I just tried to write a chess engine, and what is important to me is that I get a nice visual representation of the game. I tried to implement the Code in a Visual Studio project - the problem is that the program only shows me a black screen instead of the texture I loaded.
My Code is the following:
#include <SFML/Graphics.hpp>
#include <time.h>
using namespace sf;
int main(){
RenderWindow window(VideoMode(1000, 1000), "MattseChess!");
Texture t1;
t1.loadFromFile("images/board.png");
Sprite s(t1);
while (window.isOpen())
{
Event e;
while (window.pollEvent(e)) {
if (e.type == Event::Closed)
window.close();
//Draw
window.clear();
window.draw(s);
window.display();
}
}
return 0;
}
Do you have any idea of what I did wrong?
Make sure to put your drawing code outside your event loop. Otherwise you're only drawing whenever there's some event happening (such as cursor movement).
That code works. I am pretty sure you did not put your board.png into the images directory in your execution path.
Make sure this image is available:
t1.loadFromFile("images/board.png");
Related
I need to draw some graphics in c++, pixel by pixel on a window. In order to do this I create a SFML window, sprite and texture. I draw my desired graphics to a uint8_t array and then update the texture and sprite with it. This process takes about 2500 us. Drawing two triangles which fill the entire window takes only 10 us. How is this massive difference possible? I've tried multithreading the pixel-by-pixel drawing, but the difference of two orders of magnitude remains. I've also tried drawing the pixels using a point-map, with no improvement. I understand that SFML uses some GPU-acceleration in the background, but simply looping and assigning the values to the pixel array already takes hundreds of microseconds.
Does anyone know of a more effective way to assign the values of pixels in a window?
Here is an example of the code I'm using to compare the speed of triangle and pixel-by-pixel drawing:
#include <SFML/Graphics.hpp>
#include <chrono>
using namespace std::chrono;
#include <iostream>
#include<cmath>
uint8_t* pixels;
int main(int, char const**)
{
const unsigned int width=1200;
const unsigned int height=1200;
sf::RenderWindow window(sf::VideoMode(width, height), "MA: Rasterization Test");
pixels = new uint8_t[width*height*4];
sf::Texture pixels_texture;
pixels_texture.create(width, height);
sf::Sprite pixels_sprite(pixels_texture);
sf::Clock clock;
sf::VertexArray triangle(sf::Triangles, 3);
triangle[0].position = sf::Vector2f(0, height);
triangle[1].position = sf::Vector2f(width, height);
triangle[2].position = sf::Vector2f(width/2, height-std::sqrt(std::pow(width,2)-std::pow(width/2,2)));
triangle[0].color = sf::Color::Red;
triangle[1].color = sf::Color::Blue;
triangle[2].color = sf::Color::Green;
while (window.isOpen()){
sf::Event event;
while (window.pollEvent(event)) {
if (event.type == sf::Event::Closed) {
window.close();
}
if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape) {
window.close();
}
}
window.clear(sf::Color(255,255,255,255));
// Pixel-by-pixel
int us = duration_cast< microseconds >(system_clock::now().time_since_epoch()).count();
for(int i=0;i!=width*height*4;++i){
pixels[i]=255;
}
pixels_texture.update(pixels);
window.draw(pixels_sprite);
int duration=duration_cast< microseconds >(system_clock::now().time_since_epoch()).count()-us;
std::cout<<"Background: "<<duration<<" us\n";
// Triangle
us = duration_cast< microseconds >(system_clock::now().time_since_epoch()).count();
window.draw(triangle);
duration=duration_cast< microseconds >(system_clock::now().time_since_epoch()).count()-us;
std::cout<<"Triangle: "<<duration<<" us\n";
window.display();
}
return EXIT_SUCCESS;
}
Graphics drawing in modern devices using Graphic cards, and the speed of drawing depends on how many triangles in the data you sent to the Graphic memory. That's why just drawing two triangles is fast.
As you mentioned about multithreading, if you using OpenGL (I don't remember what SFML use, but should be the same), what you thinking you are drawing is basically send commands and data to graphic cards, so multithreading here is not very useful, the graphic card has it's own thread to do this.
If you are curious about how graphic card works, this tutorial is the
book you should read.
P.S. As you edit you question, I guess the duration 2500us vs 10us is because you for loop create a texture(even if the texture is a pure white background)(and the for loop, you probably need to start counting after the for loop), and send texture to graphic card need time, while draw triangle only send several points. Still, I suggest to read the tutorial, create a texture pixel by pixel potentially prove the miss understanding of how GPU works.
Several months ago I made a Fourier Transform program using SFML 2.0. I used anti-aliasing level 8 and it looked perfectly fine. Just recently however (not quite sure when the problem began since I have not touched it in a while), it seems to have broken.
Whenever I draw a line it looks dotted and whenever something moves, it flashes between two states and it doesn't completely clear after calling window.clear(). It's not just that program however. Anytime I use any level of anti-aliasing greater than 0, even in SFML 2.5.1, the same problem occurs.
Here is the some sample code which does not work as it should on my computer:
#include <SFML/Graphics.hpp>
int main()
{
sf::Vertex line[2] =
{
sf::Vertex(sf::Vector2f(0, 0)),
sf::Vertex(sf::Vector2f(800, 0))
};
sf::ContextSettings settings;
settings.antialiasingLevel = 8.0;
sf::RenderWindow window(sf::VideoMode(800, 600), "Test", sf::Style::Close, settings);
window.setVerticalSyncEnabled(true);
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::Closed)
window.close();
}
line[1].position.y += 1.0;
window.clear();
window.draw(line, 2, sf::Lines);
window.display();
}
return 0;
}
When the line finishes sweeping, it looks
like this
As this used to not be a problem, I don't think it's SFML's fault. I am using Windows 10 and my computer uses an integrated Intel UHD Graphics 620 graphics card, both of which have not changed since before the problem started happening. On a side note, I have not noticed any other programs on my computer break, only the ones I made.
I have just started working on a 2d game of mine. I'm currently experiencing a problem where I am trying to make some land with a grass block texture by spawning the same sprites multiple times with the same grass texture. However, instead of getting a row of the same texture, I am getting the row being stretched for some reason.
Let me show you:
Normal grass texture:
Current grass output:
This is the code:
#include <iostream>
#include <vector>
#include <random>
#include <SFML/Graphics.hpp>
using namespace std;
using namespace sf;
int main() {
RenderWindow window(VideoMode(1920, 1080), "Treko");
Color bg(0, 205, 255);
Font errorFont;
Texture grass;
Texture dirt;
if (!errorFont.loadFromFile("font/Arial/Arial.ttf")) {
RenderWindow error(VideoMode(600, 500), "Error!");
Text errorText;
errorText.setFont(errorFont);
errorText.setString("Unfortunaetly, we are unable to find Arial.ttf.\nPlease reinstall the application and report the error. Thank you.");
errorText.setCharacterSize(18);
errorText.setFillColor(Color::White);
while (error.isOpen()) {
Event errorEvent;
while (error.pollEvent(errorEvent)) {
if (errorEvent.type == Event::Closed) {
error.close();
}
}
error.clear();
error.draw(errorText);
error.display();
}
}
if (!dirt.loadFromFile("img/Dirt.png")) {
RenderWindow error(VideoMode(600, 500), "Error!");
Text errorText;
errorText.setFont(errorFont);
errorText.setString("Unfortunaetly, we are unable to find Dirt.png.\nPlease reinstall the application and report the error. Thank you.");
errorText.setCharacterSize(18);
while (error.isOpen()) {
Event errorEvent;
while (error.pollEvent(errorEvent)) {
if (errorEvent.type == Event::Closed) {
error.close();
}
}
error.clear();
error.draw(errorText);
error.display();
}
}
if (!grass.loadFromFile("img/Grass.png")) {
RenderWindow error(VideoMode(600, 500), "Error!");
Text errorText;
errorText.setFont(errorFont);
errorText.setString("Unfortunaetly, we are unable to find Grass.png.\nPlease reinstall the application and report the error. Thank you.");
errorText.setCharacterSize(18);
errorText.setFillColor(Color::White);
while (error.isOpen()) {
Event errorEvent;
while (error.pollEvent(errorEvent)) {
if (errorEvent.type == Event::Closed) {
error.close();
}
}
error.clear();
error.draw(errorText);
error.display();
}
}
Sprite grassBlock;
grassBlock.setTexture(grass);
Sprite dirtBlock;
dirtBlock.setTexture(dirt);
vector<Sprite> grassM;
/* This is a work in progress. I'm trying to add height to the land using random y axis generation. Any of you know how to do this it would be great to let me know!
std::uniform_int_distribution<int> randomColorRange(680, 720);
std::random_device rd;
std::mt19937 RandYPos(rd());
*/
//THE PROBLEM PART 1
for (int i = 0; i <= 1918; i++) {
grassBlock.setPosition(Vector2f(i + 1, 690));
grassBlock.setScale(Vector2f(0.5f, 0.5f));
grassM.push_back(Sprite(grassBlock));
}
while (window.isOpen()) {
Event event;
while (window.pollEvent(event)) {
if (event.type == Event::Closed) {
window.close();
}
}
window.clear(bg);
//THE PROBLEM PART 2
for (int i = 0; i < grassM.size(); i++) {
window.draw(grassM[i]);
}
window.display();
}
return 0;
}
If anyone knows how to do this, that would be great!
While I didn't try to run the code, to me it looks like everything is working. Your problem is, that you're just moving the sprites one pixel apart:
grassBlock.setPosition(Vector2f(i + 1, 690));
Since all show the same texture with the same origin, this will result in all the sprites essentially showing the first column of your texture (since the rest is overlapped by the next tile).
While I think you should rework your whole code structure (it feels really messy and I wouldn't recommend to create new SFML windows if you encounter errors, since that might fail as well), all you have to do is move your sprites apart by multiplying the index used for your coordinate by the desired tile width:
grassBlock.setPosition(Vector2f(i * tile_width, 690));
I am new to c++ and as well as SFML. I am trying to make my sprite object move down in position relative to its last position using a loop. I am looking for the animation of it sprite object falling when the program starts.
I thought implementing a the sleep function in my for loop would help solve the issue i was having where the program would just display the object at the last iteration of the loop. However my program just freezes and crashes.
Looking for some direction. Maybe the sleep function isn't the right thing to call here?
#include <SFML/Graphics.hpp>
#include <Windows.h>
#include <iostream>
using namespace std;
int main()
{
// Create the window here. Calling out the dimensions
sf::RenderWindow window(sf::VideoMode(800, 600), "Example Window");
// run the program as long as the window is open
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
//close window we requested
if (event.type == sf::Event::Closed)
{
window.close();
}
}
window.clear(sf::Color::Black);
sf::Texture texture;
if (!texture.loadFromFile("c:\\abstract.png"))
{
cout<<"Failed to load image...";
}
sf::Sprite sprite;
sprite.setTexture(texture);
sprite.setTextureRect(sf::IntRect(20,20,30,30));
for (float i = 0; i < 30.; i++)
{
sprite.move(sf::Vector2f(5.f, i));
window.draw(sprite);
Sleep(50);
}
window.display();
}
return 0;
}
What you are doing in your for is : Processing, drawing, processing, drawing... And finally displaying what you've drawn using window.display().
Meaning that what will be displayed on your window every frames, is the result of your "Processing, drawing" thing, in other word, 30 times your sprite at different positions.
What you want is to move your sprite a bit every frames. Thus, you have to finish your current while (window.isOpen()) iteration to move your sprite, draw it, and display it, and this over and over.
What you should do is declaring your sprite outside of your game loop (Which is while (window.isOpen())), and move it in this loop.
Step by step, your program should look like:
[Start]
Initialize your context
Create a sprite
Start looping
Clear the screen
Collect inputs
Move your sprite
Draw your sprite
Display your drawing on the window
End looping
[Exit]
The last thing you will need to handle is deltaTime (The timestep). Because if you move your sprite from (x,y) every frames, it means that the faster your computer is (Able to render a lot of frames quickly), the faster your sprite will move. In order to fix this problem, you'll have to move your sprite considering the time elapsed between the current frame and the previous frame (The slower is your PC, the more your sprite will move in one frame, the faster is your PC, the less your sprite will move in one frame). Timestep will cause your sprite to move (x,y) per second instead of (x,y) per frame, which is what you want in most graphic applications.
So I am working on a program that generates images with shapes of random selected colors. and I want to save an image of the output so I can use shaders on the image like blurring, as well as have an output file for any purpose. Here is my main loop for the window.
while (window.isOpen())
{
Event event;
while (window.pollEvent(event))
{
if (event.type == Event::Closed)
window.close();
}
window.clear(Color::Black);
for (int i = 0; i < rectangles.size(); i++)
window.draw(rectangles[i]);
Texture outputTexture;
outputTexture.create(width, height);
outputTexture.update(window);
Image output;
output.create(width, height);
output = outputTexture.copyToImage();
output.saveToFile("output.png");
Sprite sprite;
sprite.setTexture(outputTexture);
window.clear();
window.draw(sprite);
window.display();
}
I have tested this with the sprite and the window draws the sprite correctly. However I am getting an error here
output.saveToFile("output.png");
Exception thrown at 0x00007FF8D1527190 (sfml-graphics-2.dll) in name.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.
I can't seem to figure out the issue, I really need to be able to save images to a file. Thanks all for help
I came across the same problem, the solution was to change "sfml-xxx.lib" to "sfml-xxx-d.lib" in "Additional Dependencies" property in Visual Studio.