Cocos2dx-JS 在 Sprite 上使用 Shader

var url = "res/sb.jpg";
var sp = new cc.Sprite(url);
sp.setAnchorPoint(0,0);
this.addChild(sp);
this.shader = new cc.GLProgram("res/Shaders/example_Flower.vsh", "res/Shaders/example_Flower.fsh");
this.shader.retain();
this.shader.link();
this.shader.updateUniforms();
var program = this.shader.getProgram();
sp.shaderProgram = this.shader;

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;
}

#ifdef GL_ES
precision lowp float;
#endif

varying vec4 v_fragmentColor;
varying vec2 v_texCoord;

void main()
{
gl_FragColor = v_fragmentColor * texture2D(CC_Texture0, v_texCoord);
float r = gl_FragColor[0];
float g = gl_FragColor[1];
float b = gl_FragColor[2];
float a = gl_FragColor[3];
if(b > r && b > g && b > (r*0.5 + g*0.5)*1.5) {
gl_FragColor[0] = b;
gl_FragColor[2] = r;
}
}