Messages

1

General / Re: Confused About Performance

« on: February 05, 2014, 06:13:54 pm »

Vsync is disabled. The CPU is an A6-4400M (2.7Ghz). The GPU is a dual-graphics setup, with an HD 7520G + HD 7470 M. But, regardless, my issue isn't that SFML is performing poorly (200 FPS is fine and dandy); it's that it is performing extremely poorly relative to another program that should, in theory, be slower, despite the fact that it is actually doing even less. I will post the relevant sections of code below. Some things are commented out because they are disabled for testing purposes.

Initialization

#include "Game.h"
#include <iostream>
#include "GameObject.h"
#include "Player.h"
#include <sstream>

Game::Game() :
    state(State::PLAYING),
    window(sf::VideoMode(640, 480), "SFML window"),
    renderTexture(),
    renderSprite(),
    tickRate(30),
    fpsLimit(0),
    fpsUpdateTicker(0),
    fpsUpdateRate(0.5),
    fpsDrawLoopCounter(0),
    vSyncOn(false),
    gameUpdateTicker(0),
    secondsPassed(0),
    isRunning(true),
    gameClock(),
    world(),
    lastReportedFPS(0) {
    window.setFramerateLimit(fpsLimit);
    window.setVerticalSyncEnabled(vSyncOn);
    systemFont.loadFromFile("fonts/Arcadepix Plus.ttf");
}

Basic game loop

void Game::play() {
    state = State::PLAYING;
    while(isRunning) {
        secondsPassed = gameClock.getElapsedTime().asSeconds();
        gameClock.restart();
        //input();
        if (state == State::PLAYING) {
            gameUpdateTicker += secondsPassed;
            while (gameUpdateTicker >= 1.0 / tickRate) {
                gameUpdateTicker -= 1.0 / tickRate;
                //update();
            }
        } else if (state == State::PAUSED) {
            //pause the game
        }
        draw();
        fpsUpdate();
    }
    quit();
}

Draw function

void Game::draw() {
    fpsDrawLoopCounter++;
    window.clear();
    std::vector<GameObject *>::const_iterator it = world.get_objectList().begin();
    while (it != world.get_objectList().end()) {
        window.draw((**it).get_sprite());
        ++it;
    }
    std::stringstream ss;
    ss << "FPS: " << lastReportedFPS << std::endl;
    if (state == State::PAUSED) {
        ss << "PAUSED" << std::endl;
    }
    sf::Text fpsText(ss.str(), systemFont, 16);
    fpsText.setPosition(10, 10);
    window.draw(fpsText);
    window.display();
}

FPS counter

void Game::fpsUpdate() {
    fpsUpdateTicker += secondsPassed;
    if (fpsUpdateTicker > fpsUpdateRate) {
        fpsUpdateTicker -= fpsUpdateRate;
        lastReportedFPS = fpsDrawLoopCounter / fpsUpdateRate;
        fpsDrawLoopCounter = 0;
    }
}
 

Nothing else effects the code in a meaningful way. a Game object is created and .play() is called.

2

General / Confused About Performance

« on: February 05, 2014, 05:28:41 pm »

Hi.

I use Game Maker: Studio quite a bit for prototyping and rapid development, but I also have some experience with C++ and Python. I've been playing with SFML and implemented a window, sprite, and keyboard movement. It's all very basic. However, I've noticed that my Game Maker: Studio project runs at about 1000FPS on my hardware. Pretty damn fast. I figured a game written and compiled in C++ would be just a good, if not better (Game Maker: Studio uses a scripting language called GML). At 640x480, drawing one sprite, without double buffering or anything like that, I get about 950-960 FPS. Okay, so far so good. I'm surprised it's a bit lower, but it's not a big deal. However, when I maximize the window, I drop to 260 FPS. Again, this is while only drawing a single 32x32 image. Game Maker: Studio does not seem to suffer from this issue. My PySFML version, nets me about 350 FPS (it's about half as fast as the C++ version from what I can tell), but drops down to 150 FPS when I maximize the window.

I am lead to believe I have implemented something incorrectly, as such pitiful framerates without much drawing going on make the prospect of developing a full project dubious at best.

I've included the draw method from my C++ method. As you can see I also draw text to the screen in both versions. I am not the best C++ programmer, so I apologize if it's painful to read.

void Game::draw() {
    fpsDrawLoopCounter++;
    window.clear();
    std::vector<GameObject *>::const_iterator it = world.get_objectList().begin();
    while (it != world.get_objectList().end()) {
        window.draw((**it).get_sprite());
        ++it;
    }
    std::stringstream ss;
    ss << "FPS: " << lastReportedFPS << std::endl;
    if (state == State::PAUSED) {
        ss << "PAUSED" << std::endl;
    }
    sf::Text fpsText(ss.str(), systemFont, 16);
    fpsText.setPosition(10, 10);
    window.draw(fpsText);
    window.display();
}

Beyond this there is not much going on.

3

Python / Sprite without texture

« on: January 23, 2014, 03:16:30 am »

Perhaps I missed this in the documentation, but earlier I was trying to create a Sprite without a texture. I have a GameObject object which has a Sprite object, but I want to set the texture afterwards by pulling it from a texture manager (still not sure how I'm going to implement this). However, it seems I cannot create a Sprite without a texture! Why is this so? The C++ bindings allowed this. Using None creates a giant white square...

4

General / Re: Low FPS with ~1000 objects

« on: January 21, 2014, 07:36:37 pm »

The program can go slow because you're setting the radio, the position and color of each of the objects, each frame

You are correct Alejandro, and I had missed that. Moving the color out of the loop shot the fps way up. Above 60 with 5000 objects. Thanks.

5

General / Re: Low FPS with ~1000 objects

« on: January 21, 2014, 06:07:42 pm »

you must use vertexArrays to manage your objects better

This doesn't explain why Python can draw 4000 circles without a problem, but the C++ version (which is in release and optimized) performs worse with fewer. There is an error in my C++ code.

6

General / Re: Low FPS with ~1000 objects

« on: January 21, 2014, 05:05:29 pm »

It is because (most likely) you are making ~1000+ individual draw calls each frame to the GPU. You need to take a look at the vertex array tutorial to reduce your draw calls. 

Huh... I'll have to do a bit of reading, because so far I don't really understand vertex arrays, and am confused as to how to get them to play nicely with sprites or, in this case, just a simple shape.\

UPDATE: So, I tried the Python bindings for SFML, and although my code isn't exactly the same, it has no problem drawing 2000 objects at 120fps. Whereas my C++ version barely manages 30fps. Clearly something is wrong here!

7

General / Low FPS with ~1000 objects

« on: January 21, 2014, 04:23:56 pm »

I'm relatively new to both C++ and SFML. I've been slowly working my way through building a small game, but I feel as though my FPS is much lower than it should be. I am using SFML2, and when running my game with 1000 instances of the Player object, I get ~30 fps. This seems very low to me when I read about people drawing tens of thousands of bouncing cubes before their framerate dips like that. It is possible that it is just a hardware limitation, but I would appreciate it if someone would look over my code. The instances are created in the constructor of the World object. I have included all the code as well as the C::B project file.

Here is my draw method. It is slightly modified from the version in the .zip. I have also disabled calls up update() for testing purposes. As a note, my Python version handles drawing 4000+ circles at 60fps.

void Game::draw() {
    fpsDrawLoopCounter++;
    window.clear();
    std::stringstream ss;
    ss << "FPS: " << lastReportedFPS << std::endl;
    if (state == State::PAUSED) {
        ss << "PAUSED" << std::endl;
    }
    sf::Text fpsText(ss.str(), systemFont, 16);
    fpsText.setPosition(10, 10);
    window.draw(fpsText);
    sf::CircleShape s;
    std::vector<GameObject *>::const_iterator it = world.get_objectList().begin();
    while (it != world.get_objectList().end()) {
        //window.draw((**it).get_sprite());
        s.setRadius(10);
        s.setPosition((**it).get_sprite().getPosition());
        s.setFillColor(sf::Color::Green);
        window.draw(s);
        ++it;
    }
    window.display();
}

https://www.dropbox.com/s/wg9skyyyw7st9z0/FirstGame.zip