box-car-2d/GLEssentials/Game.mm

//
//  Game.m
//  iOSGLEssentials
//
//  Created by Joshua Moerman on 08/03/14.
//
//

#import "Game.h"
#include "Drawer.h"
#include "Car.h"
#include "Path.h"
#include <moggle/core/gl.hpp>
#include <Box2D/Box2D.h>
#include <string>
#include <map>
#include <functional>

using namespace moggle;

static int ncars = 10;

struct GameCPP{
    std::map<std::string, std::function<void()>> actions;
    bool should_regenerate = false;
    int steps = 2;
    
    std::string bundle;
    Drawer drawer{bundle};
    
    b2Vec2 gravity{0.0f, -10.0f};
    b2World world{gravity};
    
    std::vector<Car> cars;
    Path path{world};
    
    GameCPP(std::string const & bundle_)
    : bundle(bundle_){
        actions["regenerate"] = [this]{ should_regenerate = true; };
        actions["speed"] = [this]{ steps *= 2; if(steps >= 32) steps = 2; };
        
        path.buildUpTo(100);
        
        create_cars();
        
        drawer.SetFlags(b2Draw::e_shapeBit + b2Draw::e_jointBit);
        world.SetDebugDraw(&drawer);
    }
    
    void create_cars(){
        for(int i = 0; i < ncars; ++i){
            cars.emplace_back(world);
        }
    }
    
    void draw(){
        drawer.camera = convert(getFurthest());
        drawer.clear();
        world.DrawDebugData();
        drawer.draw();
    }
    
    void update(float dt){
        if(should_regenerate){
            should_regenerate = false;
            cars.clear();
            create_cars();
        }
        for(int i = 0; i < steps; ++i){
            path.buildUpTo(getFurthest().x + 25);
            world.Step(dt, 8, 3);
        }
    }
    
    void resize(float width, float height){
        drawer.resize(width, height);
    }
    
    b2Vec2 getFurthest() const {
        b2Vec2 furthest = {0, 0};
        for(auto&& c : cars){
            auto p = c.getPosition();
            if(p.x > furthest.x){
                furthest = p;
            }
        }
        return furthest;
    }
};

@implementation Game{
    GameCPP * game;
    NSMutableArray * actions;
}

@synthesize windowSize, actions;

- (id)init{
    if(self = [super init]){
        NSString * path = [[NSBundle mainBundle] resourcePath];
        game = new GameCPP([path UTF8String]);
        actions = [NSMutableArray arrayWithCapacity: 10];
        
        for(auto&& p : game->actions){
            [actions addObject:[NSString stringWithUTF8String:p.first.c_str()]];
        }
    }
    return self;
}

- (void)update:(float)dt{
    game->update(dt);
}

- (void)draw{
    game->draw();
}

- (void)action:(NSString *)a{
    game->actions[[a UTF8String]]();
}

- (void)setWindowSize:(CGSize)windowSize_{
    windowSize = windowSize_;
    game->resize(windowSize.width, windowSize.height);
}

@end