我们在第2部分教程中已经介绍了如何让dragon沿着8个不同的方向移动，并且播放相应的动画，同时，移动过程可以由用户touch屏幕来控制。cocos2d-x 很酷吧！好了，今天我们将多干点活，我们将创建一大批村民--实际上是N个村民。我们会使用我们已经学习过的技术，从spritesheet里面加载精灵，同时建立相应的精灵动画。
这里有本教程的完整源代码。
那么，我们到底要做成什么样子呢---看了下面的图就明白了：
上面加载了好多村民，但是，屏幕的帧速率仍然是60 fps。这是因为我们做了优化。那么，究竟是如何做的呢？让我们马上开始学习吧。
首先，我们要创建我们的adventurer （冒险者）类。---它里面存储了我们的移动和行走动画的精灵实例。在屏幕上每一个冒险家，我们都会为之创建一个adventurer 类的实例。
Adventurer.h
#include "cocos2d.h"
USING_NS_CC;
class Adventurer: public Node {
Sprite* charSprite;
Action* walkAction;
Action* moveAction;
bool moving;
};
如果你愿意的话，你也可以从Sprite继承，然后我们可以调用initWithFile方法来初始化我们的Adventure 类。但是，我更喜欢从Node继承，然后包含一个Sprite的实例。
Adventurer.cpp
#include "Adventurer.h"
bool Adventurer::init()
{
if (!Node::init())
{
return false;
}
return true;
}
很简单的init函数,上面这段代码，我们再熟悉不过了。这里创建了一个非常简单的类，但是，也给我们一些提示，如何为游戏主角创建class。
现在，我们拥有角色了，让我们来使用之。。。先回到“PlayLayer.h” ，然后做下面一些变更：
#pragma once
#include "cocos2d.h"
#include "SceneManager.h"
USING_NS_CC;
class PlayLayer: public Layer
{
public:
Vector<Action*> flyActionArray;
Texture2D* texture;
SpriteBatchNode* spritesheet;
Vector<char*> charArray;
Sprite* dragon;
Action* flyAction;
Action* moveAction;
bool moving;
CREATE_FUNC(PlayLayer);
bool virtual init();
void virtual onEnter();
bool onTouchBegan(Touch *touch, Event *event);
void onTouchMoved(Touch *touch, Event *event);
void onTouchEnded(Touch* touch, Event* event);
};
我们先导入 “Adventurer.h”，然后定义了3个实例变量。第一个变量 “texture”用来加载adventurer 精灵表单。第二变量 “spritesheet”是把我们将要创建的精灵都进行“批处理”，使之提高效率。最后，我们想要追踪所有的adventurers，所以，我们定义了一个“charArray”.数组。同时我们为每一个实例变量都声明了属性，这样我们就可以在PlayLayer.m间接使用了。（另一种方法是定义tag，在init方法里面指定tag，然后在其它方法里面就可以用self getChildByTag:tag来获得想要的孩子了）
OK，现在我们有一堆类了。不过别担心，我们会在后面把它逐步分开讲解--首先，先让我们实现
PlayLayer.cpp：
#include "PlayLayer.h"
enum {ktagSpriteSheet = 1,};
bool PlayLayer::init()
{
if (!Layer::init())
{
return false;
}
auto background = Sprite::create("Terrain.png");
background->setPosition(ccp(160,240));
this->addChild(background);
auto texture = TextureCache::getInstance()->addImage("dragon.png");
auto sheet = SpriteBatchNode::create("dragon.png",10);
this->addChild(sheet, 0, ktagSpriteSheet);
Size s = Director::getInstance()->getWinSize();
Vector<SpriteFrame*> animFrames;
for (int i = 0; i < 8; i++)
{
animFrames.clear();
for (int j = 0; j < 10; j++)
{
auto frame = SpriteFrame::createWithTexture(texture, Rect(j * 75, i * 70, 75, 70), false, Director::getInstance()->getVisibleOrigin(), Size(75, 70));
animFrames.pushBack(frame);
}
auto animation = Animation::createWithSpriteFrames(animFrames, 0.1f);
auto animate = Animate::create(animation);
auto seq = Sequence::create(animate, NULL);
this->flyAction = RepeatForever::create(seq);
flyActionArray.pushBack(this->flyAction);
}
auto frame1 = SpriteFrame::createWithTexture(texture, Rect(0, 0, 75, 70), false, Director::getInstance()->getVisibleOrigin(), Size(75, 70));
this->dragon = Sprite::createWithSpriteFrame(frame1);
dragon->setPosition(ccp(s.width/2-80,s.height/2));
sheet->addChild(dragon);
this->flyAction = flyActionArray.at(0);
dragon->runAction(flyAction);
texture = TextureCache::getInstance()->addImage("adventurer.png");
spriteSheet = SpriteBatchNode::createWithTexture(texture,100);
this->addChild(spriteSheet,0,ktagSpriteSheet);
this->schedule(schedule_selector(PlayLayer::gameLogic), 1.0f);
return true;
}
void PlayLayer::addAdventurer()
{
Vector<SpriteFrame*>animFrames;
animFrames.clear();
for (int i = 0; i < 9; i++)
{
auto *frame = SpriteFrame::createWithTexture(this->texture, Rect(i * 16, 0, 16, 29));
animFrames.pushBack(frame);
}
auto adventurer = Adventurer::create();
if (adventurer != NULL) {
auto *frame1 = SpriteFrame::createWithTexture(this->texture, Rect(0, 0, 19, 29));
adventurer->charSprite = Sprite::createWithSpriteFrame(frame1);
Size s = Director::getInstance()->getWinSize();
int minY = adventurer->charSprite->getContentSize().width/2;
int maxY = s.height - adventurer->charSprite->getContentSize().height / 2;
int rangeY = maxY - minY;
int actualY = (CCRANDOM_0_1() * rangeY) + minY;
int minX = -300;
int maxX = 0;
int rangeX = maxX - minX;
int actualX = (CCRANDOM_0_1() * rangeX) + minX;
adventurer->charSprite->setPosition(ccp(actualX, actualY));
auto *animation = Animation::createWithSpriteFrames(animFrames,0.2);
auto *animate = Animate::create(animation);
auto *seq = Sequence::create(animate,NULL);
adventurer->walkAction = RepeatForever::create(seq);
auto actionMove = MoveTo::create(10.0f,ccp(s.width + 200, actualY));
auto actionMoveDone = CallFuncN::create(CC_CALLBACK_1(PlayLayer::spriteMoveFinished,this,(void*)adventurer));
adventurer->moveAction = Sequence::create(actionMove,actionMoveDone,NULL);
adventurer->charSprite->runAction(adventurer->walkAction);
adventurer->charSprite->runAction(adventurer->moveAction);
this->addChild(adventurer->charSprite)
charArray.pushBack(adventurer);
}
}
void PlayLayer::spriteMoveFinished(Node* sender, void* adv)
{
auto adventurer = (Adventurer*)adv;
Size s = Director::getInstance()->getWinSize();
int minY = adventurer->charSprite->getContentSize().height / 2;
int maxY = s.height - adventurer->charSprite->getContentSize().height / 2;
int rangeY = maxY - minY;
int actualY = (CCRANDOM_0_1() * rangeY) + minY;
int minX = -300;
int maxX = 0;
int rangeX = maxX - minX;
int actualX = (CCRANDOM_0_1() * rangeX) + minX;
adventurer->charSprite->setPosition(ccp(actualX, actualY));
adventurer->stopAction(adventurer->moveAction);
adventurer->charSprite->runAction(adventurer->moveAction);
}
void PlayLayer::gameLogic(float dt)
{
this->addAdventurer();
}
void PlayLayer::onEnter()
{
Layer::onEnter();
auto listener = EventListenerTouchOneByOne::create();
listener->setSwallowTouches(true);
listener->onTouchBegan = CC_CALLBACK_2(PlayLayer::onTouchBegan, this);
listener->onTouchMoved = CC_CALLBACK_2(PlayLayer::onTouchMoved, this);
listener->onTouchEnded = CC_CALLBACK_2(PlayLayer::onTouchEnded, this);
auto dispatcher = Director::getInstance()->getEventDispatcher();
dispatcher->addEventListenerWithSceneGraphPriority(listener, this);
}
void PlayLayer::onTouchEnded(Touch* touch,Event* event)
{
Point touchLocation = this->convertToWorldSpace(this->convertTouchToNodeSpace(touch));
Point moveVector = touchLocation - dragon->getPosition();
float distanceToMove = ccpLength(moveVector);
float moveAngle = ccpToAngle(moveVector);
float cocosAngle = CC_RADIANS_TO_DEGREES(-1 * moveAngle);
float dragonVelocity = 480.0 / 3.0;
float moveDuration = distanceToMove / dragonVelocity;
cocosAngle += 23;
if (cocosAngle < 0)
{
cocosAngle += 360;
}
int runAnim = (int)((cocosAngle)/45);
dragon->stopAction(flyAction);
this->flyAction = flyActionArray.at(runAnim);
dragon->runAction(flyAction);
this->moveAction = Sequence::create(MoveTo::create(moveDuration,touchLocation),NULL);
dragon->runAction(moveAction);
}
OK，千万别头疼--接下来我会一点点分解：
bool PlayLayer::init()
{
if (!Layer::init())
{
return false;
}
auto background = Sprite::create("Terrain.png");
background->setPosition(ccp(160,240));
this->addChild(background);
auto texture = TextureCache::getInstance()->addImage("dragon.png");
auto sheet = SpriteBatchNode::create("dragon.png",10);
this->addChild(sheet, 0, ktagSpriteSheet);
Size s = Director::getInstance()->getWinSize();
Vector<SpriteFrame*> animFrames;
for (int i = 0; i < 8; i++)
{
animFrames.clear();
for (int j = 0; j < 10; j++)
{
auto frame = SpriteFrame::createWithTexture(texture, Rect(j * 75, i * 70, 75, 70), false, Director::getInstance()->getVisibleOrigin(), Size(75, 70));
animFrames.pushBack(frame);
}
auto animation = Animation::createWithSpriteFrames(animFrames, 0.1f);
auto animate = Animate::create(animation);
auto seq = Sequence::create(animate, NULL);
this->flyAction = RepeatForever::create(seq);
flyActionArray.pushBack(this->flyAction);
}
auto frame1 = SpriteFrame::createWithTexture(texture, Rect(0, 0, 75, 70), false, Director::getInstance()->getVisibleOrigin(), Size(75, 70));
this->dragon = Sprite::createWithSpriteFrame(frame1);
dragon->setPosition(ccp(s.width/2-80,s.height/2));
sheet->addChild(dragon);
this->flyAction = flyActionArray.at(0);
dragon->runAction(flyAction);
texture = TextureCache::getInstance()->addImage("adventurer.png");
spriteSheet = SpriteBatchNode::createWithTexture(texture,100);
this->addChild(spriteSheet,0,ktagSpriteSheet);
this->schedule(schedule_selector(PlayLayer::gameLogic), 1.0f);
return true;
}
好，首先看到“init”函数，它和我们之前的adventurer 类一样，先调super init，如果失败的话，就直接返回nil。然后我们添加了一张背景图片叫做"Terrain.png"并把它放置在屏幕的中心（因为我们知道图片的默认中心点anchorPoint是0.5，0.5）。然后直接把它加到当前层中。
接下来，我们初始化纹理和SpriteBatchNode--首先把"adventurer.png"加载到CCTexture2D变量中，然后使用createWithTexture来建立一个精灵表单。（我们也可以用create这个函数来建立SpriteBatchNode，但是，我想向你展示另外一种方法）。然后，我们把spritesheet加到Layer中。之后，我们所有的精灵，如果作为孩子加到SpriteBatchNode中的话，就可以得到“批处理”。
最后，我们触发一个回调函数gamelogic，它会每隔1秒钟回调一次。函数如下所示：
void PlayLayer::gameLogic(float dt)
{
this->addAdventurer();
}
我们将使用这个函数，每隔一秒钟创建一个新的adventurer 对象。
接下来，看看AddAventurer函数。这个函数不仅仅创建一个新的角色，同时还会使之移动并播放相应方向行走的动画。
void PlayLayer::addAdventurer()
{
Vector<SpriteFrame*>animFrames;
animFrames.clear();
for (int i = 0; i < 9; i++)
{
auto *frame = SpriteFrame::createWithTexture(this->texture, Rect(i * 16, 0, 16, 29));
animFrames.pushBack(frame);
}
上面的代码我们之前已经见过了，我们只是为walking动画存储了9个动画帧（SpriteFrames）。
auto adventurer = Adventurer::create();
if (adventurer != NULL)
{
auto *frame1 = SpriteFrame::createWithTexture(this->texture, Rect(0, 0, 19, 29));
adventurer->charSprite = Sprite::createWithSpriteFrame(frame1);
接下来，我们创建一个新的adventurer 实例，然后把charSprite成员初始化为第一个动画帧，调用的方法是createWithSpriteFrame。
Size s = Director::getInstance()->getWinSize();
int minY = adventurer->charSprite->getContentSize().width/2;
int maxY = s.height - adventurer->charSprite->getContentSize().height / 2;
int rangeY = maxY - minY;
int actualY = (CCRANDOM_0_1() * rangeY) + minY;
int minX = -300;
int maxX = 0;
int rangeX = maxX - minX;
int actualX = (CCRANDOM_0_1() * rangeX) + minX;
adventurer->charSprite->setPosition(ccp(actualX, actualY));
好了，即使我们的精灵按照粒子数量去增加，所有的精灵刚开始的位置都是在左下角，除非我们人为改变它们的位置。因此，上面的代码就是产生一个随机坐标，同时又要保证这个随机坐标在屏幕范围之内。然后把这个随机坐标点赋值给adventurer。
auto *animation = Animation::createWithSpriteFrames(animFrames,0.2);
auto *animate = Animate::create(animation);
auto *seq = Sequence::create(animate,NULL);
adventurer->walkAction = RepeatForever::create(seq);
auto actionMove = MoveTo::create(10.0f,ccp(s.width + 200, actualY));
auto actionMoveDone = CallFuncN::create(CC_CALLBACK_1(PlayLayer::spriteMoveFinished,this,(void*)adventurer));
adventurer->moveAction = Sequence::create(actionMove,actionMoveDone,NULL);
adventurer->charSprite->runAction(adventurer->walkAction);
adventurer->charSprite->runAction(adventurer->moveAction);
this->addChild(adventurer->charSprite);
charArray.pushBack(adventurer);
}
}
addAdventurer方法的最后一个部分就是处理角色在屏幕上面的行走和移动。我们把之前存储CCSpriteFrame 的animFrames拿过来，然后把它转换成动画。（每个动画帧之间的间隔是0.2秒，整个动画差不多就要2秒的时间来运行完）。然后我们把这个动画放到一个sequence 动作中（使用CCSequence 类），最后，我们使用CCRepeatForever创建walkAction，并把它赋值给adventurer。
我们现在已经可以让角色有行走的动画了，但是，我们还想让它实际移动。所以，我们需要创建另外一个action，叫做CCMoveTo 。并且使用CCSequence类把它与一个回调函数关联起来。当CCMoveTo结束的时候，就运行CCCallFuncN指定的回调函数。
Side Note: 如果你想指定带一个参数的函数，那么就使用CCCallFuncN--它会把Sprite本身传递进去，通过sender参数传递：
auto actionMoveDone = CallFuncN::create(this,callfuncN_selector(PlayLayer::spriteMoveFinished));
现在，我们还剩下一件事情没有涉及了，就是之前CCMove结束的时候，通过CCCallFuncND指定的回调函数，如下所示：
void PlayLayer::spriteMoveFinished(Node* sender, void* adv)
{
auto adventurer = (Adventurer*)adv;
Size s = Director::getInstance()->getWinSize();
int minY = adventurer->charSprite->getContentSize().height / 2;
int maxY = s.height - adventurer->charSprite->getContentSize().height / 2;
int rangeY = maxY - minY;
int actualY = (CCRANDOM_0_1() * rangeY) + minY;
int minX = -300;
int maxX = 0;
int rangeX = maxX - minX;
int actualX = (CCRANDOM_0_1() * rangeX) + minX;
adventurer->charSprite->setPosition(ccp(actualX, actualY));
adventurer->stopAction(adventurer->moveAction);
adventurer->charSprite->runAction(adventurer->moveAction);
}
这里再重复解释上面的代码的话，就有点烦人了。简言之，就是在CCMoveTo结束之后，随机再生成一个x,y坐标，然后让advertuere移动到这个位置去，再开始行走的动画。
原文链接地址：http://www.iphonegametutorials.com/2010/09/14/cocos2d-sprite-tutorial-part-3/