add default mouse event

modules/event/EventType.js

 }
 
 const MouseEventType = {
+  LEFT_DOWN: Cesium.ScreenSpaceEventType.LEFT_DOWN,
+  LEFT_UP: Cesium.ScreenSpaceEventType.LEFT_UP,
   CLICK: Cesium.ScreenSpaceEventType.LEFT_CLICK,
+  RIGHT_DOWN: Cesium.ScreenSpaceEventType.RIGHT_DOWN,
+  RIGHT_UP: Cesium.ScreenSpaceEventType.RIGHT_UP,
   RIGHT_CLICK: Cesium.ScreenSpaceEventType.RIGHT_CLICK,
   DB_CLICK: Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK,
   MOUSE_MOVE: Cesium.ScreenSpaceEventType.MOUSE_MOVE,

modules/event/type/MouseEvent.js

     this._viewer = viewer
     this._selected = undefined
     this._setInputAction()
+    this.on(MouseEventType.LEFT_DOWN, this._leftDownHandler, this)
+    this.on(MouseEventType.LEFT_UP, this._leftUpHandler, this)
     this.on(MouseEventType.CLICK, this._clickHandler, this)
     this.on(MouseEventType.DB_CLICK, this._dbClickHandler, this)
+    this.on(MouseEventType.RIGHT_DOWN, this._rightDownHandler, this)
+    this.on(MouseEventType.RIGHT_UP, this._rightUpHandler, this)
     this.on(MouseEventType.RIGHT_CLICK, this._rightClickHandler, this)
     this.on(MouseEventType.MOUSE_MOVE, this._mouseMoveHandler, this)
     this.on(MouseEventType.WHEEL, this._mouseWheelHandler, this)
    * @private
    */
   _clickHandler(movement) {
-    if (!movement || !movement.position) {
+    if (!movement?.position) {
       return false
     }
     let mouseInfo = this._getMouseInfo(movement.position)
    * @private
    */
   _dbClickHandler(movement) {
-    if (!movement || !movement.position) {
+    if (!movement?.position) {
       return false
     }
     let mouseInfo = this._getMouseInfo(movement.position)
    * @private
    */
   _rightClickHandler(movement) {
-    if (!movement || !movement.position) {
+    if (!movement?.position) {
       return false
     }
     let mouseInfo = this._getMouseInfo(movement.position)
    * @private
    */
   _mouseMoveHandler(movement) {
-    if (!movement || !movement.endPosition) {
+    if (!movement?.endPosition) {
       return false
     }
     let mouseInfo = this._getMouseInfo(movement.endPosition)
     }
   }
 
+  /**
+   * Default mouse left down event handler
+   * @param movement
+   * @private
+   */
+  _leftDownHandler(movement) {
+    if (!movement?.position) {
+      return false
+    }
+    let mouseInfo = this._getMouseInfo(movement.position)
+    this._raiseEvent(MouseEventType.LEFT_DOWN, mouseInfo)
+  }
+
+  /**
+   * Default mouse left up event handler
+   * @param movement
+   * @private
+   */
+  _leftUpHandler(movement) {
+    this._raiseEvent(MouseEventType.LEFT_UP, { movement })
+  }
+
+  /**
+   * Default mouse right down event handler
+   * @param movement
+   * @private
+   */
+  _rightDownHandler(movement) {
+    if (!movement?.position) {
+      return false
+    }
+    let mouseInfo = this._getMouseInfo(movement.position)
+    this._raiseEvent(MouseEventType.RIGHT_DOWN, mouseInfo)
+  }
+
+  /**
+   * Default mouse right up event handler
+   * @param movement
+   * @private
+   */
+  _rightUpHandler(movement) {
+    this._raiseEvent(MouseEventType.RIGHT_UP, { movement })
+  }
+
   /**
    * Default mouse wheel event handler
    * @param movement

modules/material/shader/polyline/PolylineImageTrailMaterial.glsl

    float time = fract(czm_frameNumber * speed / 1000.0);
    vec4 colorImage = texture2D(image, vec2(fract(st.s - time), st.t));
    if(color.a == 0.0){
+     if(colorImage.rgb == vec3(1.0) || colorImage.rgb == vec3(0.0)){
+       discard;
+     }
     material.alpha = colorImage.a;
     material.diffuse = colorImage.rgb;
    }else{