/**
* 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_w32gdi_c.h"
/**
* The number of CRTC:s on the system
*/
static int crtc_count;
/**
* The device contexts for each CRTC
*/
static HDC* crtcs;
/**
* Start stage of colour curve control
*
* @return Zero on success
*/
int blueshift_w32gdi_open(void)
{
int c;
DISPLAY_DEVICE display;
display.cb = sizeof(DISPLAY_DEVICE);
crtc_count = 0;
while (EnumDisplayDevices(NULL, crtc_count, &display, 0))
crtc_count++;
if (crtc_count == 0)
{
crtcs == NULL;
return 0;
}
crtcs = malloc(crtc_count * sizeof(HDC));
if (crtcs == NULL)
{
fprintf(stderr, "Out of memory\n");
return 1;
}
for (c = 0; c < crtc_count; c++)
{
/* Open device context */
if (EnumDisplayDevices(NULL, c, &display, 0) == FALSE)
{
fprintf(stderr, "Cannot find display, are you unplugging stuff?\n");
crtc_count = c;
return 1;
}
if (!(display.StateFlags & DISPLAY_DEVICE_ACTIVE))
{
fprintf(stderr, "Cannot to open device context, it is not active\n");
crtc_count = c;
return 1;
}
*(crtcs + c) = CreateDC(TEXT("DISPLAY"), display.DeviceName, NULL, NULL);
if (*(crtcs + c) == NULL)
{
fprintf(stderr, "Unable to open device context\n");
crtc_count = c;
return 1;
}
/* Check support for gamma ramps */
if (GetDeviceCaps(hDC, COLORMGMTCAPS) != CM_GAMMA_RAMP)
{
fprintf(stderr, "CRTC %i does not support gamma ramps\n", c);
ReleaseDC(NULL, *(crtcs + c));
crtc_count = c;
return 1;
}
}
return 0;
}
/**
* Get the number of CRTC:s on the system
*
* @return The number of CRTC:s on the system
*/
int blueshift_w32gdi_crtc_count(void)
{
return crtc_count;
}
/**
* Gets the current colour curves
*
* @param use_crtc The CRTC to use
* @return {the size of the each curve, *the red curve,
* *the green curve, *the blue curve},
* needs to be free:d. `NULL` on error.
*/
uint16_t* blueshift_w32gdi_read(int use_crtc)
{
uint16_t* rc = NULL;
if ((use_crtc < 0) || (use_crtc >= crtc_count))
fprintf(stderr, "CRTC %i does not exist\n", use_crtc);
else
{
rc = malloc((1 + 3 * GAMMA_RAMP_SIZE) * sizeof(uint16_t));
if (rc == NULL)
fprintf(stderr, "Out of memory\n");
else
{
*rc = GAMMA_RAMP_SIZE;
if (GetDeviceGammaRamp(*(crtcs + use_crtc), rc + 1) == FALSE)
{
fprintf(stderr, "Unable to read current gamma ramps from CRTC %i\n", use_crtc);
free(rc);
rc = NULL;
}
}
}
return rc;
}
/**
* Apply stage of colour curve control
*
* @param use_crtc The CRTC to use, -1 if all
* @param rgb_curve The concatenation of the red, the green and the blue colour curves
* @return Zero on success
*/
int blueshift_w32gdi_apply(int use_crtc, uint16_t* rgb_curves)
{
int r = 1;
if (use_crtc < crtc_count)
{
int c = use_crtc < 0 ? 0 : use_crtc;
int n = use_crtc < 0 ? crtc_count : (use_crtc + 1);
for (; c < n; c++)
if (!(r = SetDeviceGammaRamp(*(crtcs + c), rgb_curves)))
{
fprintf(stderr, "Unable to set gamma ramps\n");
break;
}
}
else
fprintf(stderr, "CRTC %i does not exist\n", use_crtc);
return !r;
}
/**
* Resource freeing stage of colour curve control
*/
void blueshift_w32gdi_close(void)
{
for (c = 0; c < crtc_count; c++)
ReleaseDC(NULL, *(crtcs + c));
if (crtcs != NULL)
free(crtcs);
}
