Sprite *getMonoColorSprite(Sprite *sprite)
{
	auto size = sprite->getContentSize();
	auto anchorPoint = sprite->getAnchorPoint();
	auto position = sprite->getPosition();
 
	auto center = Vec2(size.width / 2,size.height / 2);
 
	//如果直接用sprite，renderTexture上下是反的
	//有时sprite的锚点和位置变了，renderTexture里的纹理是空的
	//所以创建一个临时的上下翻转的精灵
	auto temp = Sprite::createWithTexture(sprite->getTexture(),sprite->getTextureRect());
	temp->setPosition(center);
	temp->setFlippedY(true);
 
	auto mask = LayerColor::create(Color4B::WHITE,size.width,size.height);
	mask->setBlendFunc({ GL_DST_ALPHA,GL_ZERO });
	
	auto renderTexture = RenderTexture::create(size.width,size.height);
	renderTexture->setAnchorPoint(Vec2::ZERO);
	renderTexture->setPosition(Vec2::ZERO);
 
	renderTexture->begin();
	temp->visit();
	mask->visit();
	renderTexture->end();
 
	//用renderTexture里的纹理创建要返回的精灵
	auto tex = renderTexture->getSprite()->getTexture();
	auto spr = Sprite::createWithTexture(tex);
 
	//恢复到与sprite相同的锚点和位置
	spr->setAnchorPoint(anchorPoint);
	spr->setPosition(position);
 
	return spr;
}

	auto sprite = Sprite::create("grossini.png");
	sprite->setPosition(100,200);
 
	auto mono = getMonoColorSprite(sprite);
	mono->setColor(Color3B::GREEN);
	mono->setPosition(300,200);
 
	addChild(sprite);
	addChild(mono);

有点像数字图像处理中的图像二值化，不过这里这有一种颜色

使用RenderTexture效率低下，而且要占用额外空间，图片多的话，可能会多占很多空间，这种方法不太实用，推荐使用下面的Shader实现

方法二 Shader@H_301_4@

#ifdef GL_ES
precision lowp float;
#endif
 
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
 
 
void main()
{
	vec4 texColor = texture2D(CC_Texture0,v_texCoord);
<span style="white-space:pre">	</span>//最终颜色完全由顶点颜色决定
	gl_FragColor=v_fragmentColor;
	gl_FragColor.a*=texColor.a;
}

//可以在游戏初始化加载Shader,并添加到<span style="font-family: Arial,Helvetica,sans-serif;">ShaderCache中，方便以后调用</span>
auto fragmentSource = FileUtils::getInstance()->getStringFromFile("monocolor.fsh");
auto shader_program = GLProgram::createWithByteArrays(ccPositionTextureColor_noMVP_vert,fragmentSource.c_str());
 
ShaderCache::getInstance()->addGLProgram(shader_program,"monocolor");

//应用使用Shader
sprite->setGLProgram(ShaderCache::getInstance()->getGLProgram("monocolor"));