I have a class of circles that appear and disappear in the window for a while, there may be several, or maybe one. Currently drawn circles are stored in the vector_of_current_circles vector. I need to make them shrink to a certain size over time. How to do it?
window while loop:
while (window.isOpen()) {
// check all the window's events that were triggered since the last iteration of the loop
sf::Event event;
while (window.pollEvent(event)) {
// "close requested" event: we close the window
if (event.type == sf::Event::Closed)
window.close();
}
for (int i = 0; i < vector_of_circles.size(); i++) {
if (std::fabs(vector_of_circles[i].getBeginOfLife() - clock.getElapsedTime().asSeconds()) < 1e-2) {
if (!vector_of_circles[i].get_is_drawn()) {
window.clear();
window.draw(sprite);
vector_of_current_circles.push_back(vector_of_circles[i]);
for (const auto &item : vector_of_current_circles) {
item.print_circle(window);
}
window.display();
vector_of_circles[i].set_is_drawn();
}
}
if (std::fabs(vector_of_circles[i].getEndOfLife() - clock.getElapsedTime().asSeconds()) < 1e-2) {
if (vector_of_circles[i].get_is_drawn()) {
vector_of_current_circles.erase(vector_of_current_circles.begin());
vector_of_circles[i].set_is_drawn();
}
window.clear();
window.draw(sprite);
for (const auto &item : vector_of_current_circles) {
item.print_circle(window);
}
window.display();
}
}
}
Here is Circle code:
private:
sf::CircleShape circle_;
//sf::Clock clock;
float begin_of_life_;
bool is_drawn_ = false;
float end_of_life_;
//sf::RenderWindow& window_;
public:
Circle();
void print_circle(sf::RenderWindow&) const;
float get_radius() const;
void set_position(float, float);
void set_texture(sf::Texture&);
void setBeginOfLife(float);
void setEndOfLife(float);
double getBeginOfLife() const;
double getEndOfLife() const;
bool get_is_drawn() const;
void set_is_drawn();
To reduce equaly a circl in a certain time with a certain speed, you need:
speed (speed_) value: the speed of the reduice of radius by second,
radius (radius_) value: the initial value of the radius.
Your circle need to have setOrigin to the center.
// your function to reduce a certain circle (class member)
void reduce()
{
float elapsed_time = ; // your time elapsed from the last call
// Getting the position of your center
// if you haven't set the origin to the center of the circle this code doesn't work
sf::Vector2f pos = circle_.getPosition();
radius_ -= (speed_ * elapsed_time); // calculating the new radius
circle_.setRadius(radius_); // set the new radius
circle_.setOrigin(sf::Vector2f(radius_ / 2, radius_ / 2)); // update the origine to the center
circle_.setPosition(pos); // not 100% sure that this line is used
}
Now you have a circle that reduce at a certain speed and staying in the same place.
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I'm programming a Breakout game in C++. I'm having a HUGE problem that's preventing me from giving the game multi-ball functionality. I think it has something to do with the destructor. Have a look:
for loop for the balls (Driver.cpp):
for (Ball& b : balls) { // Loops over all balls
(...)
// Collision for when you miss
if (b.getYPos() > HEIGHT) { // If the ball falls below the defined height of the screen
balls.erase(balls.begin() + b.getID()); // Wipe the ball out of memory to make room (Troublesome line)
Ball::addToID(-1); // Shift the ball ID to assign to the next ball back one
(...)
}
And I get this error:
Debug Error!
Program: Breakout.exe
abort() has been called
(Press Retry to debug the application)
Do you know why this mysterious crash is happening? Or more importantly, a fix for it?
Here's a replicable piece of code to help:
Driver.cpp:
#include <vector>
#include <allegro5\allegro.h>
#include "Ball.h"
using namespace std;
vector<Ball> balls(0); // Pay attention to this line
const POS WIDTH = 1600, HEIGHT = 900;
int main {
while (running) {
if (al_key_down(&key, ALLEGRO_KEY_SPACE)) { // Spawn the ball
balls.push_back(Ball(WIDTH / 2, 500, 10, 10)); // Spawn the ball
balls[Ball::getIDtoAssign()].setYSpeed(5);
}
for (Ball& b : balls) { // Pay attention to this loop
b.draw(); // This line is what's crashing.
b.move();
(...)
// Collision for when you miss
balls.erase(
remove_if(balls.begin(), balls.end(),
[=](Ball& b) {
// Collision for when you miss
return b.getYPos() > HEIGHT; // If the ball falls below the defined height of the screen, wipe the ball out of memory to make room
}
),
balls.end()
);
}
}
}
}
return 0;
}
Ball.h:
#pragma once
#include <allegro5\allegro_primitives.h>
using namespace std;
class Ball {
public:
Ball();
Ball(float x, float y, float w, float h);
~Ball();
void draw();
void move();
float getYPos();
void setYSpeed(float set);
private:
float xPos; // Horizontal position
float yPos; // Vertical position (upside down)
float width; // Sprite width
float height; // Sprite height
float xSpeed; // Horizontal speed
float ySpeed; // Vertical speed (inverted)
}
Ball.cpp:
#include "Ball.h"
short Ball::ballIDtoAssign = 0;
Ball::Ball() {
this->xPos = 0;
this->yPos = 0;
this->width = 0;
this->height = 0;
this->xSpeed = 0;
this->ySpeed = 0;
}
Ball::Ball(float x, float y, float w, float h) {
this->xPos = x;
this->yPos = y;
this->width = w;
this->height = h;
this->xSpeed = 0;
this->ySpeed = 0;
}
Ball::~Ball() {
// Destructor
}
void Ball::draw() {
al_draw_filled_rectangle(xPos, yPos, xPos + width, yPos + height, al_map_rgb(0xFF, 0xFF, 0xFF));
}
void Ball::move() {
xPos += xSpeed;
yPos += ySpeed;
}
float Ball::getYPos() {
return yPos;
}
void Ball::setYSpeed(float set) {
ySpeed = set;
}
You cannot modify a container while you are iterating through it with a range-for loop. You don't have access to the iterator that the loop uses internally, and erase() will invalidate that iterator.
You can use the container's iterators manually, paying attention to the new iterator that erase() returns, eg:
for(auto iter = balls.begin(); iter != balls.end(); ) { // Loops over all balls
Ball& b = *iter:
...
// Collision for when you miss
if (b.getYPos() > HEIGHT) { // If the ball falls below the defined height of the screen
...
iter = balls.erase(iter); // Wipe the ball out of memory to make room
}
else {
++iter;
}
}
Alternatively, use the erase-remove idiom via std::remove_if() instead:
balls.erase(
std::remove_if(balls.begin(), balls.end(),
[=](Ball &b){
// Collision for when you miss
return b.getYPos() > HEIGHT; // If the ball falls below the defined height of the screen, wipe the ball out of memory to make room
}
),
balls.end()
);
UPDATE: now that you have posted more of your code, it is clear to see that you are trying to use ID numbers as indexes into the vector, but you are not implementing those IDs correctly, and they are completely unnecessary and should be eliminated.
The Ball::ballID member is never being assigned any value, so in this statement:
balls.erase(balls.begin() + b.getID()); // The troublesome line
Trying to erase() the result of balls.begin() + b.getID() causes undefined behavior since the iterator has an indeterminate value, thus you can end up trying to erase the wrong Ball object, or even an invalid Ball object (which is likely the root cause of your runtime crash).
Also, in this section of code:
balls.push_back(Ball(WIDTH / 2, 500, 10, 10)); // Spawn the ball
balls[Ball::getIDtoAssign()].setYSpeed(5);
Ball::addToID(1);
Since you want to access the Ball object you just pushed, that code can be simplified to this:
balls.back().setYSpeed(5);
And I already gave you code further above to show you how to remove balls from the vector without using IDs.
So, there is need for an ID system at all.
With that said, try something more like this:
Driver.cpp:
#include <vector>
...
#include "Ball.h"
using namespace std;
vector<Ball> balls;
const POS WIDTH = 1600, HEIGHT = 900;
int main {
...
while (running) {
...
if (input.type == ALLEGRO_EVENT_TIMER) { // Runs at 60FPS
...
if (al_key_down(&key, ALLEGRO_KEY_SPACE)) { // Spawn the ball
balls.push_back(Ball(WIDTH / 2, 500, 10, 10)); // Spawn the ball
balls.back().setYSpeed(5);
}
for (auto iter = balls.begin(); iter != balls.end(); ) {
Ball &b = *iter;
...
if (b.getYPos() > HEIGHT) { // Collision for when you miss
iter = balls.erase(iter);
}
else {
++iter;
}
}
/* alternatively:
for (Ball& b : balls) {
b.draw();
b.move();
}
balls.erase(
std::remove_if(balls.begin(), balls.end(),
[=](Ball &b){
// Collision for when you miss
return b.getYPos() > HEIGHT; // If the ball falls below the defined height of the screen, wipe the ball out of memory to make room
}
),
balls.end()
);
*/
}
}
return 0;
}
Ball.h:
#pragma once
...
class Ball {
public:
...
// NO ID METHODS!
private:
...
// NO ID MEMBERS!
}
Ball.cpp:
#include "Ball.h"
...
// NO ID MEMBER/METHODS!
OK, so I managed to figure out why the program crashes. It was because I had the erase-remove inside the for loop which can cause all sorts of problems.
My sprite moves to the left, right, up and down when the correct corresponding key is pressed but only the row 0 animation is used, but for some odd reason when I press two keys at the same time like (W,A) or (S, D) is transfer to opposite animation to which side it is moving. I tried moving the if statements directing the animation update to a nested if statement inside the key press if statements and that did nothing good, I then tried just having it update based off the key press with no nested if statement, that also did not work... I am new to SFML so this is really hurting my head to figure this out, also I do not mind criticism, please if you see something I could be doing better in terms of sprite movement, let me know! Thanks for your help.
Below is my player class constructor
#include "Player.h"
Player::Player(Texture* texture, Vector2u imageCount, float switchTime, float speed) :
// initializer list from animation.cpp
animation(texture, imageCount, switchTime)
{
this->speed = speed;
row = 0;
body.setSize(Vector2f(100.0f, 150.0f));
body.setTexture(texture);
//sets initial position for test sprite sheet
body.setPosition(550.0f, 900.0f);
}
Player::~Player()
{
}
void Player::Update(float deltaTime)
{
Vector2f movement(0.0f, 0.0f);
if (Keyboard::isKeyPressed(Keyboard::A))
{
//if A is pressed move to the left on the x axis
movement.x -= speed * deltaTime;
}
if (Keyboard::isKeyPressed(Keyboard::D))
{
//if D is pressed move to the right on the x axis
movement.x += speed * deltaTime;
}
if (Keyboard::isKeyPressed(Keyboard::W))
{
// if W is pressed move up on the y axis
movement.y += speed * deltaTime;
}
if (Keyboard::isKeyPressed(Keyboard::S))
{
// if S is pressed move down on the y axis
movement.y -= speed * deltaTime;
}
if (movement.x == 0.0f || movement.y == 0.0f)//for idle animation
{
row = 0;//idle row for now just using walking until I get idle animation
}
else if(movement.x > 0.0f)
{
row = 1; //walking to the left animation
}
else if (movement.x < 0.0f )
{
row = 3; //walking to the right animation
}
else if (movement.y > 0.0f)
{
row = 0; // walking to stright animation
}
else if (movement.y < 0.0f)
{
row = 2;// walking back animation
}
animation.Update(row, deltaTime);
body.setTextureRect(animation.uvRect);
body.move(movement);
}
void Player::Draw(RenderWindow& window)
{
window.draw(body);
}
Below is my player class initialization
#pragma once
#include <SFML/Graphics.hpp>
#include "Animation.h"
using namespace std;
using namespace sf;
class Player
{
public:
Player(Texture* texture, Vector2u imageCount, float switchTime, float speed);
~Player();
void Update(float deltaTime);
void Draw(RenderWindow& window);
private:
RectangleShape body;
Animation animation;
unsigned int row;
float speed;
};
Below Game while loop and the Player function call
Player player(&playerTexture, Vector2u(9, 4), 0.09f, 100.0);
//*************************************************************
//clock & Time
float deltaTime = 0.0f;
Clock clock;
while (window.isOpen())
{
deltaTime = clock.restart().asSeconds();
//*********************************************************
//Player Input
if (Keyboard::isKeyPressed(Keyboard::Escape))
{
window.close();
}
//**********************************************************
//draws everything
player.Update(deltaTime);
window.clear();
window.draw(spritestartingBG);
player.Draw(window);
window.display();
}
return 0;
}
if (movement.x == 0.0f || movement.y == 0.0f) will be true unless moving diagonally-- you probably want the || to be &&.
Similarly, your left/right animations are reversed--you're moving left when movement.x is < 0.0, not > 0.0.
So I'm creating a graphing calculator. I have an input string s. From the string, I can graph it using SFML. I start from the a MIN x-coordinate to a MAX x-coordinate, get the corresponding y from a EvaluateString() method, and all the coordinates to a VertexArray v. I wrote my method and the graphing method already and it all worked well.
However, I have a small issue. I want to input my string on the screen, such as "sin(cos(tan(x)))" like this. I'm struggling to find a way to do it. I kinda figured out it has to do with the event TextEntered, but still I can't find anything completely.
Please suggest me a way.
class Calculator{
public:
void main();
private:
WindowSize DefaultWindow;
sf::RenderWindow window;
Cartesian vertexX[2],vertexY[2];
sf::Vertex axis[4];
const double MAX = 10;
const double MIN = -10;
const double INCREMENT = 0.001;
};
int main(){
DefaultWindow.Max = Cartesian(10,10);
DefaultWindow.Min = Cartesian(-10,-10);
DefaultWindow.plane.width=1500;
DefaultWindow.plane.height=1500;
// Set up x and y-axis
vertexX[0] = Cartesian(-100,0);
vertexX[1] = Cartesian(100, 0);
vertexY[0] = Cartesian(0,-100);
vertexY[1] = Cartesian(0,100);
axis[0] = sf::Vertex(convertCartesiantoWindow(vertexX[0],DefaultWindow));
axis[1] = sf::Vertex(convertCartesiantoWindow(vertexX[1],DefaultWindow));
axis[2] = sf::Vertex(convertCartesiantoWindow(vertexY[0],DefaultWindow));
axis[3] = sf::Vertex(convertCartesiantoWindow(vertexY[1],DefaultWindow));
// Set up the window
window.create(sf::VideoMode(1500, 1500), "Graphing calculator");
// Input string
string s = "sin(cos(tan(x)))";
// Stack c contains all the Cartesian coordinate vertices
// Cartesian is a struct which contains x and y coordinates
Stack<Cartesian> c;
sf::VertexArray v;
// For a certain function in string s, I evaluate it
// and return the y_coordinate from the function EvaluateString (s, i)
// Push each (x,y) evaluated in the Stack c
for (double i = MIN; i <= MAX; i+= INCREMENT)
c.Push(Cartesian(i,EvaluateString(s,i)));
// v is VertexArray which contains all the vertices (x,y)
v = plot(DefaultWindow, c);
while (window.isOpen()) {
sf::Event event;
while (window.pollEvent(event)) {
switch (event.type) {
case sf::Event::Closed:
window.close();
break;
}
}
}
// Draw the graph
window.clear(sf::Color::Black);
window.draw(axis,4,sf::Lines);
window.draw(v);
window.display();
}
As #super suggest, use a library would be a nice solution, and surely better than mine, but just in case this satisfies your needs, I implemented a super basic TextField class.
It may be plenty of errors, but it can gives you an idea on how to achieve that functionality.
A TextField is nothing more than a rectangle which contains a text. Since it will have a sf::Text, it must have a sf::Font. Additionally, I limit the number of characters that it will contain. In order for us to write inside the TextField, we have to know if it's selected, i.e. if it has the focus. So, a first approach could be:
class TextField : public sf::Transformable, public sf::Drawable{
private:
unsigned int m_size;
sf::Font m_font;
std::string m_text;
sf::RectangleShape m_rect;
bool m_hasfocus;
};
We need a constructor for this class:
class TextField : public sf::Transformable, public sf::Drawable{
public:
TextField(unsigned int maxChars) :
m_size(maxChars),
m_rect(sf::Vector2f(15 * m_size, 20)), // 15 pixels per char, 20 pixels height, you can tweak
m_hasfocus(false)
{
m_font.loadFromFile("C:/Windows/Fonts/Arial.ttf"); // I'm working on Windows, you can put your own font instead
m_rect.setOutlineThickness(2);
m_rect.setFillColor(sf::Color::White);
m_rect.setOutlineColor(sf::Color(127,127,127));
m_rect.setPosition(this->getPosition());
}
private:
unsigned int m_size;
sf::Font m_font;
std::string m_text;
sf::RectangleShape m_rect;
bool m_hasfocus;
};
We also need some basic methods, we want to get the text inside:
const std::string sf::TextField::getText() const{
return m_text;
}
and move it, placing it somewhere inside our window:
void sf::TextField::setPosition(float x, float y){
sf::Transformable::setPosition(x, y);
m_rect.setPosition(x, y);
}
this is a tricky one. We are overwritting setPosition method of sf::Transformable because we need to update our own m_rect.
Also, we need to know if a point is inside of the box:
bool sf::TextField::contains(sf::Vector2f point) const{
return m_rect.getGlobalBounds().contains(point);
}
pretty simple, we use cointains method of sf::RectangleShape, already in sfml.
Set (or unset) focus on the TextField:
void sf::TextField::setFocus(bool focus){
m_hasfocus = focus;
if (focus){
m_rect.setOutlineColor(sf::Color::Blue);
}
else{
m_rect.setOutlineColor(sf::Color(127, 127, 127)); // Gray color
}
}
easy one. For aesthetics, we also change the outline color of the box when focused.
And last, but not least, our TextField has to behave some way when input (aka an sf::Event) is received:
void sf::TextField::handleInput(sf::Event e){
if (!m_hasfocus || e.type != sf::Event::TextEntered)
return;
if (e.text.unicode == 8){ // Delete key
m_text = m_text.substr(0, m_text.size() - 1);
}
else if (m_text.size() < m_size){
m_text += e.text.unicode;
}
}
That delete key check is little dirty, I know. Maybe you can find better solution.
That's all! Now main looks like:
int main()
{
RenderWindow window({ 500, 500 }, "SFML", Style::Close);
sf::TextField tf(20);
tf.setPosition(30, 30);
while (window.isOpen())
{
for (Event event; window.pollEvent(event);)
if (event.type == Event::Closed)
window.close();
else if (event.type == Event::MouseButtonReleased){
auto pos = sf::Mouse::getPosition(window);
tf.setFocus(false);
if (tf.contains(sf::Vector2f(pos))){
tf.setFocus(true);
}
}
else{
tf.handleInput(event);
}
window.clear();
window.draw(tf);
window.display();
}
return 0;
}
Proof of concept:
std::string str;
sf::String text;
// In event loop...
if (event.Type == sf::Event::TextEntered)
{
// Handle ASCII characters only
if (event.Text.Unicode < 128)
{
str += static_cast<char>(event.Text.Unicode);
text.SetText(str);
}
}
// In main loop...
window.Draw(text);
This should create an sf::Event::TextEntered for input, and sf::String for output
I have read about an interpolation applied to game loops and tried to implement it myself. It looks almost same as I expected, but when the object ends its movement weird step back takes place. I decided to paste here full source, because this problem may be caused by everything.
#include <SFML/Graphics.hpp>
#include <chrono>
sf::RenderWindow window(sf::VideoMode(800, 600), "Interpolation");
sf::Event event;
int fps = 10; // set to 10 for testing purpose
std::chrono::nanoseconds timePerFrame = std::chrono::seconds(1);
std::chrono::nanoseconds accumulator;
std::chrono::steady_clock::time_point start;
sf::RectangleShape shape1(sf::Vector2f(50, 50));
sf::RectangleShape shape2(sf::Vector2f(50, 50));
sf::Vector2f movement(0, 0);
sf::Vector2f position1(375, 100);
sf::Vector2f position2(375, 275);
void initialization();
void processInput();
void update();
void interpolate();
void render();
int main()
{
initialization();
while(window.isOpen())
{
start = std::chrono::steady_clock::now();
processInput();
while(accumulator >= timePerFrame)
{
update();
accumulator -= timePerFrame;
}
interpolate();
render();
accumulator += std::chrono::steady_clock::now() - start;
}
return 0;
}
void initialization()
{
timePerFrame /= fps;
shape1.setPosition(position1);
shape2.setPosition(position2);
}
void processInput()
{
while(window.pollEvent(event))
{
if(event.type == sf::Event::Closed) window.close();
}
}
void update()
{
if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) movement = sf::Vector2f(-300, 0);
else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right)) movement = sf::Vector2f(300, 0);
else movement = sf::Vector2f(0, 0);
position1.x += movement.x / fps;
position2.x += movement.x / fps;
shape1.setPosition(position1);
shape2.setPosition(position2);
}
void interpolate()
{
double interpolationFactor = (double) accumulator.count() / timePerFrame.count();
shape2.setPosition(position2.x + (movement.x / fps * interpolationFactor), position2.y);
}
void render()
{
window.clear(sf::Color::Black);
window.draw(shape1);
window.draw(shape2);
window.display();
}
I do not know what may cause that kind of problem. I'm looking forward your help.
Your interpolate function can count some parts of the time interval multiple times.
Since accumulator only resets every timePerFrame ticks, a fast loop rate can add smaller intervals multiple times. If the main loop runs in 0.01 seconds, the first call to interpolate uses that 0.01 in the interpolation factor. The next time, it uses 0.02 (for a total add of 0.03). This continues until there is enough time accumulated for update to update the position using 0.1 seconds (the time step). Since interpolate added in more time than that, the object jumps back.
interpolate should only add in the time of the current step, and not the fully accumulated time. (Also, rather than calling now to get the start time every loop, the previous loop's now value used for the end time should be used as the start time for the next loop. Otherwise you'll lose occasional clock ticks when it changes between the end of one loop and the start of the next.)
So I am trying to make a simple shooter but so far i had no luck. I want to spawn bullets when the user presses right shift. And the bullets should fire at the top of the screen. The bullets do spawn but they dont move.
I created a vector to hold the created bullets named "bullets". Then I used the update function in my core struct to detect RShift presses and push an instance of the Bullet object to the vector.
Later on in my main class I iterate the vector and draw the bullets. But when I try calling the function it doesnt work.
My Code so far:
#include <SFML/Graphics.hpp>
#include <stdio.h>
const unsigned int ResX{480}, ResY{640};
struct Bullet {
sf::CircleShape shape;
Bullet(float sX, float sY, sf::Color color, float bullet_radius) {
shape.setRadius(bullet_radius);
shape.setOrigin(bullet_radius, bullet_radius);
shape.setFillColor(color);
shape.setPosition(sX, sY);
}
void update(float vel) {
sf::Vector2f velocity;
velocity.y = -abs(vel);
shape.move(velocity);
}
};
std::vector<Bullet> bullets;
struct Core {
const float core_width{64}, core_height{48}, core_velocity{0.2};
sf::RectangleShape shape;
sf::Vector2f velocity;
Core(float sX, float sY) {
shape.setSize({core_width, core_height});
shape.setPosition(sX, sY);
shape.setFillColor(sf::Color::White);
shape.setOrigin(core_width/2, core_height/2);
}
void update() {
if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left))
velocity.x = -core_velocity;
else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right))
velocity.x = core_velocity;
else
velocity.x = 0;
if(sf::Keyboard::isKeyPressed(sf::Keyboard::Up))
velocity.y = -core_velocity;
else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Down))
velocity.y = core_velocity;
else
velocity.y = 0;
shape.move(velocity);
if(sf::Keyboard::isKeyPressed(sf::Keyboard::RShift)) {
Bullet b(shape.getPosition().x, shape.getPosition().y, sf::Color::Red, 5);
bullets.push_back(b);
}
}
};
int main(int argc, char *argv[])
{
sf::RenderWindow window(sf::VideoMode(ResX, ResY), "Brick Breaker", sf::Style::None);
Core core(ResX / 2, ResY /2 + 200);
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::Closed || sf::Keyboard::isKeyPressed(sf::Keyboard::Escape))
window.close();
}
std::printf("VelocityX=%f, BulletVelocity=\n",core.velocity.x);
window.clear();
core.update();
window.draw(core.shape);
for(const auto& b : bullets)
window.draw(b.shape);
//this function is causing an error : method update could not be resolved!
b.update();
window.display();
}
return 0;
}
btw i feel the need to say i am very very unexperienced with programming in c++ I am a complete beginner so any advice is welcome. srry 4 bad english. thanks!
EDIT: I figured it out thx! (The problem was that i missed the curly brackets:
for(const auto& b : bullets)
{
window.draw(b.shape);
//this function is causing an error : method update could not be resolved!
b.update();
}
But i have another question aswell! It would be awesome if one of you explained how the iterator functions and what purpose the auto& and const keywords serve here. Thanks again!