code: function LGraphFXVigneting() {
              this.addInput("Tex.", "Texture");
              this.addInput("intensity", "number");
  
              this.addOutput("Texture", "Texture");
              this.properties = {
                  intensity: 1,
                  invert: false,
                  precision: LGraphTexture.DEFAULT
              };
  
              if (!LGraphFXVigneting._shader) {
                  LGraphFXVigneting._shader = new GL.Shader(
                      Shader.SCREEN_VERTEX_SHADER,
                      LGraphFXVigneting.pixel_shader
                  );
              }
          }
docs: Vigneting ************************************