const char* ccPositionTexture_GrayScale_frag = STRINGIFY( \n#ifdef GL_ES\n \nprecision mediump float;\n \n#endif\n \n\n \nvarying vec4 v_fragmentColor;\n \nvarying vec2 v_texCoord;\n \n\n \nvoid main(void)\n \n{\n \nvec4 c = texture2D(CC_Texture0, v_texCoord);\n \n c = v_fragmentColor * c; \n \ngl_FragColor.xyz = vec3(0.2126*c.r + 0.7152*c.g + 0.0722*c.b);\n \ngl_FragColor.w = c.w;\n \n}\n );