//创建背景贴图
  widthPixels = (int)(Screen.width * width);
  heightPixels = (int)(Screen.height * height);
  bgTexture = new Texture2D(widthPixels, heightPixels);
 
  bgImage.texture = bgTexture;
  bgImage.SetNativeSize();

int i;
  int j;
 
  if (Mathf.Abs(to.x - from.x) > Mathf.Abs(to.y - from.y))
  {
   // Horizontal line.
   i = 0;
   j = 1;
  }
  else
  {
   // Vertical line.
   i = 1;
   j = 0;
  }
 
  int x = (int)from[i];
  int delta = (int)Mathf.Sign(to[i] - from[i]);
  while (x != (int)to[i])
  {
   int y = (int)Mathf.Round(from[j] + (x - from[i]) * (to[j] - from[j]) / (to[i] - from[i]));
 
   int index;
   if (i == 0)
    index = y * widthPixels + x;
   else
    index = x * widthPixels + y;
 
   index = Mathf.Clamp(index, 0, pixelsDrawLine.Length - 1);
   pixelsDrawLine[index] = color;
 
   x += delta;
  }

Array.Copy(pixelsBg, pixelsDrawLine, pixelsBg.Length);
 
  // 基准线
  DrawLine(new Vector2(0f, heightPixels * 0.5f), new Vector2(widthPixels, heightPixels * 0.5f), zeroColor);
 
  for (int i = 0; i < listPoints.Count-1; i++)
  {
   Vector2 from = listPoints[i];
   Vector2 to = listPoints[i + 1];
   DrawLine(from, to, colorLine1);
  }
 
  bgTexture.SetPixels32(pixelsDrawLine);
  bgTexture.Apply();