Messages

1

Graphics / Re: I am encountering the "White Sprite Problem", but I think the texture is alive

« on: February 10, 2020, 09:16:36 pm »

Thanks for the detailed explanation. Everything's clear now.

PS: could you post again, so I can see if your post count really is in hex? You're at 9 in the least significant digit

2

Graphics / Re: I am encountering the "White Sprite Problem", but I think the texture is alive

« on: February 09, 2020, 07:02:41 pm »

This is a triple post, but I think it's the cleanest way to post it...

I think the problem with the first piece of code is that when I return the game from new_game(), game (along with its members) gets copied, and the texture getting copied causes the white sprite problem.

3

Graphics / Re: I am encountering the "White Sprite Problem", but I think the texture is alive

« on: February 09, 2020, 06:52:38 pm »

Moreover, changing the texture to a pointer and creating it with new works (but I'm pretty sure this is even worse C++):

#define SFML_STATIC

#include <stdint.h>
typedef uint64_t u64;

#define TILE_SIZE 32

#define WIDTH  640
#define HEIGHT 640

#include <SFML/Window.hpp>
#include <SFML/Graphics.hpp>

struct State {
    sf::Texture* dirt_texture;
    sf::Sprite dirt_sprite;

    sf::RenderWindow* window;
};

void update(State state) {
}

void draw(State state) {
    state.window->clear(sf::Color::Magenta);

    for (u64 x = 0; x < 64; x++) {
        for (u64 y = 0; y < 64; y++) {
            state.dirt_sprite.setPosition(x * TILE_SIZE, y * TILE_SIZE);
            state.window->draw(state.dirt_sprite);
        }
    }

    state.window->display();
}

State new_state(sf::RenderWindow* window) {
    State state;
    state.window = window;
   
    state.dirt_texture = new sf::Texture();
    if (!state.dirt_texture->loadFromFile("art/dirt.png")) {
        printf("Error loading dirt!!!!\n");
    }

    state.dirt_sprite.setTexture(*state.dirt_texture);

    return state;
}

int main() {
    sf::RenderWindow window(sf::VideoMode(WIDTH, HEIGHT), "My window");
    State state = new_state(&window);

    while (window.isOpen()) {
        sf::Event event;

        while (window.pollEvent(event)) {
            if (event.type == sf::Event::Closed) {
                window.close();
            }
        }

        update(state);
        draw(state);
    }

    return 0;
}
 

This suggests that my misunderstanding is coming from C++ and not from SFML. What's the problem of the first version?

4

Graphics / I am encountering the "White Sprite Problem", but I think the texture is alive

« on: February 09, 2020, 06:40:05 pm »

This is an entire, minimal, runnable example, stripped from anything that wasn't related to the problem. It's not idiomatic C++ and there are style problems, but for now I'm interested in understanding why this does not work.

The sprite seems to draw as a white square, even though I *think* I'm properly keeping the texture alive.

In my draw function I clear everything in magenta. If I don't move the sprite, only a small white square on the top left is drawn. This confirms that the sprite, of the right size, is drawn; but it's just white instead of the correct image.

#define SFML_STATIC

#include <stdint.h>
typedef uint64_t u64;

#define TILE_SIZE 32

#define WIDTH  640
#define HEIGHT 640

#include <SFML/Window.hpp>
#include <SFML/Graphics.hpp>

struct State {
    sf::Texture dirt_texture;
    sf::Sprite dirt_sprite;

    sf::RenderWindow* window;
};

void update(State state) {
}

void draw(State state) {
    state.window->clear(sf::Color::Magenta);

    for (u64 x = 0; x < 64; x++) {
        for (u64 y = 0; y < 64; y++) {
            state.dirt_sprite.setPosition(x * TILE_SIZE, y * TILE_SIZE);
            state.window->draw(state.dirt_sprite);
        }
    }

    state.window->display();
}

State new_state(sf::RenderWindow* window) {
    State state;
    state.window = window;
   
   
    if (!state.dirt_texture.loadFromFile("art/dirt.png")) {
        printf("Error loading dirt!!!!\n");
    }

    state.dirt_sprite.setTexture(state.dirt_texture);

    return state;
}

int main() {
    sf::RenderWindow window(sf::VideoMode(WIDTH, HEIGHT), "My window");
    State state = new_state(&window);

    while (window.isOpen()) {
        sf::Event event;

        while (window.pollEvent(event)) {
            if (event.type == sf::Event::Closed) {
                window.close();
            }
        }

        update(state);
        draw(state);
    }

    return 0;
}
 

I do get this warning in the console output:

An internal OpenGL call failed in Texture.cpp(98).
Expression:
   glFlush()
Error description:
   GL_INVALID_OPERATION
   The specified operation is not allowed in the current state.