Im am new to SFML and have made a simple program to draw a grid of squares and I was trying to measure performance. When I run this I can see the memory usage climb to above a gigabyte before dropping and rising again. What I don't understand is why this much memory is being allocated. It happens somewhere in the draw function. Do I have to free the Vertexarray in some way? If yes, how? (resizing to 0 doesn't help)
#include <iostream>
#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>
#include <vector>
#include <chrono>
class World {
public:
std::vector<std::vector<int>> map;
sf::Vector2i worldSize;
std::vector<sf::Color> colors;
World(int width, int height) {
worldSize = sf::Vector2i(width, height);
for (int x = 0; x < worldSize.x; x++) {
std::vector<int> temp;
for (int y = 0; y < worldSize.y; y++) {
temp.push_back(0);
}
map.push_back(temp);
}
colors.push_back(sf::Color::White);
colors.push_back(sf::Color::Black);
}
void draw(sf::RenderWindow* screen) {
sf::Vector2u screenSize = screen->getSize();
sf::View view = screen->getView();
sf::Vector2f viewCenter = view.getCenter();
sf::Vector2f viewSize = view.getSize();
float tileSize = 1;
int x0 = 0;
if ((viewCenter.x - (viewSize.x / 2)) > x0)
x0 = (viewCenter.x - (viewSize.x / 2));
int x1 = worldSize.x;
if ((viewCenter.x + (viewSize.x / 2)) + 1 < x1)
x1 = (viewCenter.x + (viewSize.x / 2)) + 1;
int y0 = 0;
if ((viewCenter.y - (viewSize.y / 2)) > y0)
y0 = (viewCenter.y - (viewSize.y / 2));
int y1 = worldSize.x;
if ((viewCenter.y + (viewSize.y / 2)) + 1< y1)
y1 = (viewCenter.y + (viewSize.y / 2)) + 1;
int xSize = x1 - x0;
int ySize = y1 - y0;
if (xSize > 0 && ySize > 0) {
sf::VertexArray vertices;
vertices.setPrimitiveType(sf::Quads);
vertices.resize(xSize * ySize * 4);
for (int x = x0; x < x1; x += 1) {
for (int y = y0; y < y1; y += 1) {
int current = (((x - x0) * ySize) + (y - y0)) * 4;
vertices[current + 0].position = sf::Vector2f(x * tileSize, y * tileSize);
vertices[current + 1].position = sf::Vector2f((x + 1) * tileSize, y * tileSize);
vertices[current + 2].position = sf::Vector2f((x + 1) * tileSize, (y + 1) * tileSize);
vertices[current + 3].position = sf::Vector2f(x * tileSize, (y + 1) * tileSize);
vertices[current + 0].color = colors[map[x][y]];
vertices[current + 1].color = colors[map[x][y]];
vertices[current + 2].color = colors[map[x][y]];
vertices[current + 3].color = colors[map[x][y]];
}
}
screen->draw(vertices);
vertices.resize(0);
}
}
};
int main()
{
sf::Vector2f screenSize(500, 500);
World myWorld(124, 124);
sf::RenderWindow window(sf::VideoMode(screenSize.x, screenSize.y), "tileworld");
window.setView(sf::View(sf::Vector2f(myWorld.worldSize) * 0.5f , sf::Vector2f(myWorld.worldSize) * (myWorld.worldSize.x / screenSize.x)));
auto start = std::chrono::high_resolution_clock::now();
for (int i = 0; i < 100000; i++) {
myWorld.draw(&window);
std::cout << i << "\r";
}
auto stop = std::chrono::high_resolution_clock::now();
std::cout << std::chrono::duration_cast<std::chrono::microseconds>(stop - start).count()/100000 << std::endl;
return 0;
}
