snake.cpp

VC编写的贪吃蛇

#include "Snake.h"

Snake::Snake()
{
	SnakeInit();
	FoodInit();
}

Snake::~Snake()
{
	Node* node = head;
	Node* next = node->next;

	while (next != NULL)
	{
		delete node;
		node = next;
		next = node->next;
	}
	delete node;
}

void	Snake::FoodInit(void)
{
	int x, y;

	x = (rand() % WIDTH) / 20;
	y = (rand() % HEIGHT) / 20;

	if (x == 0)
		x += 2;
	else if (x == GRIDX - 1)
		x -= 2;

	if (y == 0)
		y += 2;
	else if (y == GRIDY - 1)
		y -= 2;

	candy.x = x;
	candy.y = y;

	while (!IsFoodPositionOK())
	{
		x = (rand() % WIDTH) / 20;
		y = (rand() % HEIGHT) / 20;

		if (x == 0)
			x += 2;
		else if (x == GRIDX - 1)
			x -= 2;

		if (y == 0)
			y += 2;
		else if (y == GRIDY - 1)
			y -= 2;

		candy.x = x;
		candy.y = y;
	}
	candy.exist = true;
}

void	Snake::SnakeInit(void)
{
	int x, y;
	x = (rand() % WIDTH) / 20;
	y = (rand() % HEIGHT) / 20;

	if (x == 0)
		x++;
	else if (x == GRIDX - 1)
		x--;

	if (y == 0)
		y++;
	else if (y == GRIDY - 1)
		y--;

	head = tail = new Node;
	head->x = x;
	head->y = y;
	head->prev = head->next = NULL;
}

void	Snake::SnakeEat(void)
{
	candy.exist = false;

	int x = candy.x, y = candy.y;
	Node* node = new Node;

	switch (m_dir)
	{
		case DIR_UP:
			y--;
			break;
		case DIR_RIGHT:
			x++;
			break;
		case DIR_DOWN:
			y++;
			break;
		case DIR_LEFT:
			x--;
			break;
		default: break;
	}
	
	node->x = x;
	node->y = y;
	node->prev = NULL;
	node->next = head;
	head->prev = node;
	head = node;
}

void	Snake::SnakeMove(void)
{
	clear_x = tail->x;
	clear_y = tail->y;

	Node* node = tail;
	Node* prev = node->prev;
	while (prev != NULL)
	{
		node->x = prev->x;
		node->y = prev->y;
		node = prev;
		prev = node->prev;
	}
	
	switch (m_dir)
	{
		case DIR_UP:
			head->y--;
			break;
		case DIR_RIGHT:
			head->x++;
			break;
		case DIR_DOWN:
			head->y++;
			break;
		case DIR_LEFT:
			head->x--;
			break;
		default: break;
	}

	if (head->x == candy.x && head->y == candy.y && candy.exist)
	{
		SnakeEat();
	}
}

void	Snake::SnakeDraw(void)
{
	HDC		hDc;
	RECT	rect;
	HBRUSH	hBrush;

	hDc = GetDC(m_hWnd);
	
	if (candy.exist)
	{
		hBrush = CreateSolidBrush(RGB(0xff, 0x00, 0x00));
		rect.left	= candy.x * 20;
		rect.top	= candy.y * 20;
		rect.right	= rect.left + 20;
		rect.bottom = rect.top + 20;
		FillRect(hDc, &rect, hBrush);
	}

	hBrush = CreateSolidBrush(RGB(0xff, 0xff, 0xff));
	rect.left	= clear_x * 20;
	rect.top	= clear_y * 20;
	rect.right	= rect.left + 20;
	rect.bottom = rect.top + 20;
	FillRect(hDc, &rect, hBrush);

	hBrush = CreateSolidBrush(RGB(0x00, 0x00, 0xff));
	Node* node = head;
	while (node != NULL)
	{
		rect.left	= node->x * 20;
		rect.top	= node->y * 20;
		rect.right	= rect.left + 20;
		rect.bottom = rect.top + 20;
		FillRect(hDc, &rect, hBrush);
		node = node->next;
	}
}

void	Snake::SetDirection(int dir)
{
	int dir_diff = dir - m_dir;
	if (dir_diff < 0)
		dir_diff = -dir_diff;

	if (200 == dir_diff)
	{
		if (head == tail)
			m_dir = dir;
	}
	else
	{
		m_dir = dir;
	}
}

void	Snake::SetHWND(HWND hWnd)
{
	m_hWnd = hWnd;
}

bool	Snake::IsSnakeDead(void)
{
	int x, y;
	x = head->x;
	y = head->y;

	if (x < 0 || x >= GRIDX)
		return true;

	if (y < 0 || y >= GRIDY)
		return true;

	Node* node = head->next;
	while (node != NULL)
	{
		if (node->x == head->x && node->y == head->y)
			return true;
		node = node->next;
	}

	return false;
}

bool	Snake::IsFoodPositionOK(void)
{
	if (NULL == head)
		return true;
	else
	{
		Node* node = head;
		while (node != NULL)
		{
			if (node->x == candy.x && node->y == candy.y)
				return false;
			node = node->next;
		}
		return true;
	}
}