cocos2dx - 伤害实现

http://www.cnblogs.com/straTrail/p/5065911.html

本节主要讲如何通过创建简单的矩形区域来造成伤害

　　在小游戏中简单的碰撞需求应用box2d等引擎会显得过于臃肿复杂，且功能不是根据需求定制，还要封装，为此本节讲述一下如何自己实现简单的碰撞，来达到伤害效果。

这里先看下效果图:

一、定义小组类别

　　定义如下:

// 组别mask @H_616_52@enum enGroupMask { GROUP_NONE = 0x0000,GROUP_PLAYER = 0x0001:rgb(0,GROUP_MONSTER = 0x0002:rgb(0,};

　　用二进制位来定义小组，方便后面判断用位快速判断。

二、定义CBody类用于碰撞实现

　 代码如下:

#ifndef __CBody_H__
@H_616_52@#define __CBody_H__
#include "IGameDef.h"
#include cocos2d.h"
@H_616_52@#define DRAW_BODY 1
#ifdef DRAW_BODY 
#include GLES-Render.h#endif

USING_NS_Cc;
@H_616_52@class CBody : @H_616_52@public Node
{
@H_616_52@public:
    // implement the "static create()" method manually
    CREATE_FUNC(CBody);

    @H_616_52@virtual @H_616_52@bool init();

    @H_616_52@void SetRect(@H_616_52@float x,@H_616_52@float y,255); line-height:1.5!important">float w,255); line-height:1.5!important">float h){ m_cRect = Rect(x,y,w,h); }

    @H_616_52@void SetGroupMask(enGroupMask nGroupMask){ m_nGroupMask = nGroupMask; }

    enGroupMask GetGroupMask() @H_616_52@const{ @H_616_52@return m_nGroupMask; }

    enGroupMask CanContactGroup() @H_616_52@const;

    判断是否可以碰撞该类别
    @H_616_52@bool IsGroupCanContact(enGroupMask nGroupMask)  @H_616_52@const Rect GetRect()  判断矩形是否交叉
    @H_616_52@bool IntersectsRect(@H_616_52@const Rect& rect)  @H_616_52@void SetContactCallBACk(@H_616_52@const std::function<@H_616_52@void(CBody*)>& callBACk){ m_constactFunc = callBACk; }

     碰撞回调函数
    @H_616_52@void OnContact(CBody* pBody);


     绘制矩形区域
#ifdef DRAW_BODY 
    @H_616_52@void draw(Renderer *renderer,255); line-height:1.5!important">const Mat4& transform,uint32_t flags);
    @H_616_52@virtual    @H_616_52@void onDraw(@H_616_52@const Mat4 &transform,uint32_t flags);
@H_616_52@#endif

@H_616_52@private:

    CBody();
    ~CBody();

#ifdef DRAW_BODY 
    Customcatommand m_pCustomcatommand;
    b2Draw* m_debugDraw;
@H_616_52@#endif
     
    Rect m_cRect;

    std::function<@H_616_52@void(CBody*)> m_constactFunc;

    enGroupMask        m_nGroupMask;
};


@H_616_52@#endif __CBody_H__

关键实现有以下几个：

　　1、用位快速判断是否可以产生碰撞

@H_616_52@@H_616_52@bool CBody::IsGroupCanContact(enGroupMask nGroupMask)  const { @H_616_52@return nGroupMask&CanContactGroup(); }

　　2、获取矩形实际的坐标，利用cocos2dx矩形相交判断方法，判断重叠

const Rect CBody::GetRect() constVec2& pt =this->convertToWorldSpace(@H_616_52@this->getPosition()); @H_616_52@return Rect(pt.x + m_cRect.origin.x,pt.y + m_cRect.origin.y,m_cRect.size.width,m_cRect.size.height); } @H_616_52@ bool CBody::IntersectsRect(@H_616_52@const Rect& rect) @H_616_52@const { @H_616_52@return GetRect().intersectsRect(rect); }

　　3、将创建的CBody类添加到管理中vector的实例@H_586_83@m_vBody管理

CBody::~CBody() { CBattleMgr::geTinstance()->EreaseBody(@H_616_52@this); @H_616_52@#ifdef DRAW_BODY @H_616_52@if (m_debugDraw) { @H_616_52@delete m_debugDraw; m_debugDraw = NULL; } @H_616_52@#endif } @H_616_52@bool CBody::init() { @H_616_52@#ifdef DRAW_BODY m_debugDraw = @H_616_52@new GLESDebugDraw(1.0); @H_616_52@#endif CBattleMgr::geTinstance()->InsertBody(@H_616_52@this); @H_616_52@return @H_616_52@true; }

　　同时每帧在管理类中的update进行碰撞判断如下:

void CBattleMgr::update(@H_616_52@float dt) { @H_616_52@while (m_vBody.size()>0) { size_t nLast = m_vBody.size() - 1; CBody* pBody = m_vBodY[nLast]; m_vBody.pop_BACk(); @H_616_52@if (pBody) { m_vSwapBody.push_BACk(pBody); @H_616_52@for (size_t i = 0; i < nLast; ++i) { CBody* pTempBody = m_vBodY[i]; @H_616_52@if (pTempBody ) { @H_616_52@bool hurt1 = pTempBody->IsGroupCanContact(pBody->GetGroupMask()); @H_616_52@bool hurt2 = pBody->IsGroupCanContact(pTempBody->GetGroupMask()); @H_616_52@if ((hurt1 || hurt2)&&pTempBody->IntersectsRect(pBody->GetRect())) { @H_616_52@if (hurt1) { pTempBody->OnContact(pBody); } @H_616_52@if (hurt2) { pBody->OnContact(pTempBody); } } } } } } m_vSwapBody.swap(m_vBody); }

　　上述代码通过2个vector管理CBody，在update时进行一次判断碰撞并调用OnContact方法。

　　4、为了方便显示上图的灰色矩形框需要用以下的类进行显示图形

/*
* Copyright (C) 2006-2007 Erin Catto http://www.gphysics.com
*
* iPhone port by Simon Oliver - http://www.simonoliver.com - http://www.handcircus.com
*
* This software is provided 'as-is',without any express or implied
* warranty.  In no event will the authors be Held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,* including commercial applications,and to alter it and redistribute it
* freely,subject to the following reStrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product,an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such,and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source diStribution.
*/

#ifndef RENDER_H
@H_616_52@#define RENDER_H

#include Box2D/Box2D.h"

@H_616_52@struct b2AABB;

 This class implements debug drawing callBACks that are invoked
 inside b2World::Step.
@H_616_52@class GLESDebugDraw : @H_616_52@public b2Draw
{
    float32 mRatio;
    cocos2d::GLProgram* mShaderProgram;
    GLint        mColorLOCATIOn;

    @H_616_52@void initShader( @H_616_52@void );
@H_616_52@public:
    GLESDebugDraw();

    GLESDebugDraw( float32 ratio );

    @H_616_52@void DrawPolygon(@H_616_52@const b2Vec2* vertices,255); line-height:1.5!important">int vertexCount,255); line-height:1.5!important">const b2Color& color);

    @H_616_52@void DrawSolidPolygon(@H_616_52@void DrawCircle(@H_616_52@const b2Vec2& center,float32 radius,255); line-height:1.5!important">void DrawSolidCircle(@H_616_52@const b2Vec2& axis,255); line-height:1.5!important">void DrawSegment(@H_616_52@const b2Vec2& p1,255); line-height:1.5!important">const b2Vec2& p2,255); line-height:1.5!important">void DrawTransform(@H_616_52@const b2Transform& xf);

    @H_616_52@void DrawPoint(@H_616_52@const b2Vec2& p,float32 size,255); line-height:1.5!important">void DrawString(@H_616_52@int x,255); line-height:1.5!important">int y,255); line-height:1.5!important">char* @H_616_52@String,...); 

    @H_616_52@void DrawAABB(b2AABB* aabb,255); line-height:1.5!important">const b2Color& color);
};


@H_616_52@#endif

 * Copyright (C) 2006-2007 Erin Catto 
 *
 * iPhone port by Simon Oliver - 
 *
 * This software is provided 'as-is',without any express or implied
 * warranty.  In no event will the authors be Held liable for any damages
 * arising from the use of this software.
 * Permission is granted to anyone to use this software for any purpose,and to alter it and redistribute it
 * freely,subject to the following reStrictions:
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product,an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such,and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source diStribution.
 */

#include "
#include <stdio.h>
#include <stdarg.h>
#include <@H_616_52@String.h>

USING_NS_Cc;

GLESDebugDraw::GLESDebugDraw()
    : mRatio( 1.0f )
{
    @H_616_52@this->initShader();
}

GLESDebugDraw::GLESDebugDraw( float32 ratio )
    : mRatio( ratio )
{
    @H_616_52@this->initShader();
}

@H_616_52@void GLESDebugDraw::initShader( @H_616_52@void )
{
    mShaderProgram = GLProgramCache::geTinstance()->getGLProgram(GLProgram::SHADER_NAME_POSITION_U_COLOR);

    mColorLOCATIOn = glGetUniformLOCATIOn( mShaderProgram->getProgram(),u_color");
}

@H_616_52@void GLESDebugDraw::DrawPolygon(@H_616_52@const b2Vec2* old_vertices,255); line-height:1.5!important">const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuilTins();

    b2Vec2* vertices = @H_616_52@new b2VeC2[vertexCount];
    @H_616_52@for( @H_616_52@int i=0;i<vertexCount;i++) 
    {
        vertices[i] = old_vertices[i];
        vertices[i] *= mRatio;
    }

    mShaderProgram->setUniformLOCATIOnWith4f(mColorLOCATIOn,color.r,color.g,color.b,128); line-height:1.5!important">1);

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,2,GL_FLOAT,GL_falSE,128); line-height:1.5!important">0,vertices);
    glDrawArrays(GL_LINE_LOOP,vertexCount);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,vertexCount);


    checK_GL_ERROR_DEBUG();

    @H_616_52@delete[] vertices;
}

@H_616_52@void GLESDebugDraw::DrawSolidPolygon(0;i<vertexCount;i++) {
        vertices[i] = old_vertices[i];
        vertices[i] *= mRatio;
    }
    
    mShaderProgram->setUniformLOCATIOnWith4f(mColorLOCATIOn,color.r*0.5f,color.g*:rgb(128,color.b*0.5f);

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,vertices);

    glDrawArrays(GL_TRIANGLE_FAN,vertexCount);

    mShaderProgram->setUniformLOCATIOnWith4f(mColorLOCATIOn,128); line-height:1.5!important">1);
    glDrawArrays(GL_LINE_LOOP,vertexCount*2);

    checK_GL_ERROR_DEBUG();

    @H_616_52@void GLESDebugDraw::DrawCircle(@H_616_52@const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuilTins();

    @H_616_52@const float32 k_segments = 16.0f;
    @H_616_52@int vertexCount=16;
    @H_616_52@const float32 k_increment = 2.0f * b2_pi / k_segments;
    float32 theta = 0.0f;
    
    GLfloat*    glVertices = @H_616_52@new GLfloat[vertexCount*2];
    @H_616_52@int i = 0; i < k_segments; ++i)
    {
        b2Vec2 v = center + radius * b2Vec2(cosf(theta),sinf(theta));
        glVertices[i*2]=v.x * mRatio;
        glVertices[i*2+1]=v.y * mRatio;
        theta += k_increment;
    }
    
    mShaderProgram->setUniformLOCATIOnWith4f(mColorLOCATIOn,128); line-height:1.5!important">1);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,glVertices);

    glDrawArrays(GL_LINE_LOOP,vertexCount);

    checK_GL_ERROR_DEBUG();

    @H_616_52@delete[] glVertices;
}

@H_616_52@void GLESDebugDraw::DrawSolidCircle(0.5f);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,glVertices);
    glDrawArrays(GL_TRIANGLE_FAN,vertexCount);


    mShaderProgram->setUniformLOCATIOnWith4f(mColorLOCATIOn,vertexCount);

     Draw the axis line
    DrawSegment(center,center+radius*axis,color);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(void GLESDebugDraw::DrawSegment(@H_616_52@const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuilTins();

    mShaderProgram->setUniformLOCATIOnWith4f(mColorLOCATIOn,128); line-height:1.5!important">1);

    GLfloat    glVertices[] = 
    {
        p1.x * mRatio,p1.y * mRatio,p2.x * mRatio,p2.y * mRatio
    };
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,glVertices);

    glDrawArrays(GL_LInes,128); line-height:1.5!important">0,128); line-height:1.5!important">2);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,128); line-height:1.5!important">2);

    checK_GL_ERROR_DEBUG();
}

@H_616_52@void GLESDebugDraw::DrawTransform(@H_616_52@const b2Transform& xf)
{
    b2Vec2 p1 = xf.p,p2;
    @H_616_52@const float32 k_axisScale = 0.4f;
    p2 = p1 + k_axisScale * xf.q.GetXAxis();
    DrawSegment(p1,p2,b2Color(0));

    p2 = p1 + k_axisScale * xf.q.GetYAxis();
    DrawSegment(p1,128); line-height:1.5!important">0));
}

@H_616_52@void GLESDebugDraw::DrawPoint(1);

        glPointSize(sizE);

    GLfloat                glVertices[] = {
        p.x * mRatio,p.y * mRatio
    };

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,glVertices);

    glDrawArrays(GL_POINTS,128); line-height:1.5!important">1);
        glPointSize(1.0f);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1);

    checK_GL_ERROR_DEBUG();
}

@H_616_52@void GLESDebugDraw::DrawString(@H_616_52@char *:rgb(0,...)
{
    NSLog(@"DrawString: unsupported: %s",String);
    printf(String);
     Unsupported as yet. Could replace with bitmap font renderer at a later date */
}

@H_616_52@void GLESDebugDraw::DrawAABB(b2AABB* aabb,128); line-height:1.5!important">1);

    GLfloat                glVertices[] = {
        aabb->lowerBound.x * mRatio,aabb->lowerBound.y * mRatio,aabb->upperBound.x * mRatio,aabb->upperBound.y * mRatio,aabb->lowerBound.x * mRatio,aabb->upperBound.y * mRatio
    };

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,glVertices);
    glDrawArrays(GL_LINE_LOOP,128); line-height:1.5!important">4);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(4);

    checK_GL_ERROR_DEBUG();
}

　　然后在CBody的draw中做如下处理进行绘制

#ifdef DRAW_BODY 
@H_616_52@void CBody::onDraw(:rgb(0,uint32_t flags)
{

    @H_616_52@if (m_debugDraw)
    {
        b2Vec2 vs[4];
        @H_616_52@const Rect rect = GetRect();
        vs[0].Set(rect.origin.x,rect.origin.y);
        vs[1].Set(rect.origin.x + rect.size.width,128); line-height:1.5!important">2].Set(rect.origin.x + rect.size.width,rect.origin.y + rect.size.height);
        vs[3].Set(rect.origin.x,rect.origin.y + rect.size.height);
        m_debugDraw->DrawSolidPolygon(vs,128); line-height:1.5!important">4,b2Color(0.6f,128); line-height:1.5!important">0.6f));
    }
}
@H_616_52@void CBody::draw(Renderer *renderer,uint32_t flags)
{
    _globalZOrder
    m_pCustomcatommand.init(30);
    m_pCustomcatommand.func = CC_CALLBACK_0(CBody::onDraw,255); line-height:1.5!important">this,transform,flags);
    renderer->addCommand(&@H_390_51@m_pCustomcatommand);
}
@H_616_52@#endif