drawThunder method

void drawThunder(ThunderParams params, Canvas canvas, Size size)

这里主要负责绘制雷电

Implementation

void drawThunder(ThunderParams params, Canvas canvas, Size size) {
  canvas.save();
  var identity = ColorFilter.matrix(<double>[
    1,
    0,
    0,
    0,
    0,
    0,
    1,
    0,
    0,
    0,
    0,
    0,
    1,
    0,
    0,
    0,
    0,
    0,
    params.alpha,
    0,
  ]);
  _paint.colorFilter = identity;
  canvas.scale(params.widthRatio * 1.2);
  canvas.drawImage(params.image, Offset(params.x, params.y), _paint);
  canvas.restore();
}