CocoaChina论坛2014-11-10 16:38:251358 次阅读

一、目的@H_675_13@

Cocos2d-x做项目时经常会碰到要对图片进行变色的需求，最常用的就是变灰了，就要让按钮变灰来表示当前的状态是不可点的。但是Cocos2d-x的Sprite中是没有这个变灰支持的。那么，就要我们自己动手来扩展实现一个。我们让这个带变色功能的Sprite叫做FilterSprite。这个FilterSprite扩展了Sprite的功能：可以方便地变换颜色。

二、原理@H_675_13@

对图片进行颜色变换，就是对图片上的每个像素进行变换。要实现这个，要新创建一个fragmentShader，这个fragmentShader 比sprite的那个fragmentShader多了一个颜色变换矩阵。shader会让图片上每个像素与颜色变换矩阵进行相乘，输出新的像素值。

这个shader是这样的：

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@H_696_39@ 2
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#ifdefGL_ES

@H_616_69@precisionmediump float @H_616_69@;

#endif

@H_616_69@uniformsampler2Du_texture;
@H_450_84@ @H_616_69@varyingvec2v_texCoord;

@H_616_69@varyingvec4v_fragmentColor;

@H_616_69@uniformmat4fiterMat;

void @H_616_69@main( )

@H_616_69@{

@H_616_69@vec4value=v_fragmentColor*texture2D(u_texture,v_texCoord);

gl_FragColor=fiterMat*value;

@H_616_69@};

从shader上我们看到，“filterMat” 就是所谓的颜色变换矩阵，仅仅在原来像素输出前用它处理了一下：与待输出像素相乘。这个shader是opengl层级的，要应用到coco2dx引擎中，我们要着手实现cocos2dx的FilterSprite类了。

三、实现@H_675_13@

实现这个FilterSprite注意几个要点：

引擎中一个shader对应一个GLProgram，所以这个带颜色滤镜的shader（称为filterShader）对应一个GLProgram（称为filterProgram）对象，在实际使用时，是用对GLProgram进行了封装的GLProgramState（称为filterProgramState）对象，FilterSprite对象的_glProgramState要设置成filterProgramState对象，在源码中FilterSprite的initWithTexture进行这个filterShader和filterProgram的关联。

在渲染时要将滤镜传递给shader程序，在源码中就是在onDraw回调时调用：

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@H_616_69@glProgramState->setUniformMat4( "fiterMat" @H_616_69@,m_uSpriteFilter)

四、使用@H_675_13@

使用起来非常简单，只需要设置一个颜色矩阵，例如，如果要变灰就设置一个灰度矩阵，如果要恢复原貌就设置一个单位矩阵。

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Sprite*_sprite1;
@H_616_69@_sprite1=FilterSprite::create( "Images/BACkground3.png" @H_616_69@);

@H_616_69@GLfloatfilterMat[16]={
@H_450_84@ 0.3f,0.3f,0.0f,
0.59f,0.59f,

0.11f,0.11f,

0.0f,1.0f,

@H_616_69@};

dynamic_cast @H_616_69@<FilterSprite*>(_sprite1)->setFilterMat(filterMat);

五、源码@H_675_13@

FilterSprite.h:@H_675_13@

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/****************************************************************************

FilterSpirte.h

@H_450_84@ createdbyLiaoYanXuanon14-10-21.

****************************************************************************/

#ifndef__FilterSpirte_h

#define__FilterSpirte_h

#include "cocos2d.h"

USING_NS_Cc;

class @H_616_69@FilterSprite: public @H_616_69@Sprite{

:

FilterSprite();

virtual @H_616_69@~FilterSprite();

static @H_616_69@FilterSprite*create();

FilterSprite*create( const @H_616_69@std::string&fileName);

std::string&filename, Rect&rect);

FilterSprite*createWithTexture(Texture2D*pTexturE);

FilterSprite*createWithTexture(Texture2D*pTexture,monospace!important; font-size:1em!important; min-height:inherit!important; BACkground:none!important">Rect&rect, bool @H_616_69@rotated= false @H_616_69@);

FilterSprite*createWithSpriteFrame(SpriteFrame*pSpriteFramE);

FilterSprite*createWithSpriteFramename( std::string&spriteFrameName);

initWithTexture(Texture2D*pTexture,monospace!important; font-size:1em!important; min-height:inherit!important; BACkground:none!important">Rect&tRect);

virtual draw(Renderer*renderer,monospace!important; font-size:1em!important; min-height:inherit!important; BACkground:none!important">Mat4&transform,uint32_tflags)override;

onDraw( :1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,uint32_tflags);

setFilterMat(cocos2d::Mat4matrixArray);

//to-do提供一个设置滤镜的方法

protected @H_616_69@:

Customcatommand_customcatommand;

private @H_616_69@:

cocos2d::Mat4m_uSpriteFilter;

};

#endif

@H_675_13@

FilterSprite.cpp:@H_675_13@

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/****************************************************************************

****************************************************************************/

"FilterSprite.h"

FilterSprite::FilterSprite( )

{

@H_353_109@m_uSpriteFilter=Mat4::IDENTITY;

}

FilterSprite::~FilterSprite()

{

}

FilterSprite*FilterSprite::create()

{

FilterSprite*sprite= new @H_616_69@(std:: nothrow @H_616_69@)FilterSprite();

if @H_616_69@(sprite&&sprite->init())

{

sprite->autorelease();

return @H_616_69@sprite;

}

CC_SAFE_deletE(spritE);

nullptr;

}

FilterSprite*FilterSprite::create( std::string&fileName)

{

)FilterSprite();

(sprite&&sprite->initWithFile(fileName))

{

sprite->autorelease();

sprite;

}

CC_SAFE_deletE(spritE);

nullptr;

}

Rect&rect)

{

)FilterSprite();

(sprite&&sprite->initWithFile(filename,rect))

{

sprite->autorelease();

sprite;

}

CC_SAFE_deletE(spritE);

nullptr;

}

FilterSprite*FilterSprite::createWithTexture(Texture2D*pTexturE)

{

)FilterSprite();

Rectrect=Rect::ZERO;

rect.size=pTexture->getContentSize();

(sprite&&sprite->initWithTexture(pTexture,rect))

{

sprite->autorelease();

sprite;

}

CC_SAFE_deletE(spritE);

nullptr;

}

FilterSprite*FilterSprite::createWithTexture(Texture2D*texture,monospace!important; font-size:1em!important; min-height:inherit!important; BACkground:none!important">rotated)

{

)FilterSprite();

(sprite&&sprite->initWithTexture(texture,rect))

{

sprite->autorelease();

sprite;

}

CC_SAFE_deletE(spritE);

nullptr;

}

FilterSprite*FilterSprite::createWithSpriteFrame(SpriteFrame*spriteFramE)

{

)FilterSprite();

(sprite&&spriteFrame&&sprite->initWithSpriteFrame(spriteFramE))

{

sprite->autorelease();

sprite;

}

CC_SAFE_deletE(spritE);

nullptr;
@H_673_1133@ }

FilterSprite*FilterSprite::createWithSpriteFramename( std::string&spriteFrameName)
@H_450_1145@ {
SpriteFrame*frame=SpriteFrameCache::geTinstance()->getSpriteFrameByName(spriteFrameName);

# COCOS2D_DEBUG>0

char @H_616_69@msg[256]={0};

sprintf @H_616_69@(msg, "InvalidspriteFramename:%s" :1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,spriteFramename.c_str());

CCassERT(frame!=nullptr,msg);

#endif

createWithSpriteFrame(framE);

}

FilterSprite::initWithTexture(Texture2D*pTexture,monospace!important; font-size:1em!important; min-height:inherit!important; BACkground:none!important">Rect&tRect){

do @H_616_69@{

CC_BREAK_IF(!Sprite::initWithTexture(pTexture,tRect));

GLchar*pszFragsource=

"#ifdefGL_ES\n\

;\n\

#endif\n\

uniformsampler2Du_texture;\n\

varyingvec2v_texCoord;\n\

varyingvec4v_fragmentColor;\n\

uniformmat4fiterMat;\n\

)\n\

{\n\

:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,v_texCoord);\n\

gl_FragColor=fiterMat*value;\n\
@H_197_1261@ }";

autoglprogram=GLProgram::createWithByteArrays(ccPositiontextureColor_vert,pszFragsourcE);

autoglprogramstate=GLProgramState::getOrCreateWithGLProgram(glprogram);

setGLProgramState(glprogramstatE);

checK_GL_ERROR_DEBUG();

return true @H_616_69@;

} while @H_616_69@(0);

;

}

FilterSprite::setFilterMat(cocos2d::Mat4matrixArray)

{

@H_353_109@m_uSpriteFilter=matrixArray;

}

FilterSprite::draw(Renderer*renderer,uint32_tflags)

{

_customcatommand.init(_globalZOrder);

_customcatommand.func=CC_CALLBACK_0(FilterSprite::onDraw,153)!important; BACkground:none!important">this :1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,transform,flags);

renderer->addCommand(&_customcatommand);

}

FilterSprite::onDraw( :1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,uint32_tflags)

{

autoglProgramState=getGLProgramState();

:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,m_uSpriteFilter);

glProgramState->apply(transform);

GL::blendFunc(_blendFunc.src,_blendFunc.dst);

GL::bindTexture2D(_texture->getName());

GL::enableVertexAttribs(GL::VERTEX_ATTRIB_FLAG_POS_COLOR_TEX);

#definekQuadSize sizeof @H_616_69@(_quad.bl)

size_t @H_616_69@offset=( )&_quad;

//vertex

int @H_616_69@diff=offsetof(V3F_C4B_T2F,vertices);

glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION,3,GL_FLOAT,GL_falSE,kQuadSize,( *)(offset+diff));

//texCoods

:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,texCoords);
@H_801_1439@ glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_TEX_COORD,2,monospace!important; font-size:1em!important; min-height:inherit!important; BACkground:none!important">*)(offset+diff));

//color

:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,colors);

glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_COLOR,4,GL_UNSIGNED_BYTE,GL_TRUE,monospace!important; font-size:1em!important; min-height:inherit!important; BACkground:none!important">*)(offset+diff));

glDrawArrays(GL_TRIANGLE_StriP,4);

checK_GL_ERROR_DEBUG();

CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,4);

}

来源网址：http://www.cocoachina.com/bbs/read.php?tid-238457.html

@H_182_1489@
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文章评论 (3)

tjunxin 2014-12-11 15:07:22

是不是直接继承自sprite的类想用shader都要重写draw啊？

@L_696_7@ 回复(0)

q312998164 2014-11-12 10:23:01

Reference to 'Rect' is ambiguous ? 这是什么错误呀

zxcvbnm0014 2014-11-11 17:16:33

Node下有个setColor函数实现的就是这种效果。拿setcolor传入参数乘于像素的颜色得到最终的效果

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