最近写lua写得没有力气了，所以想让脑袋放松一下，刚好看到有人在用swift做游戏：
于是脑子一短路，就想到了利用这些素材来做一个游戏。
本来不想记笔记的，但是由于选择物理引擎的时候遇到诸多问题，所以选择记录下来，目前只做了个雏形，需要再完善一点。
需要知识：
1 cocos2dx-3.2 基本知识
2 box2d有一定的了解。
由于比较简单，所以把所有代码给上了先，然后再简单介绍下遇到的问题之类的东西。
首先是主角，熊猫类：
Panda.h
1 #ifndef __PANDA_H__
2 #define __PANDA_H__
3
4 #include "cocos2d.h"
5 USING_NS_CC;
6
7 class Panda : public cocos2d::Node
8 {
9 public:
10 Vector<SpriteFrame*> run_frames;
11 Vector<SpriteFrame*> jump_effect_frames;
12 Vector<SpriteFrame*> roll_frames;
13 Vector<SpriteFrame*> jump_frames;
14 Animation * run_anim;
15 Animation * jump_anim;
16 Animation * jump_effect_anim;
17 Animation * roll_anim;
18 Sprite * shape;
19 Animation * anim;
20 int cur_state;//current state
21 // Here‘s a difference. Method ‘init‘ in cocos2d-x returns bool, instead of returning ‘id‘ in cocos2d-iphone
22 virtual bool init();
23 //play status RUM||ROLL||JUMP etc
24 void play(unsigned int state);
25
26 void updateState();
27 // implement the "static create()" method manually
28 CREATE_FUNC(Panda);
29
30 int getCurrentState();
31 //panda 4 states
32 enum {
33 RUN = 1,
34 JUMP = 2,
35 JUMP2 = 3
36 };
37 };
38
39 #endif // __PANDA_H__
1 #include "Panda.h"
2 #include "cocos2d.h"
3
4 USING_NS_CC;
5
6 bool Panda::init()
7 {
8 if(!Node::init())
9 return false;
10
11 run_frames = Vector<SpriteFrame*>(8);
12 roll_frames = Vector<SpriteFrame*>(8);
13 jump_effect_frames = Vector<SpriteFrame*>(4);
14 jump_frames = Vector<SpriteFrame*>(8);
15 char str[40] = {0};
16 for(int i=1; i<=8;i++)
17 {
18 sprintf(str,"jump.atlas/panda_jump_0%d.png",i);
19 auto frame = SpriteFrameCache::getInstance()->getSpriteFrameByName(str);
20 if( frame != NULL )
21 {
22 jump_frames.pushBack(frame);
23 }
24
25 sprintf(str,"roll.atlas/panda_roll_0%d.png",i);
26 auto frame_0 = SpriteFrameCache::getInstance()->getSpriteFrameByName(str);
27 if( frame_0 != NULL )
28 {
29 roll_frames.pushBack(frame_0);
30 }
31
32 sprintf(str,"run.atlas/panda_run_0%d.png",i);
33 auto frame_1 = SpriteFrameCache::getInstance()->getSpriteFrameByName(str);
34 if( frame_1 != NULL )
35 {
36 run_frames.pushBack(frame_1);
37 }
38
39 sprintf(str,"jump_effect.atlas/jump_effect_0%d.png",i);
40 auto frame_2 = SpriteFrameCache::getInstance()->getSpriteFrameByName(str);
41 if( frame_2 != NULL )
42 {
43 jump_effect_frames.pushBack(frame_2);
44 }
45 }
46
47 run_anim = Animation::createWithSpriteFrames(run_frames,0.05f);
48 run_anim->retain();
49 roll_anim = Animation::createWithSpriteFrames(roll_frames,0.05f);
50 roll_anim->retain();
51 jump_anim = Animation::createWithSpriteFrames(jump_frames,0.05f);
52 jump_anim->retain();
53 jump_effect_anim = Animation::createWithSpriteFrames(jump_effect_frames,0.05f);
54 jump_effect_anim->retain();
55 shape= Sprite::createWithSpriteFrameName("run.atlas/panda_run_01.png");
56 addChild(shape);
57 return true;
58 }
59
60 void Panda::play(unsigned int state)
61 {
62 Action * animate;
63 switch(state)
64 {
65 case RUN:
66 cur_state = Panda::RUN;
67 animate = RepeatForever::create(Animate::create(run_anim));
68 animate->setTag(100);
69 shape->runAction(animate);
70 break;
71 case JUMP:
72 cur_state = Panda::JUMP;
73 animate = Animate::create(jump_anim);
74 animate->setTag(200);
75 shape->stopActionByTag(100);
76 shape->runAction(animate);
77 break;
78 case JUMP2:
79 animate = Sequence::create(Animate::create(jump_effect_anim),Animate::create(roll_anim));
80 animate->setTag(300);
81 cur_state = Panda::JUMP2;
82 shape->runAction(animate);
83 break;
84 }
85 }
86
87 int Panda::getCurrentState()
88 {
89 return cur_state;
90 }
91
92 void Panda::updateState()
93 {
94 if (shape->getActionByTag(200) == nullptr && shape->getActionByTag(300) == nullptr)
95 {
96 play(Panda::RUN);
97 }
98 }
Panda.cpp
然后是场景类，里面有一些逻辑处理：
1 #ifndef __GAMEMAIN_H__
2 #define __GAMEMAIN_H__
3
4 #include "cocos2d.h"
5 #include "Panda.h"
6 #include "Box2D\Box2D.h"
7 #include "GLES-Render.h"
8
9 USING_NS_CC;
10 //whether show assets
11 #define SHOW_DEBUG true
12 //draw scale of physics world
13 #define DRAW_SCALE 30.0f
14 #define ALL_ALHA 0.5f
15
16 class GameMain : public cocos2d::Layer
17 {
18 public:
19 //physic engine related
20 b2World * world;
21 Map<b2Body,Sprite> * map;
22 b2Body * panda_body;
23 //objects move speed
24 float speed;
25 Sprite * far_bg;
26 Sprite * middle_bg_0;
27 Sprite * middle_bg_1;
28 Size cSize;
29 Size visibleSize;
30 Layer * platform_container;
31 Panda * panda;
32 GLESDebugDraw * debugDraw;
33 // there‘s no ‘id‘ in cpp, so we recommend returning the class instance pointer
34 static cocos2d::Scene* createScene();
35
36 // Here‘s a difference. Method ‘init‘ in cocos2d-x returns bool, instead of returning ‘id‘ in cocos2d-iphone
37 virtual bool init();
38
39 virtual void onEnter();
40
41 virtual void onExit();
42
43 void update(float dt);
44
45 virtual bool onTouchBegan(Touch * touch, Event * event);
46 virtual void onTouchEnded(Touch * touch, Event * event);
47 virtual void onTouchMoved(Touch * touch, Event * event);
48
49 virtual bool onContactBegin(const PhysicsContact& contact);
50 // implement the "static create()" method manually
51 CREATE_FUNC(GameMain);
52
53 //
54 // Overrides
55 //
56 virtual void draw(Renderer *renderer, const Mat4 &transform, uint32_t flags) override;
57 private:
58 void create_ground();
59 void gen_step(const std::string& res, float posX, float posY);
60 void init_physics_world();
61 };
62
63 #endif // __HELLOWORLD_SCENE_H__
GameMain.h
1 #include "GameMain.h"
2 #include "cocos2d.h"
3 #include "Box2D\Box2D.h"
4 #include "GLES-Render.h"
5 USING_NS_CC;
6
7 Scene* GameMain::createScene()
8 {
9 auto scene = Scene::create();
10 auto layer = GameMain::create();
11 scene->addChild(layer);
12 return scene;
13 }
14
15
16 bool GameMain::init()
17 {
18 if ( !Layer::init() )
19 {
20 return false;
21 }
22 speed = 5.0f;
23 auto listener = EventListenerTouchOneByOne::create();
24 listener->onTouchBegan = CC_CALLBACK_2(GameMain::onTouchBegan,this);
25 listener->onTouchEnded = CC_CALLBACK_2(GameMain::onTouchEnded,this);
26 listener->onTouchMoved = CC_CALLBACK_2(GameMain::onTouchMoved,this);
27
28 Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, this);
29
30 visibleSize = Director::getInstance()->getVisibleSize();
31 Vec2 origin = Director::getInstance()->getVisibleOrigin();
32 SpriteFrameCache::getInstance()->addSpriteFramesWithFile("panda.plist");//add panda animate
33 SpriteFrameCache::getInstance()->addSpriteFramesWithFile("scene.plist");//add scene resources
34
35 middle_bg_0 = Sprite::create("bbg_snow_bone.jpg");
36 cSize = middle_bg_0->getContentSize();
37 middle_bg_0->setPosition(visibleSize.width*0.5, visibleSize.height*0.5);
38 middle_bg_0->setVisible(SHOW_DEBUG);
39 addChild(middle_bg_0);
40
41 init_physics_world();
42
43 //gen_step();
44 create_ground();
45
46 //init panda and its physics data
47 Point p(visibleSize.width/2,visibleSize.height/2);
48 b2BodyDef bodyDef;
49 bodyDef.type = b2_dynamicBody;
50 bodyDef.position.Set(p.x/DRAW_SCALE, p.y/DRAW_SCALE);
51 panda_body = world->CreateBody(&bodyDef);
52 b2MassData massdata;
53 massdata.mass = 100.0f;
54 panda_body->SetMassData(&massdata);
55
56 b2PolygonShape shape;
57 shape.SetAsBox(50.0f/DRAW_SCALE, 100.0f/DRAW_SCALE);
58
59 b2FixtureDef fixtureDef;
60 fixtureDef.shape = &shape;
61 fixtureDef.density = 1.0f;
62 fixtureDef.friction = 0.3f;
63 panda_body->CreateFixture(&fixtureDef);
64
65 panda = Panda::create();
66 panda->setPosition(visibleSize.width/2, visibleSize.height/2);
67 Size panda_size = Size(50.0f,100.0f);
68 panda->play(Panda::RUN);
69 this->addChild(panda);
70 panda_body->SetUserData(panda);
71 panda->setVisible(SHOW_DEBUG);
72
73 gen_step("platform_l.png",51.0,100.0f);
74 gen_step("platform_m.png",196.0f,100.0f);
75 gen_step("platform_r.png",392.0f,100.0f);
76 return true;
77 }
78
79 void GameMain::init_physics_world()
80 {
81 b2Vec2 gravity;
82 gravity.Set(0.0f,-10.0f);
83 world = new b2World(gravity);
84 world->SetAllowSleeping(true);
85 world->SetContinuousPhysics(true);
86 debugDraw = new GLESDebugDraw(DRAW_SCALE);
87 uint32 flags = 0;
88 flags += GLESDebugDraw::e_shapeBit;
89 flags += GLESDebugDraw::e_aabbBit;
90 flags += GLESDebugDraw::e_centerOfMassBit;
91 debugDraw->SetFlags(flags);
92 world->SetDebugDraw(debugDraw);
93 }
94
95 void GameMain::draw(Renderer *renderer, const Mat4 &transform, uint32_t flags)
96 {
97 world->DrawDebugData();
98 Layer::draw(renderer,transform,flags);
99 }
100
101 void GameMain::create_ground()
102 {
103 b2BodyDef ground_def;
104 ground_def.position.Set(visibleSize.width/2/DRAW_SCALE, visibleSize.height/2/DRAW_SCALE);
105
106 b2Body * ground_body = world->CreateBody(&ground_def);
107
108 /***/
109 //bottom
110 b2PolygonShape ground_shape;
111 ground_shape.SetAsBox(visibleSize.width/2/DRAW_SCALE,0,b2Vec2(0,-visibleSize.height/2/DRAW_SCALE),0);
112 ground_body->CreateFixture(&ground_shape,0);
113 //top
114 ground_shape.SetAsBox(visibleSize.width/2/DRAW_SCALE,0,b2Vec2(0,visibleSize.height/2/DRAW_SCALE),0);
115 ground_body->CreateFixture(&ground_shape,0);
116 //left
117 ground_shape.SetAsBox(0,visibleSize.height/2/DRAW_SCALE,b2Vec2(-visibleSize.width/2/DRAW_SCALE,0),0);
118 ground_body->CreateFixture(&ground_shape,0);
119 //right
120 ground_shape.SetAsBox(0,visibleSize.height/2/DRAW_SCALE,b2Vec2(visibleSize.width/2/DRAW_SCALE,0),0);
121 ground_body->CreateFixture(&ground_shape,0);
122 }
123
124 bool GameMain::onTouchBegan(Touch * touch, Event * event)
125 {
126 Sprite * ball = Sprite::create("apple.png");
127 ball->setVisible(SHOW_DEBUG);
128 Size contentSize = ball->getContentSize();
129 addChild(ball);
130 b2BodyDef ballDef;
131 ballDef.type = b2_dynamicBody;
132 ballDef.position.Set(touch->getLocation().x/DRAW_SCALE, touch->getLocation().y/DRAW_SCALE);
133 b2Body * ballBody = world->CreateBody(&ballDef);
134 ballBody->SetUserData(ball);
135 b2MassData massData;
136 massData.center = b2Vec2(contentSize.width/2/DRAW_SCALE,contentSize.height/2/DRAW_SCALE);
137 massData.mass = 50;
138 b2CircleShape ballShape;
139 ballShape.ComputeMass(&massData,1.5f);
140 ballShape.m_radius=45.0f/DRAW_SCALE;
141 b2FixtureDef ballFixture;
142 ballFixture.density = 10.0f;
143 ballFixture.friction = 1.0f;
144 ballFixture.restitution = 0.6f;
145 ballFixture.shape = &ballShape;
146
147 ballBody->CreateFixture(&ballFixture);
148 ballBody->SetGravityScale(10);
149 /**
150 float vx = touch->getLocation().x > panda->getPositionX() ? 100.0f : -100.0f;
151 panda->updateState();
152 int cur_state = panda->getCurrentState();
153 if( cur_state == Panda::RUN )
154 {
155 panda_body->ApplyForce(b2Vec2(vx,1000),panda_body->GetPosition(),true);
156 panda->play(Panda::JUMP);
157 }else if(cur_state == Panda::JUMP)
158 {
159 panda_body->ApplyForce(b2Vec2(vx,800),panda_body->GetPosition(),true);
160 panda->play(Panda::JUMP2);
161 }*/
162 return true;
163 }
164
165 void GameMain::update(float dt)
166 {
167 world->Step(dt,10,10);
168 b2Body* b = world->GetBodyList();
169 while (b)
170 {
171 b2Body* bNext = b->GetNext();
172 Sprite * sp = (Sprite *)b->GetUserData();
173 if( sp != nullptr )
174 sp->setPosition(b->GetPosition().x*DRAW_SCALE,b->GetPosition().y*DRAW_SCALE);
175
176 b = bNext;
177 }
178 }
179
180 //generate floors
181 void GameMain::gen_step(const std::string& res, float posX, float posY)
182 {
183 Sprite * sp = Sprite::create(res);
184 sp->setPosition(posX, posY);
185 addChild(sp);
186
187 Size contentSize = sp->getContentSize();
188
189 b2BodyDef bodyDef;
190 bodyDef.position.Set(posX/DRAW_SCALE, posY/DRAW_SCALE);
191 b2Body * body = world->CreateBody(&bodyDef);
192
193 b2PolygonShape shape;
194 shape.SetAsBox(contentSize.width/DRAW_SCALE, contentSize.height/DRAW_SCALE);
195
196 b2FixtureDef fixtureDef;
197 fixtureDef.shape = &shape;
198 fixtureDef.density = 1.0f;
199 fixtureDef.friction = 0.3f;
200 body->CreateFixture(&fixtureDef);
201 sp->setVisible(SHOW_DEBUG);
202 }
203
204 bool GameMain::onContactBegin(const PhysicsContact& contact)
205 {
206 log("Contacted...");
207 return true;
208 }
209
210 void GameMain::onTouchEnded(Touch * touch, Event * event)
211 {
212
213 }
214
215 void GameMain::onTouchMoved(Touch * touch, Event * event)
216 {
217
218 }
219
220 void GameMain::onEnter()
221 {
222 Layer::onEnter();
223 this->schedule(schedule_selector(GameMain::update),0.03f);
224 }
225
226 void GameMain::onExit()
227 {
228 delete world;
229 delete debugDraw;
230 Layer::onExit();
231 this->unschedule(schedule_selector(GameMain::update));
232 }
GameMain.cpp
需要注意：
1 所有的熊猫动作打包成一个plist，所有的场景素材打包到另一个plist
这就是我们在场景类的init方法里面预加载的两个文件：
1 SpriteFrameCache::getInstance()->addSpriteFramesWithFile("panda.plist");//add panda animate
2 SpriteFrameCache::getInstance()->addSpriteFramesWithFile("scene.plist");//add scene resources
资源目录应该是这样的：
2 去cocos2d-x-3.2\tests\cpp-tests\Classes\Box2DTestBed下面将GLES-Render.h和GLES-Render.cpp拷到项目里面来，因为Box2d没有b2Debug的实现，这个是我们手头上需要的实现。
3 使用Box2d的时候极有可能会出现编译连接错误，找不到Box2d相关的类，这个时候需要将cocos2d-x-3.2\external\Box2D编译一下，然后在项目的连接器中加入引用：
4 通过b2World::SetDebugDraw(b2Draw * draw)将GLESDebugDraw实例设置为world的debugDraw之后，每帧调用world->DrawDebugData()是不会生效的，只有复写Layer::draw()方法并在其中调用此方法才会显示debugDraw。
由于debugDraw是调用显卡去渲染的，所以debugDraw是位于场景最底层的，当你把所有场景内的显示对象的通过setVisible设置为false的时候，你就可以看到了。
可以设置SHOW_DEBUG的值来设置显示对象的visible。
如下：
可以看到下面的debugDraw有点测漏了。
5 cocos2dx 3.2内置了chipmunk物理引擎，用起来比较简单，但是我之前学习ActionScript的时候有用过Box2d，并且Box2d的功能比较强大一些，所以选择了Box2d。ActionScript还有一个效率比Box2d稍强的无力引擎：Nape
以下是一开始用chipmunk实现的一些功能的代码：
1 #include "GameMain.h"
2 #include "cocos2d.h"
3
4 USING_NS_CC;
5
6 Scene* GameMain::createScene()
7 {
8 auto scene = Scene::createWithPhysics();
9 scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);
10 scene->getPhysicsWorld()->setUpdateRate(0.5);
11 auto layer = GameMain::create();
12 scene->addChild(layer);
13 return scene;
14 }
15
16
17 bool GameMain::init()
18 {
19 if ( !Layer::init() )
20 {
21 return false;
22 }
23
24 speed = 5.0f;
25
26 auto listener = EventListenerTouchOneByOne::create();
27 listener->onTouchBegan = CC_CALLBACK_2(GameMain::onTouchBegan,this);
28 listener->onTouchEnded = CC_CALLBACK_2(GameMain::onTouchEnded,this);
29 listener->onTouchMoved = CC_CALLBACK_2(GameMain::onTouchMoved,this);
30
31 auto contact_listener = EventListenerPhysicsContact::create();
32 contact_listener->onContactBegin = CC_CALLBACK_1(GameMain::onContactBegin,this);
33
34 Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, this);
35 Director::getInstance()->getEventDispatcher()->addEventListenerWithFixedPriority(contact_listener,1);
36
37 visibleSize = Director::getInstance()->getVisibleSize();
38 Vec2 origin = Director::getInstance()->getVisibleOrigin();
39 SpriteFrameCache::getInstance()->addSpriteFramesWithFile("panda.plist");//add panda animate
40 SpriteFrameCache::getInstance()->addSpriteFramesWithFile("scene.plist");//add scene resources
41
42 middle_bg_0 = Sprite::create("bbg_snow_bone.jpg");
43 cSize = middle_bg_0->getContentSize();
44 middle_bg_0->setPosition(visibleSize.width*0.5, visibleSize.height*0.5);
45 middle_bg_1 = Sprite::create("bbg_snow_bone.jpg");
46 middle_bg_1->setPosition(visibleSize.width*1.5, visibleSize.height*0.5);
47 addChild(middle_bg_0);
48 addChild(middle_bg_1);
49
50 gen_floor();
51
52 panda = Panda::create();
53 panda->setPosition(visibleSize.width/2, visibleSize.height/2);
54 Size panda_size = Size(50.0f,100.0f);
55 panda->play(Panda::RUN);
56 auto panda_body = PhysicsBody::createBox(panda_size);
57 panda_body->retain();
58 panda->setPhysicsBody(panda_body);
59 this->addChild(panda);
60
61 auto edge_sp = Sprite::create();
62 auto edge_body = PhysicsBody::createEdgeBox(visibleSize,PHYSICSBODY_MATERIAL_DEFAULT,3);
63 edge_sp->setPosition(visibleSize.width/2, visibleSize.height/2);
64 edge_sp->setPhysicsBody(edge_body);
65 edge_sp->setTag(0);
66 addChild(edge_sp);
67 return true;
68 }
69
70 bool GameMain::onContactBegin(const PhysicsContact& contact)
71 {
72 log("Contacted...");
73 return true;
74 }
75
76 bool GameMain::onTouchBegan(Touch * touch, Event * event)
77 {
78 log("Touched.....");
79 int cur_state = panda->getCurrentState();
80 panda->getPhysicsBody()->applyForce(Vect(500.0f,500.0f));
81 if( cur_state == Panda::RUN )
82 {
83 panda->play(Panda::JUMP);
84 }else if(cur_state == Panda::JUMP)
85 {
86 panda->play(Panda::JUMP2);
87 }
88 return true;
89 }
90
91 void GameMain::onTouchEnded(Touch * touch, Event * event)
92 {
93
94 }
95
96 void GameMain::onTouchMoved(Touch * touch, Event * event)
97 {
98
99 }
100
101 void GameMain::update(float dt)
102 {
103 /**
104 middle_bg_0->setPositionX(middle_bg_0->getPositionX()-speed);
105
106 if(middle_bg_0->getPositionX() < -cSize.width*0.5)
107 {
108 middle_bg_0->setPositionX(cSize.width*1.5);
109 }
110
111 middle_bg_1->setPositionX(middle_bg_1->getPositionX()-speed);
112 if(middle_bg_1->getPositionX() < -cSize.width*0.5)
113 {
114 middle_bg_1->setPositionX(cSize.width*1.5);
115 }*/
116 }
117
118 void GameMain::onEnter()
119 {
120 Layer::onEnter();
121 this->schedule(schedule_selector(GameMain::update),0.05f);
122 }
123
124 void GameMain::onExit()
125 {
126 Layer::onExit();
127 this->unschedule(schedule_selector(GameMain::update));
128 }
129
130 void GameMain::createFloor(int posx,int posy,int w,int h)
131 {
132
133 }
134 //generate floors
135 void GameMain::gen_floor()
136 {
137 Sprite * sp_l = Sprite::create("platform_l.png");
138 auto body_l = PhysicsBody::createBox(sp_l->getContentSize());
139 body_l->setDynamic(false);
140 sp_l->setPhysicsBody(body_l);
141 sp_l->setPosition(50.0f,150);
142 addChild(sp_l);
143
144 Sprite * sp_m = Sprite::create("platform_m.png");
145 auto body_m = PhysicsBody::createBox(sp_m->getContentSize());
146 body_m->setDynamic(false);
147 sp_m->setPhysicsBody(body_m);
148 sp_m->setPosition(sp_l->getPositionX() + (sp_l->getContentSize().width+sp_m->getContentSize().width)/2,150);
149 addChild(sp_m);
150
151 Sprite * sp_r = Sprite::create("platform_r.png");
152 auto body_r = PhysicsBody::createBox(sp_r->getContentSize());
153 body_r->setDynamic(false);
154 sp_r->setPhysicsBody(body_r);
155 sp_r->setPosition(sp_m->getPositionX() + (sp_m->getContentSize().width+sp_r->getContentSize().width)/2,150);
156 addChild(sp_r);
157 }
GameMain.cpp
建议：
不想吐槽搜索引擎，建议大家遇到问题先尝试自己解决，解决不了的然后可以用国外的搜索引擎搜索一下，或者可以直接去StackFlow去搜索
参考文章：
（翻译）介绍Box2D的Cocos2D 2.X教程：弹球 [Cocos2D-x For WP8]Box2D物理引擎 How to enable Box2d debug draw with Coco2d-x 3.0 beta 2时间： 2024-10-07 06:10:32