/**
* libgamma -- Display server abstraction layer for gamma ramp adjustments
* Copyright (C) 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This library 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 3 of the License, or
* (at your option) any later version.
*
* This library 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 library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef HAVE_LIBGAMMA_METHOD_W32_GDI
# error Compiling fake-w32-gdi.c without FAKE_LIBGAMMA_METHOD_W32_GDI
#endif
/* This file very sloppily translates Windows GDI calls to X RandR calls.
* It should by no means be used, without additional modification, as a
* part of a compatibility layer. The purpose of this file is only to make
* it possible to test for logical errors in Windows specific code on
* a GNU/Linux system under X. */
#include "fake-w32-gdi.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef HAVE_LIBGAMMA_METHOD_X_RANDR
/* Use dummy translation. */
/**
* Get the device context for a window or the entire screen.
*
* @param hWnd The windows, `NULL` for the entire screen.
* @return The device context.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd144871(v=vs.85).aspx
*/
HDC GetDC(HWND hWnd)
{
/* Just a non-NULL value. */
(void) hWnd;
return (HDC*)16;
}
/**
* Free a device context.
*
* @param hWnd The window whose device context is `hDC`, `NULL` for the entire screen.
* @param hDC The device context to free.
* @return Whether the call was successful.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd162920(v=vs.85).aspx
*/
int ReleaseDC(HWND hWnd, HDC hDC)
{
/* Always successful. */
(void) hWnd;
(void) hDC;
return 1;
}
/**
* Get information (capabilities) for a device context.
*
* @param hDC The device context.
* @param nIndex The information to retrieve, may be `COLORMGMTCAPS`.
* @return The details of the queried information, can return `CM_GAMMA_RAMP`
* if `nIndex` is `COLORMGMTCAPS`.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd144877(v=vs.85).aspx
*/
int GetDeviceCaps(HDC hDC, int nIndex)
{
/* We have gamma ramps if the user asks for colour management capabilities. */
(void) hDC;
return CM_GAMMA_RAMP + nIndex - COLORMGMTCAPS;
}
/**
* Set the gamma ramps for a device.
*
* @param hDC The device context.
* @param lpRamp The gamma ramps joined in the order: red, green, blue.
* This is a `WORD*` casted to `void*`.
* @return Whether the call was successful.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd372194(v=vs.85).aspx
*/
BOOL SetDeviceGammaRamp(HDC hDC, LPVOID restrict lpRamp)
{
/* Always successful. */
(void) hDC;
(void) lpRamp;
return TRUE;
}
/**
* Get the current gamma ramps for a device.
*
* @param hDC The device context.
* @param lpRamp The output for the gamma ramps joined in the order: red, green, blue.
* This is a `WORD*` casted to `void*`.
* @return Whether the call was successful.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd316946(v=vs.85).aspx
*/
BOOL GetDeviceGammaRamp(HDC hDC, LPVOID restrict lpRamp)
{
/* Always successful. */
(void) hDC;
(void) lpRamp;
return TRUE;
}
/**
* Get the context for a device
*
* @param lpszDriver The driver or a display device, use "DISPLAY" if you want a display.
* @param lpszDevice The name of the device. If you want a display use can use the member
* name `DeviceName` in the third parameter, an output parameter, of
* `EnumDisplayDevices`.
* @param lpszOutput We will always use `NULL` here.
* @param lpInitData We will always use `NULL` here. This should actually by a `const DEVMODE*`.
* @return -
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd183490(v=vs.85).aspx
*/
HDC CreateDC(LPCTSTR restrict lpszDriver, LPCTSTR restrict lpszDevice,
LPCTSTR restrict lpszOutput, const void* restrict lpInitData)
{
/* `NULL` if not asking for a CRTC, otherwise a non-NULL value. */
(void) lpszOutput;
(void) lpInitData;
(void) lpszDevice;
return strcmp(lpszDriver, "DISPLAY") ? NULL : (HDC*)16;
}
/**
* Get a display device by its name or index.
*
* @param lpDevice The name of the device, use `NULL` to base the call on `iDevNum` instead.
* @param iDevNum The index of the device.
* @param lpDisplayDevice Output for the found device.
* @param dwFlags Flags, we will always use zero.
* @return Whether the call was successful. Zero is also returned if `iDevNum`
* is greater than the largest device index on the system.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd162609(v=vs.85).aspx
*/
BOOL EnumDisplayDevices(LPCTSTR lpDevice, restrict DWORD iDevNum,
PDISPLAY_DEVICE restrict lpDisplayDevice, DWORD dwFlags)
{
(void) dwFlags;
/* Check correctness of `lpDevice`. */
if (lpDevice != NULL)
{
fprintf(stderr, "lpDevice (argument 1) for EnumDisplayDevices should be NULL\n");
abort();
return FALSE;
}
/* Pretend that we have two CRTC:s. */
if (iDevNum >= 2)
return FALSE;
/* Check correctness of `lpDisplayDevice`. */
if (lpDisplayDevice->cb != sizeof(DISPLAY_DEVICE))
{
fprintf(stderr, "lpDisplayDevice->cb for EnumDisplayDevices is not sizeof(DISPLAY_DEVICE)\n");
abort();
return FALSE;
}
/* Store an arbitrary name for the monitor. */
strcmp(lpDisplayDevice->DeviceName, "some monitor");
/* The connector is always enabled. */
lpDisplayDevice->StateFlags = DISPLAY_DEVICE_ACTIVE;
return TRUE;
}
#else
/* Use translation to X RandR. */
#include <xcb/xcb.h>
#include <xcb/randr.h>
/**
* The gamma ramp size that devices will
* always have in Windows GDI.
*/
#define GAMMA_RAMP_SIZE 256
/**
* Connection to the X RandR display.
*/
static xcb_connection_t* restrict connection = NULL;
/**
* Resouces for the screen.
* We only have one screen, again this is a very sloppy compatibility layer.
*/
static xcb_randr_get_screen_resources_current_reply_t* restrict res_reply = NULL;
/**
* The number of available CRTC:s, -1 if not known yet.
*/
static ssize_t crtc_count = -1;
/**
* List of X RandR CRTC:s.
*/
static xcb_randr_crtc_t* restrict crtcs = NULL;
/**
* The number of opened CRTC:s.
*/
static size_t dc_count = 0;
/**
* Get the device context for a window or the entire screen.
*
* @param hWnd The windows, `NULL` for the entire screen.
* @return The device context.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd144871(v=vs.85).aspx
*/
HDC GetDC(HWND hWnd)
{
/* Return the primary CRTC. */
(void) hWnd;
return CreateDC(TEXT("DISPLAY"), "0", NULL, NULL);
}
/**
* Free a device context.
*
* @param hWnd The window whose device context is `hDC`, `NULL` for the entire screen.
* @param hDC The device context to free.
* @return Whether the call was successful.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd162920(v=vs.85).aspx
*/
int ReleaseDC(HWND hWnd, HDC hDC)
{
/* Disconnect from the RandR display when all monitors have been closed. */
(void) hWnd;
(void) hDC;
dc_count--;
if (dc_count == 0)
{
if (connection != NULL)
xcb_disconnect(connection);
connection = NULL;
free(res_reply);
res_reply = NULL;
}
return 1;
}
/**
* Get information (capabilities) for a device context.
*
* @param hDC The device context.
* @param nIndex The information to retrieve, may be `COLORMGMTCAPS`.
* @return The details of the queried information, can return `CM_GAMMA_RAMP`
* if `nIndex` is `COLORMGMTCAPS`.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd144877(v=vs.85).aspx
*/
int GetDeviceCaps(HDC hDC, int nIndex)
{
/* We have gamma ramps if the user asks for colour management capabilities. */
(void) hDC;
return CM_GAMMA_RAMP + nIndex - COLORMGMTCAPS;
}
/* xcb violates the rule to never return `struct`:s. */
#ifdef __GCC__
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Waggregate-return"
#endif
/**
* Set the gamma ramps for a device.
*
* @param hDC The device context.
* @param lpRamp The gamma ramps joined in the order: red, green, blue.
* This is a `WORD*` casted to `void*`.
* @return Whether the call was successful.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd372194(v=vs.85).aspx
*/
BOOL SetDeviceGammaRamp(HDC hDC, LPVOID restrict lpRamp)
{
/* We assume that our gamma ramps are of the same size
as used by Windows GDI (we are so sloppy.) */
xcb_void_cookie_t gamma_cookie =
xcb_randr_set_crtc_gamma_checked(connection, *(xcb_randr_crtc_t*)hDC, GAMMA_RAMP_SIZE,
((uint16_t*)lpRamp) + 0 * GAMMA_RAMP_SIZE,
((uint16_t*)lpRamp) + 1 * GAMMA_RAMP_SIZE,
((uint16_t*)lpRamp) + 2 * GAMMA_RAMP_SIZE);
xcb_generic_error_t* error = xcb_request_check(connection, gamma_cookie);
return error == NULL ? TRUE : FALSE;
}
/**
* Get the current gamma ramps for a device.
*
* @param hDC The device context.
* @param lpRamp The output for the gamma ramps joined in the order: red, green, blue.
* This is a `WORD*` casted to `void*`.
* @return Whether the call was successful.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd316946(v=vs.85).aspx
*/
BOOL GetDeviceGammaRamp(HDC hDC, LPVOID restrict lpRamp)
{
xcb_randr_get_crtc_gamma_cookie_t gamma_cookie;
xcb_randr_get_crtc_gamma_reply_t* restrict gamma_reply;
xcb_generic_error_t* error;
/* Read current gamma ramps. */
gamma_cookie = xcb_randr_get_crtc_gamma(connection, *(xcb_randr_crtc_t*)hDC);
gamma_reply = xcb_randr_get_crtc_gamma_reply(connection, gamma_cookie, &error);
if (error)
return FALSE;
#define DEST_RAMP(I) (((uint16_t*)lpRamp) + (I) * GAMMA_RAMP_SIZE)
#define SRC_RAMP(C) (xcb_randr_get_crtc_gamma_##C(gamma_reply))
/* Copy the ramps into the output parameter. (coalesced) */
memcpy(DEST_RAMP(0), SRC_RAMP(red), GAMMA_RAMP_SIZE * sizeof(uint16_t));
memcpy(DEST_RAMP(1), SRC_RAMP(green), GAMMA_RAMP_SIZE * sizeof(uint16_t));
memcpy(DEST_RAMP(2), SRC_RAMP(blue), GAMMA_RAMP_SIZE * sizeof(uint16_t));
#undef SRC_RAMP
#undef DEST_RAMP
free(gamma_reply);
return TRUE;
}
/**
* Get the context for a device
*
* @param lpszDriver The driver or a display device, use "DISPLAY" if you want a display.
* @param lpszDevice The name of the device. If you want a display use can use the member
* name `DeviceName` in the third parameter, an output parameter, of
* `EnumDisplayDevices`.
* @param lpszOutput We will always use `NULL` here.
* @param lpInitData We will always use `NULL` here. This should actually by a `const DEVMODE*`.
* @return -
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd183490(v=vs.85).aspx
*/
HDC CreateDC(LPCTSTR restrict lpszDriver, LPCTSTR restrict lpszDevice,
LPCTSTR restrict lpszOutput, const void* restrict lpInitData)
{
int crtc_index = atoi(lpszDevice);
(void) lpszOutput;
(void) lpInitData;
/* Check correctness of input. */
if (strcmp(lpszDriver, "DISPLAY"))
return NULL;
/* Connect to the display and get screen data if not already done so. */
if (dc_count == 0)
{
xcb_generic_error_t* error;
xcb_screen_iterator_t iter;
xcb_randr_get_screen_resources_current_cookie_t res_cookie;
/* Connect to the display. */
connection = xcb_connect(NULL, NULL);
/* Get the first screen. */
iter = xcb_setup_roots_iterator(xcb_get_setup(connection));
/* Get the resources of the screen. */
res_cookie = xcb_randr_get_screen_resources_current(connection, iter.data->root);
res_reply = xcb_randr_get_screen_resources_current_reply(connection, res_cookie, &error);
if (error)
{
fprintf(stderr, "Failed to open X connection.\n");
xcb_disconnect(connection);
crtc_count = -1;
return NULL;
}
/* Get the number of CRTC:s. */
crtc_count = res_reply->num_crtcs;
/* Get the CRTC ID:s. */
crtcs = xcb_randr_get_screen_resources_current_crtcs(res_reply);
}
/* Was the index too high. */
if (crtc_index >= crtc_count)
{
/* Disconnect and release resouces and
mark that we do not know the number of
available CRTC:s if we have not opened
any monitors yet. */
if (dc_count == 0)
{
xcb_disconnect(connection);
free(res_reply);
res_reply = NULL;
crtc_count = -1;
}
return NULL;
}
/* We have opened a new CRTC. */
dc_count++;
/* Return the ID of the CRTC. */
return crtcs + crtc_index;
}
#ifdef __GCC__
# pragma GCC diagnostic pop
#endif
/**
* Get a display device by its name or index.
*
* @param lpDevice The name of the device, use `NULL` to base the call on `iDevNum` instead.
* @param iDevNum The index of the device.
* @param lpDisplayDevice Output for the found device.
* @param dwFlags Flags, we will always use zero.
* @return Whether the call was successful. Zero is also returned if `iDevNum`
* is greater than the largest device index on the system.
* @see http://msdn.microsoft.com/en-us/library/windows/desktop/dd162609(v=vs.85).aspx
*/
BOOL EnumDisplayDevices(LPCTSTR restrict lpDevice, DWORD iDevNum,
PDISPLAY_DEVICE restrict lpDisplayDevice, DWORD dwFlags)
{
size_t count = (size_t)crtc_count;
(void) dwFlags;
/* Check the correctness of the input. */
if (lpDevice != NULL)
{
fprintf(stderr, "lpDevice (argument 1) for EnumDisplayDevices should be NULL\n");
abort();
return FALSE;
}
/* Do we know how many CRTC:s are available? */
if (crtc_count < 0)
{
/* If not open the first CRTC so that will be figured out. */
if (GetDC(NULL) == NULL)
return FALSE;
count = (size_t)crtc_count;
/* Close the primary monitor that we just closed. */
ReleaseDC(NULL, NULL);
}
/* Check that the request CRTC exists. */
if (iDevNum >= count)
return FALSE;
/* Check the correctness of the input. */
if (lpDisplayDevice->cb != sizeof(DISPLAY_DEVICE))
{
fprintf(stderr, "lpDisplayDevice->cb for EnumDisplayDevices is not sizeof(DISPLAY_DEVICE)\n");
abort();
return FALSE;
}
/* Store name for the CRTC. */
sprintf(lpDisplayDevice->DeviceName, "%i", iDevNum);
/* The connector that the CRTC belongs to is enabled. */
lpDisplayDevice->StateFlags = DISPLAY_DEVICE_ACTIVE;
return TRUE;
}
#endif
