title: How to draw circle on texture in unity?
body: <p>I try to find and show corners using opencv and unity3d. I capture by unity camera. I send texture2d to c++ code that uses opencv. I detect corners using opencv(harris corner detector). And c++ code send to unity code corners points(x,y position on image).</p>
  
  <p>Finally, I want to show these points. I try to draw circle on texture2d in unity. I use below code. But unity says that <code>Type UnityEngine.Texture2D does not contain a definition for DrawCircle and no extension method DrawCircle of type UnityEngine.Texture2D could be found</code></p>
  
  <p>How can I draw simple shape on unity3d?</p>
  
  <pre><code>    Texture2D texture = new Texture2D(w, h,TextureFormat.RGB24 , false);
      texture.DrawCircle(100, 100, 20, Color.green);
      // Apply all SetPixel calls
      texture.Apply();
      mesh_renderer.material.mainTexture = texture;
  </code></pre>