Cocos lua图片置灰

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/lxt610/article/details/83505640

1、引言

  在实际的开发过程中，我们有时可以看到同样的按钮，按钮图片在不同状态表现也不一样！我们需要考虑优化这种问题。就是相同的图片只做一张图就可以了，没有必要多做很多灰度图片。我们该怎么做呢？先卖一个关子，嘻嘻(#^.#)

2、思路

  上面我们已经发现问题了，猜想一下呗？好的，你没猜错。就是shader,通过一段代码，来改变图片的色值。班门弄斧了，废话少说我们直接上代码：

function setSpriteGray(sp,flag)  
    -- 默认vert
    local vertShaderByteArray = "\n"..  
        "attribute vec4 a_position; \n" ..  
        "attribute vec2 a_texCoord; \n" ..  
        "attribute vec4 a_color; \n"..  
        "#ifdef GL_ES  \n"..  
        "varying lowp vec4 v_fragmentColor;\n"..  
        "varying mediump vec2 v_texCoord;\n"..  
        "#else                      \n" ..  
        "varying vec4 v_fragmentColor; \n" ..  
        "varying vec2 v_texCoord;  \n"..  
        "#endif    \n"..  
        "void main() \n"..  
        "{\n" ..  
        "gl_Position = CC_PMatrix * a_position; \n"..  
        "v_fragmentColor = a_color;\n"..  
        "v_texCoord = a_texCoord;\n"..  
        "}"  

    -- 置灰frag
    local flagShaderByteArray = "#ifdef GL_ES \n" ..  
        "precision mediump float; \n" ..  
        "#endif \n" ..  
        "varying vec4 v_fragmentColor; \n" ..  
        "varying vec2 v_texCoord; \n" ..  
        "void main(void) \n" ..  
        "{ \n" ..  
        "vec4 c = texture2D(CC_Texture0, v_texCoord); \n" ..  
        "gl_FragColor.xyz = vec3(0.4*c.r + 0.4*c.g +0.4*c.b); \n"..  
        "gl_FragColor.w = c.w; \n"..  
        "}"  

    -- 移除置灰frag  
    local pszRemoveGrayShader = "#ifdef GL_ES \n" ..  
        "precision mediump float; \n" ..  
        "#endif \n" ..  
        "varying vec4 v_fragmentColor; \n" ..  
        "varying vec2 v_texCoord; \n" ..  
        "void main(void) \n" ..  
        "{ \n" ..  
        "gl_FragColor = texture2D(CC_Texture0, v_texCoord); \n" ..  
        "}" 
    if flag then 
        local glProgram = cc.GLProgram:createWithByteArrays(vertShaderByteArray,flagShaderByteArray)  
        glProgram:bindAttribLocation(cc.ATTRIBUTE_NAME_POSITION,cc.VERTEX_ATTRIB_POSITION)  
        glProgram:bindAttribLocation(cc.ATTRIBUTE_NAME_COLOR,cc.VERTEX_ATTRIB_COLOR)  
        glProgram:bindAttribLocation(cc.ATTRIBUTE_NAME_TEX_COORD,cc.VERTEX_ATTRIB_FLAG_TEX_COORDS)  
        glProgram:link()  
        glProgram:updateUniforms()  
        sp:getVirtualRenderer():getSprite():setGLProgram(glProgram)  
    else 
        local glProgram = cc.GLProgram:createWithByteArrays(vertShaderByteArray,pszRemoveGrayShader)  
        glProgram:bindAttribLocation(cc.ATTRIBUTE_NAME_POSITION,cc.VERTEX_ATTRIB_POSITION)  
        glProgram:bindAttribLocation(cc.ATTRIBUTE_NAME_COLOR,cc.VERTEX_ATTRIB_COLOR)  
        glProgram:bindAttribLocation(cc.ATTRIBUTE_NAME_TEX_COORD,cc.VERTEX_ATTRIB_FLAG_TEX_COORDS)  
        glProgram:link()  
        glProgram:updateUniforms()  
        sp:getVirtualRenderer():getSprite():setGLProgram(glProgram) 
    end 
end

3、使用

  使用就很简单了，直接传入按钮或者图片纹理和是否置灰就可以了！

setSpriteGray(self.btnGoldReLive,not result.Data.Gold.Enable)

4、结束语

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The End
  好了，今天的分享就到这里，如有不足之处，还望大家及时指正，随时欢迎探讨交流！！！

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