title: Rotate curve in webgl
body: <p>I approximate a curve with line segments:</p>
  
  <pre><code>for (i=1; i&lt;=100; i=i+0.2)
      {
          arr = calculateCurve(i, 1, 1, 1, 1); //function returns an array of verticles
          gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
              prevArr[0]/scale,
              prevArr[1]/scale,
              prevArr[2]/scale,
              arr[0]/scale,
              arr[1]/scale,
              arr[2]/scale
          ]), gl.STATIC_DRAW);
          gl.drawArrays(gl.LINES, 0, 2);
  
          prevArr = arr;
  
      }
  </code></pre>
  
  <p>I need to rotate the curve without using gl.drawArrays() again, because performance is extremely slow in this case.
  I would create a huge buffer with 100 vertices, but I wonder if there's a way to redraw the scene just by changing rotation matrix in vertex shader.</p>