#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <dos.h>
#include <time.h>


void Init_Video(char Drctry[50]);
void Flip(void);
void Storm(void);
void Rain(int nD);

char *pMsg = "Storm!...               Lightning!...";

int nDrps = 700, Ltng = 1;

struct POINT { int x,y,c; };
struct POINT pix[700];

int xmax, ymax, cmax;


int main()
{
	int i;
	randomize();
	Init_Video("d:\\tc\\bgi");
	xmax = getmaxx();
	ymax = getmaxy();
	cmax = getmaxcolor();

	for (i=0; i<nDrps; i++)
	{
		pix[i].x = random(xmax);
		pix[i].y = 0;

		switch (rand()%4)
		{
			case 0:
				pix[i].c = 8;
				break;
			case 1:
				pix[i].c = 7;
				break;
			case 2:
				pix[i].c = 15;
				break;
			default:
				pix[i].c = random(cmax);
		}
	}

	Storm();
	closegraph();

	return 0;
}


void Rain(int nD)
{
	int i;
	for (i=0; i<nD ;i++)
	{
		if (pix[i].x > xmax || pix[i].x < 0)
		{
			pix[i].x = random(xmax);
			pix[i].y = 0;

			switch (rand()%4)
			{
				case 0:
					pix[i].c = 8;
					break;
				case 1:
					pix[i].c = 7;
					break;
				case 2:
					pix[i].c = 15;
					break;
				default:
					pix[i].c = random(cmax);
			}
		}

		if (pix[i].y > ymax || pix[i].y < 0)
		{
			pix[i].x = random(xmax);
			pix[i].y = 0;

			switch (rand()%4)
			{
				case 0:
					pix[i].c = 8;
					break;
				case 1:
					pix[i].c = 7;
					break;
				case 2:
					pix[i].c = 15;
					break;
				default:
					pix[i].c = random(cmax);
			}
		}

		switch (pix[i].c)
		{
			case 8:
				pix[i].y = pix[i].y + random(2);
				pix[i].x = pix[i].x + random(2);
				putpixel(pix[i].x, pix[i].y, pix[i].c);
				break;
			case 7:
				pix[i].y = pix[i].y + random(2) + 1;
				pix[i].x = pix[i].x + random(2);
				putpixel(pix[i].x, pix[i].y, pix[i].c);
				//break;
			case 15:
				pix[i].y = pix[i].y + random(2) + 2;
				pix[i].x = pix[i].x + random(2);
				putpixel(pix[i].x, pix[i].y, pix[i].c);
				//break;
			default:
				pix[i].y = pix[i].y + random(2) + 1;
				pix[i].x = pix[i].x + random(2) - 1;
				putpixel(pix[i].x, pix[i].y, pix[i].c);
		}
	}
}


void Storm()
{
	char c;
	Flip();

	while ((c=getch())=='m' || c=='l')
	{
		if (c=='m')
		{
			printf("Enter Message:");
			gets(pMsg);
			c=' ';
			Flip();
		}

		if (c=='l')
		{
			Ltng = Ltng * -1;
			c=' ';
			setbkcolor(BLACK);
			Flip();
		}
	}
}


void Init_Video(char Drctry[50])
{
	 /* select a driver and mode that supports multiple pages. */
	int gdriver = VGA, gmode = VGAMED, errorcode;

	/* initialize graphics and local variables */
	initgraph(&gdriver, &gmode, Drctry);

	/* read result of initialization */
	errorcode = graphresult();
	if (errorcode != grOk)  /* an error occurred */
	{
		printf("Graphics error: %s\n", grapherrormsg(errorcode));
		printf("Press any key to halt:");
		getch();
		exit(1); /* terminate with an error code */
	}
}


void Flip()
{
	int i, j, k;

	setvisualpage(0);

	j = xmax;

	while (!kbhit())
	{
		settextstyle(random(10), HORIZ_DIR, random(12));
		setcolor(random(cmax));
		k = random(ymax);
		while (j>-textwidth(pMsg) && !kbhit())
		{
			for (i=0; i<2; ++i)
			{
				setactivepage(1 - i);
				cleardevice();

				outtextxy(j, 100, pMsg);
				Rain(nDrps);

				if (Ltng==1)
				{
					if (random(20)==13)
					   k = 3;

					switch(k)
					{
						case 3:
						       setbkcolor(WHITE);
						       //delay(25);
						       break;
						case 2:
						       setbkcolor(LIGHTGRAY);
						       //delay(25);
						       break;
						case 1:
						       setbkcolor(DARKGRAY);
						       //delay(25);
						       break;
						default:
							setbkcolor(BLACK);
					}

					k--;
				}

				j--;
				setvisualpage(i);
                                //delay(500);
			}
		}

		j = xmax;
	}
}