(原答复:)
我没有足够的信誉发表评论,因此我得把它放在这儿......
所以,如果我理解正确的话,你是说你想要朝着鼠标的位置射击弹丸,但不希望它们一旦被解雇就追随它的位置?在这种情况下:
我看到你有代码在那个for-loop里面画出射弹,这让我相信你正在不断地调用循环。但是同样的循环也包含用于射弹的代码,这意味着你也在不断地调用这个“火”代码。因此,您在每次循环迭代中将射弹转向当前鼠标位置,这意味着它们将始终遵循当前鼠标位置。
你应该做的是移动代码来拍摄投射物并且只调用一次(你只能投射一次投射物,对吗?)所以一个投射物的方向矢量不会经常改变,导致你陈述的问题。
并确保始终分离逻辑和渲染。理想情况下,您应该以固定的时间间隔更新物理(例如弹丸更新),以便游戏在所有机器上运行相同,并分别绘制所有东西。
如果你想在弹丸始终跟随鼠标,你可以使用这个(半伪)代码(我用我的游戏之一这段代码):
sf::Vector2f normalizedVector = normalize(mousePos - projectilePos);
normalizedVector.x *= speed * deltaTime;
normalizedVector.y *= speed * deltaTime;
projectile.move(normalizedVector);
(编辑:)
我做了一个快速的示例项目,工程。这并没有使用你的所有代码,但希望能给你一个想法如何做。
下面是一个简短的视频显示什么下面的代码所做的:https://webmshare.com/play/jQqvd
的main.cpp
#include <SFML/Graphics.hpp>
#include "projectile.h"
int main() {
const sf::FloatRect viewRect(0.0f, 0.0f, 800.0f, 600.0f);
sf::RenderWindow window(sf::VideoMode(viewRect.width, viewRect.height), "Test");
window.setFramerateLimit(120);
window.setVerticalSyncEnabled(false);
window.setKeyRepeatEnabled(false);
sf::Clock deltaClock;
const sf::Time timePerFrame = sf::seconds(1.0f/60.0f);
sf::Time timeSinceLastUpdate = sf::Time::Zero;
std::vector<Projectile> projectiles;
while (window.isOpen()) {
timeSinceLastUpdate += deltaClock.restart();
// process events
{
sf::Event evt;
while (window.pollEvent(evt)) {
switch (evt.type) {
case sf::Event::Closed: { window.close(); } break;
// shoot with left mouse button
case sf::Event::MouseButtonPressed: { switch (evt.mouseButton.button) { case sf::Mouse::Button::Left: {
const sf::Vector2f center(viewRect.left + viewRect.width/2, viewRect.top + viewRect.height/2);
const sf::Vector2f mousePos(window.mapPixelToCoords(sf::Mouse::getPosition(window)));
const float angle = atan2(mousePos.y - center.y, mousePos.x - center.x);
projectiles.push_back(Projectile(center, angle));
} break; default: {} break; } } break;
default: {} break;
}
}
}
// update
{
while (timeSinceLastUpdate > timePerFrame) {
timeSinceLastUpdate -= timePerFrame;
// update projectiles
{
for (std::size_t i = 0; i < projectiles.size(); ++i) {
Projectile &proj = projectiles[i];
proj.update(timePerFrame);
if (!viewRect.intersects(proj.getBoundingBox())) { proj.destroy(); }
}
projectiles.erase(std::remove_if(projectiles.begin(), projectiles.end(), [](Projectile const &p) { return p.getCanBeRemoved(); }), projectiles.end());
}
}
}
// render
{
window.clear();
for (std::size_t i = 0; i < projectiles.size(); ++i) {
window.draw(projectiles[i]);
}
window.display();
}
}
return EXIT_SUCCESS;
}
弹。H:
#ifndef PROJECTILE_H_INCLUDED
#define PROJECTILE_H_INCLUDED
#include <SFML/Graphics.hpp>
class Projectile : public sf::Drawable {
public:
Projectile();
Projectile(const sf::Vector2f pos, const float angle);
virtual ~Projectile();
const bool &getCanBeRemoved() const;
const sf::FloatRect &getBoundingBox() const;
void destroy();
void update(const sf::Time dt);
private:
virtual void draw(sf::RenderTarget &renderTarget, sf::RenderStates renderStates) const;
bool canBeRemoved_;
sf::FloatRect boundingBox_;
float angle_;
float speed_;
sf::RectangleShape shape_;
};
#endif
projectile.cpp:
#include "projectile.h"
Projectile::Projectile() :
canBeRemoved_(true),
boundingBox_(sf::FloatRect()),
angle_(0.0f),
speed_(0.0f)
{
}
Projectile::Projectile(const sf::Vector2f pos, const float angle) {
canBeRemoved_ = false;
boundingBox_ = sf::FloatRect(pos, sf::Vector2f(10.0f, 10.0f));
angle_ = angle;
speed_ = 0.5f;
shape_.setPosition(sf::Vector2f(boundingBox_.left, boundingBox_.top));
shape_.setSize(sf::Vector2f(boundingBox_.width, boundingBox_.height));
shape_.setFillColor(sf::Color(255, 255, 255));
}
Projectile::~Projectile() {
}
const bool &Projectile::getCanBeRemoved() const {
return canBeRemoved_;
}
const sf::FloatRect &Projectile::getBoundingBox() const {
return boundingBox_;
}
void Projectile::destroy() {
canBeRemoved_ = true;
}
void Projectile::update(const sf::Time dt) {
boundingBox_.left += static_cast<float>(std::cos(angle_) * speed_ * dt.asMilliseconds());
boundingBox_.top += static_cast<float>(std::sin(angle_) * speed_ * dt.asMilliseconds());
shape_.setPosition(boundingBox_.left, boundingBox_.top);
}
void Projectile::draw(sf::RenderTarget &renderTarget, sf::RenderStates renderStates) const {
renderTarget.draw(shape_);
}
顺便说一句,你可以写'为(自动凸出:projVec)',而不是'的for(int i = 0 ...'等,并然后使用'proj'而不是'projVec [i]' –
谢谢,我现在试着这样做,但所有发生的事情是,弹丸卡在开始。超级怪异!:S – sockevalley
你的激发码有绘图代码。这不是很好,请保持关注分开,你在哪里移动射弹一旦被解雇?你能发布一个[mcve]吗? – nvoigt