Cocos2D-X Platformer tutorial Part 5 – Camera

You know, to tell you the truth when I’m writing this I’m actually rediscovering cocos2d-x myself :D, how to do some things easier, but then again I only did board games on cocos2d-x … anyways back to tutorial.

Camera in cocos2d-x follows a certain target, normally this would be the player, but you need to define some boundaries to center the camera. This is actually a problem, because if I define boundaries I need to set the size of the playfield. I don’t like boundaries and the tmx map can have more than one map in it so screw that.

I defined a boundless camera which is going to follow an invisible target, this target’s y value will be always centered and x value will change according to player’s x value.

New stuff

cameraTarget – invisible target that camera follows
camera – camera object, don’t ask me why the class is called Follow
oh yeah and camera is run by the layer itself


#pragma once
 
#include "cocos2d.h"
#include "Level.h"
#include "Player.h"
#include <algorithm>
#include <vector>
#include <string>
 
using namespace std;
USING_NS_CC;
 
class GameScene : public cocos2d::Layer
{
public:
   
    //FIELDS
    Level * level;
    Player *player;
    Sprite *player_sprite;
	Sprite *cameraTarget;

	Animate *walkRight;
	Animate *jumping;
	Animate *falling;

	Follow *camera;

    vector<EventKeyboard::KeyCode> heldKeys;
 
    //CONSTRUCTOR & METHODS
 
    virtual void onKeyPressed(EventKeyboard::KeyCode keyCode, Event* event);
    virtual void onKeyReleased(EventKeyboard::KeyCode keyCode, Event* event);
    
	void updateScene(float interval);
	void updatePlayer(float interval);
	void updatePlayerSprite(float interval);

    int signum(float x);
 
    static cocos2d::Scene* createScene();
 
    virtual bool init();  
    
    void menuCloseCallback(cocos2d::Ref* pSender);
	void setupAnimations();
    
    CREATE_FUNC(GameScene);
 
    GameScene(void);
    virtual ~GameScene(void);
};

#pragma once

#include "cocos2d.h"

#include "Level.h"

#include "Player.h"

#include <algorithm>

#include <vector>

#include <string>

using namespace std;

USING_NS_CC;

class GameScene : public cocos2d::Layer

{

public:

//FIELDS

Level * level;

Player *player;

Sprite *player_sprite;

Sprite *cameraTarget;

Animate *walkRight;

Animate *jumping;

Animate *falling;

Follow *camera;

vector<EventKeyboard::KeyCode> heldKeys;

//CONSTRUCTOR & METHODS

virtual void onKeyPressed(EventKeyboard::KeyCode keyCode, Event* event);

virtual void onKeyReleased(EventKeyboard::KeyCode keyCode, Event* event);

void updateScene(float interval);

void updatePlayer(float interval);

void updatePlayerSprite(float interval);

int signum(float x);

static cocos2d::Scene* createScene();

virtual bool init();

void menuCloseCallback(cocos2d::Ref* pSender);

void setupAnimations();

CREATE_FUNC(GameScene);

GameScene(void);

virtual ~GameScene(void);

};


#include "GameScene.h"
#include "globals.h"
 
Scene* GameScene::createScene()
{
    auto scene = Scene::create();
    
    auto layer = GameScene::create();
 
    scene->addChild(layer);
   
    return scene;
}
 
bool GameScene::init()
{
    if ( !Layer::init() )
    {
        return false;
    }
 
    level = new Level();
    level->loadMap("level1.tmx");
    level->retain();
 
    auto director = Director::getInstance();
    level->getMap()->setScale(SCALE_FACTOR);
 
    this->addChild(level->getMap());
 
    SpriteFrameCache::getInstance()->addSpriteFramesWithFile("solbrain.plist");
	AnimationCache::getInstance()->addAnimationsWithFile("solbrain-animations.plist");
 
    player_sprite = Sprite::createWithSpriteFrameName("idle");
	player_sprite->setScale(SCALE_FACTOR);
    player_sprite->setFlippedX(true);

    Point point = Point(10,2);
    Size size = player_sprite->getContentSize();
 

    player_sprite->setPosition(level->positionForTileCoordinate(size, point));
 
    player = new Player();
    player->retain();
	player->state = Player::State::Standing;

	Point origin = Director::getInstance()->getVisibleOrigin();
    Size wsize = Director::getInstance()->getVisibleSize();  //default screen size (or design resolution size, if you are using design resolution)
    Point *center = new Point(wsize.width/2 + origin.x, wsize.height/2 + origin.y);

	cameraTarget = Sprite::create();
	cameraTarget->setPositionX(player_sprite->getPosition().x); // set to players x
	cameraTarget->setPositionY(wsize.height/2 + origin.y); // center of height

	cameraTarget->retain();

	this->setupAnimations();
    this->addChild(player_sprite);
    this->schedule(schedule_selector(GameScene::updateScene));
	this->addChild(cameraTarget);

	camera = Follow::create(cameraTarget, Rect::ZERO);
	camera->retain();

	this->runAction(camera);
    return true;
}

void GameScene::setupAnimations(){

	AnimationCache *cache = AnimationCache::getInstance(); 
	Animation *animation = cache->getAnimation("walk");
	Animate* animate = Animate::create(animation);
	animate->getAnimation()->setRestoreOriginalFrame(true);
	animate->setDuration(0.80f);
	animate->setTarget(player_sprite);
	
	this->walkRight = animate;
	this->walkRight->retain();

}
 
void GameScene::updateScene(float delta){
 
	cameraTarget->setPositionX( player_sprite->getPosition().x );
	this->updatePlayer(delta);
 
}

void GameScene::updatePlayer(float delta){

	    if(std::find(heldKeys.begin(), heldKeys.end(), RIGHT_ARROW) != heldKeys.end()){

            player->velocity.x = PLAYER_MAX_VELOCITY;
            
			if(player->grounded){
                player->state = Player::State::Walking;				
            }

            player->facingRight = true;
        }
 
        if(std::find(heldKeys.begin(), heldKeys.end(), LEFT_ARROW) != heldKeys.end()){
               player->velocity.x = -PLAYER_MAX_VELOCITY;
            if(player->grounded){
                player->state = Player::State::Walking;
            }
            player->facingRight = false;
        }
        // clamp the velocity to the maximum, x-axis only
        if (std::abs(player->velocity.x) > PLAYER_MAX_VELOCITY) {
            player->velocity.x = signum(player->velocity.x) * PLAYER_MAX_VELOCITY;
        }
        // clamp the velocity to 0 if it's < 1, and set the state to standing
        if (std::abs(player->velocity.x) < 1) {
            player->velocity.x = 0;
            if (player->grounded) {
               player->state = Player::State::Standing;
            }
        }
 
        // unscale the velocity by the inverse delta time and set
        // the latest position
        player->velocity = player->velocity * delta;
        player->position = player->position + player->velocity;
        player->velocity = player->velocity * 1/delta;
 
        player->velocity.x *= DAMPING;
		this->updatePlayerSprite(delta);
}

void GameScene::updatePlayerSprite(float delta){

	if(player->state == Player::State::Walking){

		if(walkRight->isDone()){
           walkRight->startWithTarget(player_sprite);
        }

		walkRight->step(delta);

		if(player->facingRight){    
			player_sprite->setFlippedX(true);
		}else {
			player_sprite->setFlippedX(false);
		}

	}else if(player->state == Player::State::Jumping){
		
	}else{
		player_sprite->setSpriteFrame(Sprite::createWithSpriteFrameName("idle")->getSpriteFrame());
	}
    
    player_sprite->setPositionX(player_sprite->getPositionX() + player->velocity.x);
}
 
void GameScene::onKeyPressed(EventKeyboard::KeyCode keyCode, Event* event)
{
    if(std::find(heldKeys.begin(), heldKeys.end(), keyCode) == heldKeys.end()){
            heldKeys.push_back(keyCode);
    }
}
 
void GameScene::onKeyReleased(EventKeyboard::KeyCode keyCode, Event* event)
{
    heldKeys.erase(std::remove(heldKeys.begin(), heldKeys.end(), keyCode), heldKeys.end());
}
 
int GameScene::signum(float x) 
{ 
  if (x > 0.0L) 
    return 1.0L; 
  else if (x < 0.0L)   
    return -1.0L; 
  else   
    return 0.0L; 
}
 
void GameScene::menuCloseCallback(Ref* pSender)
{
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WP8) || (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT)
    return;
#endif
 
    Director::getInstance()->end();
 
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
    exit(0);
#endif
}
 
GameScene::GameScene(void)
{
    setKeyboardEnabled(true);    
}
GameScene::~GameScene(void)
{
}

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#include "GameScene.h"

#include "globals.h"

Scene* GameScene::createScene()

{

auto scene = Scene::create();

auto layer = GameScene::create();

scene->addChild(layer);

return scene;

}

bool GameScene::init()

{

if ( !Layer::init() )

{

return false;

}

level = new Level();

level->loadMap("level1.tmx");

level->retain();

auto director = Director::getInstance();

level->getMap()->setScale(SCALE_FACTOR);

this->addChild(level->getMap());

SpriteFrameCache::getInstance()->addSpriteFramesWithFile("solbrain.plist");

AnimationCache::getInstance()->addAnimationsWithFile("solbrain-animations.plist");

player_sprite = Sprite::createWithSpriteFrameName("idle");

player_sprite->setScale(SCALE_FACTOR);

player_sprite->setFlippedX(true);

Point point = Point(10,2);

Size size = player_sprite->getContentSize();

player_sprite->setPosition(level->positionForTileCoordinate(size, point));

player = new Player();

player->retain();

player->state = Player::State::Standing;

Point origin = Director::getInstance()->getVisibleOrigin();

Size wsize = Director::getInstance()->getVisibleSize(); //default screen size (or design resolution size, if you are using design resolution)

Point *center = new Point(wsize.width/2 + origin.x, wsize.height/2 + origin.y);

cameraTarget = Sprite::create();

cameraTarget->setPositionX(player_sprite->getPosition().x); // set to players x

cameraTarget->setPositionY(wsize.height/2 + origin.y); // center of height

cameraTarget->retain();

this->setupAnimations();

this->addChild(player_sprite);

this->schedule(schedule_selector(GameScene::updateScene));

this->addChild(cameraTarget);

camera = Follow::create(cameraTarget, Rect::ZERO);

camera->retain();

this->runAction(camera);

return true;

}

void GameScene::setupAnimations(){

AnimationCache *cache = AnimationCache::getInstance();

Animation *animation = cache->getAnimation("walk");

Animate* animate = Animate::create(animation);

animate->getAnimation()->setRestoreOriginalFrame(true);

animate->setDuration(0.80f);

animate->setTarget(player_sprite);

this->walkRight = animate;

this->walkRight->retain();

}

void GameScene::updateScene(float delta){

cameraTarget->setPositionX( player_sprite->getPosition().x );

this->updatePlayer(delta);

}

void GameScene::updatePlayer(float delta){

if(std::find(heldKeys.begin(), heldKeys.end(), RIGHT_ARROW) != heldKeys.end()){

player->velocity.x = PLAYER_MAX_VELOCITY;

if(player->grounded){

player->state = Player::State::Walking;

}

player->facingRight = true;

}

if(std::find(heldKeys.begin(), heldKeys.end(), LEFT_ARROW) != heldKeys.end()){

player->velocity.x = -PLAYER_MAX_VELOCITY;

if(player->grounded){

player->state = Player::State::Walking;

}

player->facingRight = false;

}

// clamp the velocity to the maximum, x-axis only

if (std::abs(player->velocity.x) > PLAYER_MAX_VELOCITY) {

player->velocity.x = signum(player->velocity.x) * PLAYER_MAX_VELOCITY;

}

// clamp the velocity to 0 if it's < 1, and set the state to standing

if (std::abs(player->velocity.x) < 1) {

player->velocity.x = 0;

if (player->grounded) {

player->state = Player::State::Standing;

}

// unscale the velocity by the inverse delta time and set

// the latest position

player->velocity = player->velocity * delta;

player->position = player->position + player->velocity;

player->velocity = player->velocity * 1/delta;

player->velocity.x *= DAMPING;

this->updatePlayerSprite(delta);

}

void GameScene::updatePlayerSprite(float delta){

if(player->state == Player::State::Walking){

if(walkRight->isDone()){

walkRight->startWithTarget(player_sprite);

}

walkRight->step(delta);

if(player->facingRight){

player_sprite->setFlippedX(true);

}else {

player_sprite->setFlippedX(false);

}

}else if(player->state == Player::State::Jumping){

}else{

player_sprite->setSpriteFrame(Sprite::createWithSpriteFrameName("idle")->getSpriteFrame());

}

player_sprite->setPositionX(player_sprite->getPositionX() + player->velocity.x);

}

void GameScene::onKeyPressed(EventKeyboard::KeyCode keyCode, Event* event)

{

if(std::find(heldKeys.begin(), heldKeys.end(), keyCode) == heldKeys.end()){

heldKeys.push_back(keyCode);

}

void GameScene::onKeyReleased(EventKeyboard::KeyCode keyCode, Event* event)

{

heldKeys.erase(std::remove(heldKeys.begin(), heldKeys.end(), keyCode), heldKeys.end());

}

int GameScene::signum(float x)

{

if (x > 0.0L)

return 1.0L;

else if (x < 0.0L)

return -1.0L;

else

return 0.0L;

}

void GameScene::menuCloseCallback(Ref* pSender)

{

#if (CC_TARGET_PLATFORM == CC_PLATFORM_WP8) || (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT)

return;

#endif

Director::getInstance()->end();

#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)

exit(0);

#endif

}

GameScene::GameScene(void)

{

setKeyboardEnabled(true);

}

GameScene::~GameScene(void)

{

}

This entry was posted in Cocos2D-X and tagged camera,cocos2dx,platformer on September 27, 2014

Cocos2D-X Platformer tutorial Part 5 – Camera

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