holesome/src/game/physics/map/map_simulation.cpp

#include "map_simulation.hpp"
#include "../../../config.h"
#include "../../player/player_collection.hpp"

MapSimulation::MapSimulation()
{
    mapPlayersById = std::map<int, std::shared_ptr<MapPlayer>>();
}

std::shared_ptr<MapSimulation> MapSimulation::getInstance()
{
    if (singletonInstance == nullptr)
    {
        singletonInstance = std::make_shared<MapSimulation>();
    }
    return singletonInstance;
}

void MapSimulation::physicsUpdate()
{
    // Update simulation positions
    for (auto &mapPlayer: mapPlayersById)
    {
        mapPlayer.second->updateSimulationPosition();
    }

    world->Step(FRAME_TIME.asSeconds(), MAPSIM_VELOCITY_ITERATIONS, MAPSIM_POSITION_ITERATIONS);

    // Update player positions
    for (auto &mapPlayer: mapPlayersById)
    {
        mapPlayer.second->updatePlayerPosition();
    }
}

void MapSimulation::resetMap(sf::Vector2<int> worldMapSize)
{
    // Clear all players
    for (auto &mapPlayer: mapPlayersById)
    {
        removePlayer(mapPlayer.second->player);
    }

    // No gravity, since this a top-down view of the map
    world = std::make_shared<b2World>(b2Vec2(0.0f, 0.0f));

    // Create map borders
    constructSquareObstacle(-MAPSIM_WALL_THICKNESS, -MAPSIM_WALL_THICKNESS, 0, worldMapSize.y + MAPSIM_WALL_THICKNESS);  // Bottom left
    constructSquareObstacle(0, -MAPSIM_WALL_THICKNESS, worldMapSize.x, 0);  // Bottom right
    constructSquareObstacle(worldMapSize.x, -MAPSIM_WALL_THICKNESS, worldMapSize.x + MAPSIM_WALL_THICKNESS, worldMapSize.y + MAPSIM_WALL_THICKNESS); // Top right
    constructSquareObstacle(0, worldMapSize.y, worldMapSize.x, worldMapSize.y + MAPSIM_WALL_THICKNESS); // Top left
}

void MapSimulation::constructSquareObstacle(float minX, float minY, float maxX, float maxY)
{
    b2BodyDef bodyDef;
    bodyDef.type = b2_staticBody;
    bodyDef.position.Set((maxX + minX) / 2.f, (maxY + minY) / 2.f);
    b2Body *body = world->CreateBody(&bodyDef);

    b2PolygonShape shape;
    shape.SetAsBox((maxX - minX) / 2.f, (maxY - minY) / 2.f);

    b2FixtureDef fixtureDef;
    fixtureDef.shape = &shape;
    fixtureDef.density = 1.0f;

    body->CreateFixture(&fixtureDef);
}

void MapSimulation::addPlayer(const std::shared_ptr<Player> &player)
{
    b2BodyDef bodyDef;
    bodyDef.type = b2_dynamicBody;
    bodyDef.position.Set(player->spawnPosition.world().x, player->spawnPosition.world().y);
    b2Body *body = world->CreateBody(&bodyDef);
    mapPlayersById[player->getPlayerId()] = std::make_shared<MapPlayer>(player, body);
}

void MapSimulation::update()
{
    // Update players from player collection
    // New player
    for (auto &player: PlayerCollection::getInstance()->getNewPlayers())
    {
        addPlayer(player);
    }
    // Removed players
    for (auto &player: PlayerCollection::getInstance()->getRemovedPlayers())
    {
        removePlayer(player);
    }
}

void MapSimulation::removePlayer(std::shared_ptr<Player> &player)
{
    // Remove body from simulation
    int playerId = player->getPlayerId();
    world->DestroyBody(mapPlayersById[playerId]->body);
    mapPlayersById.erase(playerId);
}