snake.c

/*	
	Author			:	ROHIT BABU KADAM
	Description		:	Snake game using opengl
	Technology		:	C , OpenGl
	Platform		:	Linux

*/

#include "GameHeader.h"

void helpDisplay()
{
	system("clear");
	printf("\n---------------------[ Snake Game ]------------------------\n");
	printf("\n              Developed by Rohit kadam\n\n");
	printf("-----------------------------------------------------------\n");
	printf("\n p : Start / Play / Pause ");
	printf("\n q : Exit");
	printf("\n     Use arrow key to move the snake ");
	printf("\n [1 - 9] : change level of your game");
	printf("\n-----------------------------------------------------------\n");
	fflush(stdin);
}

void playDisplay()
{
	system("clear");
	helpDisplay();
	printf("\n\n");
	printf("         -------------\n");
	printf("           Score: %d \n",snake_size - 5);
	printf("         -------------");
	printf("\n");
}

void out()
{
	playDisplay();
	printf("\n----GAME OVER----\n");
	initGame();
}

void quit()
{
	printf("\nThank for Playing Game\n");
	printf("-----------------------------------------------------------\n");
	exit(0);
}

void myinit(void)
{
	glPointSize(4.0);
	glMatrixMode( GL_PROJECTION );
	glLoadIdentity();
	gluOrtho2D(0.0, 640.0, 0.0, 480.0);
	glClearColor(0.127, 0.252, 0.0, 0.0);
	initGame();
	play = TRUE;
}

void moveSnake(void)
{	
	int move_x = change -> prev -> x + change_x;
	int move_y = change -> prev -> y + change_y;
	if( (move_x >= 640 ) || ( move_y >= 480) || ( move_x <= 0 ) || ( move_y <= 0 ) || search(move_x , move_y) )
			out();
	else
	{
		if(checkEqualNode(move_x , move_y , food_x , food_y))
		{
			addNode(change);
			playDisplay();
			createFood();	
		}	

		change -> x  =  move_x;
		change -> y  =  move_y;

		drawSnake();
		drawHead( change -> x , change -> y);
		displayFood();

		glFlush();	
		wait_for_time(speed);

		change = change -> next;	
		glutPostRedisplay();	
	}		
}

void mydisplay(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
    glFlush();
    if(play)
		moveSnake();
	else
	{
		playDisplay();
		drawSnake();
		drawHead( change -> prev -> x , change -> prev -> y );
		displayFood();
		glFlush();
	}
}

void mySpecialKeyboard(int key, int x, int y)
{ 
	if(play)
	{
 		switch(key)
		{ 
			case GLUT_KEY_RIGHT	: 	
				if( direction != LEFT )
				{
					direction = RIGHT;
					change_x = 11;
					change_y = 0;
				}	
				break;
		
			case GLUT_KEY_LEFT	: 	
				if( direction != RIGHT )
				{
					direction = LEFT;
					change_x = -11;
					change_y = 0;
				}	
				break;

	  		case GLUT_KEY_UP	: 	
				if( direction != DOWN )
				{
					direction = UP;
					change_x = 0;
					change_y = 11;
				}		
			 	break;

			case GLUT_KEY_DOWN	: 	
				if( direction != UP )
				{
					direction = DOWN;
					change_x = 0;
					change_y = -11;
				}	
				break;
		}
		
		glutPostRedisplay();

	}
}

void myKeyboard(unsigned char key, int x, int y)
{ 


 	switch(key)
	{ 
		case 'p':	
			if(play)
			{
				play = FALSE;
			}
			else
				play = TRUE;
			break;
  		
  		case 'q':	
			out();
  			quit();
  			break;

  		case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9':
  			speed = (int) key - 48;
  			break;
	
	}
	glutPostRedisplay();

}


	

int main(int argc, char** argv)
{
	char ch;
	helpDisplay();
	while(1)
	{
		fflush(stdin);
		printf("\n\nEnter your Choice: ");
		scanf(" %c",&ch);
		if( ch == 'p')
		{
    		glutInit(&argc, argv);
	    	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    		glutInitWindowSize(640,480);
    		glutInitWindowPosition(800,300);
    		glutCreateWindow("Snake Game");
    		glutDisplayFunc(mydisplay);// Registering the display function
			glutSpecialFunc(mySpecialKeyboard);
			glutKeyboardFunc(myKeyboard);
			myinit();
			glutMainLoop();
		}else if(ch == 'q')
		{
			quit();
		}else
			helpDisplay();
	}
	printf("\n");	    
	return 0;
}