这是我的第一篇文章,所以我希望我得到这个权利。SFML游戏开发书籍 - 了解FPS计算
我目前正在通过SFML游戏开发书。我想了解介绍示例中FPS的计算方式。
我的游戏类看起来是这样的:
#include "Game.h"
const sf::Time Game::TIME_PER_FRAME = sf::seconds(1.f/60.f);
const float Game::PLAYER_SPEED = 100.f;
Game::Game() : Window(sf::VideoMode(640,480), "ORGELLA") {
isMovingUp = false;
isMovingDown = false;
isMovingLeft = false;
isMovingRight = false;
Player.setRadius(40.f);
Player.setPosition(100.f, 100.f);
Player.setFillColor(sf::Color::Cyan);
font.loadFromFile(resourcePath() + "sansation.ttf");
statsText.setFont(font);
statsText.setPosition(5.f, 5.f);
statsText.setCharacterSize(10);
}
void Game::run() {
sf::Clock clock;
sf::Time timeSinceLastUpdate = sf::Time::Zero;
while (Window.isOpen()) {
sf::Time dt = clock.restart();
timeSinceLastUpdate += dt;
while (timeSinceLastUpdate > TIME_PER_FRAME) {
timeSinceLastUpdate -= TIME_PER_FRAME;
handleEvents();
update(TIME_PER_FRAME);
}
updateGameStats(dt);
render();
}
}
void Game::handleEvents() {
sf::Event event;
while (Window.pollEvent(event)) {
switch (event.type) {
case sf::Event::KeyPressed:
handlePlayerInput(event.key.code, true);
break;
case sf::Event::KeyReleased:
handlePlayerInput(event.key.code, false);
break;
case sf::Event::Closed:
Window.close();
break;
}
}
}
void Game::update(sf::Time dt) {
sf::Vector2f movement(0.f, 0.f);
if (isMovingUp)
movement.y -= PLAYER_SPEED;
if (isMovingDown)
movement.y += PLAYER_SPEED;
if(isMovingLeft)
movement.x -= PLAYER_SPEED;
if (isMovingRight)
movement.x += PLAYER_SPEED;
Player.move(movement * dt.asSeconds());
}
void Game::render() {
Window.clear();
Window.draw(Player);
Window.draw(statsText);
Window.display();
}
void Game::handlePlayerInput(sf::Keyboard::Key key, bool isPressed) {
switch (key) {
case sf::Keyboard::W:
isMovingUp = isPressed;
break;
case sf::Keyboard::S:
isMovingDown = isPressed;
break;
case sf::Keyboard::A:
isMovingLeft = isPressed;
break;
case sf::Keyboard::D:
isMovingRight = isPressed;
break;
}
}
void Game::updateGameStats(sf::Time dt) {
statsTotalTimeElapsed += dt ;
statsNumberOfFrames += 1;
if (statsTotalTimeElapsed >= sf::seconds(1.0f)) {
statsText.setString(
"FPS = " + to_string(statsNumberOfFrames) + "\n" +
"Time/Update = " + to_string(statsTotalTimeElapsed.asMicroseconds()/statsNumberOfFrames) + "us");
statsTotalTimeElapsed -= sf::seconds(1.0f);
statsNumberOfFrames = 0;
}
}
现在,我的问题是这样的。计算出的FPS是如何计算的,并显示在我的屏幕上。从我所能理解的FPS上限为60fps,但是当我运行该应用程序时,显示的FPS约为500 - 1200 FPS。
我在计算这个错误还是只是没有正确理解这个?
我希望这篇文章是好的,我似乎无法找到类似的问题。
任何意见或帮助将不胜感激。
嗨,感谢您的答复。这是有道理的,但不是在当前的游戏循环中发生了什么? Where TIME_PER_FRAME = framerate,第二个循环应该跟踪将其限制为60FPS?再次感谢。 – 2014-09-21 06:17:33