cocos2dx 渲染任意形状贴图

//

// cPolySprite.h

// cardmap

// Created by sunny on 12-12-4.

//

#ifndef __cardmap__cPolySprite__

#define __cardmap__cPolySprite__

#include "cocos2d.h"

//多边形精灵

class cPolySprite :public cocos2d::CCSprite

{

public:

cPolySprite() : vertexs_(NULL),uvs_(NULL),indices_(NULL),verCnt_(0) {}

virtual ~cPolySprite();

static cPolySprite* create(const char *pFile,

constcocos2d::CCPoint *uvs,

intverCnt,

constint *indices);

//重载父类draw

void draw();

private:

//初始化顶点信息

bool initWithUV(const cocos2d::CCPoint *uvs,

constint *indices,

intverCnt);

//计算中点

cocos2d::CCPoint getCenter();

void translate(const cocos2d::CCPoint&);

void drawPoly();

void releasePoly();

private:

//多边形顶点

cocos2d::ccVertex2F *vertexs_;

//定点纹理坐标

cocos2d::ccVertex2F *uvs_;

//三角形索引

unsigned short *indices_;

//顶点颜色

unsigned char *colors_;

//顶点数目

int verCnt_;

};

#endif

//

//cPolySprite.cpp

//cardmap

//Created by sunny on 12-12-4.

#include "cPolySprite.h"

#include "cocos2d.h"

using namespacecocos2d;

cPolySprite*cPolySprite::create(constchar *pFile,

const cocos2d::CCPoint *uvs,0); margin:0px"> int verCnt,0); margin:0px"> const int *indices)

{

cPolySprite *pobSprite = new cPolySprite();

//创建精灵

if(pobSprite &&

pobSprite->initWithFile(pFile)&&

pobSprite->initWithUV(uvs,indices,verCnt)) {

pobSprite->autorelease();

return pobSprite;

}

CC_SAFE_DELETE(pobSprite);

return false;

}

cPolySprite::~cPolySprite()

releasePoly();

//初始化顶点信息

bool cPolySprite::initWithUV(const cocos2d::CCPoint *uvs,0); margin:0px"> const int *indices,0); margin:0px"> int verCnt)

//内存分配

vertexs_ = new ccVertex2F[verCnt];

uvs_ =new ccVertex2F[verCnt];

indices_ = new unsigned short[(verCnt-2)*3];

colors_ = new unsigned char[verCnt*4];

//失败处理

if(!vertexs_|| !uvs_ || !indices_ || !colors_) {

releasePoly();

returnfalse;

//贴图大小

CCSize rc =m_pobTexture->getContentSize();

for(inti = 0; i <verCnt; ++i) {

//根据纹理坐标以及纹理大小计算顶点坐标

vertexs_[i].x = uvs[i].x*rc.width;

//cocos2dx纹理坐标以左上角为原点

vertexs_[i].y = (1.0-uvs[i].y)*rc.height;

uvs_[i].x= uvs[i].x;

uvs_[i].y= uvs[i].y;

for(inti = 0; i <(verCnt-2)*3; ++i)

indices_[i] = indices[i];

memset(colors_, 255,sizeof(unsigned char)*verCnt*4);

verCnt_ = verCnt;

translate(getCenter());

return true;

//计算中点

CCPointcPolySprite::getCenter()

if(!vertexs_) return ccp(0,0);

float minx =vertexs_[0].x,0); margin:0px"> maxx = vertexs_[0].x,0); margin:0px"> miny = vertexs_[0].y,0); margin:0px"> maxy = vertexs_[0].y;

//计算所有顶点坐标的中心点坐标

for(inti = 0; i <verCnt_; ++i) {

minx =minx>vertexs_[i].x?vertexs_[i].x:minx;

maxx =maxx

miny =miny>vertexs_[i].y?vertexs_[i].y:miny;

maxy =maxy

returnccp((minx+maxx)*0.5,(miny+maxy)*0.5);

void cPolySprite::translate(const cocos2d::CCPoint&pos)

//设置锚点

setAnchorPoint(ccp(pos.x/rc.width,pos.y/rc.height));

void cPolySprite::drawPoly()

CC_NODE_DRAW_SETUP();

ccGLBlendFunc( m_sBlendFunc.src,m_sBlendFunc.dst );

if(m_pobTexture != NULL) {

ccGLBindTexture2D( m_pobTexture->getName() );

else {

ccGLBindTexture2D(0);

ccGLEnableVertexAttribs(kCCVertexAttribFlag_PosColorTex);

//顶点，纹理，颜色

glVertexAttribPointer(kCCVertexAttrib_Position,2,GL_FLOAT,GL_FALSE,0,vertexs_);

glVertexAttribPointer(kCCVertexAttrib_TexCoords,uvs_);

glVertexAttribPointer(kCCVertexAttrib_Color,4,GL_UNSIGNED_BYTE,GL_TRUE,colors_);

//根据索引draw三角形

glDrawElements(GL_TRIANGLES,(verCnt_-2)*3,GL_UNSIGNED_SHORT,indices_);

CC_INCREMENT_GL_DRAWS(1);

void cPolySprite::releasePoly()

CC_SAFE_DELETE(vertexs_);

CC_SAFE_DELETE(uvs_);

CC_SAFE_DELETE(indices_);

CC_SAFE_DELETE(colors_);

void cPolySprite::draw(void)

drawPoly();

//示例

//CCPoint p[] ={ccp(0,1.0),ccp(0.3,0.3),ccp(0.4,0.4),0.2)};

//int index[] = {0,1,3,2,3};

//cPolySprite *csp =cPolySprite::create("HelloWorld.png",p,4,index);

有点笨拙，但是还能用，需要注意的地方就是坐标系，纹理坐标左上角为原点，屏幕坐标左下角是原点。

渲染了个四边形贴图：

原文地址：http://blog.sina.com.cn/s/blog_62b2318d0101du43.html

（编辑：李大同）

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