cocos2d-x 3.5，lua环境下实现按钮变灰；

代码调用：

    local program = cc.GLProgram:create("Shaders/Gray.vsh","Shaders/Gray.fsh")
    program:bindAttribLocation(cc.ATTRIBUTE_NAME_POSITION,cc.VERTEX_ATTRIB_POSITION) 
    program:bindAttribLocation(cc.ATTRIBUTE_NAME_TEX_COORD,cc.VERTEX_ATTRIB_TEX_COORD)
    program:link()
    program:updateUniforms()

label:setGLProgram( program )

自己的vsh和fsh

attribute vec4 a_position;
attribute vec2 a_texCoord;
attribute vec4 a_color;
                    


varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
                                
void main()    
{                            
    gl_Position = CC_PMatrix * a_position;
    v_fragmentColor = a_color;
    v_texCoord = a_texCoord;
}
gray.vsh

varying vec4 v_fragmentColor;    
varying vec2 v_texCoord;    
uniform sampler2D CC_Texture0;    
        
void main()            
{
    vec4 v_orColor = v_fragmentColor * texture2D(CC_Texture0,v_texCoord);
    float gray = dot(v_orColor.rgb,vec3(0.299,0.587,0.114));
    gl_FragColor = vec4(gray,gray,v_orColor.a);
}                

gray.fsh