#ifdef WIN32
#include <windows.h>

#define DPYTYPE HDC
#define DPYOPEN(dpy) GetDC(dpy)
#define DPYCLOSE(dpy, disp) ReleaseDC(dpy, disp)
#define DPYGETRAMP(disp, ramp) GetDeviceGammaRamp(disp, ramp)
#define DPYSETRAMP(disp, ramp) SetDeviceGammaRamp(disp, ramp)
#define True TRUE
#define False FALSE
#else
#include <X11/Xlib.h>
#include <X11/extensions/Xext.h>
#include <X11/extensions/xf86vmode.h>

#define DPYTYPE Display *
#define DPYOPEN(dpy) XOpenDisplay(dpy)
#define DPYCLOSE(dpy, disp) XCloseDisplay(disp)
#define DPYGETRAMP(disp, ramp) XF86VidModeGetGammaRamp(disp, DefaultScreen(disp), GAMMA_RESOLUTION, (ramp)[0], (ramp)[1], (ramp)[2])
#define DPYSETRAMP(disp, ramp) XF86VidModeSetGammaRamp(disp, DefaultScreen(disp), GAMMA_RESOLUTION, (ramp)[0], (ramp)[1], (ramp)[2])
#endif

#define GAMMA_COMPONENTS 3
#define GAMMA_RESOLUTION 256 // req'd for win32

/*
 * Ben Winslow <rain@bluecherry.net> - 9/28/2001
 * gcc -o invgamma invgamma.c -L/usr/X11R6/lib -lX11 -lXext -lXxf86vm         
 */

int main(int argc, char *argv[])
{
	DPYTYPE disp;
	unsigned short ramp_in[GAMMA_COMPONENTS][GAMMA_RESOLUTION];
	unsigned short ramp_out[GAMMA_COMPONENTS][GAMMA_RESOLUTION];
	int x, y;
	
	if ((disp = DPYOPEN(NULL)) == NULL) {
		printf("Failed to open display\n");
		return 1;
	}

	if (DPYGETRAMP(disp, ramp_in) == False) {
		DPYCLOSE(NULL, disp);
		printf("Failed to get gamma ramp\n");
		return 1;
	}
	
	for (x = 0; x < GAMMA_COMPONENTS; x++) {
		for (y = 0; y < GAMMA_RESOLUTION; y++) {
			ramp_out[x][y] = ramp_in[x][(GAMMA_RESOLUTION - 1) - y];
		}
	}
	
	if (DPYSETRAMP(disp, ramp_out) == False) {
		DPYCLOSE(NULL, disp);
		printf("Failed to set gamma ramp\n");
		return 1;
	}
	
	DPYCLOSE(NULL, disp);

	return 0;
}