ofxHueShader:色调滤镜

ofxHueShader 如何使用 ofxHueShader::beginShader(hue, aplha); tex.draw(0, 0); ofxHueShader::endShader(); or ofxHueShader hueShader; hueShader.begin(hue, alpha); tex.draw(0, 0); hueShader.end();