cocos2dx lua 图片去色shader

function FreeCardTool:setNodeGray(node)
    local vertShaderByteArray = "
"..
        "attribute vec4 a_position; 
" ..
        "attribute vec2 a_texCoord; 
" ..
        "attribute vec4 a_color; 
"..
        "#ifdef GL_ES  
"..
        "varying lowp vec4 v_fragmentColor;
"..
        "varying mediump vec2 v_texCoord;
"..
        "#else                      
" ..
        "varying vec4 v_fragmentColor; 
" ..
        "varying vec2 v_texCoord;  
"..
        "#endif    
"..
        "void main() 
"..
        "{
" ..
        "gl_Position = CC_PMatrix * a_position; 
"..
        "v_fragmentColor = a_color;
"..
        "v_texCoord = a_texCoord;
"..
        "}"

    local flagShaderByteArray = "#ifdef GL_ES 
" ..
        "precision mediump float; 
" ..
        "#endif 
" ..
        "varying vec4 v_fragmentColor; 
" ..
        "varying vec2 v_texCoord; 
" ..
        "void main(void) 
" ..
        "{ 
" ..
        "vec4 c = texture2D(CC_Texture0, v_texCoord); 
" ..
        "gl_FragColor.xyz = vec3(0.2126*c.r + 0.7152*c.g +0.0722*c.b); 
"..
        "gl_FragColor.w = c.w; 
"..
        "}"
    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()
    node:setGLProgram( glProgram )
end

虽然是参数node不过暂时发现只对sprite有效，对文本竟然没有效果