I have taken the excellent vertex array example from the tutorial here:
https://www.sfml-dev.org/tutorials/2.5/graphics-vertex-array.php and doubled the tilemap size (by simply copy pasting the existing level array and increasing the size of the map size passed to the load method). I then changed the sf::View and added a handler for the down key to move by one tile height each time the down key is pressed.
Here is the code I've got to so far, any help much appreciated. I am working on Ubuntu 20.04 if that makes any difference.
#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>
#include <string>
#include <iostream>
class TileMap : public sf::Drawable, public sf::Transformable
{
public:
bool load(const std::string& tileset, sf::Vector2u tileSize, const int* tiles, unsigned int width, unsigned int height)
{
// load the tileset texture
if (!m_tileset.loadFromFile(tileset))
return false;
// resize the vertex array to fit the level size
m_vertices.setPrimitiveType(sf::Quads);
m_vertices.resize(width * height * 4);
// populate the vertex array, with one quad per tile
for (unsigned int i = 0; i < width; ++i)
for (unsigned int j = 0; j < height; ++j)
{
// get the current tile number
const int tileNumber = tiles[i + j * width];
// find its position in the tileset texture
int tu = tileNumber % (m_tileset.getSize().x / tileSize.x);
int tv = tileNumber / (m_tileset.getSize().x / tileSize.x);
// get a pointer to the current tile's quad
sf::Vertex* quad = &m_vertices[(i + j * width) * 4];
// define its 4 corners
quad[0].position = sf::Vector2f(i * tileSize.x, j * tileSize.y);
quad[1].position = sf::Vector2f((i + 1) * tileSize.x, j * tileSize.y);
quad[2].position = sf::Vector2f((i + 1) * tileSize.x, (j + 1) * tileSize.y);
quad[3].position = sf::Vector2f(i * tileSize.x, (j + 1) * tileSize.y);
// define its 4 texture coordinates
quad[0].texCoords = sf::Vector2f(tu * tileSize.x, tv * tileSize.y);
quad[1].texCoords = sf::Vector2f((tu + 1) * tileSize.x, tv * tileSize.y);
quad[2].texCoords = sf::Vector2f((tu + 1) * tileSize.x, (tv + 1) * tileSize.y);
quad[3].texCoords = sf::Vector2f(tu * tileSize.x, (tv + 1) * tileSize.y);
}
return true;
}
private:
virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const
{
// apply the transform
states.transform *= getTransform();
// apply the tileset texture
states.texture = &m_tileset;
// draw the vertex array
target.draw(m_vertices, states);
}
sf::VertexArray m_vertices;
sf::Texture m_tileset;
};
int main()
{
// create the window
sf::RenderWindow window(sf::VideoMode(512, 256), "Tilemap");
window.setVerticalSyncEnabled(true);
// define the level with an array of tile indices
const int level[] =
{
0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0,
1, 1, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3, 3, 3,
0, 1, 0, 0, 2, 0, 3, 3, 3, 0, 1, 1, 1, 0, 0, 0,
0, 1, 1, 0, 3, 3, 3, 0, 0, 0, 1, 1, 1, 2, 0, 0,
0, 0, 1, 0, 3, 0, 2, 2, 0, 0, 1, 1, 1, 1, 2, 0,
2, 0, 1, 0, 3, 0, 2, 2, 2, 0, 1, 1, 1, 1, 1, 1,
0, 0, 1, 0, 3, 2, 2, 2, 0, 0, 0, 0, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0,
1, 1, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3, 3, 3,
0, 1, 0, 0, 2, 0, 3, 3, 3, 0, 1, 1, 1, 0, 0, 0,
0, 1, 1, 0, 3, 3, 3, 0, 0, 0, 1, 1, 1, 2, 0, 0,
0, 0, 1, 0, 3, 0, 2, 2, 0, 0, 1, 1, 1, 1, 2, 0,
2, 0, 1, 0, 3, 0, 2, 2, 2, 0, 1, 1, 1, 1, 1, 1,
0, 0, 1, 0, 3, 2, 2, 2, 0, 0, 0, 0, 1, 1, 1, 1,
};
// create the tilemap from the level definition
TileMap map;
if (!map.load("tileset.png", sf::Vector2u(32, 32), level, 32, 16))
return -1;
sf::View view(sf::FloatRect (0.f, 0.f, 512.f, 256.f));
window.setView(view);
// run the main loop
while (window.isOpen())
{
// handle events
sf::Event event;
while (window.pollEvent(event))
{
if(event.type == sf::Event::Closed)
window.close();
switch (event.type)
{
case sf::Event::KeyPressed:
switch (event.key.code)
{
case sf::Keyboard::Down:
view.move(0.0f, 32.0f);
window.setView(view);
break;
}
break;
}
}
window.clear();
window.draw(map);
window.display();
}
return 0;
}
