/**
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "blueshift_vidmode_c.h"
/**
* The X server display
*/
static Display* connection;
/**
* The X screen
*/
static int screen;
/**
* Size of colour curves on the X-axis
*/
static int curve_size;
/**
* Start stage of colour curve control
*
* @param use_screen The screen to use
* @param display The display to use, `NULL` for the current one
* @return Zero on error, otherwise the size of colours curves
*/
int blueshift_vidmode_open(int use_screen, char* display)
{
int _major, _minor;
/* Get X display */
if ((connection = XOpenDisplay(display)) == NULL)
{
fprintf(stderr, "Cannot open X display\n");
return 0;
}
/* Check for VidMode extension */
if (XF86VidModeQueryVersion(connection, &_major, &_minor) == 0)
{
fprintf(stderr, "VidMode version query failed\n");
XCloseDisplay(connection);
return 0;
}
/* Get curve's size on the encoding axis */
screen = use_screen;
if (XF86VidModeGetGammaRampSize(connection, screen, &curve_size) == 0)
{
fprintf(stderr, "VidMode gamma size query failed\n");
XCloseDisplay(connection);
return 0;
}
if (curve_size <= 1)
{
fprintf(stderr, "VidMode gamma size query failed, impossible dimension\n");
XCloseDisplay(connection);
return 0;
}
return curve_size;
}
/**
* Gets the current colour curves
*
* @param r_gamma Storage location for the red colour curve
* @param g_gamma Storage location for the green colour curve
* @param b_gamma Storage location for the blue colour curve
* @return Zero on success
*/
int blueshift_vidmode_read(uint16_t* r_gamma, uint16_t* g_gamma, uint16_t* b_gamma)
{
/* Read curves */
if (XF86VidModeGetGammaRamp(connection, screen, curve_size, r_gamma, g_gamma, b_gamma) == 0)
{
fprintf(stderr, "VidMode gamma query failed\n");
XCloseDisplay(connection);
return 1;
}
return 0;
}
/**
* Apply stage of colour curve control
*
* @param r_curve The red colour curve
* @param g_curve The green colour curve
* @param b_curve The blue colour curve
* @return Zero on success
*/
int blueshift_vidmode_apply(uint16_t* r_curve, uint16_t* g_curve, uint16_t* b_curve)
{
/* Apply curves */
if (XF86VidModeSetGammaRamp(connection, screen, curve_size, r_curve, g_curve, b_curve) == 0)
{
fprintf(stderr, "VidMode gamma control failed\n");
return 1;
}
return 0;
}
/**
* Resource freeing stage of colour curve control
*/
void blueshift_vidmode_close(void)
{
/* Free remaining resources */
XCloseDisplay(connection);
}
