SFML 精灵根本不显示

Question

I have a method which should take a spritesheet which is 64x128 and turn it into 8x8 sprites.

after each texture is found from the stored Image, it is added to a sprite, and that sprite is added to a sprite array which is being called in my main method.

I have tested displaying a static sprite before, and my code worked (I displayed 1 8x8 sprite successfully)

However, when trying to display any of the 128 sprites in my list of sprites, now none are being rendered.

I believe the logic error may be in my MakeSprite method, but I'm unsure, and I can't see where the issue is.

[EDIT]: it seems that every sprite I call is returning the sprite at the very end of the spritesheet (sprite 128)

[Edit 2]: the texture (tex) of the previous sprite is overwritten by the next sprite to be spawned.

Below is a full verifiable working example of my code:

main.cpp

#include "Main.h"




int main() {

    srand(time(NULL));


    RenderWindow window(VideoMode(1280, 720), "Conduit");


    MakeCircle(10, 100, 100, Color::White);
    MakeCircle(30, 10, 100, Color::Cyan);
    MakeCircle(100, 200, 100, Color::Magenta);
    MakeCircle(100, 400, 100, Color::Cyan);



    if (!LoadSpritesheet())
    {
        return 1;
    }

    while (window.isOpen()) {

        Event event;
        while (window.pollEvent(event)) {

            if (event.type == Event::Closed)
                window.close();
            else if (event.key.code == Keyboard::Num1)
            {

                DrawRandomSprite(window);
            }
        }



        window.clear();
        DrawCircles(window);


        int c = 0;

        for (int i = 0; i < 128; i++)
        {

            Spritesheet.at(i).setPosition(c, c);
            window.draw(Spritesheet.at(i));
            c += 8;
        }





        window.display();
    }

}


void DrawRandomSprite(RenderWindow &window)
{

    //DEBUG METHOD: draws a random sprite for testing.

    int sprite = rand() % 128 + 1;



    Spritesheet.at(sprite).setPosition(rand() % 128 + 1, rand() % 128 + 1);

    window.draw(Spritesheet.at(sprite));



}

void MakeCircle(float radius, float xpos, float ypos, Color color)
{
    //makes a circle then adds it to the circle vector.
    CircleShape shape;
    shape.setRadius(radius);
    shape.setPosition(xpos, ypos);
    shape.setFillColor(color);

    Circles.push_back(shape);
}

void DrawCircles(RenderWindow &window)
{
    //Renders the circles in the circles vector.

    for (int i = 0; i < Circles.size(); i++)
    {
        window.draw(Circles.at(i));
    }
}

int LoadSpritesheet()
{
    //make sure spritesheet exists, then loads it into an image.

    Texture sheet;
    if (!sheet.loadFromFile("Sprites/A.png"))
    {
        return 0;
    }
    else
    {
        sheetIMG = sheet.copyToImage();
        SetMask();
        MakeSprite(8, 4);
        return 1;
    }


}

void SetMask()
{
    //creates a mask.

    sheetIMG.createMaskFromColor(sf::Color(151, 56, 14, 0), 100);


}

void MakeSprite(int dimension, int scale)
{
    //seperates the spritesheet into a list of 8x8 modular sprites.

    int c = 0, r = 0;

    do
    {
        for (int i = 0; i <= (sheetIMG.getSize().x * sheetIMG.getSize().y) / 64; i++)
        {
            if (r == 64)
                break;
            if (!tex.loadFromImage(sheetIMG, IntRect(c, r, dimension, dimension)))
                break;
            else
            {
                Sprite spr;
                spr.setTexture(tex);
                spr.setScale(scale, scale);
                Spritesheet.push_back(spr);
                c += dimension;
                if (c == sheetIMG.getSize().x) { c = 0; r+=8; };
            }
        }
    } while (r < sheetIMG.getSize().y);     
}

Main.h

#pragma once
#include <SFML/Graphics.hpp>
#include <vector>
#include <stdio.h>      /* printf, scanf, puts, NULL */
#include <stdlib.h>     /* srand, rand */
#include <time.h>       /* time */


//standard and SFML namespaces;
using namespace std;
using namespace sf;



//===============================VARIBLES===========================


//the main spritesheet.

Texture tex;

Image sheetIMG;

//array to hold circles.
vector<CircleShape> Circles;

//array to hold sprites.
vector<Sprite> Spritesheet;

//===============================PROTOTYPES=============================



void DrawCircles(RenderWindow &window);
void MakeCircle(float radius, float xpos, float ypos, Color color);
void MakeSprite(int dimension, int scale);
void SetMask();
int LoadSpritesheet();
void DrawRandomSprite(RenderWindow &window);

Answer 1

There's two major issues with your code:

1. You're using global variables. While this might be okay with some libraries, with SFML this is not a good thing at all.

2. You're clear ing the window after calling DrawRandomSprite . Therefore your sprite will never show up.

Answer 2

All your sprites have the same texture: tex . And as tex is a single global variable, when your loop finishes, it's set to the last texture. So all sprites will draw the last texture. You need to get rid of the globals and have one texture per sprite (or at least one per sprite that you want to have a different texture).