code: function(repeat) {
          if (!this.isActive())
              throw "Trying to set repeat property of texture that isn't active";
          if (repeat && !this.powerOfTwo) {
              throw "Can't create a repeating image whose dimensions aren't a power of 2 in WebGL contexts";
          }
          var gl = this.gl;
          this.repeatMode = repeat ? gl.REPEAT : gl.CLAMP_TO_EDGE;
          gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, this.repeatMode);
          gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, this.repeatMode);
      }
docs: set image wrapping