我发现了一个SFML C ++蛇游戏，我一直在搞乱它并改变一些东西，但我能解决的一个问题是如何让它变得更加流畅/响应更快箭头键按下。现在它正在使用enum Direction {Up, Down, Left, Right};和
while (window.isOpen())
{
sf::Vector2f lastPosition(snakeBody[0].getPosition().x, snakeBody[0].getPosition().y);
// Event
sf::Event event;
while (window.pollEvent(event))
{
//.....
if (event.type == sf::Event::KeyPressed && event.key.code
== sf::Keyboard::Return)
{
//clock.restart;
if (!currentlyPlaying)
currentlyPlaying = true;
move = Down;
New_Game(snakeBody, window_width, window_height, engine, apple, score, scoreText, lowBounds);
mode = 1;
moveClock.restart();
//start game
}
if(inputClock.getElapsedTime().asSeconds() >= 0.07)
{
if(event.key.code == sf::Keyboard::Up && move != Down)
move = Up;
inputClock.restart();
if(event.key.code == sf::Keyboard::Down && move != Up)
move = Down;
inputClock.restart();
if(event.key.code == sf::Keyboard::Left && move != Right)
move = Left;
inputClock.restart();
if(event.key.code == sf::Keyboard::Right && move != Left)
move = Right;
inputClock.restart();
}
}
目前比赛令人沮丧，因为我无法按照自己的意愿行动。有没有办法让控件更具响应性，或者它是否已经能够像我的硬件那样快速响应按键？
我是OOP和SFML的完全初学者，所以我在理解时钟方面遇到了一些麻烦，并且在其他语言中查看蛇形游戏以便将其转换为此。如果需要，我可以发布整个代码。
所以我知道它并不漂亮，但这里是整个代码：
#include <iostream>
#include <SFML/Graphics.hpp>
#include <vector>
#include <string>
#include <fstream>
#include <sstream>
// Global directions
enum Direction {Up, Down, Left, Right};
// Reads high scores
void High_Scores(std::vector<int> &top10scores)
{
top10scores.clear();
std::string line;
std::ifstream highscores("highscores.txt");
while (std::getline(highscores, line))
top10scores.push_back(stoi(line));
highscores.close();
}
// Checks new score against high scores
void New_High(std::vector<int> newScores)
{
std::ofstream fileoutput;
fileoutput.open("highscores.txt");
for (int i = 0; i < 10; i++)
fileoutput << newScores[i] << "\n";
fileoutput.close();
}
// Writes over highscores.txt file
int Update_Scores(int &score, std::vector<int> &top10scores)
{
for (int i = 0; i < 10; i++)
{
if (score >= top10scores[i])
{
for (int j = 9; j >= 0+i; j--)
{
top10scores[j] = top10scores[j-1];
}
top10scores[i] = score;
New_High(top10scores);
High_Scores(top10scores);
return i;
}
}
return 11;
}
// Start menu
void Welcome_Screen(sf::RenderWindow &window)
{
sf::Texture texture;
texture.loadFromFile("welcome2.png");
sf::Sprite background(texture);
// Create welcome text
sf::Font font;
if (!font.loadFromFile("bonzai.ttf"))
std::cout << "Can't find the font file 'bonzai.ttf'" << std::endl;
sf::Text text("\n\n\n\n \t\t\t Welcome!\n\t Press 'Enter' to begin.", font, 50);
text.setColor(sf::Color::White);
sf::Text quitText(" 'Esc' to quit", font, 17);
quitText.setColor(sf::Color::Black);
window.clear();
window.draw(background);
window.draw(text);
window.draw(quitText);
window.display();
}
// Basic collision check for apple placement
bool Collision_Detect(std::vector<sf::RectangleShape> &snakeBody, sf::CircleShape &apple)
{
for (int i = 0; i != snakeBody.size(); i++)
{
if (snakeBody[i].getPosition() == apple.getPosition())
return true;
}
return false;
}
// Sets up starting values for game
void New_Game(std::vector<sf::RectangleShape> &snakeBody, int window_width, int window_height,
std::default_random_engine &engine, sf::CircleShape &apple, int score, sf::Text &scoreText,
int lowBounds)
{
score = 0;
scoreText.setString("Score: 0");
snakeBody.clear();
snakeBody.push_back(sf::RectangleShape(sf::Vector2f(20,20))); // one square
snakeBody[0].setPosition(window_width / 2, window_height / 2 - 120);
snakeBody[0].setFillColor(sf::Color(200,255,200));
snakeBody[0].setOutlineThickness(-1);
snakeBody[0].setOutlineColor(sf::Color::Black);
std::uniform_int_distribution<int> xPosition(lowBounds, 39);
auto randX = std::bind(xPosition, std::ref(engine));
std::uniform_int_distribution<int> yPosition(lowBounds, 23); // path length of 20 pixels I think
auto randY = std::bind(yPosition, std::ref(engine));
do
apple.setPosition(randX()*20+10, randY()*20+10);
while (Collision_Detect(snakeBody, apple));
for (int i = 0; i < 2; i++)
{
snakeBody.push_back(sf::RectangleShape(sf::Vector2f(20,20)));
snakeBody[snakeBody.size()-1].setFillColor(sf::Color(100,150,100));
snakeBody[snakeBody.size()-1].setOutlineThickness(-1);
snakeBody[snakeBody.size()-1].setOutlineColor(sf::Color::Black);
snakeBody.back().setPosition(snakeBody.begin()->getPosition().x,
snakeBody.begin()->getPosition().y);
}
}
//Display all blocks of snake
void Draw_Snake(sf::RenderWindow &window, std::vector<sf::RectangleShape> &snakeBody)
{
for (int i = 0; i != snakeBody.size(); i++)
window.draw(snakeBody[i]);
}
// Moves snake's head and tail
void Move_Snake(std::vector<sf::RectangleShape> &snakeBody, sf::Vector2f &lastPosition, int move)
{
switch (move)
{
case Up:
snakeBody[0].move(0, -20);
break;
case Down:
snakeBody[0].move(0, 20);
break;
case Left:
snakeBody[0].move(-20, 0);
break;
case Right:
snakeBody[0].move(20, 0);
break;
default:
break;
}
sf::Vector2f newPosition(lastPosition);
if (snakeBody.size() > 1)
{
for (int i = 1; i != snakeBody.size(); i++)
{
lastPosition = snakeBody[i].getPosition();
snakeBody[i].setPosition(newPosition);
newPosition = lastPosition;
}
}
}
// Apple placement
bool Apple_Placement(int lowBounds, std::default_random_engine &engine,
std::vector<sf::RectangleShape> &snakeBody, sf::CircleShape &apple, sf::Clock &immuneTimer)
{
std::uniform_int_distribution<int> xPosition(lowBounds, 39);
auto randX = std::bind(xPosition, std::ref(engine));
std::uniform_int_distribution<int> yPosition(lowBounds, 23);
auto randY = std::bind(yPosition, std::ref(engine));
if ((apple.getPosition().x == snakeBody[0].getPosition().x + 10) &&
(apple.getPosition().y == snakeBody[0].getPosition().y + 10))
{
// for (int i = 0; i < 2; i++)
// {
snakeBody.push_back(sf::RectangleShape(sf::Vector2f(20,20)));
snakeBody[snakeBody.size()-1].setFillColor(sf::Color(100,150,100));
snakeBody[snakeBody.size()-1].setOutlineThickness(-1);
snakeBody[snakeBody.size()-1].setOutlineColor(sf::Color::Black);
snakeBody.back().setPosition(snakeBody.begin()->getPosition().x, snakeBody.begin()->getPosition().y);
// }
do
apple.setPosition(randX()*20+10, randY()*20+10);
while (Collision_Detect(snakeBody, apple));
immuneTimer.restart();
return true;
}
else
return false;
}
// Checks body collision and out of bounds
bool Snake_Alive(std::vector<sf::RectangleShape> &snakeBody, sf::Clock &immuneTimer)
{
if (snakeBody[0].getPosition().x < 0 || snakeBody[0].getPosition().x > 790
|| snakeBody[0].getPosition().y < 0 || snakeBody[0].getPosition().y > 460)
{
// snakeBody[0].setFillColor(sf::Color::Yellow);
return false;
}
if(immuneTimer.getElapsedTime().asSeconds() >= .15)
{
for (int i = 1; i != snakeBody.size(); i++)
{
if (snakeBody[0].getPosition() == snakeBody[i].getPosition())
{
// snakeBody[i].setFillColor(sf::Color::Yellow);
return false;
}
}
}
return true;
}
int main()
{
int window_width = 800, window_height = 600;
int bitsPerPixel = 24, start = 0, mode = 0, score = 0, difficulty = 2, lowBounds = 0;
std::vector<int> top10scores;
std::vector<sf::RectangleShape> snakeBody;
int move;
bool currentlyPlaying = false;
// Create main window
sf::RenderWindow window(sf::VideoMode(window_width, window_height,
bitsPerPixel), "Snake!", sf::Style::Close);
window.setVerticalSyncEnabled(true);
// Set the icon
sf::Image icon;
if (!icon.loadFromFile("icon.png"))
return EXIT_FAILURE;
window.setIcon(icon.getSize().x, icon.getSize().y, icon.getPixelsPtr());
// Game board
sf::Texture texture;
texture.loadFromFile("grass.png"); //replace with game board
sf::Sprite grass(texture);
// Apple
sf::CircleShape apple(10);
apple.setOutlineThickness(-1); // should be diameter of 20
apple.setOutlineColor(sf::Color::Black);
apple.setFillColor(sf::Color::Red);
apple.setOrigin(apple.getRadius(), apple.getRadius());
// Random generator
std::random_device seed_device;
std::default_random_engine engine(seed_device());
// Clocks
sf::Clock moveClock;
sf::Clock inputClock;
sf::Clock immuneTimer;
// Score box
sf::RectangleShape scoreBox(sf::Vector2f(window_width, window_height - 480));
scoreBox.setFillColor(sf::Color(0,200,0));
scoreBox.setOutlineColor(sf::Color::Black);
scoreBox.setOutlineThickness(-3.f);
scoreBox.setPosition(0, 480);
sf::Font font;
if (!font.loadFromFile("bonzai.ttf"))
std::cout << "Can't find the font file 'bonzai.ttf'" << std::endl;
sf::Text scoreText("Score: ", font, 60);
scoreText.setColor(sf::Color::White);
scoreText.setPosition(314, 497);
sf::Text pauseText("GAME PAUSED", font, 80);
pauseText.setColor(sf::Color::Black);
pauseText.setPosition(174, 185);
sf::Text overText(" GAME OVER", font, 78);
overText.setColor(sf::Color(150,0,0));
overText.setPosition(174, 185);
sf::Text newquitText("Pause: 'P'\nNew game: 'Enter'\nQuit to main menu: 'Q'", font, 20);
newquitText.setColor(sf::Color::Black);
newquitText.setPosition(5, 525);
sf::Text highScoreText("", font, 85);
highScoreText.setColor(sf::Color::Black);
//High scores
High_Scores(top10scores);
if (difficulty == 2)
lowBounds = 0;
New_Game(snakeBody, window_width, window_height, engine, apple, score, scoreText, lowBounds);
// Main game loop
while (window.isOpen())
{
sf::Vector2f lastPosition(snakeBody[0].getPosition().x, snakeBody[0].getPosition().y);
// Event
sf::Event event;
while (window.pollEvent(event))
{
// Welcome screen
if (start <= 1)
{
Welcome_Screen(window);
start++;
}
// Close window: Exit
if (event.type == sf::Event::Closed)
window.close();
// Esc pressed: Exit
if (event.type == sf::Event::KeyPressed && event.key.code
== sf::Keyboard::Escape)
window.close();
// Q pressed: Exit to main menu
if (event.type == sf::Event::KeyPressed && event.key.code
== sf::Keyboard::Q)
{
start = 1;
mode = 0;
}
if (event.type == sf::Event::KeyPressed && event.key.code
== sf::Keyboard::Return)
{
if (!currentlyPlaying)
currentlyPlaying = true;
move = Down;
New_Game(snakeBody, window_width, window_height, engine, apple, score, scoreText, lowBounds);
mode = 1;
score = 0;
moveClock.restart();
inputClock.restart();
immuneTimer.restart();
}
if(event.type == sf::Event::KeyPressed && inputClock.getElapsedTime().asSeconds() >= 0.06) //0.07
{
if(event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Up && move != Down)
{
move = Up;
inputClock.restart();
}
if(event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Down && move != Up)
{
move = Down;
inputClock.restart();
}
if(event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Left && move != Right)
{
move = Left;
inputClock.restart();
}
if(event.key.code == sf::Keyboard::Right && move != Left)
{
move = Right;
inputClock.restart();
}
}
// P pressed: Pause simulation
if (event.type == sf::Event::KeyPressed && event.key.code
== sf::Keyboard::P)
{
if (mode == 1)
{
window.draw(pauseText);
window.display();
}
mode *= -1;
moveClock.restart();
immuneTimer.restart();
inputClock.restart();
}
}
if (mode == 1)
{
window.clear();
window.draw(grass);
window.draw(apple);
Draw_Snake(window, snakeBody);
window.draw(scoreBox);
window.draw(scoreText);
window.draw(newquitText);
if(moveClock.getElapsedTime().asSeconds() >= .075) // change back to 0.09
{
Move_Snake(snakeBody, lastPosition, move);
moveClock.restart();
}
if(Apple_Placement(lowBounds, engine, snakeBody, apple, immuneTimer))
{
if (difficulty == 1)
score += 5;
else if (difficulty == 2)
score += 10;
else
score += 20;
std::string newScore = std::to_string(score);
scoreText.setString("Score: " + newScore);
}
if(!Snake_Alive(snakeBody, immuneTimer))
{
window.draw(overText);
int scorePlacement = Update_Scores(score, top10scores);
if (scorePlacement != 11)
{
std::string newHighText = std::to_string(scorePlacement+1);
highScoreText.setString("#" + newHighText
+ " out of top 10 scores!");
if (scorePlacement == 9)
highScoreText.setPosition(15, 50);
else
highScoreText.setPosition(30, 50);
window.draw(highScoreText);
}
window.display();
mode = 0;
window.display();
}
window.display();
}
}
return EXIT_SUCCESS;
}
答案 0 :(得分：6)
如果我正确阅读，您的目标是：
有没有办法让控件更具响应性
例如，一直很难进行紧急掉头（没有使用额外空间）。
（1）以下内容:(放入每帧调用的更新函数）
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Up)
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Down)
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Left)
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Right)
将实现平滑移动已指示here。此外，这里有一点article，提供了一些有关“事件检查”与“isKeyPressed（）”的有趣见解。
（2）如果这不起作用，则可能是：
if(inputClock.getElapsedTime().asSeconds() >= 0.07)
如果“inputClock”延迟了再次移动的能力，那么任何障碍（即使是0.07的小增量）都可能导致非期望的输出。
否则，请提供更多代码，以便我自己测试，或者让我知道您从我的建议中获得了什么。
答案 1 :(得分：4)
所以我最终做的是从定时循环中移除控件，但让它们控制第二个移动变量。然后将原始移动设置为等于定时循环内的第二移动变量。最终删除了错误并保持良好的响应能力。
答案 2 :(得分：2)
您的代码中有两个错误，我可以在原始示例代码中看到：
您只需要对KeyPressed事件采取行动，然后完全删除时序逻辑。
通过其余的路径\答案，我不认为这两个错误一下子就被修复了......
只是删除时间逻辑（如注释中所述）会导致显然奇怪的行为，释放移动键可能会改变蛇的方向，具体取决于多次按键\释放的顺序。
检查isKeyPressed（根据@Donald的回答）而不是解决按下\发布问题，但是当你同时按下多个时，你还需要决定做什么。当事件通过返回按下时间顺序的顺序解决所有事情时，这可能会使代码过于复杂。
您当前的完整程序似乎修复了KeyPressed问题，但未删除计时器。这样可以防止按键按照您的需要响应。