new LineGrowthComponent()
线生长动画组件类，用于通过操作UV坐标控制线条的生长动画效果。
Example
// 创建并添加组件到线条
const line = new THING.RouteLine();
const growth = line.addComponent(THING.LineGrowthComponent);
// 控制线可见范围
growth.progress = 0.3; // 隐藏起点30%// 创建并添加组件到线条
const line = new THING.RouteLine();
const growth = line.addComponent(THING.LineGrowthComponent);
// 控制线可见范围
growth.progress = 0.3; // 隐藏起点30%