C - SDL (Simple Directmedia Layer) - Creating a multicolored window

May you want to create a night club with the SDL library?

It is maybe possible.
With the code below of this tutorial, you can generate a different color every millisecond.

So, why waiting?
Let’s dance!

#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <unistd.h>
#include <sys/time.h>
#include <SDL/SDL.h>

typedef struct s_sdl
{
	SDL_Surface *screen;
	SDL_Surface *rectangle;
	SDL_Rect *position;
} t_sdl;

int creation_rect(t_sdl *sdl, int r1, int r2, int r3)
{
	sdl->rectangle = NULL;
	if (SDL_FillRect(sdl->screen, NULL, SDL_MapRGB(sdl->screen->format, r1, r2, r3)) == -1)
	{
		fprintf(stderr, "Error: %s\n", SDL_GetError());
		return (1);
	}
	if (SDL_Flip(sdl->screen) == -1)
	{
		fprintf(stderr, "Error: %s\n", SDL_GetError());
		return (1);
	}
	return (0);
}

int init(t_sdl *sdl)
{
	int i = 0;
	if (SDL_Init(SDL_INIT_EVERYTHING) == -1)
	{
		fprintf(stderr, "Error: %s\n", strerror(errno));
		return (1);
	}
	if ((sdl->screen = SDL_SetVideoMode(800, 600, 32, SDL_HWSURFACE)) == NULL)
	{
		fprintf(stderr, "Error: %s", SDL_GetError());
		return (1);
	}
	SDL_WM_SetCaption("Night club! :D", NULL);
	if (SDL_FillRect(sdl->screen, NULL, SDL_MapRGB(sdl->screen->format, 255, 32, 45)) == -1)
	{
		fprintf(stderr, "Error: %s\n", SDL_GetError());
		return (1);
	}
	if (SDL_Flip(sdl->screen) == -1)
	{
		fprintf(stderr, "Error: %s\n", SDL_GetError());
		return (1);
	}
	while (i < 100)
	{
		creation_rect(sdl, my_random(), my_random(), my_random());
		++i;
	}
	SDL_FreeSurface(sdl->rectangle);
	return (0);
}

int my_random()
{
	double seed;
	int fp;
	time_t t1;
	struct timeval tv;
	gettimeofday(&tv, NULL);
	seed = (tv.tv_sec) * 1000 + (tv.tv_usec) / 1000;
	srand(seed);
	usleep(10000);
	return (rand() % 255);
}

int main()
{
	t_sdl sdl;
	sdl.screen = NULL;
	if (init(&sdl))
		return (1);
	return (0);
}

Of course, we need to run this:

$ gcc main.c -c ; gcc main.o -o go -lSDL ; ./go

I hope you like colors.