break;
+	}
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static int x11_event(int fd, uint32_t mask, void *data) {
+	struct wlr_x11_backend *x11 = data;
+	xcb_generic_event_t *e;
+	bool quit = false;
+
+	while (!quit && (e = xcb_poll_for_event(x11->xcb_conn))) {
+		quit = handle_x11_event(x11, e);
+		free(e);
+	}
+
+	return 0;
+}
+
+static int signal_frame(void *data) {
+	struct wlr_x11_backend *x11 = data;
+	wl_signal_emit(&x11->output.wlr_output.events.frame, &x11->output);
+	wl_event_source_timer_update(x11->frame_timer, 16);
+	return 0;
+}
+
+static void init_atom(struct wlr_x11_backend *x11, struct wlr_x11_atom *atom,
+		uint8_t only_if_exists, const char *name) {
+	atom->cookie = xcb_intern_atom(x11->xcb_conn, only_if_exists, strlen(name), name);
+	atom->reply = xcb_intern_atom_reply(x11->xcb_conn, atom->cookie, NULL);
+}
+
+struct wlr_backend *wlr_x11_backend_create(struct wl_display *display,
+		const char *x11_display) {
+	struct wlr_x11_backend *x11 = calloc(1, sizeof(*x11));
+	if (!x11) {
+		return NULL;
+	}
+
+	wlr_backend_init(&x11->backend, &backend_impl);
+	x11->wl_display = display;
+
+	x11->xlib_conn = XOpenDisplay(x11_display);
+	if (!x11->xlib_conn) {
+		wlr_log(L_ERROR, "Failed to open X connection");
+		return NULL;
+	}
+
+	x11->xcb_conn = XGetXCBConnection(x11->xlib_conn);
+	if (!x11->xcb_conn || xcb_connection_has_error(x11->xcb_conn)) {
+		wlr_log(L_ERROR, "Failed to open xcb connection");
+		goto error_x11;
+	}
+
+	XSetEventQueueOwner(x11->xlib_conn, XCBOwnsEventQueue);
+
+	int fd = xcb_get_file_descriptor(x11->xcb_conn);
+	struct wl_event_loop *ev = wl_display_get_event_loop(display);
+	x11->event_source = wl_event_loop_add_fd(ev, fd, WL_EVENT_READABLE, x11_event, x11);
+	if (!x11->event_source) {
+		wlr_log(L_ERROR, "Could not create event source");
+		goto error_x11;
+	}
+
+	x11->frame_timer = wl_event_loop_add_timer(ev, signal_frame, x11);
+
+	x11->screen = xcb_setup_roots_iterator(xcb_get_setup(x11->xcb_conn)).data;
+
+	if (!wlr_egl_init(&x11->egl, EGL_PLATFORM_X11_KHR,
+			x11->screen->root_visual, x11->xlib_conn)) {
+		goto error_event;
+	}
+
+	wlr_input_device_init(&x11->keyboard_dev, WLR_INPUT_DEVICE_KEYBOARD,
+		NULL, "X11 keyboard", 0, 0);
+	wlr_keyboard_init(&x11->keyboard, NULL);
+	x11->keyboard_dev.keyboard = &x11->keyboard;
+
+	wlr_input_device_init(&x11->pointer_dev, WLR_INPUT_DEVICE_POINTER,
+		NULL, "X11 pointer", 0, 0);
+	wlr_pointer_init(&x11->pointer, NULL);
+	x11->pointer_dev.pointer = &x11->pointer;
+
+	return &x11->backend;
+
+error_event:
+	wl_event_source_remove(x11->event_source);
+error_x11:
+	xcb_disconnect(x11->xcb_conn);
+	XCloseDisplay(x11->xlib_conn);
+	free(x11);
+	return NULL;
+}
+
+static bool wlr_x11_backend_start(struct wlr_backend *backend) {
+	struct wlr_x11_backend *x11 = (struct wlr_x11_backend *)backend;
+	struct wlr_x11_output *output = &x11->output;
+
+	uint32_t mask = XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK;
+	uint32_t values[2] = {
+		x11->screen->white_pixel,
+		XCB_EVENT_MASK_EXPOSURE |
+		XCB_EVENT_MASK_KEY_PRESS | XCB_EVENT_MASK_KEY_RELEASE |
+		XCB_EVENT_MASK_BUTTON_PRESS | XCB_EVENT_MASK_BUTTON_RELEASE |
+		XCB_EVENT_MASK_POINTER_MOTION |
+		XCB_EVENT_MASK_STRUCTURE_NOTIFY
+	};
+
+	output->x11 = x11;
+
+	wlr_output_init(&output->wlr_output, &output_impl);
+	snprintf(output->wlr_output.name, sizeof(output->wlr_output.name), "X11-1");
+
+	output->win = xcb_generate_id(x11->xcb_conn);
+	xcb_create_window(x11->xcb_conn, XCB_COPY_FROM_PARENT, output->win, x11->screen->root,
+		0, 0, 1024, 768, 1, XCB_WINDOW_CLASS_INPUT_OUTPUT,
+		x11->screen->root_visual, mask, values);
+
+	output->surf = wlr_egl_create_surface(&x11->egl, &output->win);
+	if (!output->surf) {
+		wlr_log(L_ERROR, "Failed to create EGL surface");
+		return false;
+	}
+
+	init_atom(x11, &x11->atoms.wm_protocols, 1, "WM_PROTOCOLS");
+	init_atom(x11, &x11->atoms.wm_delete_window, 0, "WM_DELETE_WINDOW");
+
+	xcb_change_property(x11->xcb_conn, XCB_PROP_MODE_REPLACE, output->win,
+		x11->atoms.wm_protocols.reply->atom, XCB_ATOM_ATOM, 32, 1,
+		&x11->atoms.wm_delete_window.reply->atom);
+
+	xcb_map_window(x11->xcb_conn, output->win);
+	xcb_flush(x11->xcb_conn);
+
+	wl_signal_emit(&x11->backend.events.output_add, output);
+	wl_signal_emit(&x11->backend.events.input_add, &x11->keyboard_dev);
+	wl_signal_emit(&x11->backend.events.input_add, &x11->pointer_dev);
+
+	wl_event_source_timer_update(x11->frame_timer, 16);
+
+	return true;
+}
+
+static void wlr_x11_backend_destroy(struct wlr_backend *backend) {
+	if (!backend) {
+		return;
+	}
+
+	struct wlr_x11_backend *x11 = (struct wlr_x11_backend *)backend;
+
+	wl_event_source_remove(x11->frame_timer);
+	wlr_egl_free(&x11->egl);
+
+	xcb_disconnect(x11->xcb_conn);
+	free(x11);
+}
+
+static struct wlr_egl *wlr_x11_backend_get_egl(struct wlr_backend *backend) {
+	struct wlr_x11_backend *x11 = (struct wlr_x11_backend *)backend;
+	return &x11->egl;
+}
+
+bool wlr_backend_is_x11(struct wlr_backend *backend) {
+	return backend->impl == &backend_impl;
+}
+
+static struct wlr_backend_impl backend_impl = {
+	.start = wlr_x11_backend_start,
+	.destroy = wlr_x11_backend_destroy,
+	.get_egl = wlr_x11_backend_get_egl,
+};
+
+static void output_transform(struct wlr_output *wlr_output, enum wl_output_transform transform) {
+	struct wlr_x11_output *output = (struct wlr_x11_output *)wlr_output;
+	output->wlr_output.transform = transform;
+}
+
+static void output_destroy(struct wlr_output *wlr_output) {
+	struct wlr_x11_output *output = (struct wlr_x11_output *)wlr_output;
+	struct wlr_x11_backend *x11 = output->x11;
+
+	eglDestroySurface(x11->egl.display, output->surf);
+	xcb_destroy_window(x11->xcb_conn, output->win);
+}
+
+static void output_make_current(struct wlr_output *wlr_output) {
+	struct wlr_x11_output *output = (struct wlr_x11_output *)wlr_output;
+	struct wlr_x11_backend *x11 = output->x11;
+
+	if (!eglMakeCurrent(x11->egl.display, output->surf, output->surf, x11->egl.context)) {
+		wlr_log(L_ERROR, "eglMakeCurrent failed: %s", egl_error());
+	}
+}
+
+static void output_swap_buffers(struct wlr_output *wlr_output) {
+	struct wlr_x11_output *output = (struct wlr_x11_output *)wlr_output;
+	struct wlr_x11_backend *x11 = output->x11;
+
+	if (!eglSwapBuffers(x11->egl.display, output->surf)) {
+		wlr_log(L_ERROR, "eglSwapBuffers failed: %s", egl_error());
+	}
+}
+
+static struct wlr_output_impl output_impl = {
+	.transform = output_transform,
+	.destroy = output_destroy,
+	.make_current = output_make_current,
+	.swap_buffers = output_swap_buffers,
+};