SFML sprite is a white square when making multiple textures - c++

Question

I am making a SFML framework, and when I use the function loadImage one time, the image loads correctly with all colors, but if I use it two times for another texture, there is only one sprite rendered and it's all white. I read that you don't want to delete the texture or the sprite or it will be white. But in this code I'm storing all the textures in a vector. Does any one know what is wrong in this function?
FM::Image FM::graphics::loadImage(const char* fileName) {
texturesindex++;
sf::Texture texture;
texture.loadFromFile(fileName);
textures.push_back(texture);
sf::Sprite sprite(textures[texturesindex]);
Image image;
image.sprite = sprite;
return image;
}
Here's all the code:
SFFM.cpp:
#include "SFFM.h"
#include <SFML/Graphics.hpp>
#include <vector>
#include <string>
int backgroundcolor[3] = { 0,0,0};
sf::RenderWindow Window(sf::VideoMode(800, 600), "MyGame");
std::vector<sf::Texture> textures;
int texturesindex = -1;
void FM::window::setWindowOptions(unsigned int Width, unsigned int Height, const char* Title, int FrameLimit) {
Window.setSize(sf::Vector2u(Width, Height));
Window.setFramerateLimit(FrameLimit);
Window.setTitle(Title);
}
void FM::window::setBackgroundColor(int r, int g, int b) {
backgroundcolor[0] = r;
backgroundcolor[1] = g;
backgroundcolor[2] = b;
}
FM::Image FM::graphics::loadImage(const char* fileName) {
texturesindex++;
sf::Texture texture;
texture.loadFromFile(fileName);
textures.push_back(texture);
sf::Sprite sprite(textures[texturesindex]);
Image image;
image.sprite = sprite;
return image;
}
void FM::graphics::drawImage(Image image, int x, int y, int scalex, int scaley, int rotation) {
image.sprite.setPosition(x, -y);
image.sprite.setRotation(rotation);
image.sprite.setScale(sf::Vector2f(scalex, scaley));
Window.draw(image.sprite);
}
void FM::graphics::drawImage(Image image, int x, int y, int scalex, int scaley) {
image.sprite.setPosition(x, -y);
image.sprite.setScale(sf::Vector2f(scalex, scaley));
Window.draw(image.sprite);
}
void FM::graphics::drawImage(Image image, int x, int y) {
image.sprite.setPosition(x, -y);
Window.draw(image.sprite);
}
int main()
{
FM::Start();
while (Window.isOpen())
{
sf::Event event;
while (Window.pollEvent(event))
{
if (event.type == sf::Event::Closed)
Window.close();
else if (event.type == sf::Event::Resized)
{
Window.setView(sf::View(sf::FloatRect(0, 0, event.size.width, event.size.height)));
}
}
Window.clear(sf::Color(backgroundcolor[0], backgroundcolor[1], backgroundcolor[2]));
FM::Update();
Window.display();
}
return 0;
}
SFFM.h:
#pragma once
#include <SFML/Graphics.hpp>
namespace FM
{
void Update();
void Start();
class window {
public:
static void setWindowOptions(unsigned int Width, unsigned int Height, const char * Title, int FrameLimit);
static void setBackgroundColor(int r, int g, int b);
};
class Image {
public:
sf::Sprite sprite;
};
class graphics {
public:
static Image loadImage(const char* fileName);
static void drawImage(Image image, int x, int y, int scalex, int scaley, int rotation);
static void drawImage(Image image, int x, int y, int scalex, int scaley);
static void drawImage(Image image, int x, int y);
};
class Input {
public:
};
};
main.cpp:
#include "SFFM.h"
#include <SFML\Graphics.hpp>
FM::Image Gangster;
FM::Image Block;
int x = 0;
int y = 0;
void FM::Start() {
window::setWindowOptions(1280, 720, "Platformer", 120);
window::setBackgroundColor(0, 127, 255);
Gangster = graphics::loadImage("assets/Gangster.png");
}
void FM::Update() {
graphics::drawImage(Gangster, x, y, 5, 5);
graphics::drawImage(Block, 100, 100, 5, 5);
if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) {
y += 1;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) {
y -= 1;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) {
x += 1;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) {
x -= 1;
}
}
Here's a screenshot:

Answer 1

TL;DR Solutions, either:
Use a container other than std::vector<sf::Texture> - std::list<sf::Texture> or std::forward_list<sf::Texture>.
Store pointers to textures - std::vector<std::unique_ptr<sf::Texture>>.
Explanation
You store texture objects along with sprites referring them. This is correct because a spite just keeps a reference (a pointer) to its texture. This also implies that the texture address must remain unchanged during the sprite lifetime.
It looks like you did not take into account how std::vector push_back() works. A vector initally allocates some memory, and once there is no place to insert a new item, the vector allocates more memory and copies all inserted items and the new one there. So all the item addresses change.
In your case an item is a texture, its address is changed upon an isertion of another texture, so some sprite "looses" its texture. This usually results in white squares drawn.