source: mainline/uspace/srv/hid/compositor/compositor.c@ fafb8e5

/*
 * Copyright (c) 2012 Petr Koupy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup compositor
 * @{
 */
/** @file
 */

#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <str_error.h>
#include <byteorder.h>
#include <stdio.h>
#include <libc.h>

#include <align.h>
#include <as.h>
#include <stdlib.h>

#include <refcount.h>
#include <fibril_synch.h>
#include <adt/prodcons.h>
#include <adt/list.h>
#include <io/input.h>
#include <ipc/graph.h>
#include <ipc/window.h>

#include <async.h>
#include <loc.h>
#include <task.h>

#include <io/keycode.h>
#include <io/mode.h>
#include <io/visualizer.h>
#include <io/window.h>
#include <io/console.h>

#include <transform.h>
#include <rectangle.h>
#include <surface.h>
#include <cursor.h>
#include <source.h>
#include <drawctx.h>
#include <codec/tga.h>

#include "compositor.h"

#define NAME       "compositor"
#define NAMESPACE  "comp"

/*
 * Until there is blitter support and some further optimizations, window
 * animations are too slow to be practically usable.
 */
#ifndef ANIMATE_WINDOW_TRANSFORMS
#define ANIMATE_WINDOW_TRANSFORMS 0
#endif

static char *server_name;
static sysarg_t coord_origin;
static pixel_t bg_color;
static filter_t filter = filter_bilinear;
static unsigned int filter_index = 1;

typedef struct {
        link_t link;
        atomic_refcount_t ref_cnt;
        window_flags_t flags;
        service_id_t in_dsid;
        service_id_t out_dsid;
        prodcons_t queue;
        transform_t transform;
        double dx;
        double dy;
        double fx;
        double fy;
        double angle;
        uint8_t opacity;
        surface_t *surface;
} window_t;

static service_id_t winreg_id;
static sysarg_t window_id = 0;
static FIBRIL_MUTEX_INITIALIZE(window_list_mtx);
static LIST_INITIALIZE(window_list);
static double scale_back_x;
static double scale_back_y;

typedef struct {
        link_t link;
        sysarg_t id;
        uint8_t state;
        desktop_point_t pos;
        sysarg_t btn_num;
        desktop_point_t btn_pos;
        desktop_vector_t accum;
        sysarg_t grab_flags;
        bool pressed;
        cursor_t cursor;
        window_t ghost;
        desktop_vector_t accum_ghost;
} pointer_t;

static sysarg_t pointer_id = 0;
static FIBRIL_MUTEX_INITIALIZE(pointer_list_mtx);
static LIST_INITIALIZE(pointer_list);

typedef struct {
        link_t link;
        service_id_t dsid;
        vslmode_t mode;
        async_sess_t *sess;
        desktop_point_t pos;
        surface_t *surface;
} viewport_t;

static desktop_rect_t viewport_bound_rect;
static FIBRIL_MUTEX_INITIALIZE(viewport_list_mtx);
static LIST_INITIALIZE(viewport_list);

static FIBRIL_MUTEX_INITIALIZE(discovery_mtx);

/** Input server proxy */
static input_t *input;
static bool active = false;

static errno_t comp_active(input_t *);
static errno_t comp_deactive(input_t *);
static errno_t comp_key_press(input_t *, kbd_event_type_t, keycode_t, keymod_t, wchar_t);
static errno_t comp_mouse_move(input_t *, int, int);
static errno_t comp_abs_move(input_t *, unsigned, unsigned, unsigned, unsigned);
static errno_t comp_mouse_button(input_t *, int, int);

static input_ev_ops_t input_ev_ops = {
        .active = comp_active,
        .deactive = comp_deactive,
        .key = comp_key_press,
        .move = comp_mouse_move,
        .abs_move = comp_abs_move,
        .button = comp_mouse_button
};

static pointer_t *input_pointer(input_t *input)
{
        return input->user;
}

static pointer_t *pointer_create(void)
{
        pointer_t *p = (pointer_t *) malloc(sizeof(pointer_t));
        if (!p)
                return NULL;

        link_initialize(&p->link);
        p->pos.x = coord_origin;
        p->pos.y = coord_origin;
        p->btn_num = 1;
        p->btn_pos = p->pos;
        p->accum.x = 0;
        p->accum.y = 0;
        p->grab_flags = GF_EMPTY;
        p->pressed = false;
        p->state = 0;
        cursor_init(&p->cursor, CURSOR_DECODER_EMBEDDED, NULL);

        /* Ghost window for transformation animation. */
        transform_identity(&p->ghost.transform);
        transform_translate(&p->ghost.transform, coord_origin, coord_origin);
        p->ghost.dx = coord_origin;
        p->ghost.dy = coord_origin;
        p->ghost.fx = 1;
        p->ghost.fy = 1;
        p->ghost.angle = 0;
        p->ghost.opacity = 255;
        p->ghost.surface = NULL;
        p->accum_ghost.x = 0;
        p->accum_ghost.y = 0;

        return p;
}

static void pointer_destroy(pointer_t *p)
{
        if (p) {
                cursor_release(&p->cursor);
                free(p);
        }
}

static window_t *window_create(void)
{
        window_t *win = (window_t *) malloc(sizeof(window_t));
        if (!win)
                return NULL;

        link_initialize(&win->link);
        /* One initial reference will be for being in the window list */
        refcount_init(&win->ref_cnt);
        prodcons_initialize(&win->queue);
        transform_identity(&win->transform);
        transform_translate(&win->transform, coord_origin, coord_origin);
        win->dx = coord_origin;
        win->dy = coord_origin;
        win->fx = 1;
        win->fy = 1;
        win->angle = 0;
        win->opacity = 255;
        win->surface = NULL;

        return win;
}

static void window_destroy(window_t *win)
{
        if (win == NULL)
                return;

        if (!refcount_down(&win->ref_cnt))
                return;

        while (!list_empty(&win->queue.list)) {
                window_event_t *event = (window_event_t *) list_first(&win->queue.list);
                list_remove(&event->link);
                free(event);
        }

        if (win->surface)
                surface_destroy(win->surface);

        free(win);
}

static bool comp_coord_to_client(sysarg_t x_in, sysarg_t y_in, transform_t win_trans,
    sysarg_t x_lim, sysarg_t y_lim, sysarg_t *x_out, sysarg_t *y_out)
{
        double x = x_in;
        double y = y_in;
        transform_invert(&win_trans);
        transform_apply_affine(&win_trans, &x, &y);

        /*
         * Since client coordinate origin is (0, 0), it is necessary to check
         * coordinates to avoid underflow. Moreover, it is convenient to also
         * check against provided upper limits to determine whether the converted
         * coordinates are within the client window.
         */
        if ((x < 0) || (y < 0))
                return false;

        (*x_out) = (sysarg_t) (x + 0.5);
        (*y_out) = (sysarg_t) (y + 0.5);

        if (((*x_out) >= x_lim) || ((*y_out) >= y_lim))
                return false;

        return true;
}

static void comp_coord_from_client(double x_in, double y_in, transform_t win_trans,
    sysarg_t *x_out, sysarg_t *y_out)
{
        double x = x_in;
        double y = y_in;
        transform_apply_affine(&win_trans, &x, &y);

        /*
         * It is assumed that compositor coordinate origin is chosen in such way,
         * that underflow/overflow here would be unlikely.
         */
        (*x_out) = (sysarg_t) (x + 0.5);
        (*y_out) = (sysarg_t) (y + 0.5);
}

static void comp_coord_bounding_rect(double x_in, double y_in,
    double w_in, double h_in, transform_t win_trans,
    sysarg_t *x_out, sysarg_t *y_out, sysarg_t *w_out, sysarg_t *h_out)
{
        if ((w_in > 0) && (h_in > 0)) {
                sysarg_t x[4];
                sysarg_t y[4];

                comp_coord_from_client(x_in, y_in, win_trans, &x[0], &y[0]);
                comp_coord_from_client(x_in + w_in - 1, y_in, win_trans, &x[1], &y[1]);
                comp_coord_from_client(x_in + w_in - 1, y_in + h_in - 1, win_trans, &x[2], &y[2]);
                comp_coord_from_client(x_in, y_in + h_in - 1, win_trans, &x[3], &y[3]);

                (*x_out) = x[0];
                (*y_out) = y[0];
                (*w_out) = x[0];
                (*h_out) = y[0];

                for (unsigned int i = 1; i < 4; ++i) {
                        (*x_out) = (x[i] < (*x_out)) ? x[i] : (*x_out);
                        (*y_out) = (y[i] < (*y_out)) ? y[i] : (*y_out);
                        (*w_out) = (x[i] > (*w_out)) ? x[i] : (*w_out);
                        (*h_out) = (y[i] > (*h_out)) ? y[i] : (*h_out);
                }

                (*w_out) = (*w_out) - (*x_out) + 1;
                (*h_out) = (*h_out) - (*y_out) + 1;
        } else {
                (*x_out) = 0;
                (*y_out) = 0;
                (*w_out) = 0;
                (*h_out) = 0;
        }
}

static void comp_update_viewport_bound_rect(void)
{
        fibril_mutex_lock(&viewport_list_mtx);

        sysarg_t x_res = coord_origin;
        sysarg_t y_res = coord_origin;
        sysarg_t w_res = 0;
        sysarg_t h_res = 0;

        if (!list_empty(&viewport_list)) {
                viewport_t *vp = (viewport_t *) list_first(&viewport_list);
                x_res = vp->pos.x;
                y_res = vp->pos.y;
                surface_get_resolution(vp->surface, &w_res, &h_res);
        }

        list_foreach(viewport_list, link, viewport_t, vp) {
                sysarg_t w_vp, h_vp;
                surface_get_resolution(vp->surface, &w_vp, &h_vp);
                rectangle_union(x_res, y_res, w_res, h_res,
                    vp->pos.x, vp->pos.y, w_vp, h_vp,
                    &x_res, &y_res, &w_res, &h_res);
        }

        viewport_bound_rect.x = x_res;
        viewport_bound_rect.y = y_res;
        viewport_bound_rect.w = w_res;
        viewport_bound_rect.h = h_res;

        fibril_mutex_unlock(&viewport_list_mtx);
}

static void comp_restrict_pointers(void)
{
        comp_update_viewport_bound_rect();

        fibril_mutex_lock(&pointer_list_mtx);

        list_foreach(pointer_list, link, pointer_t, ptr) {
                ptr->pos.x = ptr->pos.x > viewport_bound_rect.x ? ptr->pos.x : viewport_bound_rect.x;
                ptr->pos.y = ptr->pos.y > viewport_bound_rect.y ? ptr->pos.y : viewport_bound_rect.y;
                ptr->pos.x = ptr->pos.x < viewport_bound_rect.x + viewport_bound_rect.w ?
                    ptr->pos.x : viewport_bound_rect.x + viewport_bound_rect.w;
                ptr->pos.y = ptr->pos.y < viewport_bound_rect.y + viewport_bound_rect.h ?
                    ptr->pos.y : viewport_bound_rect.y + viewport_bound_rect.h;
        }

        fibril_mutex_unlock(&pointer_list_mtx);
}

static void comp_damage(sysarg_t x_dmg_glob, sysarg_t y_dmg_glob,
    sysarg_t w_dmg_glob, sysarg_t h_dmg_glob)
{
        fibril_mutex_lock(&viewport_list_mtx);
        fibril_mutex_lock(&window_list_mtx);
        fibril_mutex_lock(&pointer_list_mtx);

        list_foreach(viewport_list, link, viewport_t, vp) {
                /* Determine what part of the viewport must be updated. */
                sysarg_t x_dmg_vp, y_dmg_vp, w_dmg_vp, h_dmg_vp;
                surface_get_resolution(vp->surface, &w_dmg_vp, &h_dmg_vp);
                bool isec_vp = rectangle_intersect(
                    x_dmg_glob, y_dmg_glob, w_dmg_glob, h_dmg_glob,
                    vp->pos.x, vp->pos.y, w_dmg_vp, h_dmg_vp,
                    &x_dmg_vp, &y_dmg_vp, &w_dmg_vp, &h_dmg_vp);

                if (isec_vp) {

                        /* Paint background color. */
                        for (sysarg_t y = y_dmg_vp - vp->pos.y; y <  y_dmg_vp - vp->pos.y + h_dmg_vp; ++y) {
                                pixel_t *dst = pixelmap_pixel_at(
                                    surface_pixmap_access(vp->surface), x_dmg_vp - vp->pos.x, y);
                                sysarg_t count = w_dmg_vp;
                                while (count-- != 0) {
                                        *dst++ = bg_color;
                                }
                        }
                        surface_add_damaged_region(vp->surface,
                            x_dmg_vp - vp->pos.x, y_dmg_vp - vp->pos.y, w_dmg_vp, h_dmg_vp);

                        transform_t transform;
                        source_t source;
                        drawctx_t context;

                        source_init(&source);
                        source_set_filter(&source, filter);
                        drawctx_init(&context, vp->surface);
                        drawctx_set_compose(&context, compose_over);
                        drawctx_set_source(&context, &source);

                        /* For each window. */
                        for (link_t *link = window_list.head.prev;
                            link != &window_list.head; link = link->prev) {

                                /*
                                 * Determine what part of the window intersects with the
                                 * updated area of the current viewport.
                                 */
                                window_t *win = list_get_instance(link, window_t, link);
                                if (!win->surface) {
                                        continue;
                                }
                                sysarg_t x_dmg_win, y_dmg_win, w_dmg_win, h_dmg_win;
                                surface_get_resolution(win->surface, &w_dmg_win, &h_dmg_win);
                                comp_coord_bounding_rect(0, 0, w_dmg_win, h_dmg_win, win->transform,
                                    &x_dmg_win, &y_dmg_win, &w_dmg_win, &h_dmg_win);
                                bool isec_win = rectangle_intersect(
                                    x_dmg_vp, y_dmg_vp, w_dmg_vp, h_dmg_vp,
                                    x_dmg_win, y_dmg_win, w_dmg_win, h_dmg_win,
                                    &x_dmg_win, &y_dmg_win, &w_dmg_win, &h_dmg_win);

                                if (isec_win) {
                                        /*
                                         * Prepare conversion from global coordinates to viewport
                                         * coordinates.
                                         */
                                        transform = win->transform;
                                        double_point_t pos;
                                        pos.x = vp->pos.x;
                                        pos.y = vp->pos.y;
                                        transform_translate(&transform, -pos.x, -pos.y);

                                        source_set_transform(&source, transform);
                                        source_set_texture(&source, win->surface,
                                            PIXELMAP_EXTEND_TRANSPARENT_SIDES);
                                        source_set_alpha(&source, PIXEL(win->opacity, 0, 0, 0));

                                        drawctx_transfer(&context,
                                            x_dmg_win - vp->pos.x, y_dmg_win - vp->pos.y, w_dmg_win, h_dmg_win);
                                }
                        }

                        list_foreach(pointer_list, link, pointer_t, ptr) {
                                if (ptr->ghost.surface) {

                                        sysarg_t x_bnd_ghost, y_bnd_ghost, w_bnd_ghost, h_bnd_ghost;
                                        sysarg_t x_dmg_ghost, y_dmg_ghost, w_dmg_ghost, h_dmg_ghost;
                                        surface_get_resolution(ptr->ghost.surface, &w_bnd_ghost, &h_bnd_ghost);
                                        comp_coord_bounding_rect(0, 0, w_bnd_ghost, h_bnd_ghost, ptr->ghost.transform,
                                            &x_bnd_ghost, &y_bnd_ghost, &w_bnd_ghost, &h_bnd_ghost);
                                        bool isec_ghost = rectangle_intersect(
                                            x_dmg_vp, y_dmg_vp, w_dmg_vp, h_dmg_vp,
                                            x_bnd_ghost, y_bnd_ghost, w_bnd_ghost, h_bnd_ghost,
                                            &x_dmg_ghost, &y_dmg_ghost, &w_dmg_ghost, &h_dmg_ghost);

                                        if (isec_ghost) {
                                                /*
                                                 * FIXME: Ghost is currently drawn based on the bounding
                                                 * rectangle of the window, which is sufficient as long
                                                 * as the windows can be rotated only by 90 degrees.
                                                 * For ghost to be compatible with arbitrary-angle
                                                 * rotation, it should be drawn as four lines adjusted
                                                 * by the transformation matrix. That would however
                                                 * require to equip libdraw with line drawing functionality.
                                                 */

                                                transform_t transform = ptr->ghost.transform;
                                                double_point_t pos;
                                                pos.x = vp->pos.x;
                                                pos.y = vp->pos.y;
                                                transform_translate(&transform, -pos.x, -pos.y);

                                                pixel_t ghost_color;

                                                if (y_bnd_ghost == y_dmg_ghost) {
                                                        for (sysarg_t x = x_dmg_ghost - vp->pos.x;
                                                            x < x_dmg_ghost - vp->pos.x + w_dmg_ghost; ++x) {
                                                                ghost_color = surface_get_pixel(vp->surface,
                                                                    x, y_dmg_ghost - vp->pos.y);
                                                                surface_put_pixel(vp->surface,
                                                                    x, y_dmg_ghost - vp->pos.y, INVERT(ghost_color));
                                                        }
                                                }

                                                if (y_bnd_ghost + h_bnd_ghost == y_dmg_ghost + h_dmg_ghost) {
                                                        for (sysarg_t x = x_dmg_ghost - vp->pos.x;
                                                            x < x_dmg_ghost - vp->pos.x + w_dmg_ghost; ++x) {
                                                                ghost_color = surface_get_pixel(vp->surface,
                                                                    x, y_dmg_ghost - vp->pos.y + h_dmg_ghost - 1);
                                                                surface_put_pixel(vp->surface,
                                                                    x, y_dmg_ghost - vp->pos.y + h_dmg_ghost - 1, INVERT(ghost_color));
                                                        }
                                                }

                                                if (x_bnd_ghost == x_dmg_ghost) {
                                                        for (sysarg_t y = y_dmg_ghost - vp->pos.y;
                                                            y < y_dmg_ghost - vp->pos.y + h_dmg_ghost; ++y) {
                                                                ghost_color = surface_get_pixel(vp->surface,
                                                                    x_dmg_ghost - vp->pos.x, y);
                                                                surface_put_pixel(vp->surface,
                                                                    x_dmg_ghost - vp->pos.x, y, INVERT(ghost_color));
                                                        }
                                                }

                                                if (x_bnd_ghost + w_bnd_ghost == x_dmg_ghost + w_dmg_ghost) {
                                                        for (sysarg_t y = y_dmg_ghost - vp->pos.y;
                                                            y < y_dmg_ghost - vp->pos.y + h_dmg_ghost; ++y) {
                                                                ghost_color = surface_get_pixel(vp->surface,
                                                                    x_dmg_ghost - vp->pos.x + w_dmg_ghost - 1, y);
                                                                surface_put_pixel(vp->surface,
                                                                    x_dmg_ghost - vp->pos.x + w_dmg_ghost - 1, y, INVERT(ghost_color));
                                                        }
                                                }
                                        }

                                }
                        }

                        list_foreach(pointer_list, link, pointer_t, ptr) {

                                /*
                                 * Determine what part of the pointer intersects with the
                                 * updated area of the current viewport.
                                 */
                                sysarg_t x_dmg_ptr, y_dmg_ptr, w_dmg_ptr, h_dmg_ptr;
                                surface_t *sf_ptr = ptr->cursor.states[ptr->state];
                                surface_get_resolution(sf_ptr, &w_dmg_ptr, &h_dmg_ptr);
                                bool isec_ptr = rectangle_intersect(
                                    x_dmg_vp, y_dmg_vp, w_dmg_vp, h_dmg_vp,
                                    ptr->pos.x, ptr->pos.y, w_dmg_ptr, h_dmg_ptr,
                                    &x_dmg_ptr, &y_dmg_ptr, &w_dmg_ptr, &h_dmg_ptr);

                                if (isec_ptr) {
                                        /*
                                         * Pointer is currently painted directly by copying pixels.
                                         * However, it is possible to draw the pointer similarly
                                         * as window by using drawctx_transfer. It would allow
                                         * more sophisticated control over drawing, but would also
                                         * cost more regarding the performance.
                                         */

                                        sysarg_t x_vp = x_dmg_ptr - vp->pos.x;
                                        sysarg_t y_vp = y_dmg_ptr - vp->pos.y;
                                        sysarg_t x_ptr = x_dmg_ptr - ptr->pos.x;
                                        sysarg_t y_ptr = y_dmg_ptr - ptr->pos.y;

                                        for (sysarg_t y = 0; y < h_dmg_ptr; ++y) {
                                                pixel_t *src = pixelmap_pixel_at(
                                                    surface_pixmap_access(sf_ptr), x_ptr, y_ptr + y);
                                                pixel_t *dst = pixelmap_pixel_at(
                                                    surface_pixmap_access(vp->surface), x_vp, y_vp + y);
                                                sysarg_t count = w_dmg_ptr;
                                                while (count-- != 0) {
                                                        *dst = (*src & 0xff000000) ? *src : *dst;
                                                        ++dst;
                                                        ++src;
                                                }
                                        }
                                        surface_add_damaged_region(vp->surface, x_vp, y_vp, w_dmg_ptr, h_dmg_ptr);
                                }

                        }
                }
        }

        fibril_mutex_unlock(&pointer_list_mtx);
        fibril_mutex_unlock(&window_list_mtx);

        /* Notify visualizers about updated regions. */
        if (active) {
                list_foreach(viewport_list, link, viewport_t, vp) {
                        sysarg_t x_dmg_vp, y_dmg_vp, w_dmg_vp, h_dmg_vp;
                        surface_get_damaged_region(vp->surface, &x_dmg_vp, &y_dmg_vp, &w_dmg_vp, &h_dmg_vp);
                        surface_reset_damaged_region(vp->surface);
                        visualizer_update_damaged_region(vp->sess,
                            x_dmg_vp, y_dmg_vp, w_dmg_vp, h_dmg_vp, 0, 0);
                }
        }

        fibril_mutex_unlock(&viewport_list_mtx);
}

static void comp_window_get_event(window_t *win, ipc_call_t *icall)
{
        window_event_t *event = (window_event_t *) prodcons_consume(&win->queue);

        ipc_call_t call;
        size_t len;

        if (!async_data_read_receive(&call, &len)) {
                async_answer_0(icall, EINVAL);
                free(event);
                return;
        }

        errno_t rc = async_data_read_finalize(&call, event, len);
        if (rc != EOK) {
                async_answer_0(icall, ENOMEM);
                free(event);
                return;
        }

        async_answer_0(icall, EOK);
        free(event);
}

static void comp_window_damage(window_t *win, ipc_call_t *icall)
{
        double x = ipc_get_arg1(icall);
        double y = ipc_get_arg2(icall);
        double width = ipc_get_arg3(icall);
        double height = ipc_get_arg4(icall);

        if ((width == 0) || (height == 0)) {
                comp_damage(0, 0, UINT32_MAX, UINT32_MAX);
        } else {
                fibril_mutex_lock(&window_list_mtx);
                sysarg_t x_dmg_glob, y_dmg_glob, w_dmg_glob, h_dmg_glob;
                comp_coord_bounding_rect(x - 1, y - 1, width + 2, height + 2,
                    win->transform, &x_dmg_glob, &y_dmg_glob, &w_dmg_glob, &h_dmg_glob);
                fibril_mutex_unlock(&window_list_mtx);
                comp_damage(x_dmg_glob, y_dmg_glob, w_dmg_glob, h_dmg_glob);
        }

        async_answer_0(icall, EOK);
}

static void comp_window_grab(window_t *win, ipc_call_t *icall)
{
        sysarg_t pos_id = ipc_get_arg1(icall);
        sysarg_t grab_flags = ipc_get_arg2(icall);

        /*
         * Filter out resize grab flags if the window
         * is not resizeable.
         */
        if ((win->flags & WINDOW_RESIZEABLE) != WINDOW_RESIZEABLE)
                grab_flags &= ~(GF_RESIZE_X | GF_RESIZE_Y);

        fibril_mutex_lock(&pointer_list_mtx);
        list_foreach(pointer_list, link, pointer_t, pointer) {
                if (pointer->id == pos_id) {
                        pointer->grab_flags = pointer->pressed ? grab_flags : GF_EMPTY;
                        // TODO change pointer->state according to grab_flags
                        break;
                }
        }
        fibril_mutex_unlock(&pointer_list_mtx);

        if ((grab_flags & GF_RESIZE_X) || (grab_flags & GF_RESIZE_Y)) {
                scale_back_x = 1;
                scale_back_y = 1;
        }

        async_answer_0(icall, EOK);
}

static void comp_recalc_transform(window_t *win)
{
        transform_t translate;
        transform_identity(&translate);
        transform_translate(&translate, win->dx, win->dy);

        transform_t scale;
        transform_identity(&scale);
        if ((win->fx != 1) || (win->fy != 1))
                transform_scale(&scale, win->fx, win->fy);

        transform_t rotate;
        transform_identity(&rotate);
        if (win->angle != 0)
                transform_rotate(&rotate, win->angle);

        transform_t transform;
        transform_t temp;
        transform_identity(&transform);
        temp = transform;
        transform_product(&transform, &temp, &translate);
        temp = transform;
        transform_product(&transform, &temp, &rotate);
        temp = transform;
        transform_product(&transform, &temp, &scale);

        win->transform = transform;
}

static void comp_window_resize(window_t *win, ipc_call_t *icall)
{
        ipc_call_t call;
        size_t size;
        unsigned int flags;

        /* Start sharing resized window with client. */
        if (!async_share_out_receive(&call, &size, &flags)) {
                async_answer_0(icall, EINVAL);
                return;
        }

        void *new_cell_storage;
        errno_t rc = async_share_out_finalize(&call, &new_cell_storage);
        if ((rc != EOK) || (new_cell_storage == AS_MAP_FAILED)) {
                async_answer_0(icall, ENOMEM);
                return;
        }

        /* Create new surface for the resized window. */
        surface_t *new_surface = surface_create(ipc_get_arg3(icall),
            ipc_get_arg4(icall), new_cell_storage, SURFACE_FLAG_SHARED);
        if (!new_surface) {
                as_area_destroy(new_cell_storage);
                async_answer_0(icall, ENOMEM);
                return;
        }

        sysarg_t offset_x = ipc_get_arg1(icall);
        sysarg_t offset_y = ipc_get_arg2(icall);
        window_placement_flags_t placement_flags =
            (window_placement_flags_t) ipc_get_arg5(icall);

        comp_update_viewport_bound_rect();

        /* Switch new surface with old surface and calculate damage. */
        fibril_mutex_lock(&window_list_mtx);

        sysarg_t old_width = 0;
        sysarg_t old_height = 0;

        if (win->surface) {
                surface_get_resolution(win->surface, &old_width, &old_height);
                surface_destroy(win->surface);
        }

        win->surface = new_surface;

        sysarg_t new_width = 0;
        sysarg_t new_height = 0;
        surface_get_resolution(win->surface, &new_width, &new_height);

        if (placement_flags & WINDOW_PLACEMENT_CENTER_X)
                win->dx = viewport_bound_rect.x + viewport_bound_rect.w / 2 -
                    new_width / 2;

        if (placement_flags & WINDOW_PLACEMENT_CENTER_Y)
                win->dy = viewport_bound_rect.y + viewport_bound_rect.h / 2 -
                    new_height / 2;

        if (placement_flags & WINDOW_PLACEMENT_LEFT)
                win->dx = viewport_bound_rect.x;

        if (placement_flags & WINDOW_PLACEMENT_TOP)
                win->dy = viewport_bound_rect.y;

        if (placement_flags & WINDOW_PLACEMENT_RIGHT)
                win->dx = viewport_bound_rect.x + viewport_bound_rect.w -
                    new_width;

        if (placement_flags & WINDOW_PLACEMENT_BOTTOM)
                win->dy = viewport_bound_rect.y + viewport_bound_rect.h -
                    new_height;

        if (placement_flags & WINDOW_PLACEMENT_ABSOLUTE_X)
                win->dx = coord_origin + offset_x;

        if (placement_flags & WINDOW_PLACEMENT_ABSOLUTE_Y)
                win->dy = coord_origin + offset_y;

        /* Transform the window and calculate damage. */
        sysarg_t x1;
        sysarg_t y1;
        sysarg_t width1;
        sysarg_t height1;

        comp_coord_bounding_rect(0, 0, old_width, old_height, win->transform,
            &x1, &y1, &width1, &height1);

        comp_recalc_transform(win);

        sysarg_t x2;
        sysarg_t y2;
        sysarg_t width2;
        sysarg_t height2;

        comp_coord_bounding_rect(0, 0, new_width, new_height, win->transform,
            &x2, &y2, &width2, &height2);

        sysarg_t x;
        sysarg_t y;
        sysarg_t width;
        sysarg_t height;

        rectangle_union(x1, y1, width1, height1, x2, y2, width2, height2,
            &x, &y, &width, &height);

        fibril_mutex_unlock(&window_list_mtx);

        comp_damage(x, y, width, height);

        async_answer_0(icall, EOK);
}

static void comp_post_event_win(window_event_t *event, window_t *target)
{
        fibril_mutex_lock(&window_list_mtx);

        list_foreach(window_list, link, window_t, window) {
                if (window == target) {
                        prodcons_produce(&window->queue, &event->link);
                        fibril_mutex_unlock(&window_list_mtx);
                        return;
                }
        }

        fibril_mutex_unlock(&window_list_mtx);
        free(event);
}

static void comp_post_event_top(window_event_t *event)
{
        fibril_mutex_lock(&window_list_mtx);

        window_t *win = (window_t *) list_first(&window_list);
        if (win)
                prodcons_produce(&win->queue, &event->link);
        else
                free(event);

        fibril_mutex_unlock(&window_list_mtx);
}

static void comp_window_close(window_t *win, ipc_call_t *icall)
{
        /* Stop managing the window. */
        fibril_mutex_lock(&window_list_mtx);
        list_remove(&win->link);
        window_t *win_focus = (window_t *) list_first(&window_list);
        window_event_t *event_focus = (window_event_t *) malloc(sizeof(window_event_t));
        if (event_focus) {
                link_initialize(&event_focus->link);
                event_focus->type = ET_WINDOW_FOCUS;
        }
        fibril_mutex_unlock(&window_list_mtx);

        if (event_focus && win_focus) {
                comp_post_event_win(event_focus, win_focus);
        }

        loc_service_unregister(win->in_dsid);
        loc_service_unregister(win->out_dsid);

        /*
         * In case the client was killed, input fibril of the window might be
         * still blocked on the condition within comp_window_get_event.
         */
        window_event_t *event_dummy = (window_event_t *) malloc(sizeof(window_event_t));
        if (event_dummy) {
                link_initialize(&event_dummy->link);
                prodcons_produce(&win->queue, &event_dummy->link);
        }

        /* Calculate damage. */
        sysarg_t x = 0;
        sysarg_t y = 0;
        sysarg_t width = 0;
        sysarg_t height = 0;
        if (win->surface) {
                surface_get_resolution(win->surface, &width, &height);
                comp_coord_bounding_rect(
                    0, 0, width, height, win->transform, &x, &y, &width, &height);
        }

        /* Down refcount for removing from the window list */
        window_destroy(win);

        comp_damage(x, y, width, height);
        async_answer_0(icall, EOK);
}

static void comp_window_close_request(window_t *win, ipc_call_t *icall)
{
        window_event_t *event = (window_event_t *) malloc(sizeof(window_event_t));
        if (event == NULL) {
                async_answer_0(icall, ENOMEM);
                return;
        }

        link_initialize(&event->link);
        event->type = ET_WINDOW_CLOSE;

        prodcons_produce(&win->queue, &event->link);
        async_answer_0(icall, EOK);
}

static void client_connection(ipc_call_t *icall, void *arg)
{
        ipc_call_t call;
        service_id_t service_id = (service_id_t) ipc_get_arg2(icall);

        /* Allocate resources for new window and register it to the location service. */
        if (service_id == winreg_id) {
                async_accept_0(icall);

                async_get_call(&call);
                if (ipc_get_imethod(&call) == WINDOW_REGISTER) {
                        fibril_mutex_lock(&window_list_mtx);

                        window_t *win = window_create();
                        if (!win) {
                                async_answer_0(&call, EHANGUP);
                                fibril_mutex_unlock(&window_list_mtx);
                                return;
                        }

                        win->flags = ipc_get_arg1(&call);

                        char name_in[LOC_NAME_MAXLEN + 1];
                        snprintf(name_in, LOC_NAME_MAXLEN, "%s%s/win%zuin", NAMESPACE,
                            server_name, window_id);

                        char name_out[LOC_NAME_MAXLEN + 1];
                        snprintf(name_out, LOC_NAME_MAXLEN, "%s%s/win%zuout", NAMESPACE,
                            server_name, window_id);

                        ++window_id;

                        if (loc_service_register(name_in, &win->in_dsid) != EOK) {
                                window_destroy(win);
                                async_answer_0(&call, EHANGUP);
                                fibril_mutex_unlock(&window_list_mtx);
                                return;
                        }

                        if (loc_service_register(name_out, &win->out_dsid) != EOK) {
                                loc_service_unregister(win->in_dsid);
                                window_destroy(win);
                                async_answer_0(&call, EHANGUP);
                                fibril_mutex_unlock(&window_list_mtx);
                                return;
                        }

                        window_t *win_unfocus = (window_t *) list_first(&window_list);
                        list_prepend(&win->link, &window_list);

                        window_event_t *event_unfocus = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event_unfocus) {
                                link_initialize(&event_unfocus->link);
                                event_unfocus->type = ET_WINDOW_UNFOCUS;
                        }

                        async_answer_2(&call, EOK, win->in_dsid, win->out_dsid);
                        fibril_mutex_unlock(&window_list_mtx);

                        if (event_unfocus && win_unfocus) {
                                comp_post_event_win(event_unfocus, win_unfocus);
                        }

                        async_get_call(&call);
                }
                async_answer_0(&call, EHANGUP);
                return;
        }

        /* Match the client with pre-allocated window. */
        window_t *win = NULL;
        fibril_mutex_lock(&window_list_mtx);
        list_foreach(window_list, link, window_t, cur) {
                if (cur->in_dsid == service_id || cur->out_dsid == service_id) {
                        win = cur;
                        break;
                }
        }

        if (win)
                refcount_up(&win->ref_cnt);

        fibril_mutex_unlock(&window_list_mtx);

        if (win) {
                async_accept_0(icall);
        } else {
                async_answer_0(icall, EINVAL);
                return;
        }

        /* Each client establishes two separate connections. */
        if (win->in_dsid == service_id) {
                while (true) {
                        async_get_call(&call);

                        if (!ipc_get_imethod(&call)) {
                                async_answer_0(&call, EOK);
                                window_destroy(win);
                                return;
                        }

                        switch (ipc_get_imethod(&call)) {
                        case WINDOW_GET_EVENT:
                                comp_window_get_event(win, &call);
                                break;
                        default:
                                async_answer_0(&call, EINVAL);
                        }
                }
        } else if (win->out_dsid == service_id) {
                while (true) {
                        async_get_call(&call);

                        if (!ipc_get_imethod(&call)) {
                                comp_window_close(win, &call);
                                window_destroy(win);
                                return;
                        }

                        switch (ipc_get_imethod(&call)) {
                        case WINDOW_DAMAGE:
                                comp_window_damage(win, &call);
                                break;
                        case WINDOW_GRAB:
                                comp_window_grab(win, &call);
                                break;
                        case WINDOW_RESIZE:
                                comp_window_resize(win, &call);
                                break;
                        case WINDOW_CLOSE:
                                /*
                                 * Postpone the closing until the phone is hung up to cover
                                 * the case when the client is killed abruptly.
                                 */
                                async_answer_0(&call, EOK);
                                break;
                        case WINDOW_CLOSE_REQUEST:
                                comp_window_close_request(win, &call);
                                break;
                        default:
                                async_answer_0(&call, EINVAL);
                        }
                }
        }
}

static void comp_mode_change(viewport_t *vp, ipc_call_t *icall)
{
        sysarg_t mode_idx = ipc_get_arg2(icall);
        fibril_mutex_lock(&viewport_list_mtx);

        /* Retrieve the mode that shall be set. */
        vslmode_t new_mode;
        errno_t rc = visualizer_get_mode(vp->sess, &new_mode, mode_idx);
        if (rc != EOK) {
                fibril_mutex_unlock(&viewport_list_mtx);
                async_answer_0(icall, EINVAL);
                return;
        }

        /* Create surface with respect to the retrieved mode. */
        surface_t *new_surface = surface_create(new_mode.screen_width,
            new_mode.screen_height, NULL, SURFACE_FLAG_SHARED);
        if (!new_surface) {
                fibril_mutex_unlock(&viewport_list_mtx);
                async_answer_0(icall, ENOMEM);
                return;
        }

        /* Try to set the mode and share out the surface. */
        rc = visualizer_set_mode(vp->sess,
            new_mode.index, new_mode.version, surface_direct_access(new_surface));
        if (rc != EOK) {
                surface_destroy(new_surface);
                fibril_mutex_unlock(&viewport_list_mtx);
                async_answer_0(icall, rc);
                return;
        }

        /* Destroy old surface and update viewport. */
        surface_destroy(vp->surface);
        vp->mode = new_mode;
        vp->surface = new_surface;

        fibril_mutex_unlock(&viewport_list_mtx);
        async_answer_0(icall, EOK);

        comp_restrict_pointers();
        comp_damage(0, 0, UINT32_MAX, UINT32_MAX);
}

static void viewport_destroy(viewport_t *vp)
{
        if (vp) {
                visualizer_yield(vp->sess);
                surface_destroy(vp->surface);
                async_hangup(vp->sess);
                free(vp);
        }
}

#if 0
static void comp_shutdown(void)
{
        loc_service_unregister(winreg_id);
        input_disconnect();

        /* Close all clients and their windows. */
        fibril_mutex_lock(&window_list_mtx);
        list_foreach(window_list, link, window_t, win) {
                window_event_t *event = (window_event_t *) malloc(sizeof(window_event_t));
                if (event) {
                        link_initialize(&event->link);
                        event->type = WINDOW_CLOSE;
                        prodcons_produce(&win->queue, &event->link);
                }
        }
        fibril_mutex_unlock(&window_list_mtx);

        async_answer_0(icall, EOK);

        /* All fibrils of the compositor will terminate soon. */
}
#endif

static void comp_visualizer_disconnect(viewport_t *vp, ipc_call_t *icall)
{
        /* Release viewport resources. */
        fibril_mutex_lock(&viewport_list_mtx);

        list_remove(&vp->link);
        viewport_destroy(vp);

        fibril_mutex_unlock(&viewport_list_mtx);

        async_answer_0(icall, EOK);

        comp_restrict_pointers();
        comp_damage(0, 0, UINT32_MAX, UINT32_MAX);
}

static void vsl_notifications(ipc_call_t *icall, void *arg)
{
        viewport_t *vp = NULL;
        fibril_mutex_lock(&viewport_list_mtx);
        list_foreach(viewport_list, link, viewport_t, cur) {
                if (cur->dsid == (service_id_t) ipc_get_arg1(icall)) {
                        vp = cur;
                        break;
                }
        }
        fibril_mutex_unlock(&viewport_list_mtx);

        if (!vp)
                return;

        /* Ignore parameters, the connection is already opened. */
        while (true) {
                ipc_call_t call;
                async_get_call(&call);

                if (!ipc_get_imethod(&call)) {
                        async_hangup(vp->sess);
                        return;
                }

                switch (ipc_get_imethod(&call)) {
                case VISUALIZER_MODE_CHANGE:
                        comp_mode_change(vp, &call);
                        break;
                case VISUALIZER_DISCONNECT:
                        comp_visualizer_disconnect(vp, &call);
                        return;
                default:
                        async_answer_0(&call, EINVAL);
                }
        }
}

static async_sess_t *vsl_connect(service_id_t sid, const char *svc)
{
        errno_t rc;
        async_sess_t *sess;

        sess = loc_service_connect(sid, INTERFACE_DDF, 0);
        if (sess == NULL) {
                printf("%s: Unable to connect to visualizer %s\n", NAME, svc);
                return NULL;
        }

        async_exch_t *exch = async_exchange_begin(sess);

        port_id_t port;
        rc = async_create_callback_port(exch, INTERFACE_VISUALIZER_CB, 0, 0,
            vsl_notifications, NULL, &port);

        async_exchange_end(exch);

        if (rc != EOK) {
                async_hangup(sess);
                printf("%s: Unable to create callback connection to service %s (%s)\n",
                    NAME, svc, str_error(rc));
                return NULL;
        }

        return sess;
}

static viewport_t *viewport_create(service_id_t sid)
{
        errno_t rc;
        char *vsl_name = NULL;
        viewport_t *vp = NULL;
        bool claimed = false;

        rc = loc_service_get_name(sid, &vsl_name);
        if (rc != EOK)
                goto error;

        vp = (viewport_t *) calloc(1, sizeof(viewport_t));
        if (!vp)
                goto error;

        link_initialize(&vp->link);
        vp->pos.x = coord_origin;
        vp->pos.y = coord_origin;

        /* Establish output bidirectional connection. */
        vp->dsid = sid;
        vp->sess = vsl_connect(sid, vsl_name);
        if (vp->sess == NULL)
                goto error;

        /* Claim the given visualizer. */
        rc = visualizer_claim(vp->sess, 0);
        if (rc != EOK) {
                printf("%s: Unable to claim visualizer (%s)\n", NAME, str_error(rc));
                goto error;
        }

        claimed = true;

        /* Retrieve the default mode. */
        rc = visualizer_get_default_mode(vp->sess, &vp->mode);
        if (rc != EOK) {
                printf("%s: Unable to retrieve mode (%s)\n", NAME, str_error(rc));
                goto error;
        }

        /* Create surface with respect to the retrieved mode. */
        vp->surface = surface_create(vp->mode.screen_width, vp->mode.screen_height,
            NULL, SURFACE_FLAG_SHARED);
        if (vp->surface == NULL) {
                printf("%s: Unable to create surface (%s)\n", NAME, str_error(rc));
                goto error;
        }

        /* Try to set the mode and share out the surface. */
        rc = visualizer_set_mode(vp->sess,
            vp->mode.index, vp->mode.version, surface_direct_access(vp->surface));
        if (rc != EOK) {
                printf("%s: Unable to set mode (%s)\n", NAME, str_error(rc));
                goto error;
        }

        return vp;
error:
        if (claimed)
                visualizer_yield(vp->sess);

        if (vp->sess != NULL)
                async_hangup(vp->sess);

        free(vp);
        free(vsl_name);
        return NULL;
}

static void comp_window_animate(pointer_t *pointer, window_t *win,
    sysarg_t *dmg_x, sysarg_t *dmg_y, sysarg_t *dmg_width, sysarg_t *dmg_height)
{
        /* window_list_mtx locked by caller */
        /* pointer_list_mtx locked by caller */

        int dx = pointer->accum.x;
        int dy = pointer->accum.y;
        pointer->accum.x = 0;
        pointer->accum.y = 0;

        bool move = (pointer->grab_flags & GF_MOVE_X) || (pointer->grab_flags & GF_MOVE_Y);
        bool scale = (pointer->grab_flags & GF_SCALE_X) || (pointer->grab_flags & GF_SCALE_Y);
        bool resize = (pointer->grab_flags & GF_RESIZE_X) || (pointer->grab_flags & GF_RESIZE_Y);

        sysarg_t width, height;
        surface_get_resolution(win->surface, &width, &height);

        if (move) {
                double cx = 0;
                double cy = 0;

                if (pointer->grab_flags & GF_MOVE_X)
                        cx = 1;

                if (pointer->grab_flags & GF_MOVE_Y)
                        cy = 1;

                if (((scale) || (resize)) && (win->angle != 0)) {
                        transform_t rotate;
                        transform_identity(&rotate);

                        transform_rotate(&rotate, win->angle);
                        transform_apply_linear(&rotate, &cx, &cy);
                }

                cx = (cx < 0) ? (-1 * cx) : cx;
                cy = (cy < 0) ? (-1 * cy) : cy;

                win->dx += (cx * dx);
                win->dy += (cy * dy);
        }

        if ((scale) || (resize)) {
                double _dx = dx;
                double _dy = dy;
                if (win->angle != 0) {
                        transform_t unrotate;
                        transform_identity(&unrotate);
                        transform_rotate(&unrotate, -win->angle);
                        transform_apply_linear(&unrotate, &_dx, &_dy);
                }
                _dx = (pointer->grab_flags & GF_MOVE_X) ? -_dx : _dx;
                _dy = (pointer->grab_flags & GF_MOVE_Y) ? -_dy : _dy;

                if ((pointer->grab_flags & GF_SCALE_X) || (pointer->grab_flags & GF_RESIZE_X)) {
                        double fx = 1.0 + (_dx / ((width - 1) * win->fx));
                        if (fx > 0) {
#if ANIMATE_WINDOW_TRANSFORMS == 0
                                if (scale)
                                        win->fx *= fx;
#endif
#if ANIMATE_WINDOW_TRANSFORMS == 1
                                win->fx *= fx;
#endif
                                scale_back_x *= fx;
                        }
                }

                if ((pointer->grab_flags & GF_SCALE_Y) || (pointer->grab_flags & GF_RESIZE_Y)) {
                        double fy = 1.0 + (_dy / ((height - 1) * win->fy));
                        if (fy > 0) {
#if ANIMATE_WINDOW_TRANSFORMS == 0
                                if (scale)
                                        win->fy *= fy;
#endif
#if ANIMATE_WINDOW_TRANSFORMS == 1
                                win->fy *= fy;
#endif
                                scale_back_y *= fy;
                        }
                }
        }

        sysarg_t x1, y1, width1, height1;
        sysarg_t x2, y2, width2, height2;
        comp_coord_bounding_rect(0, 0, width, height, win->transform,
            &x1, &y1, &width1, &height1);
        comp_recalc_transform(win);
        comp_coord_bounding_rect(0, 0, width, height, win->transform,
            &x2, &y2, &width2, &height2);
        rectangle_union(x1, y1, width1, height1, x2, y2, width2, height2,
            dmg_x, dmg_y, dmg_width, dmg_height);
}

#if ANIMATE_WINDOW_TRANSFORMS == 0
static void comp_ghost_animate(pointer_t *pointer,
    desktop_rect_t *rect1, desktop_rect_t *rect2, desktop_rect_t *rect3, desktop_rect_t *rect4)
{
        /* window_list_mtx locked by caller */
        /* pointer_list_mtx locked by caller */

        int dx = pointer->accum_ghost.x;
        int dy = pointer->accum_ghost.y;
        pointer->accum_ghost.x = 0;
        pointer->accum_ghost.y = 0;

        bool move = (pointer->grab_flags & GF_MOVE_X) || (pointer->grab_flags & GF_MOVE_Y);
        bool scale = (pointer->grab_flags & GF_SCALE_X) || (pointer->grab_flags & GF_SCALE_Y);
        bool resize = (pointer->grab_flags & GF_RESIZE_X) || (pointer->grab_flags & GF_RESIZE_Y);

        sysarg_t width, height;
        surface_get_resolution(pointer->ghost.surface, &width, &height);

        if (move) {
                double cx = 0;
                double cy = 0;
                if (pointer->grab_flags & GF_MOVE_X) {
                        cx = 1;
                }
                if (pointer->grab_flags & GF_MOVE_Y) {
                        cy = 1;
                }

                if (scale || resize) {
                        transform_t rotate;
                        transform_identity(&rotate);
                        transform_rotate(&rotate, pointer->ghost.angle);
                        transform_apply_linear(&rotate, &cx, &cy);
                }

                cx = (cx < 0) ? (-1 * cx) : cx;
                cy = (cy < 0) ? (-1 * cy) : cy;

                pointer->ghost.dx += (cx * dx);
                pointer->ghost.dy += (cy * dy);
        }

        if (scale || resize) {
                double _dx = dx;
                double _dy = dy;
                transform_t unrotate;
                transform_identity(&unrotate);
                transform_rotate(&unrotate, -pointer->ghost.angle);
                transform_apply_linear(&unrotate, &_dx, &_dy);
                _dx = (pointer->grab_flags & GF_MOVE_X) ? -_dx : _dx;
                _dy = (pointer->grab_flags & GF_MOVE_Y) ? -_dy : _dy;

                if ((pointer->grab_flags & GF_SCALE_X) || (pointer->grab_flags & GF_RESIZE_X)) {
                        double fx = 1.0 + (_dx / ((width - 1) * pointer->ghost.fx));
                        pointer->ghost.fx *= fx;
                }

                if ((pointer->grab_flags & GF_SCALE_Y) || (pointer->grab_flags & GF_RESIZE_Y)) {
                        double fy = 1.0 + (_dy / ((height - 1) * pointer->ghost.fy));
                        pointer->ghost.fy *= fy;
                }
        }

        sysarg_t x1, y1, width1, height1;
        sysarg_t x2, y2, width2, height2;
        comp_coord_bounding_rect(0, 0, width, height, pointer->ghost.transform,
            &x1, &y1, &width1, &height1);
        comp_recalc_transform(&pointer->ghost);
        comp_coord_bounding_rect(0, 0, width, height, pointer->ghost.transform,
            &x2, &y2, &width2, &height2);

        sysarg_t x_u, y_u, w_u, h_u;
        rectangle_union(x1, y1, width1, height1, x2, y2, width2, height2,
            &x_u, &y_u, &w_u, &h_u);

        sysarg_t x_i, y_i, w_i, h_i;
        rectangle_intersect(x1, y1, width1, height1, x2, y2, width2, height2,
            &x_i, &y_i, &w_i, &h_i);

        if (w_i == 0 || h_i == 0) {
                rect1->x = x_u;
                rect2->x = 0;
                rect3->x = 0;
                rect4->x = 0;

                rect1->y = y_u;
                rect2->y = 0;
                rect3->y = 0;
                rect4->y = 0;

                rect1->w = w_u;
                rect2->w = 0;
                rect3->w = 0;
                rect4->w = 0;

                rect1->h = h_u;
                rect2->h = 0;
                rect3->h = 0;
                rect4->h = 0;
        } else {
                rect1->x = x_u;
                rect1->y = y_u;
                rect1->w = x_i - x_u + 1;
                rect1->h = h_u;

                rect2->x = x_u;
                rect2->y = y_u;
                rect2->w = w_u;
                rect2->h = y_i - y_u + 1;

                rect3->x = x_i + w_i - 1;
                rect3->y = y_u;
                rect3->w = w_u - w_i - x_i + x_u + 1;
                rect3->h = h_u;

                rect4->x = x_u;
                rect4->y = y_i + h_i - 1;
                rect4->w = w_u;
                rect4->h = h_u - h_i - y_i + y_u + 1;
        }
}
#endif

static errno_t comp_abs_move(input_t *input, unsigned x, unsigned y,
    unsigned max_x, unsigned max_y)
{
        /* XXX TODO Use absolute coordinates directly */

        pointer_t *pointer = input_pointer(input);

        sysarg_t width, height;

        fibril_mutex_lock(&viewport_list_mtx);
        if (list_empty(&viewport_list)) {
                printf("No viewport found\n");
                fibril_mutex_unlock(&viewport_list_mtx);
                return EOK; /* XXX */
        }
        link_t *link = list_first(&viewport_list);
        viewport_t *vp = list_get_instance(link, viewport_t, link);
        surface_get_resolution(vp->surface, &width, &height);
        desktop_point_t vp_pos = vp->pos;
        fibril_mutex_unlock(&viewport_list_mtx);

        desktop_point_t pos_in_viewport;
        pos_in_viewport.x = x * width / max_x;
        pos_in_viewport.y = y * height / max_y;

        /* Calculate offset from pointer */
        fibril_mutex_lock(&pointer_list_mtx);
        desktop_vector_t delta;
        delta.x = (vp_pos.x + pos_in_viewport.x) - pointer->pos.x;
        delta.y = (vp_pos.y + pos_in_viewport.y) - pointer->pos.y;
        fibril_mutex_unlock(&pointer_list_mtx);

        return comp_mouse_move(input, delta.x, delta.y);
}

static errno_t comp_mouse_move(input_t *input, int dx, int dy)
{
        pointer_t *pointer = input_pointer(input);

        comp_update_viewport_bound_rect();

        /* Update pointer position. */
        fibril_mutex_lock(&pointer_list_mtx);

        desktop_point_t old_pos = pointer->pos;

        sysarg_t cursor_width;
        sysarg_t cursor_height;
        surface_get_resolution(pointer->cursor.states[pointer->state],
            &cursor_width, &cursor_height);

        if (pointer->pos.x + dx < viewport_bound_rect.x)
                dx = -1 * (pointer->pos.x - viewport_bound_rect.x);

        if (pointer->pos.y + dy < viewport_bound_rect.y)
                dy = -1 * (pointer->pos.y - viewport_bound_rect.y);

        if (pointer->pos.x + dx > viewport_bound_rect.x + viewport_bound_rect.w)
                dx = (viewport_bound_rect.x + viewport_bound_rect.w - pointer->pos.x);

        if (pointer->pos.y + dy > viewport_bound_rect.y + viewport_bound_rect.h)
                dy = (viewport_bound_rect.y + viewport_bound_rect.h - pointer->pos.y);

        pointer->pos.x += dx;
        pointer->pos.y += dy;
        fibril_mutex_unlock(&pointer_list_mtx);
        comp_damage(old_pos.x, old_pos.y, cursor_width, cursor_height);
        comp_damage(old_pos.x + dx, old_pos.y + dy, cursor_width, cursor_height);

        fibril_mutex_lock(&window_list_mtx);
        fibril_mutex_lock(&pointer_list_mtx);
        window_t *top = (window_t *) list_first(&window_list);
        if (top && top->surface) {

                if (pointer->grab_flags == GF_EMPTY) {
                        /* Notify top-level window about move event. */
                        bool within_client = false;
                        sysarg_t point_x, point_y;
                        sysarg_t width, height;
                        surface_get_resolution(top->surface, &width, &height);
                        within_client = comp_coord_to_client(pointer->pos.x, pointer->pos.y,
                            top->transform, width, height, &point_x, &point_y);

                        window_event_t *event = NULL;
                        if (within_client) {
                                event = (window_event_t *) malloc(sizeof(window_event_t));
                                if (event) {
                                        link_initialize(&event->link);
                                        event->type = ET_POSITION_EVENT;
                                        event->data.pos.pos_id = pointer->id;
                                        event->data.pos.type = POS_UPDATE;
                                        event->data.pos.btn_num = pointer->btn_num;
                                        event->data.pos.hpos = point_x;
                                        event->data.pos.vpos = point_y;
                                }
                        }

                        fibril_mutex_unlock(&pointer_list_mtx);
                        fibril_mutex_unlock(&window_list_mtx);

                        if (event) {
                                comp_post_event_top(event);
                        }

                } else {
                        /* Pointer is grabbed by top-level window action. */
                        pointer->accum.x += dx;
                        pointer->accum.y += dy;
                        pointer->accum_ghost.x += dx;
                        pointer->accum_ghost.y += dy;
#if ANIMATE_WINDOW_TRANSFORMS == 0
                        if (pointer->ghost.surface == NULL) {
                                pointer->ghost.surface = top->surface;
                                pointer->ghost.dx = top->dx;
                                pointer->ghost.dy = top->dy;
                                pointer->ghost.fx = top->fx;
                                pointer->ghost.fy = top->fy;
                                pointer->ghost.angle = top->angle;
                                pointer->ghost.transform = top->transform;
                        }
                        desktop_rect_t dmg_rect1, dmg_rect2, dmg_rect3, dmg_rect4;
                        comp_ghost_animate(pointer, &dmg_rect1, &dmg_rect2, &dmg_rect3, &dmg_rect4);
#endif
#if ANIMATE_WINDOW_TRANSFORMS == 1
                        sysarg_t x, y, width, height;
                        comp_window_animate(pointer, top, &x, &y, &width, &height);
#endif
                        fibril_mutex_unlock(&pointer_list_mtx);
                        fibril_mutex_unlock(&window_list_mtx);
#if ANIMATE_WINDOW_TRANSFORMS == 0
                        comp_damage(dmg_rect1.x, dmg_rect1.y, dmg_rect1.w, dmg_rect1.h);
                        comp_damage(dmg_rect2.x, dmg_rect2.y, dmg_rect2.w, dmg_rect2.h);
                        comp_damage(dmg_rect3.x, dmg_rect3.y, dmg_rect3.w, dmg_rect3.h);
                        comp_damage(dmg_rect4.x, dmg_rect4.y, dmg_rect4.w, dmg_rect4.h);
#endif
#if ANIMATE_WINDOW_TRANSFORMS == 1
                        comp_damage(x, y, width, height);
#endif
                }
        } else {
                fibril_mutex_unlock(&pointer_list_mtx);
                fibril_mutex_unlock(&window_list_mtx);
        }

        return EOK;
}

static errno_t comp_mouse_button(input_t *input, int bnum, int bpress)
{
        pointer_t *pointer = input_pointer(input);

        fibril_mutex_lock(&window_list_mtx);
        fibril_mutex_lock(&pointer_list_mtx);
        window_t *win = NULL;
        sysarg_t point_x = 0;
        sysarg_t point_y = 0;
        sysarg_t width, height;
        bool within_client = false;

        /* Determine the window which the mouse click belongs to. */
        list_foreach(window_list, link, window_t, cw) {
                win = cw;
                if (win->surface) {
                        surface_get_resolution(win->surface, &width, &height);
                        within_client = comp_coord_to_client(pointer->pos.x, pointer->pos.y,
                            win->transform, width, height, &point_x, &point_y);
                }
                if (within_client) {
                        break;
                }
        }

        /* Check whether the window is top-level window. */
        window_t *top = (window_t *) list_first(&window_list);
        if (!win || !top) {
                fibril_mutex_unlock(&pointer_list_mtx);
                fibril_mutex_unlock(&window_list_mtx);
                return EOK;
        }

        window_event_t *event_top = NULL;
        window_event_t *event_unfocus = NULL;
        window_t *win_unfocus = NULL;
        sysarg_t dmg_x, dmg_y;
        sysarg_t dmg_width = 0;
        sysarg_t dmg_height = 0;

#if ANIMATE_WINDOW_TRANSFORMS == 0
        desktop_rect_t dmg_rect1, dmg_rect2, dmg_rect3, dmg_rect4;
#endif

        if (bpress && !pointer->pressed) {
                pointer->btn_pos = pointer->pos;
                pointer->btn_num = bnum;
                pointer->pressed = true;

                /* Bring the window to the foreground. */
                if ((win != top) && within_client) {
                        win_unfocus = (window_t *) list_first(&window_list);
                        list_remove(&win->link);
                        list_prepend(&win->link, &window_list);
                        event_unfocus = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event_unfocus) {
                                link_initialize(&event_unfocus->link);
                                event_unfocus->type = ET_WINDOW_UNFOCUS;
                        }
                        comp_coord_bounding_rect(0, 0, width, height, win->transform,
                            &dmg_x, &dmg_y, &dmg_width, &dmg_height);
                }

                /* Notify top-level window about mouse press. */
                if (within_client) {
                        event_top = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event_top) {
                                link_initialize(&event_top->link);
                                event_top->type = ET_POSITION_EVENT;
                                event_top->data.pos.pos_id = pointer->id;
                                event_top->data.pos.type = POS_PRESS;
                                event_top->data.pos.btn_num = bnum;
                                event_top->data.pos.hpos = point_x;
                                event_top->data.pos.vpos = point_y;
                        }
                        pointer->grab_flags = GF_EMPTY;
                }

        } else if (pointer->pressed && pointer->btn_num == (unsigned)bnum) {
                pointer->pressed = false;

#if ANIMATE_WINDOW_TRANSFORMS == 0
                sysarg_t pre_x = 0;
                sysarg_t pre_y = 0;
                sysarg_t pre_width = 0;
                sysarg_t pre_height = 0;

                if (pointer->grab_flags != GF_EMPTY) {
                        if (pointer->ghost.surface) {
                                comp_ghost_animate(pointer, &dmg_rect1, &dmg_rect2, &dmg_rect3, &dmg_rect4);
                                pointer->ghost.surface = NULL;
                        }
                        comp_window_animate(pointer, top, &pre_x, &pre_y, &pre_width, &pre_height);
                        dmg_x = pre_x;
                        dmg_y = pre_y;
                        dmg_width = pre_width;
                        dmg_height = pre_height;
                }
#endif

                if ((pointer->grab_flags & GF_RESIZE_X) || (pointer->grab_flags & GF_RESIZE_Y)) {

                        surface_get_resolution(top->surface, &width, &height);
#if ANIMATE_WINDOW_TRANSFORMS == 1
                        top->fx *= (1.0 / scale_back_x);
                        top->fy *= (1.0 / scale_back_y);
                        comp_recalc_transform(top);
#endif

                        /* Commit proper resize action. */
                        event_top = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event_top) {
                                link_initialize(&event_top->link);
                                event_top->type = ET_WINDOW_RESIZE;

                                event_top->data.resize.offset_x = 0;
                                event_top->data.resize.offset_y = 0;

                                int dx = (int) (((double) width) * (scale_back_x - 1.0));
                                int dy = (int) (((double) height) * (scale_back_y - 1.0));

                                if (pointer->grab_flags & GF_RESIZE_X)
                                        event_top->data.resize.width =
                                            ((((int) width) + dx) >= 0) ? (width + dx) : 0;
                                else
                                        event_top->data.resize.width = width;

                                if (pointer->grab_flags & GF_RESIZE_Y)
                                        event_top->data.resize.height =
                                            ((((int) height) + dy) >= 0) ? (height + dy) : 0;
                                else
                                        event_top->data.resize.height = height;

                                event_top->data.resize.placement_flags =
                                    WINDOW_PLACEMENT_ANY;
                        }

                        pointer->grab_flags = GF_EMPTY;

                } else if (within_client && (pointer->grab_flags == GF_EMPTY) && (top == win)) {

                        /* Notify top-level window about mouse release. */
                        event_top = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event_top) {
                                link_initialize(&event_top->link);
                                event_top->type = ET_POSITION_EVENT;
                                event_top->data.pos.pos_id = pointer->id;
                                event_top->data.pos.type = POS_RELEASE;
                                event_top->data.pos.btn_num = bnum;
                                event_top->data.pos.hpos = point_x;
                                event_top->data.pos.vpos = point_y;
                        }
                        pointer->grab_flags = GF_EMPTY;

                } else {
                        pointer->grab_flags = GF_EMPTY;
                }

        }

        fibril_mutex_unlock(&pointer_list_mtx);
        fibril_mutex_unlock(&window_list_mtx);

#if ANIMATE_WINDOW_TRANSFORMS == 0
        comp_damage(dmg_rect1.x, dmg_rect1.y, dmg_rect1.w, dmg_rect1.h);
        comp_damage(dmg_rect2.x, dmg_rect2.y, dmg_rect2.w, dmg_rect2.h);
        comp_damage(dmg_rect3.x, dmg_rect3.y, dmg_rect3.w, dmg_rect3.h);
        comp_damage(dmg_rect4.x, dmg_rect4.y, dmg_rect4.w, dmg_rect4.h);
#endif

        if (dmg_width > 0 && dmg_height > 0) {
                comp_damage(dmg_x, dmg_y, dmg_width, dmg_height);
        }

        if (event_unfocus && win_unfocus) {
                comp_post_event_win(event_unfocus, win_unfocus);
        }

        if (event_top) {
                comp_post_event_top(event_top);
        }

        return EOK;
}

static errno_t comp_active(input_t *input)
{
        active = true;
        comp_damage(0, 0, UINT32_MAX, UINT32_MAX);

        return EOK;
}

static errno_t comp_deactive(input_t *input)
{
        active = false;
        return EOK;
}

static errno_t comp_key_press(input_t *input, kbd_event_type_t type, keycode_t key,
    keymod_t mods, wchar_t c)
{
        bool win_transform = (mods & KM_ALT) &&
            (key == KC_W || key == KC_S || key == KC_A || key == KC_D ||
            key == KC_Q || key == KC_E || key == KC_R || key == KC_F);
        bool win_resize = (mods & KM_ALT) &&
            (key == KC_T || key == KC_G || key == KC_B || key == KC_N);
        bool win_opacity = (mods & KM_ALT) && (key == KC_C || key == KC_V);
        bool win_close = (mods & KM_ALT) && (key == KC_X);
        bool win_switch = (mods & KM_ALT) && (key == KC_TAB);
        bool viewport_move = (mods & KM_ALT) &&
            (key == KC_I || key == KC_K || key == KC_J || key == KC_L);
        bool viewport_change = (mods & KM_ALT) && (key == KC_O || key == KC_P);
        bool kconsole_switch = (key == KC_PAUSE) || (key == KC_BREAK);
        bool filter_switch = (mods & KM_ALT) && (key == KC_Y);

        bool key_filter = (type == KEY_RELEASE) && (win_transform || win_resize ||
            win_opacity || win_close || win_switch || viewport_move ||
            viewport_change || kconsole_switch || filter_switch);

        if (key_filter) {
                /* no-op */
        } else if (win_transform) {
                fibril_mutex_lock(&window_list_mtx);
                window_t *win = (window_t *) list_first(&window_list);
                if (win && win->surface) {
                        switch (key) {
                        case KC_W:
                                win->dy += -20;
                                break;
                        case KC_S:
                                win->dy += 20;
                                break;
                        case KC_A:
                                win->dx += -20;
                                break;
                        case KC_D:
                                win->dx += 20;
                                break;
                        case KC_Q:
                                win->angle += 0.1;
                                break;
                        case KC_E:
                                win->angle -= 0.1;
                                break;
                        case KC_R:
                                win->fx *= 0.95;
                                win->fy *= 0.95;
                                break;
                        case KC_F:
                                win->fx *= 1.05;
                                win->fy *= 1.05;
                                break;
                        default:
                                break;
                        }

                        /* Transform the window and calculate damage. */
                        sysarg_t x, y, width, height;
                        surface_get_resolution(win->surface, &width, &height);
                        sysarg_t x1, y1, width1, height1;
                        sysarg_t x2, y2, width2, height2;
                        comp_coord_bounding_rect(0, 0, width, height, win->transform,
                            &x1, &y1, &width1, &height1);
                        comp_recalc_transform(win);
                        comp_coord_bounding_rect(0, 0, width, height, win->transform,
                            &x2, &y2, &width2, &height2);
                        rectangle_union(x1, y1, width1, height1, x2, y2, width2, height2,
                            &x, &y, &width, &height);
                        fibril_mutex_unlock(&window_list_mtx);

                        comp_damage(x, y, width, height);
                } else {
                        fibril_mutex_unlock(&window_list_mtx);
                }
        } else if (win_resize) {
                fibril_mutex_lock(&window_list_mtx);
                window_t *win = (window_t *) list_first(&window_list);
                if ((win) && (win->surface) && (win->flags & WINDOW_RESIZEABLE)) {
                        window_event_t *event = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event == NULL) {
                                fibril_mutex_unlock(&window_list_mtx);
                                return ENOMEM;
                        }

                        sysarg_t width, height;
                        surface_get_resolution(win->surface, &width, &height);

                        link_initialize(&event->link);
                        event->type = ET_WINDOW_RESIZE;

                        event->data.resize.offset_x = 0;
                        event->data.resize.offset_y = 0;

                        switch (key) {
                        case KC_T:
                                event->data.resize.width = width;
                                event->data.resize.height = (height >= 20) ? height - 20 : 0;
                                break;
                        case KC_G:
                                event->data.resize.width = width;
                                event->data.resize.height = height + 20;
                                break;
                        case KC_B:
                                event->data.resize.width = (width >= 20) ? width - 20 : 0;
                                event->data.resize.height = height;
                                break;
                        case KC_N:
                                event->data.resize.width = width + 20;
                                event->data.resize.height = height;
                                break;
                        default:
                                event->data.resize.width = 0;
                                event->data.resize.height = 0;
                                break;
                        }

                        event->data.resize.placement_flags = WINDOW_PLACEMENT_ANY;

                        fibril_mutex_unlock(&window_list_mtx);
                        comp_post_event_top(event);
                } else {
                        fibril_mutex_unlock(&window_list_mtx);
                }
        } else if (win_opacity) {
                fibril_mutex_lock(&window_list_mtx);
                window_t *win = (window_t *) list_first(&window_list);
                if (win && win->surface) {
                        switch (key) {
                        case KC_C:
                                if (win->opacity > 0) {
                                        win->opacity -= 5;
                                }
                                break;
                        case KC_V:
                                if (win->opacity < 255) {
                                        win->opacity += 5;
                                }
                                break;
                        default:
                                break;
                        }

                        /* Calculate damage. */
                        sysarg_t x, y, width, height;
                        surface_get_resolution(win->surface, &width, &height);
                        comp_coord_bounding_rect(0, 0, width, height, win->transform,
                            &x, &y, &width, &height);
                        fibril_mutex_unlock(&window_list_mtx);

                        comp_damage(x, y, width, height);
                } else {
                        fibril_mutex_unlock(&window_list_mtx);
                }
        } else if (win_close) {
                window_event_t *event = (window_event_t *) malloc(sizeof(window_event_t));
                if (event == NULL)
                        return ENOMEM;

                link_initialize(&event->link);
                event->type = ET_WINDOW_CLOSE;

                comp_post_event_top(event);
        } else if (win_switch) {
                fibril_mutex_lock(&window_list_mtx);
                if (!list_empty(&window_list)) {
                        window_t *win1 = (window_t *) list_first(&window_list);
                        list_remove(&win1->link);
                        list_append(&win1->link, &window_list);
                        window_t *win2 = (window_t *) list_first(&window_list);

                        window_event_t *event1 = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event1) {
                                link_initialize(&event1->link);
                                event1->type = ET_WINDOW_UNFOCUS;
                        }

                        window_event_t *event2 = (window_event_t *) malloc(sizeof(window_event_t));
                        if (event2) {
                                link_initialize(&event2->link);
                                event2->type = ET_WINDOW_FOCUS;
                        }

                        sysarg_t x1 = 0;
                        sysarg_t y1 = 0;
                        sysarg_t width1 = 0;
                        sysarg_t height1 = 0;
                        if (win1->surface) {
                                sysarg_t width, height;
                                surface_get_resolution(win1->surface, &width, &height);
                                comp_coord_bounding_rect(0, 0, width, height, win1->transform,
                                    &x1, &y1, &width1, &height1);
                        }

                        sysarg_t x2 = 0;
                        sysarg_t y2 = 0;
                        sysarg_t width2 = 0;
                        sysarg_t height2 = 0;
                        if (win2->surface) {
                                sysarg_t width, height;
                                surface_get_resolution(win2->surface, &width, &height);
                                comp_coord_bounding_rect(0, 0, width, height, win2->transform,
                                    &x2, &y2, &width2, &height2);
                        }

                        sysarg_t x, y, width, height;
                        rectangle_union(x1, y1, width1, height1, x2, y2, width2, height2,
                            &x, &y, &width, &height);

                        fibril_mutex_unlock(&window_list_mtx);

                        if (event1 && win1) {
                                comp_post_event_win(event1, win1);
                        }

                        if (event2 && win2) {
                                comp_post_event_win(event2, win2);
                        }

                        comp_damage(x, y, width, height);
                } else {
                        fibril_mutex_unlock(&window_list_mtx);
                }
        } else if (viewport_move) {
                fibril_mutex_lock(&viewport_list_mtx);
                viewport_t *vp = (viewport_t *) list_first(&viewport_list);
                if (vp) {
                        switch (key) {
                        case KC_I:
                                vp->pos.x += 0;
                                vp->pos.y += -20;
                                break;
                        case KC_K:
                                vp->pos.x += 0;
                                vp->pos.y += 20;
                                break;
                        case KC_J:
                                vp->pos.x += -20;
                                vp->pos.y += 0;
                                break;
                        case KC_L:
                                vp->pos.x += 20;
                                vp->pos.y += 0;
                                break;
                        default:
                                vp->pos.x += 0;
                                vp->pos.y += 0;
                                break;
                        }

                        sysarg_t x = vp->pos.x;
                        sysarg_t y = vp->pos.y;
                        sysarg_t width, height;
                        surface_get_resolution(vp->surface, &width, &height);
                        fibril_mutex_unlock(&viewport_list_mtx);

                        comp_restrict_pointers();
                        comp_damage(x, y, width, height);
                } else {
                        fibril_mutex_unlock(&viewport_list_mtx);
                }
        } else if (viewport_change) {
                fibril_mutex_lock(&viewport_list_mtx);

                viewport_t *vp;
                switch (key) {
                case KC_O:
                        vp = (viewport_t *) list_first(&viewport_list);
                        if (vp) {
                                list_remove(&vp->link);
                                list_append(&vp->link, &viewport_list);
                        }
                        break;
                case KC_P:
                        vp = (viewport_t *) list_last(&viewport_list);
                        if (vp) {
                                list_remove(&vp->link);
                                list_prepend(&vp->link, &viewport_list);
                        }
                        break;
                default:
                        break;
                }

                fibril_mutex_unlock(&viewport_list_mtx);
        } else if (kconsole_switch) {
                if (console_kcon())
                        active = false;
        } else if (filter_switch) {
                filter_index++;
                if (filter_index > 1)
                        filter_index = 0;
                if (filter_index == 0) {
                        filter = filter_nearest;
                } else {
                        filter = filter_bilinear;
                }
                comp_damage(0, 0, UINT32_MAX, UINT32_MAX);
        } else {
                window_event_t *event = (window_event_t *) malloc(sizeof(window_event_t));
                if (event == NULL)
                        return ENOMEM;

                link_initialize(&event->link);
                event->type = ET_KEYBOARD_EVENT;
                event->data.kbd.type = type;
                event->data.kbd.key = key;
                event->data.kbd.mods = mods;
                event->data.kbd.c = c;

                comp_post_event_top(event);
        }

        return EOK;
}

static errno_t input_connect(const char *svc)
{
        async_sess_t *sess;
        service_id_t dsid;

        errno_t rc = loc_service_get_id(svc, &dsid, 0);
        if (rc != EOK) {
                printf("%s: Input service %s not found\n", NAME, svc);
                return rc;
        }

        sess = loc_service_connect(dsid, INTERFACE_INPUT, 0);
        if (sess == NULL) {
                printf("%s: Unable to connect to input service %s\n", NAME,
                    svc);
                return EIO;
        }

        fibril_mutex_lock(&pointer_list_mtx);
        pointer_t *pointer = pointer_create();
        if (pointer != NULL) {
                pointer->id = pointer_id++;
                list_append(&pointer->link, &pointer_list);
        }
        fibril_mutex_unlock(&pointer_list_mtx);

        if (pointer == NULL) {
                printf("%s: Cannot create pointer.\n", NAME);
                async_hangup(sess);
                return ENOMEM;
        }

        rc = input_open(sess, &input_ev_ops, pointer, &input);
        if (rc != EOK) {
                async_hangup(sess);
                printf("%s: Unable to communicate with service %s (%s)\n",
                    NAME, svc, str_error(rc));
                return rc;
        }

        return EOK;
}

static void input_disconnect(void)
{
        pointer_t *pointer = input->user;
        input_close(input);
        pointer_destroy(pointer);
}

static void discover_viewports(void)
{
        fibril_mutex_lock(&discovery_mtx);

        /* Create viewports and connect them to visualizers. */
        category_id_t cat_id;
        errno_t rc = loc_category_get_id("visualizer", &cat_id, IPC_FLAG_BLOCKING);
        if (rc != EOK)
                goto ret;

        service_id_t *svcs;
        size_t svcs_cnt = 0;
        rc = loc_category_get_svcs(cat_id, &svcs, &svcs_cnt);
        if (rc != EOK)
                goto ret;

        fibril_mutex_lock(&viewport_list_mtx);
        for (size_t i = 0; i < svcs_cnt; ++i) {
                bool exists = false;
                list_foreach(viewport_list, link, viewport_t, vp) {
                        if (vp->dsid == svcs[i]) {
                                exists = true;
                                break;
                        }
                }

                if (exists)
                        continue;

                viewport_t *vp = viewport_create(svcs[i]);
                if (vp != NULL)
                        list_append(&vp->link, &viewport_list);
        }
        fibril_mutex_unlock(&viewport_list_mtx);

        if (!list_empty(&viewport_list))
                input_activate(input);

ret:
        fibril_mutex_unlock(&discovery_mtx);
}

static void category_change_cb(void *arg)
{
        discover_viewports();
}

static errno_t compositor_srv_init(char *input_svc, char *name)
{
        /* Coordinates of the central pixel. */
        coord_origin = UINT32_MAX / 4;

        /* Color of the viewport background. Must be opaque. */
        bg_color = PIXEL(255, 69, 51, 103);

        /* Register compositor server. */
        async_set_fallback_port_handler(client_connection, NULL);

        errno_t rc = loc_server_register(NAME);
        if (rc != EOK) {
                printf("%s: Unable to register server (%s)\n", NAME, str_error(rc));
                return -1;
        }

        server_name = name;

        char svc[LOC_NAME_MAXLEN + 1];
        snprintf(svc, LOC_NAME_MAXLEN, "%s/%s", NAMESPACE, server_name);

        service_id_t service_id;
        rc = loc_service_register(svc, &service_id);
        if (rc != EOK) {
                printf("%s: Unable to register service %s\n", NAME, svc);
                return rc;
        }

        /* Prepare window registrator (entrypoint for clients). */
        char winreg[LOC_NAME_MAXLEN + 1];
        snprintf(winreg, LOC_NAME_MAXLEN, "%s%s/winreg", NAMESPACE, server_name);
        if (loc_service_register(winreg, &winreg_id) != EOK) {
                printf("%s: Unable to register service %s\n", NAME, winreg);
                return -1;
        }

        /* Establish input bidirectional connection. */
        rc = input_connect(input_svc);
        if (rc != EOK) {
                printf("%s: Failed to connect to input service.\n", NAME);
                return rc;
        }

        rc = loc_register_cat_change_cb(category_change_cb, NULL);
        if (rc != EOK) {
                printf("%s: Failed to register category change callback\n", NAME);
                input_disconnect();
                return rc;
        }

        discover_viewports();

        comp_restrict_pointers();
        comp_damage(0, 0, UINT32_MAX, UINT32_MAX);

        return EOK;
}

static void usage(char *name)
{
        printf("Usage: %s <input_dev> <server_name>\n", name);
}

int main(int argc, char *argv[])
{
        if (argc < 3) {
                usage(argv[0]);
                return 1;
        }

        printf("%s: HelenOS Compositor server\n", NAME);

        errno_t rc = compositor_srv_init(argv[1], argv[2]);
        if (rc != EOK)
                return rc;

        printf("%s: Accepting connections\n", NAME);
        task_retval(0);
        async_manager();

        /* Never reached */
        return 0;
}

/** @}
 */