LookingGlass/c-host/linux/capture/xcb.c

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2019-03-02 00:59:03 +00:00
/*
Looking Glass - KVM FrameRelay (KVMFR) Client
Copyright (C) 2017-2019 Geoffrey McRae <geoff@hostfission.com>
https://looking-glass.hostfission.com
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "capture/interface.h"
#include "debug.h"
#include <assert.h>
#include <stdlib.h>
#include <inttypes.h>
#include <xcb/shm.h>
#include <xcb/xfixes.h>
#include <sys/ipc.h>
#include <sys/shm.h>
struct xcb
{
bool initialized;
xcb_connection_t * xcb;
xcb_screen_t * xcbScreen;
uint32_t seg;
int shmID;
void * data;
unsigned int width;
unsigned int height;
xcb_shm_get_image_cookie_t imgC;
xcb_xfixes_get_cursor_image_cookie_t curC;
};
struct xcb * this = NULL;
// forwards
static bool xcb_deinit();
static unsigned int xcb_getMaxFrameSize();
// implementation
static const char * xcb_getName()
{
return "XCB";
}
static bool xcb_create()
{
assert(!this);
this = (struct xcb *)calloc(sizeof(struct xcb), 1);
this->shmID = -1;
this->data = (void *)-1;
return true;
}
static bool xcb_init()
{
assert(this);
assert(!this->initialized);
this->xcb = xcb_connect(NULL, NULL);
if (!this->xcb || xcb_connection_has_error(this->xcb))
{
DEBUG_ERROR("Unable to open the X display");
goto fail;
}
if (!xcb_get_extension_data(this->xcb, &xcb_shm_id)->present)
{
DEBUG_ERROR("Missing the SHM extension");
goto fail;
}
xcb_screen_iterator_t iter;
iter = xcb_setup_roots_iterator(xcb_get_setup(this->xcb));
this->xcbScreen = iter.data;
this->width = iter.data->width_in_pixels;
this->height = iter.data->height_in_pixels;
DEBUG_INFO("Frame Size : %u x %u", this->width, this->height);
this->seg = xcb_generate_id(this->xcb);
this->shmID = shmget(IPC_PRIVATE, xcb_getMaxFrameSize(), IPC_CREAT | 0777);
if (this->shmID == -1)
{
DEBUG_ERROR("shmget failed");
goto fail;
}
xcb_shm_attach(this->xcb, this->seg ,this->shmID, false);
this->data = shmat(this->shmID, NULL, 0);
if ((uintptr_t)this->data == -1)
{
DEBUG_ERROR("shmat failed");
goto fail;
}
DEBUG_INFO("Frame Data : 0x%" PRIXPTR, (uintptr_t)this->data);
this->initialized = true;
return true;
fail:
xcb_deinit();
return false;
}
static bool xcb_deinit()
{
assert(this);
if ((uintptr_t)this->data != -1)
{
shmdt(this->data);
this->data = (void *)-1;
}
if (this->shmID != -1)
{
shmctl(this->shmID, IPC_RMID, NULL);
this->shmID = -1;
}
if (this->xcb)
{
xcb_disconnect(this->xcb);
this->xcb = NULL;
}
this->initialized = false;
return false;
}
static void xcb_free()
{
free(this);
this = NULL;
}
static unsigned int xcb_getMaxFrameSize()
{
return this->width * this->height * 4;
}
static CaptureResult xcb_capture(bool * hasFrameUpdate, bool * hasPointerUpdate)
{
assert(this);
assert(this->initialized);
this->imgC = xcb_shm_get_image_unchecked(
this->xcb,
this->xcbScreen->root,
0, 0,
this->width,
this->height,
~0,
XCB_IMAGE_FORMAT_Z_PIXMAP,
this->seg,
0);
*hasFrameUpdate = true;
return CAPTURE_RESULT_OK;
}
struct CaptureInterface Capture_XCB =
{
.getName = xcb_getName,
.create = xcb_create,
.init = xcb_init,
.deinit = xcb_deinit,
.free = xcb_free,
.getMaxFrameSize = xcb_getMaxFrameSize,
.capture = xcb_capture
};