path: root/xorg-server/hw/kdrive/ephyr/hostx.c

/*
 * Xephyr - A kdrive X server thats runs in a host X window.
 *          Authored by Matthew Allum <mallum@o-hand.com>
 * 
 * Copyright © 2004 Nokia 
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Nokia not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission. Nokia makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * NOKIA DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL NOKIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#ifdef HAVE_CONFIG_H
#include <kdrive-config.h>
#endif

#include "hostx.h"
#include "input.h"

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>             /* for memset */
#include <errno.h>
#include <time.h>

#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/time.h>

#include <X11/keysym.h>
#include <xcb/xcb.h>
#include <xcb/xproto.h>
#include <xcb/xcb_icccm.h>
#include <xcb/xcb_aux.h>
#include <xcb/shm.h>
#include <xcb/xcb_image.h>
#include <xcb/shape.h>
#include <xcb/xcb_keysyms.h>
#ifdef XF86DRI
#include <xcb/xf86dri.h>
#include <xcb/glx.h>
#endif /* XF86DRI */
#include "ephyrlog.h"
#include "ephyr.h"

struct EphyrHostXVars {
    char *server_dpy_name;
    xcb_connection_t *conn;
    int screen;
    xcb_visualtype_t *visual;
    Window winroot;
    xcb_gcontext_t  gc;
    int depth;
    Bool use_sw_cursor;
    Bool use_fullscreen;
    Bool have_shm;

    int n_screens;
    KdScreenInfo **screens;

    long damage_debug_msec;

    unsigned long cmap[256];
};

/* memset ( missing> ) instead of below  */
/*static EphyrHostXVars HostX = { "?", 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};*/
static EphyrHostXVars HostX;

static int HostXWantDamageDebug = 0;

extern EphyrKeySyms ephyrKeySyms;

extern int monitorResolution;

extern Bool EphyrWantResize;

char *ephyrResName = NULL;
int ephyrResNameFromCmd = 0;
char *ephyrTitle = NULL;

static void
 hostx_set_fullscreen_hint(void);

#define host_depth_matches_server(_vars) (HostX.depth == (_vars)->server_depth)

int
hostx_want_screen_size(KdScreenInfo *screen, int *width, int *height)
{
    EphyrScrPriv *scrpriv = screen->driver;

    if (scrpriv && (scrpriv->win_pre_existing != None ||
                    HostX.use_fullscreen == TRUE)) {
        *width = scrpriv->win_width;
        *height = scrpriv->win_height;
        return 1;
    }

    return 0;
}

void
hostx_add_screen(KdScreenInfo *screen, unsigned long win_id, int screen_num)
{
    EphyrScrPriv *scrpriv = screen->driver;
    int index = HostX.n_screens;

    HostX.n_screens += 1;
    HostX.screens = realloc(HostX.screens,
                            HostX.n_screens * sizeof(HostX.screens[0]));
    HostX.screens[index] = screen;

    scrpriv->screen = screen;
    scrpriv->win_pre_existing = win_id;
}

void
hostx_set_display_name(char *name)
{
    HostX.server_dpy_name = strdup(name);
}

void
hostx_set_screen_number(KdScreenInfo *screen, int number)
{
    EphyrScrPriv *scrpriv = screen->driver;

    if (scrpriv) {
        scrpriv->mynum = number;
        hostx_set_win_title(screen, "");
    }
}

void
hostx_set_win_title(KdScreenInfo *screen, const char *extra_text)
{
    EphyrScrPriv *scrpriv = screen->driver;

    if (!scrpriv)
        return;

    if (ephyrTitle) {
        xcb_icccm_set_wm_name(HostX.conn,
                              scrpriv->win,
                              XCB_ATOM_STRING,
                              8,
                              strlen(ephyrTitle),
                              ephyrTitle);
    } else {
#define BUF_LEN 256
        char buf[BUF_LEN + 1];

        memset(buf, 0, BUF_LEN + 1);
        snprintf(buf, BUF_LEN, "Xephyr on %s.%d %s",
                 HostX.server_dpy_name,
                 scrpriv->mynum, (extra_text != NULL) ? extra_text : "");

        xcb_icccm_set_wm_name(HostX.conn,
                              scrpriv->win,
                              XCB_ATOM_STRING,
                              8,
                              strlen(buf),
                              buf);
        xcb_flush(HostX.conn);
    }
}

int
hostx_want_host_cursor(void)
{
    return !HostX.use_sw_cursor;
}

void
hostx_use_sw_cursor(void)
{
    HostX.use_sw_cursor = TRUE;
}

int
hostx_want_preexisting_window(KdScreenInfo *screen)
{
    EphyrScrPriv *scrpriv = screen->driver;

    if (scrpriv && scrpriv->win_pre_existing) {
        return 1;
    }
    else {
        return 0;
    }
}

void
hostx_use_fullscreen(void)
{
    HostX.use_fullscreen = TRUE;
}

int
hostx_want_fullscreen(void)
{
    return HostX.use_fullscreen;
}

static xcb_intern_atom_cookie_t cookie_WINDOW_STATE,
				cookie_WINDOW_STATE_FULLSCREEN;

static void
hostx_set_fullscreen_hint(void)
{
    xcb_atom_t atom_WINDOW_STATE, atom_WINDOW_STATE_FULLSCREEN;
    int index;
    xcb_intern_atom_reply_t *reply;

    reply = xcb_intern_atom_reply(HostX.conn, cookie_WINDOW_STATE, NULL);
    atom_WINDOW_STATE = reply->atom;
    free(reply);

    reply = xcb_intern_atom_reply(HostX.conn, cookie_WINDOW_STATE_FULLSCREEN,
                                  NULL);
    atom_WINDOW_STATE_FULLSCREEN = reply->atom;
    free(reply);

    for (index = 0; index < HostX.n_screens; index++) {
        EphyrScrPriv *scrpriv = HostX.screens[index]->driver;
        xcb_change_property(HostX.conn,
                            PropModeReplace,
                            scrpriv->win,
                            atom_WINDOW_STATE,
                            XCB_ATOM_ATOM,
                            32,
                            1,
                            &atom_WINDOW_STATE_FULLSCREEN);
    }
}

static void
hostx_toggle_damage_debug(void)
{
    HostXWantDamageDebug ^= 1;
}

void
hostx_handle_signal(int signum)
{
    hostx_toggle_damage_debug();
    EPHYR_DBG("Signal caught. Damage Debug:%i\n", HostXWantDamageDebug);
}

void
hostx_use_resname(char *name, int fromcmd)
{
    ephyrResName = name;
    ephyrResNameFromCmd = fromcmd;
}

void
hostx_set_title(char *title)
{
    ephyrTitle = title;
}

#ifdef __SUNPRO_C
/* prevent "Function has no return statement" error for x_io_error_handler */
#pragma does_not_return(exit)
#endif

int
hostx_init(void)
{
    uint32_t attr;
    xcb_cursor_t empty_cursor;
    xcb_pixmap_t cursor_pxm;
    uint16_t red, green, blue;
    uint32_t pixel;
    int index;
    char *tmpstr;
    char *class_hint;
    size_t class_len;
    const xcb_query_extension_reply_t *shm_rep;
    xcb_screen_t *xscreen;

    attr =
        XCB_EVENT_MASK_BUTTON_PRESS
        | XCB_EVENT_MASK_BUTTON_RELEASE
        | XCB_EVENT_MASK_POINTER_MOTION
        | XCB_EVENT_MASK_KEY_PRESS
        | XCB_EVENT_MASK_KEY_RELEASE
        | XCB_EVENT_MASK_EXPOSURE
        | XCB_EVENT_MASK_STRUCTURE_NOTIFY;

    EPHYR_DBG("mark");

    if ((HostX.conn = xcb_connect(NULL, &HostX.screen)) == NULL) {
        fprintf(stderr, "\nXephyr cannot open host display. Is DISPLAY set?\n");
        exit(1);
    }

    xscreen = xcb_aux_get_screen(HostX.conn, HostX.screen);
    HostX.winroot = xscreen->root;
    HostX.gc = xcb_generate_id(HostX.conn);
    HostX.depth = xscreen->root_depth;
    HostX.visual  = xcb_aux_find_visual_by_id(xscreen, xscreen->root_visual);

    xcb_create_gc(HostX.conn, HostX.gc, HostX.winroot, 0, NULL);
    cookie_WINDOW_STATE = xcb_intern_atom(HostX.conn, FALSE,
                                          strlen("_NET_WM_STATE"),
                                          "_NET_WM_STATE");
    cookie_WINDOW_STATE_FULLSCREEN =
        xcb_intern_atom(HostX.conn, FALSE,
                        strlen("_NET_WM_STATE_FULLSCREEN"),
                        "_NET_WM_STATE_FULLSCREEN");

    for (index = 0; index < HostX.n_screens; index++) {
        KdScreenInfo *screen = HostX.screens[index];
        EphyrScrPriv *scrpriv = screen->driver;

        scrpriv->win = xcb_generate_id(HostX.conn);
        scrpriv->server_depth = HostX.depth;
        scrpriv->ximg = NULL;

        if (scrpriv->win_pre_existing != XCB_WINDOW_NONE) {
            xcb_get_geometry_reply_t *prewin_geom;
            xcb_get_geometry_cookie_t cookie;
            xcb_generic_error_t *e = NULL;

            /* Get screen size from existing window */
            cookie = xcb_get_geometry(HostX.conn,
                                      scrpriv->win_pre_existing);
            prewin_geom = xcb_get_geometry_reply(HostX.conn, cookie, &e);

            if (e) {
                free(e);
                free(prewin_geom);
                fprintf (stderr, "\nXephyr -parent window' does not exist!\n");
                exit (1);
            }

            scrpriv->win_width  = prewin_geom->width;
            scrpriv->win_height = prewin_geom->height;

            free(prewin_geom);

            xcb_create_window(HostX.conn,
                              XCB_COPY_FROM_PARENT,
                              scrpriv->win,
                              scrpriv->win_pre_existing,
                              0,0,
                              scrpriv->win_width,
                              scrpriv->win_height,
                              0,
                              XCB_WINDOW_CLASS_COPY_FROM_PARENT,
                              XCB_COPY_FROM_PARENT,
                              XCB_CW_EVENT_MASK,
                              &attr);
        }
        else {
            xcb_create_window(HostX.conn,
                              XCB_COPY_FROM_PARENT,
                              scrpriv->win,
                              HostX.winroot,
                              0,0,100,100, /* will resize */
                              0,
                              XCB_WINDOW_CLASS_COPY_FROM_PARENT,
                              XCB_COPY_FROM_PARENT,
                              XCB_CW_EVENT_MASK,
                              &attr);

            hostx_set_win_title(screen,
                                "(ctrl+shift grabs mouse and keyboard)");

            if (HostX.use_fullscreen) {
                scrpriv->win_width  = xscreen->width_in_pixels;
                scrpriv->win_height = xscreen->height_in_pixels;

                hostx_set_fullscreen_hint();
            }

            tmpstr = getenv("RESOURCE_NAME");
            if (tmpstr && (!ephyrResNameFromCmd))
                ephyrResName = tmpstr;
            class_len = strlen(ephyrResName) + 1 + strlen("Xephyr") + 1;
            class_hint = malloc(class_len);
            if (class_hint) {
                strcpy(class_hint, ephyrResName);
                strcpy(class_hint + strlen(ephyrResName) + 1, "Xephyr");
                xcb_change_property(HostX.conn,
                                    XCB_PROP_MODE_REPLACE,
                                    scrpriv->win,
                                    XCB_ATOM_WM_CLASS,
                                    XCB_ATOM_STRING,
                                    8,
                                    class_len,
                                    class_hint);
                free(class_hint);
            }
        }
    }

    if (!xcb_aux_parse_color("red", &red, &green, &blue)) {
        xcb_lookup_color_cookie_t c =
            xcb_lookup_color(HostX.conn, xscreen->default_colormap, 3, "red");
        xcb_lookup_color_reply_t *reply =
            xcb_lookup_color_reply(HostX.conn, c, NULL);
        red = reply->exact_red;
        green = reply->exact_green;
        blue = reply->exact_blue;
        free(reply);
    }

    {
        xcb_alloc_color_cookie_t c = xcb_alloc_color(HostX.conn,
                                                     xscreen->default_colormap,
                                                     red, green, blue);
        xcb_alloc_color_reply_t *r = xcb_alloc_color_reply(HostX.conn, c, NULL);
        red = r->red;
        green = r->green;
        blue = r->blue;
        pixel = r->pixel;
        free(r);
    }

    xcb_change_gc(HostX.conn, HostX.gc, XCB_GC_FOREGROUND, &pixel);

    if (!hostx_want_host_cursor ()) {
        CursorVisible = TRUE;
        /* Ditch the cursor, we provide our 'own' */
        cursor_pxm = xcb_generate_id(HostX.conn);
        xcb_create_pixmap(HostX.conn, 1, cursor_pxm, HostX.winroot, 1, 1);
        empty_cursor = xcb_generate_id(HostX.conn);
        xcb_create_cursor(HostX.conn,
                          empty_cursor,
                          cursor_pxm, cursor_pxm,
                          0,0,0,
                          0,0,0,
                          1,1);
        for (index = 0; index < HostX.n_screens; index++) {
            KdScreenInfo *screen = HostX.screens[index];
            EphyrScrPriv *scrpriv = screen->driver;

            xcb_change_window_attributes(HostX.conn,
                                         scrpriv->win,
                                         XCB_CW_CURSOR,
                                         &empty_cursor);
        }
        xcb_free_pixmap(HostX.conn, cursor_pxm);
    }

    /* Try to get share memory ximages for a little bit more speed */
    shm_rep = xcb_get_extension_data(HostX.conn, &xcb_shm_id);
    if (!shm_rep || !shm_rep->present || getenv("XEPHYR_NO_SHM")) {
        fprintf(stderr, "\nXephyr unable to use SHM XImages\n");
        HostX.have_shm = FALSE;
    }
    else {
        /* Really really check we have shm - better way ?*/
        xcb_shm_segment_info_t shminfo;
        xcb_generic_error_t *e;
        xcb_void_cookie_t cookie;
        xcb_shm_seg_t shmseg;

        HostX.have_shm = TRUE;

        shminfo.shmid = shmget(IPC_PRIVATE, 1, IPC_CREAT|0777);
        shminfo.shmaddr = shmat(shminfo.shmid,0,0);

        shmseg = xcb_generate_id(HostX.conn);
        cookie = xcb_shm_attach_checked(HostX.conn, shmseg, shminfo.shmid,
                                        TRUE);
        e = xcb_request_check(HostX.conn, cookie);

        if (e) {
            fprintf(stderr, "\nXephyr unable to use SHM XImages\n");
            HostX.have_shm = FALSE;
            free(e);
        }

        shmdt(shminfo.shmaddr);
        shmctl(shminfo.shmid, IPC_RMID, 0);
    }

    xcb_flush(HostX.conn);

    /* Setup the pause time between paints when debugging updates */

    HostX.damage_debug_msec = 20000;    /* 1/50 th of a second */

    if (getenv("XEPHYR_PAUSE")) {
        HostX.damage_debug_msec = strtol(getenv("XEPHYR_PAUSE"), NULL, 0);
        EPHYR_DBG("pause is %li\n", HostX.damage_debug_msec);
    }

    return 1;
}

int
hostx_get_depth(void)
{
    return HostX.depth;
}

int
hostx_get_server_depth(KdScreenInfo *screen)
{
    EphyrScrPriv *scrpriv = screen->driver;

    return scrpriv ? scrpriv->server_depth : 0;
}

int
hostx_get_bpp(KdScreenInfo *screen)
{
    EphyrScrPriv *scrpriv = screen->driver;

    if (!scrpriv)
        return 0;

    if (host_depth_matches_server(scrpriv))
        return HostX.visual->bits_per_rgb_value;
    else
        return scrpriv->server_depth; /*XXX correct ?*/
}

void
hostx_get_visual_masks(KdScreenInfo *screen,
                       CARD32 *rmsk, CARD32 *gmsk, CARD32 *bmsk)
{
    EphyrScrPriv *scrpriv = screen->driver;

    if (!scrpriv)
        return;

    if (host_depth_matches_server(scrpriv)) {
        *rmsk = HostX.visual->red_mask;
        *gmsk = HostX.visual->green_mask;
        *bmsk = HostX.visual->blue_mask;
    }
    else if (scrpriv->server_depth == 16) {
        /* Assume 16bpp 565 */
        *rmsk = 0xf800;
        *gmsk = 0x07e0;
        *bmsk = 0x001f;
    }
    else {
        *rmsk = 0x0;
        *gmsk = 0x0;
        *bmsk = 0x0;
    }
}

static int
hostx_calculate_color_shift(unsigned long mask)
{
    int shift = 1;

    /* count # of bits in mask */
    while ((mask = (mask >> 1)))
        shift++;
    /* cmap entry is an unsigned char so adjust it by size of that */
    shift = shift - sizeof(unsigned char) * 8;
    if (shift < 0)
        shift = 0;
    return shift;
}

void
hostx_set_cmap_entry(unsigned char idx,
                     unsigned char r, unsigned char g, unsigned char b)
{
/* need to calculate the shifts for RGB because server could be BGR. */
/* XXX Not sure if this is correct for 8 on 16, but this works for 8 on 24.*/
    static int rshift, bshift, gshift = 0;
    static int first_time = 1;

    if (first_time) {
        first_time = 0;
        rshift = hostx_calculate_color_shift(HostX.visual->red_mask);
        gshift = hostx_calculate_color_shift(HostX.visual->green_mask);
        bshift = hostx_calculate_color_shift(HostX.visual->blue_mask);
    }
    HostX.cmap[idx] = ((r << rshift) & HostX.visual->red_mask) |
        ((g << gshift) & HostX.visual->green_mask) |
        ((b << bshift) & HostX.visual->blue_mask);
}

/**
 * hostx_screen_init creates the XImage that will contain the front buffer of
 * the ephyr screen, and possibly offscreen memory.
 *
 * @param width width of the screen
 * @param height height of the screen
 * @param buffer_height  height of the rectangle to be allocated.
 *
 * hostx_screen_init() creates an XImage, using MIT-SHM if it's available.
 * buffer_height can be used to create a larger offscreen buffer, which is used
 * by fakexa for storing offscreen pixmap data.
 */
void *
hostx_screen_init(KdScreenInfo *screen,
                  int width, int height, int buffer_height,
                  int *bytes_per_line, int *bits_per_pixel)
{
    EphyrScrPriv *scrpriv = screen->driver;
    Bool shm_success = FALSE;

    if (!scrpriv) {
        fprintf(stderr, "%s: Error in accessing hostx data\n", __func__);
        exit(1);
    }

    EPHYR_DBG("host_screen=%p wxh=%dx%d, buffer_height=%d",
              host_screen, width, height, buffer_height);

    if (scrpriv->ximg != NULL) {
        /* Free up the image data if previously used
         * i.ie called by server reset
         */

        if (HostX.have_shm) {
            xcb_shm_detach(HostX.conn, scrpriv->shminfo.shmseg);
            xcb_image_destroy(scrpriv->ximg);
            shmdt(scrpriv->shminfo.shmaddr);
            shmctl(scrpriv->shminfo.shmid, IPC_RMID, 0);
        }
        else {
            free(scrpriv->ximg->data);
            scrpriv->ximg->data = NULL;

            xcb_image_destroy(scrpriv->ximg);
        }
    }

    if (HostX.have_shm) {
        scrpriv->ximg = xcb_image_create_native(HostX.conn,
                                                width,
                                                buffer_height,
                                                XCB_IMAGE_FORMAT_Z_PIXMAP,
                                                HostX.depth,
                                                NULL,
                                                ~0,
                                                NULL);

        scrpriv->shminfo.shmid =
            shmget(IPC_PRIVATE,
                   scrpriv->ximg->stride * buffer_height,
                   IPC_CREAT | 0777);
        scrpriv->ximg->data = shmat(scrpriv->shminfo.shmid, 0, 0);
        scrpriv->shminfo.shmaddr = scrpriv->ximg->data;

        if (scrpriv->ximg->data == (uint8_t *) -1) {
            EPHYR_DBG
                ("Can't attach SHM Segment, falling back to plain XImages");
            HostX.have_shm = FALSE;
            xcb_image_destroy (scrpriv->ximg);
            shmctl(scrpriv->shminfo.shmid, IPC_RMID, 0);
        }
        else {
            EPHYR_DBG("SHM segment attached %p", scrpriv->shminfo.shmaddr);
            scrpriv->shminfo.shmseg = xcb_generate_id(HostX.conn);
            xcb_shm_attach(HostX.conn,
                           scrpriv->shminfo.shmseg,
                           scrpriv->shminfo.shmid,
                           FALSE);
            shm_success = TRUE;
        }
    }

    if (!shm_success) {
        EPHYR_DBG("Creating image %dx%d for screen scrpriv=%p\n",
                  width, buffer_height, scrpriv);
        scrpriv->ximg = xcb_image_create_native(HostX.conn,
                                                    width,
                                                    buffer_height,
                                                    XCB_IMAGE_FORMAT_Z_PIXMAP,
                                                    HostX.depth,
                                                    NULL,
                                                    ~0,
                                                    NULL);

        scrpriv->ximg->data =
            malloc(scrpriv->ximg->stride * buffer_height);
    }

    if (scrpriv->win_pre_existing == None && !EphyrWantResize) {
        /* Ask the WM to keep our size static */
        xcb_size_hints_t size_hints = {0};
        size_hints.max_width = size_hints.min_width = width;
        size_hints.max_height = size_hints.min_height = height;
        size_hints.flags = (XCB_ICCCM_SIZE_HINT_P_MIN_SIZE |
                            XCB_ICCCM_SIZE_HINT_P_MAX_SIZE);
        xcb_icccm_set_wm_normal_hints(HostX.conn, scrpriv->win,
                                      &size_hints);
    }

    xcb_map_window(HostX.conn, scrpriv->win);

    xcb_aux_sync(HostX.conn);

    scrpriv->win_width = width;
    scrpriv->win_height = height;

    if (host_depth_matches_server(scrpriv)) {
        *bytes_per_line = scrpriv->ximg->stride;
        *bits_per_pixel = scrpriv->ximg->bpp;

        EPHYR_DBG("Host matches server");
        return scrpriv->ximg->data;
    }
    else {
        int bytes_per_pixel = scrpriv->server_depth >> 3;
        int stride = (width * bytes_per_pixel + 0x3) & ~0x3;

        *bytes_per_line = stride;
        *bits_per_pixel = scrpriv->server_depth;

        EPHYR_DBG("server bpp %i", bytes_per_pixel);
        scrpriv->fb_data = malloc (stride * buffer_height);
        return scrpriv->fb_data;
    }
}

static void hostx_paint_debug_rect(KdScreenInfo *screen,
                                   int x, int y, int width, int height);

void
hostx_paint_rect(KdScreenInfo *screen,
                 int sx, int sy, int dx, int dy, int width, int height)
{
    EphyrScrPriv *scrpriv = screen->driver;

    EPHYR_DBG("painting in screen %d\n", scrpriv->mynum);

    /*
     *  Copy the image data updated by the shadow layer
     *  on to the window
     */

    if (HostXWantDamageDebug) {
        hostx_paint_debug_rect(screen, dx, dy, width, height);
    }

    /* 
     * If the depth of the ephyr server is less than that of the host,
     * the kdrive fb does not point to the ximage data but to a buffer
     * ( fb_data ), we shift the various bits from this onto the XImage
     * so they match the host.
     *
     * Note, This code is pretty new ( and simple ) so may break on 
     *       endian issues, 32 bpp host etc. 
     *       Not sure if 8bpp case is right either. 
     *       ... and it will be slower than the matching depth case.
     */

    if (!host_depth_matches_server(scrpriv)) {
        int x, y, idx, bytes_per_pixel = (scrpriv->server_depth >> 3);
        int stride = (scrpriv->win_width * bytes_per_pixel + 0x3) & ~0x3;
        unsigned char r, g, b;
        unsigned long host_pixel;

        EPHYR_DBG("Unmatched host depth scrpriv=%p\n", scrpriv);
        for (y = sy; y < sy + height; y++)
            for (x = sx; x < sx + width; x++) {
                idx = y * stride + x * bytes_per_pixel;

                switch (scrpriv->server_depth) {
                case 16:
                {
                    unsigned short pixel =
                        *(unsigned short *) (scrpriv->fb_data + idx);

                    r = ((pixel & 0xf800) >> 8);
                    g = ((pixel & 0x07e0) >> 3);
                    b = ((pixel & 0x001f) << 3);

                    host_pixel = (r << 16) | (g << 8) | (b);

                    xcb_image_put_pixel(scrpriv->ximg, x, y, host_pixel);
                    break;
                }
                case 8:
                {
                    unsigned char pixel =
                        *(unsigned char *) (scrpriv->fb_data + idx);
                    xcb_image_put_pixel(scrpriv->ximg, x, y,
                                        HostX.cmap[pixel]);
                    break;
                }
                default:
                    break;
                }
            }
    }

    if (HostX.have_shm) {
        xcb_image_shm_put(HostX.conn, scrpriv->win,
                          HostX.gc, scrpriv->ximg,
                          scrpriv->shminfo,
                          sx, sy, dx, dy, width, height, FALSE);
    }
    else {
        xcb_image_put(HostX.conn, scrpriv->win, HostX.gc, scrpriv->ximg,
                      dx, dy, 0);
    }

    xcb_aux_sync(HostX.conn);
}

static void
hostx_paint_debug_rect(KdScreenInfo *screen,
                       int x, int y, int width, int height)
{
    EphyrScrPriv *scrpriv = screen->driver;
    struct timespec tspec;
    xcb_rectangle_t rect = { .x = x, .y = y, .width = width, .height = height };
    xcb_void_cookie_t cookie;
    xcb_generic_error_t *e;

    tspec.tv_sec = HostX.damage_debug_msec / (1000000);
    tspec.tv_nsec = (HostX.damage_debug_msec % 1000000) * 1000;

    EPHYR_DBG("msec: %li tv_sec %li, tv_msec %li",
              HostX.damage_debug_msec, tspec.tv_sec, tspec.tv_nsec);

    /* fprintf(stderr, "Xephyr updating: %i+%i %ix%i\n", x, y, width, height); */

    cookie = xcb_poly_fill_rectangle_checked(HostX.conn, scrpriv->win,
                                             HostX.gc, 1, &rect);
    e = xcb_request_check(HostX.conn, cookie);
    free(e);

    /* nanosleep seems to work better than usleep for me... */
    nanosleep(&tspec, NULL);
}

void
hostx_load_keymap(void)
{
    int min_keycode, max_keycode;

    min_keycode = xcb_get_setup(HostX.conn)->min_keycode;
    max_keycode = xcb_get_setup(HostX.conn)->max_keycode;

    EPHYR_DBG("min: %d, max: %d", min_keycode, max_keycode);

    ephyrKeySyms.minKeyCode = min_keycode;
    ephyrKeySyms.maxKeyCode = max_keycode;
}

xcb_connection_t *
hostx_get_xcbconn(void)
{
    return HostX.conn;
}

int
hostx_get_screen(void)
{
    return HostX.screen;
}

int
hostx_get_window(int a_screen_number)
{
    EphyrScrPriv *scrpriv;
    if (a_screen_number < 0 || a_screen_number >= HostX.n_screens) {
        EPHYR_LOG_ERROR("bad screen number:%d\n", a_screen_number);
        return 0;
    }
    scrpriv = HostX.screens[a_screen_number]->driver;
    return scrpriv->win;
}

int
hostx_get_window_attributes(int a_window, EphyrHostWindowAttributes * a_attrs)
{
    xcb_get_geometry_cookie_t geom_cookie;
    xcb_get_window_attributes_cookie_t attr_cookie;
    xcb_get_geometry_reply_t *geom_reply;
    xcb_get_window_attributes_reply_t *attr_reply;

    geom_cookie = xcb_get_geometry(HostX.conn, a_window);
    attr_cookie = xcb_get_window_attributes(HostX.conn, a_window);
    geom_reply = xcb_get_geometry_reply(HostX.conn, geom_cookie, NULL);
    attr_reply = xcb_get_window_attributes_reply(HostX.conn, attr_cookie, NULL);

    a_attrs->x = geom_reply->x;
    a_attrs->y = geom_reply->y;
    a_attrs->width = geom_reply->width;
    a_attrs->height = geom_reply->height;
    a_attrs->visualid = attr_reply->visual;

    free(geom_reply);
    free(attr_reply);
    return TRUE;
}

int
hostx_get_visuals_info(EphyrHostVisualInfo ** a_visuals, int *a_num_entries)
{
    Bool is_ok = FALSE;
    EphyrHostVisualInfo *host_visuals = NULL;
    int nb_items = 0, i = 0, screen_num;
    xcb_screen_iterator_t screens;
    xcb_depth_iterator_t depths;

    EPHYR_RETURN_VAL_IF_FAIL(a_visuals && a_num_entries, FALSE);
    EPHYR_LOG("enter\n");

    screens = xcb_setup_roots_iterator(xcb_get_setup(HostX.conn));
    for (screen_num = 0; screens.rem; screen_num++, xcb_screen_next(&screens)) {
        depths = xcb_screen_allowed_depths_iterator(screens.data);
        for (; depths.rem; xcb_depth_next(&depths)) {
            xcb_visualtype_t *visuals = xcb_depth_visuals(depths.data);
            EphyrHostVisualInfo *tmp_visuals =
                realloc(host_visuals,
                        (nb_items + depths.data->visuals_len)
                        * sizeof(EphyrHostVisualInfo));
            if (!tmp_visuals) {
                goto out;
            }
            host_visuals = tmp_visuals;
            for (i = 0; i < depths.data->visuals_len; i++) {
                host_visuals[nb_items + i].visualid = visuals[i].visual_id;
                host_visuals[nb_items + i].screen = screen_num;
                host_visuals[nb_items + i].depth = depths.data->depth;
                host_visuals[nb_items + i].class = visuals[i]._class;
                host_visuals[nb_items + i].red_mask = visuals[i].red_mask;
                host_visuals[nb_items + i].green_mask = visuals[i].green_mask;
                host_visuals[nb_items + i].blue_mask = visuals[i].blue_mask;
                host_visuals[nb_items + i].colormap_size = visuals[i].colormap_entries;
                host_visuals[nb_items + i].bits_per_rgb = visuals[i].bits_per_rgb_value;
            }
            nb_items += depths.data->visuals_len;
        }
    }

    EPHYR_LOG("host advertises %d visuals\n", nb_items);
    *a_visuals = host_visuals;
    *a_num_entries = nb_items;
    host_visuals = NULL;

    is_ok = TRUE;
out:
    free(host_visuals);
    host_visuals = NULL;
    EPHYR_LOG("leave\n");
    return is_ok;

}

int
hostx_create_window(int a_screen_number,
                    EphyrBox * a_geometry,
                    int a_visual_id, int *a_host_peer /*out parameter */ )
{
    Bool is_ok = FALSE;
    xcb_window_t win;
    int winmask = 0;
    uint32_t attrs[2];
    xcb_screen_t *screen = xcb_aux_get_screen(HostX.conn, hostx_get_screen());
    xcb_visualtype_t *visual;
    int depth = 0;
    EphyrScrPriv *scrpriv = HostX.screens[a_screen_number]->driver;

    EPHYR_RETURN_VAL_IF_FAIL(screen && a_geometry, FALSE);

    EPHYR_LOG("enter\n");

    visual = xcb_aux_find_visual_by_id(screen, a_visual_id);
    if (!visual) {
        EPHYR_LOG_ERROR ("argh, could not find a remote visual with id:%d\n",
                         a_visual_id);
        goto out;
    }
    depth = xcb_aux_get_depth_of_visual(screen, a_visual_id);

    winmask = XCB_CW_EVENT_MASK | XCB_CW_COLORMAP;
    attrs[0] = XCB_EVENT_MASK_BUTTON_PRESS
              |XCB_EVENT_MASK_BUTTON_RELEASE
              |XCB_EVENT_MASK_POINTER_MOTION
              |XCB_EVENT_MASK_KEY_PRESS
              |XCB_EVENT_MASK_KEY_RELEASE
              |XCB_EVENT_MASK_EXPOSURE;
    attrs[1] = xcb_generate_id(HostX.conn);
    xcb_create_colormap(HostX.conn,
                        XCB_COLORMAP_ALLOC_NONE,
                        attrs[1],
                        hostx_get_window(a_screen_number),
                        a_visual_id);

    win = xcb_generate_id(HostX.conn);
    xcb_create_window(HostX.conn,
                      depth,
                      win,
                      hostx_get_window (a_screen_number),
                      a_geometry->x, a_geometry->y,
                      a_geometry->width, a_geometry->height, 0,
                      XCB_WINDOW_CLASS_COPY_FROM_PARENT,
                      a_visual_id, winmask, attrs);

    if (scrpriv->peer_win == XCB_NONE) {
        scrpriv->peer_win = win;
    }
    else {
        EPHYR_LOG_ERROR("multiple peer windows created for same screen\n");
    }
    xcb_flush(HostX.conn);
    xcb_map_window(HostX.conn, win);
    *a_host_peer = win;
    is_ok = TRUE;
 out:
    EPHYR_LOG("leave\n");
    return is_ok;
}

int
hostx_destroy_window(int a_win)
{
    xcb_destroy_window(HostX.conn, a_win);
    xcb_flush(HostX.conn);
    return TRUE;
}

int
hostx_set_window_geometry(int a_win, EphyrBox * a_geo)
{
    uint32_t mask = XCB_CONFIG_WINDOW_X
                  | XCB_CONFIG_WINDOW_Y
                  | XCB_CONFIG_WINDOW_WIDTH
                  | XCB_CONFIG_WINDOW_HEIGHT;
    uint32_t values[4];

    EPHYR_RETURN_VAL_IF_FAIL(a_geo, FALSE);

    EPHYR_LOG("enter. x,y,w,h:(%d,%d,%d,%d)\n",
              a_geo->x, a_geo->y, a_geo->width, a_geo->height);

    values[0] = a_geo->x;
    values[1] = a_geo->y;
    values[2] = a_geo->width;
    values[3] = a_geo->height;
    xcb_configure_window(HostX.conn, a_win, mask, values);

    EPHYR_LOG("leave\n");
    return TRUE;
}

int
hostx_set_window_bounding_rectangles(int a_window,
                                     EphyrRect * a_rects, int a_num_rects)
{
    Bool is_ok = FALSE;
    int i = 0;
    xcb_rectangle_t *rects = NULL;

    EPHYR_RETURN_VAL_IF_FAIL(a_rects, FALSE);

    EPHYR_LOG("enter. num rects:%d\n", a_num_rects);

    rects = calloc(a_num_rects, sizeof (xcb_rectangle_t));
    if (!rects)
        goto out;
    for (i = 0; i < a_num_rects; i++) {
        rects[i].x = a_rects[i].x1;
        rects[i].y = a_rects[i].y1;
        rects[i].width = abs(a_rects[i].x2 - a_rects[i].x1);
        rects[i].height = abs(a_rects[i].y2 - a_rects[i].y1);
        EPHYR_LOG("borders clipped to rect[x:%d,y:%d,w:%d,h:%d]\n",
                  rects[i].x, rects[i].y, rects[i].width, rects[i].height);
    }
    xcb_shape_rectangles(HostX.conn,
                         XCB_SHAPE_SO_SET,
                         XCB_SHAPE_SK_BOUNDING,
                         XCB_CLIP_ORDERING_YX_BANDED,
                         a_window,
                         0, 0,
                         a_num_rects,
                         rects);
    is_ok = TRUE;

out:
    free(rects);
    rects = NULL;
    EPHYR_LOG("leave\n");
    return is_ok;
}

#ifdef XF86DRI
typedef struct {
    int is_valid;
    int local_id;
    int remote_id;
} ResourcePair;

#define RESOURCE_PEERS_SIZE 1024*10
static ResourcePair resource_peers[RESOURCE_PEERS_SIZE];

int
hostx_allocate_resource_id_peer(int a_local_resource_id,
                                int *a_remote_resource_id)
{
    int i = 0;
    ResourcePair *peer = NULL;

    /*
     * first make sure a resource peer
     * does not exist already for
     * a_local_resource_id
     */
    for (i = 0; i < RESOURCE_PEERS_SIZE; i++) {
        if (resource_peers[i].is_valid
            && resource_peers[i].local_id == a_local_resource_id) {
            peer = &resource_peers[i];
            break;
        }
    }
    /*
     * find one free peer entry, an feed it with
     */
    if (!peer) {
        for (i = 0; i < RESOURCE_PEERS_SIZE; i++) {
            if (!resource_peers[i].is_valid) {
                peer = &resource_peers[i];
                break;
            }
        }
        if (peer) {
            peer->remote_id = xcb_generate_id(HostX.conn);
            peer->local_id = a_local_resource_id;
            peer->is_valid = TRUE;
        }
    }
    if (peer) {
        *a_remote_resource_id = peer->remote_id;
        return TRUE;
    }
    return FALSE;
}

int
hostx_get_resource_id_peer(int a_local_resource_id, int *a_remote_resource_id)
{
    int i = 0;
    ResourcePair *peer = NULL;

    for (i = 0; i < RESOURCE_PEERS_SIZE; i++) {
        if (resource_peers[i].is_valid
            && resource_peers[i].local_id == a_local_resource_id) {
            peer = &resource_peers[i];
            break;
        }
    }
    if (peer) {
        *a_remote_resource_id = peer->remote_id;
        return TRUE;
    }
    return FALSE;
}

#endif                          /* XF86DRI */