cocos2d-js 图片灰度处理

使用shader把图片进行灰度处理，并支持切回原色

潜在bug：如果调用两次灰度处理，则无法进行色彩还原

LayoutConfig.setWidgetEffectWithEnabled = function (widget,enable) {
    if(!widget){return;}
    widget.setTouchEnabled(enable);
    LayoutConfig.setWidgetGrayEffect(widget,!enable);
}

LayoutConfig.setWidgetGrayEffect = function (widget,enable) {
var shader = LayoutConfig.getShaderMap(enable ? "ui_gray" : "ui_normal");
if (widget) {
var children = widget.getChildren();
for (var i in children) {
LayoutConfig.setWidgetGrayEffect(children[i], enable);
}

if (!widget.getString) {
widget.setShaderProgram(shader);
}

if (widget.getVirtualRenderer) {
var children = widget.getVirtualRenderer().getChildren();
for (var i in children) {
LayoutConfig.setWidgetGrayEffect(children[i], enable);
}

if (!widget.getVirtualRenderer().getString) {
widget.getVirtualRenderer().setShaderProgram(shader);
}
}
}
};

LayoutConfig.getShaderMap = function (n) {
var _s = this._shaderMap
;
if (_s) {
//cc.log("LayoutConfig.getShaderMap: " + n + " Cache");
return _s;
}

var b_n = "res/shader/" + n;
var v_n = b_n + ".vsh";
var f_n = b_n + ".fsh";

_s = new cc.GLProgram(v_n, f_n);
_s.addAttribute(cc.ATTRIBUTE_NAME_POSITION, cc.VERTEX_ATTRIB_POSITION);
_s.addAttribute(cc.ATTRIBUTE_NAME_COLOR, cc.VERTEX_ATTRIB_COLOR);
_s.addAttribute(cc.ATTRIBUTE_NAME_TEX_COORD, cc.VERTEX_ATTRIB_TEX_COORDS);
_s.link();
_s.updateUniforms();

this._shaderMap
= _s;

//cc.log("LayoutConfig.getShaderMap: " + n + " New");
return _s;
};