Part I - Fundamentals of C language_ 11. Comprehensive project - greedy snake

1. Program analysis

  I believe everyone knows the game of greedy snake , It is a classic mobile game . Eat food by controlling the direction of the snake head , Make the snake grow longer , To get points , It's simple and fun . Control the direction of the snake through the up, down, left and right keys , Looking for food , You can get a certain score for each bite , And the snake's body will eat longer , The longer the body, the more difficult it is to play , Don't touch the wall , Don't bite your body , I can't bite my tail , Wait for a certain score , You can get through , Then continue to play the next level . 

1.1  Module design

In this game , Get the relationship between the moving direction and the snake's movement from the keyboard input

 

1.2  Module description

Snake initialization

The initialization of snake is actually the initialization of two-dimensional array , The two-dimensional array stores two values , It contains the coordinate information of the snake's body , Its initial position is the middle position of the horizontal and vertical coordinates .

The movement of the snake

The movement of the snake is achieved by changing the coordinate position of the two-dimensional array , For example, when the snake advances one unit to the right , Then change the coordinates of each body position of the tail , At the same time, change the snake head 、 The direction of the snake's body and tail . In this way, on the whole, the snake has advanced one unit .

Snake growth

When the snake eats normal food , The length of the snake will increase , To increase the length of the snake is to add a two-dimensional array to the position of the food and change this position into the head of the snake .

The death of snakes

When a snake hits an obstacle 、 Oneself or when passing customs , Snakes die , Snake death is the destruction of two-dimensional arrays .

The production of food

The location of food is random , These factors are determined by random numbers obtained by random functions . The location of food should not appear on Obstacles and boundaries .

Control keyboard input

By getting the W/w( On )、 S/s( Next )、 A/a( Left )、 D/d( Right ) To change the direction of movement in the snake module , Thus affecting the moving direction of the snake .

2. Project implementation

2.1 Create source files and header files

 

 

2.2 Code implementation

2.2.1 snake .h part

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <ctype.h>
#include <assert.h>
#include <stdbool.h>

#define WIDE 60         // Width 
#define HIGH 20         // Height 


//0. The structure of a snake 
struct Body
{
	int X;
	int Y;
};


//1. Define snake objects 
struct Snack
{
	struct Body body[WIDE * HIGH];
	int size;
}snake;


//2. Define food objects 
struct Food
{
	int X;
	int Y;
}food;


//3. fraction 
int score = 0;


//4. Declarative snake function 
void  InitSnake();


//5. Declare the food function 
void InitFood();


//6. User input awsd The corresponding coordinates when pressing the key 
int kx = 0;
int ky = 0;


//7. The coordinates of the tail of the snake 
int lastX = 0;
int lastY = 0;


//8. Break time 
int sleeptime = 300;

2.2.2  snake .c part

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <ctype.h>
#include <assert.h>
#include <stdbool.h>


#include <conio.h>
#include <Windows.h>
#include " snake .h"



//9. Print scores 
void ShowScore()
{
	//3. Move the cursor 
	COORD coord;
	coord.X = 0;
	coord.Y = HIGH + 2;
	SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
	printf("Game Over!\n");
	printf(" The result is ：%d\n", score);
}


//8. Draw the wall 
void InitWall()
{
	for (size_t i = 0; i <= HIGH; i++)
	{
		for (size_t j = 0; j <= WIDE; j++)
		{
			if (j == WIDE)
			{
				printf("|");
			}
			else if (i == HIGH)
			{
				printf("_");
			}
			else
			{
				printf(" ");
			}
		}

		printf("\n");
	}
}


//4. Define initialization snake function 
void  InitSnake()
{
	snake.size = 2;

	snake.body[0].X = WIDE / 2;      // Snakehead initialization 
	snake.body[0].Y = HIGH / 2;

	snake.body[1].X = WIDE / 2 - 1;  // Snake body initialization 
	snake.body[1].Y = HIGH / 2;
}


//5. Initialization of food 
void InitFood()
{
	food.X = rand() % WIDE;   //0-59
	food.Y = rand() % HIGH;   //0-59
}


//6. Initialize the interface control 
void InitUI()
{
	//1. Draw a snake 
	COORD coord;
	for (size_t i = 0; i < snake.size; i++)
	{
		coord.X = snake.body[i].X;
		coord.Y = snake.body[i].Y;
		SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);

		if (i == 0)
		{
			putchar('@');
		}
		else
		{
			putchar('*');
		}
	}


	// Remove the snaketail 
	coord.X = lastX;
	coord.Y = lastY;
	SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
	putchar(' ');

	//2. Painting food 
	coord.X = food.X;
	coord.Y = food.Y;
	SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
	putchar('#');

}


//7. Start the game 
void PlayGame()
{
	char key = 'd';
	//1. Judge whether the snake hit the wall 
	while (snake.body[0].X >= 0 && snake.body[0].X < WIDE && snake.body[0].Y >= 0 && snake.body[0].Y < HIGH)
	{
		
		InitUI();    // Update the snake 
		//2. Accept user key input 
		if (_kbhit())
		{
			key = _getch();
		}

		switch (key)
		{
		case 'w':kx = 0; ky = -1; break;
		case 's':kx = 0; ky = +1; break;
		case 'd':kx = +1; ky = 0; break;
		case 'a':kx = -1; ky = 0; break;
		default:
			break;
		}



		//3. Snake bumps into body 
		for (size_t i = 1; i < snake.size; i++)
		{
			if (snake.body[0].X == snake.body[i].X && snake.body[0].Y == snake.body[i].Y)
			{
				return;      // Game over 
			}
		}

		//4. Snake strikes food 
		if (snake.body[0].X == food.X && snake.body[0].Y == food.Y)
		{
			
			InitFood();                 // The food disappeared 
			snake.size++;               // Physical growth 
			score = score + 10;         // Bonus points 
			sleeptime = sleeptime - 10; // Speed up 
		}


		//5.1 Store snaketail coordinates 
		lastX = snake.body[snake.size - 1].X;
		lastY = snake.body[snake.size - 1].Y;

		//5. Snake moves 
		for (size_t i = snake.size - 1; i > 0; i--)
		{
			snake.body[i].X = snake.body[i - 1].X;
			snake.body[i].Y = snake.body[i - 1].Y;
		}
		snake.body[0].X = snake.body[0].X + kx;
		snake.body[0].Y = snake.body[0].Y + ky;

		Sleep(sleeptime);
	}
	return;// Game over 
}



int main()
{
	CONSOLE_CURSOR_INFO cci;
	cci.dwSize = sizeof(cci);
	cci.bVisible = FALSE;
	SetConsoleCursorInfo(GetStdHandle(STD_OUTPUT_HANDLE), &cci);

	srand(time(NULL));    // Plant random seeds 
	InitSnake();          // Initialize snake 
	InitWall();           // Draw the wall 
	InitFood();           // Initializing food 
	InitUI();             // Draw food and snakes 

	//3. Move the cursor 
	COORD coord;
	coord.X = WIDE + 2;
	coord.Y = HIGH;
	SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
	printf(" Direction key ：W、S、A、D\n");

	PlayGame();           // Start the game 
	ShowScore();          // Number of printed copies 

	system("pause");

	return 0;
}