Topics

1

System / SFML already use 4 threads (include main)?

« on: July 27, 2020, 06:35:01 pm »

My debugger shows to me that I have already 4 threads:

(click to show/hide)

If I create two more threads thereat I have 6 threads already:

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Does it mean that I be able to create only

std::thread::hardware_concurrency() - 4

threads?
May I disable threads which I don't know for what? 

2

Graphics / Why the coordinate system in sf::RenderTarget begins with (1, 0)?

« on: April 28, 2018, 09:27:01 pm »

While I has been generate an texture I noticed to strange implementation:
the coordinate system has been moved on one pixel to right.
It is from here I can draw and see what I draw. Why?
I don't understand, explain me this aspect, please.

(click to show/hide)

cmake_minimum_required(VERSION 3.9)
project(Test_SFML)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++17 -pedantic -Wall -Wextra")
set(CMAKE_EXE_LINKER_FLAGS "-static -static-libgcc")
set(SFML_STATIC_LIBRARIES TRUE)


set(SFML_ROOT "W:/Programs/Programming environment/Librares/SFML-2.4.2")
set(CMAKE_MODULE_PATH "${SFML_ROOT}/cmake/Modules" ${CMAKE_MODULE_PATH})
find_package(SFML 2 REQUIRED graphics network audio window system)

add_executable(${PROJECT_NAME} main.cpp)
if(SFML_FOUND)
    include_directories(${SFML_INCLUDE_DIR})
    target_link_libraries(${PROJECT_NAME} ${SFML_LIBRARIES} ${SFML_DEPENDENCIES})
endif()
 

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#include <iostream>
#include <iomanip>
 
#include <windows.h>
#include <SFML/Graphics.hpp>
 
class ErrorPrinter {
  public:
    ErrorPrinter(std::string cause): cause(cause) { }
    void print() {
        ShowWindow(GetConsoleWindow(), SW_SHOW);
        std::cerr << "Program will stop. Error: \n   \'" << cause << '\'' << std::endl;
        system("PAUSE");
        exit(1);
    }
 
  private:
    std::string cause;
};
 
class Test {
  public:
    Test(sf::VideoMode screen = { 250, 150 }, std::string title = "Test"): window(screen, title) { }
   
    void run() {
        ShowWindow(GetConsoleWindow(), SW_HIDE);
       
        while(window.isOpen()) {
            HandleEvents();
            draw();
        }
    }
 
  private:
    void HandleEvents() {
        sf::Event e;
        while(window.pollEvent(e)) {
            switch(e.type) {
                case sf::Event::EventType::Closed:
                    window.close();
                    break;
                default:
                    break;
            }
        }
    }
    void draw() {
        window.clear(sf::Color(50, 50, 50));
   
        sf::RenderTexture buffer;
        buffer.create(200, 100);
       
        // Top
        buffer.draw(std::unique_ptr<sf::Vertex>(new sf::Vertex[2] {
            {{0, 0}}, {{200, 0}}
        }).get(), 2, sf::Lines);
       
        // Bottom
        buffer.draw(std::unique_ptr<sf::Vertex>(new sf::Vertex[2] {
            {{0, 99}}, {{200, 99}}
        }).get(), 2, sf::Lines);
   
        // Left
        buffer.draw(std::unique_ptr<sf::Vertex>(new sf::Vertex[2] {
            {{0, 0}}, {{0, 100}}
        }).get(), 2, sf::Lines, sf::Transform().translate(0, 0));
       
        // Right
        buffer.draw(std::unique_ptr<sf::Vertex>(new sf::Vertex[2] {
            {{199, 0}}, {{199, 99}}
        }).get(), 2, sf::Lines, sf::Transform().translate(0, 0));
       
        buffer.display();
   
        sf::Texture texture = buffer.getTexture();
        sf::Sprite sprite(texture);
       
        window.draw(sprite, sf::Transform().translate(10, 10));
   
        window.display();
    }
 
 
  private:
    sf::RenderWindow window;
};
 
int main() {
    try { Test().run(); } catch(std::exception const& e) {
        ErrorPrinter(e.what()).print();
    }
    return 0;
}