/* gcc -o psycho psycho.c -I/usr/X11R6/include -L/usr/X11R6/lib -lX11 -lXext -lXxf86vm -lm
*/
#include <math.h>
#include "SDL.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#define GAMMA_COMPONENTS 3
#define GAMMA_RESOLUTION 256

/*
 * Ben Winslow <rain bluecherry.net> - 9/28/2001
 *
 * Modified Fri Sep 28 20:16:59 CDT 2001 by Zinx Verituse - Psychadelic color cycling :P
 */

unsigned short ramp_in[GAMMA_COMPONENTS][GAMMA_RESOLUTION];

void cleanup(void) {
	SDL_SetGammaRamp(ramp_in[0], ramp_in[1], ramp_in[2]);
	exit(0);
}

int main(int argc, char *argv[])
{
	Uint16 ramp_out[GAMMA_COMPONENTS][GAMMA_RESOLUTION];
	int x, y;
	int n[GAMMA_COMPONENTS], nd[GAMMA_COMPONENTS], nt[GAMMA_COMPONENTS];
	SDL_Event event;

	SDL_Init(SDL_INIT_VIDEO);
	SDL_SetVideoMode(32, 32, 0, 0);

	srand(time(NULL)+getpid());

	for (x = 0; x < GAMMA_COMPONENTS; x++) {
		n[x] = rand()%360;
		nd[x] = (rand()&1)?-1:1;
		nt[x] = rand()%720 + 100;
	}
	
	for (;;) {
		for (x = 0; x < GAMMA_COMPONENTS; x++) {
			for (y = 0; y < GAMMA_RESOLUTION; y++) {
				double t = (double)(y-GAMMA_RESOLUTION/2) / (double)(GAMMA_RESOLUTION/2);

				t = cos((t*M_PI) + ((n[x]*M_PI)/180.0));

				ramp_out[x][y] = (t * 32767) + 32767;
			}

			if (--nt[x] < 0) {
				nd[x] = -nd[x];
				nt[x] = rand()%720 + 100;
			}

			n[x] += nd[x];

			if (n[x] < 0) n[x] += 360;
			else if (n[x] >= 360) n[x] -= 360;
		}

		if (SDL_SetGammaRamp(ramp_out[0], ramp_out[1], ramp_out[2]) < 0){ 
			printf("%s\n", SDL_GetError());
			sleep(1);
			return 1;
		}
			
		SDL_Delay(10);
		while (SDL_PollEvent(&event)) {
			switch (event.type) {
				case SDL_KEYDOWN:
					if (event.key.keysym.sym == SDLK_q)
						cleanup();
					break;
			}
		}
	}

	/* Not reached */
}