如何在Cocos2D物理世界中定義不規則形狀的精靈

Question

我想從26個英文字符中創建精靈並讓它們在一幀內相互碰撞（例如，如下圖中的X和E） 。

什麼是創造了26個形狀推薦的方式？

Answer 1

你拿26圖像雪碧字母表（PNG圖片者優先），然後定義每個字符的夾具，每個字符（與vertexHelper的幫助，請參閱THIS鏈接，瞭解更多關於vertextHelper）像 '我' 這將是：

//OBSTACLE_Adjustments 
    { 
     CCSprite *sprite = [CCSprite spriteWithFile:@"I.png"]; 
     sprite.position = ccp(96,96); 
     sprite.tag = 2; 
     [self addChild:sprite]; 

     //SHAPE 1: 
     { 
      b2BodyDef bodyDefinition; 
      bodyDefinition.type = b2_dynamicBody; 
      bodyDefinition.position.Set(96/PTM_RATIO, 96/PTM_RATIO); 
      bodyDefinition.userData = sprite; 

      obstacle_AdjustmentsBody= world->CreateBody(&bodyDefinition); 

      // Create body shape 
      b2PolygonShape bodyShape; 
      //row 1, col 1 
      int num = 4; 
      b2Vec2 verts[] = { 
       b2Vec2(6.5f/PTM_RATIO, -25.0f/PTM_RATIO), 
       b2Vec2(6.5f/PTM_RATIO, 27.0f/PTM_RATIO), 
       b2Vec2(-7.5f/PTM_RATIO, 27.0f/PTM_RATIO), 
       b2Vec2(-7.5f/PTM_RATIO, -26.0f/PTM_RATIO) 
      }; 

      bodyShape.Set(verts, num); 

      // Create shape definition and add to body 
      b2FixtureDef bodyFixtureDefinition; 
      bodyFixtureDefinition.shape = &bodyShape; 
      bodyFixtureDefinition.density = 100.0f; 
      bodyFixtureDefinition.friction = 0.01f; 
      bodyFixtureDefinition.restitution = 0.50f;    
      obstacle_AdjustmentsFixture=obstacle_AdjustmentsBody->CreateFixture(&bodyFixtureDefinition);    
     } 
} 

這裏obstacle_AdjustmentsBody是b2Body，並且obstacle_AdjustmentsFixture是b2Fixture。

這裏是形狀X：

//OBSTACLE_ALPHABATE 
    { 
     CCSprite *sprite = [CCSprite spriteWithFile:@"X.png"]; 
     sprite.position = ccp(96,96); 
     sprite.tag = 2; 
     [self addChild:sprite]; 

     //SHAPE FIRST LEG OF X: 
     { 
      b2BodyDef bodyDefinition; 
      bodyDefinition.type = b2_dynamicBody; 
      bodyDefinition.position.Set(96/PTM_RATIO, 96/PTM_RATIO); 
      bodyDefinition.userData = sprite; 

      obstacle_AdjustmentsBody= world->CreateBody(&bodyDefinition); 

      // Create body shape 
      b2PolygonShape bodyShape; 
      //row 1, col 1 
      int num = 4; 
      b2Vec2 verts[] = { 
       b2Vec2(108.0f/PTM_RATIO, -71.5f/PTM_RATIO), 
       b2Vec2(56.0f/PTM_RATIO, 2.5f/PTM_RATIO), 
       b2Vec2(47.0f/PTM_RATIO, -3.5f/PTM_RATIO), 
       b2Vec2(96.0f/PTM_RATIO, -75.5f/PTM_RATIO) 
      }; 

      bodyShape.Set(verts, num); 

      // Create shape definition and add to body 
      b2FixtureDef bodyFixtureDefinition; 
      bodyFixtureDefinition.shape = &bodyShape; 
      bodyFixtureDefinition.density = 100.0f; 
      bodyFixtureDefinition.friction = 0.01f; 
      bodyFixtureDefinition.restitution = 0.50f;    
      obstacle_AdjustmentsFixture=obstacle_AdjustmentsBody->CreateFixture(&bodyFixtureDefinition);    
     } 

     //SHAPE SECOND LEG OF X: 
     { 
      b2BodyDef bodyDefinition; 
      bodyDefinition.type = b2_dynamicBody; 
      bodyDefinition.position.Set(96/PTM_RATIO, 96/PTM_RATIO); 
      bodyDefinition.userData = sprite; 

      obstacle_AdjustmentsBody= world->CreateBody(&bodyDefinition); 

      // Create body shape 
      b2PolygonShape bodyShape; 
      //row 1, col 1 
      int num = 4; 
      b2Vec2 verts[] = { 
       b2Vec2(117.0f/PTM_RATIO, -4.5f/PTM_RATIO), 
       b2Vec2(113.0f/PTM_RATIO, -1.5f/PTM_RATIO), 
       b2Vec2(54.0f/PTM_RATIO, -51.5f/PTM_RATIO), 
       b2Vec2(61.0f/PTM_RATIO, -56.5f/PTM_RATIO) 
      }; 

      bodyShape.Set(verts, num); 

      // Create shape definition and add to body 
      b2FixtureDef bodyFixtureDefinition; 
      bodyFixtureDefinition.shape = &bodyShape; 
      bodyFixtureDefinition.density = 100.0f; 
      bodyFixtureDefinition.friction = 0.01f; 
      bodyFixtureDefinition.restitution = 0.50f;    
      obstacle_AdjustmentsFixture=obstacle_AdjustmentsBody->CreateFixture(&bodyFixtureDefinition);    
     } 
}