贪吃蛇（七）方向和屏幕刷新

由于用户玩游戏的时候，程序需要一边接收用户的输入，一边需要刷新屏幕，此时就需要引用线程来解决此问题。

实现思路

linux线程库pthread，只需要创建pthread_t 类型的线程变量，然后将线程变量与函数进行绑定即可，不需要额外的调用。

#include"curses.h"
#include "stdlib.h"
#include "pthread.h"


struct SnakeNode
{
  int row;
  int col;
  struct SnakeNode* next; 
};


int key;  // user input
struct SnakeNode* head = NULL;
struct SnakeNode* tail = NULL;

void addNode();
void mapinit();



void snakeinit()
{
  // free 
  struct SnakeNode* p;
  while(head != NULL)
  {
    p = head;
    head = head->next;
    free(p);
  }
  head = (struct SnakeNode*)malloc(sizeof(struct SnakeNode));
  head->row = 2;
  head->col = 2;
  head->next = NULL;
  tail = head;

  addNode();
  addNode();
}

void addNode()
{  
  struct SnakeNode* node = (struct SnakeNode*)malloc(sizeof(struct SnakeNode));
  node->row = tail->row;
  node->col = tail->col + 1;
  node->next = NULL;
  tail->next = node;
  tail = node;
}

void deleteNode()
{
  struct SnakeNode* p;
  p = head;
  head = head->next;
  free(p);
}

void moveSnake()
{
  addNode();
  deleteNode();
  // if snake is over.
  if(tail->row == 0 || tail->col == 0 || tail->row >= 20 || tail->col >= 19)
  {
    snakeinit();
  }
}

void cursesinit()
{
   
  initscr();
  keypad(stdscr,1);
}

int hasSnake(int row,int col)
{
  struct SnakeNode* p = head;
  while(p!=NULL)
  {
    if(row == p->row && col == p->col)
	return 1;
    p = p->next;
  }
  return 0; 
}


void mapinit()
{
  int row;
  int col;
  move(0,0);
  for(row = 0;row < 20;row++)
  {
   // one
   if(row == 0 || row == 19)
   {
     for(col = 0;col < 19;col++)
        printw("--");
   }
   // two
   else
   {
     for(col = 0;col < 20;col++)
     {
        if(col == 0 || col == 19 ) printw("|");
	else if(hasSnake(row,col))
	{
	  printw("[]");
	}
	else
	{
	  printw("  "); 
	}
     }
   }

    printw("\n");
  }

  printw("By hongzhe key:%d\n",key);
}


void refreshScreen()
{
  while(1)
  {
	moveSnake(); // snake forward 
	mapinit();   // fresh map
	refresh();   // fresh screen
	usleep(500000);	// sleep(0.5)
  }
  return;
}


void changeDir()
{
  
  while(1)
  {
    key = getch();
    switch(key)
    {
      case KEY_DOWN:
	printw("\rDOWN\t");
	break;
      case KEY_RIGHT:
	printw("\rRIGHT\t");
	break;
      case KEY_LEFT:
	printw("\rLEFT\t");
	break;
      case KEY_UP:
	printw("\rUP\t");
	break;

    }
  }
  return;
}

int main()
{
  pthread_t t1;
  pthread_t t2;
 
  cursesinit();  
  snakeinit();
  mapinit();
  

  pthread_create(&t1,NULL,refreshScreen,NULL);
  pthread_create(&t2,NULL,changeDir,NULL);

  while(1);

  getch();  
  endwin();
  return 0;
}

学习打卡