sdk4.0/src/Obj/Materail/FlowDashedLineFlowMaterialProperty.js

/*
 * @Description: 流动线
 */
function FlowDashedLine() {
  class FlowDashedLineFlowMaterialProperty {
    constructor(options) {
      this._definitionChanged = new Cesium.Event();
      this._color = undefined;
      this._speed = undefined;
      this._uType = undefined;
      this.color = new Cesium.Color.fromCssColorString(options.color || "rgba(255,255,255,1)");
      this.speed = options.speed || 0.25;//速度
      this.uType = options.uType === undefined ? 1 : options.uType;//类型：0：普通流动线 1：虚化虚线
      this.lineBackAlpha = options.lineBackAlpha || 0.05;
    }

    get isConstant() {
      return false;
    }

    get definitionChanged() {
      return this._definitionChanged;
    }

    getType(time) {
      return Cesium.Material.FlowDashedLineMaterialType;
    }

    getValue(time, result) {
      if (!Cesium.defined(result)) {
        result = {};
      }

      result.color = Cesium.Property.getValueOrDefault(
        this._color,
        time,
        Cesium.Color.RED,
        result.color
      );
      result.speed = Cesium.Property.getValueOrDefault(
        this._speed,
        time,
        10,
        result.speed
      );
      result.uType = Cesium.Property.getValueOrDefault(
        this._uType,
        time,
        1,
        result.uType
      );
      result.lineBackAlpha = this.lineBackAlpha;
      result.frameNumber = Cesium.getTimestamp();
      return result;
    }

    equals(other) {
      return (
        this === other ||
        (other instanceof FlowDashedLineFlowMaterialProperty &&
          Cesium.Property.equals(this._color, other._color) &&
          Cesium.Property.equals(this._speed, other.speed) &&
          Cesium.Property.equals(this._uType, other.uType) &&
          Cesium.Property.equals(this.lineBackAlpha, other.lineBackAlpha))
      );
    }
  }

  Object.defineProperties(FlowDashedLineFlowMaterialProperty.prototype, {
    color: Cesium.createPropertyDescriptor("color"),
    speed: Cesium.createPropertyDescriptor("speed"),
    uType: Cesium.createPropertyDescriptor("uType"),
    transparency: Cesium.createPropertyDescriptor("lineBackAlpha"),
  });

  Cesium.FlowDashedLineFlowMaterialProperty = FlowDashedLineFlowMaterialProperty;
  Cesium.Material.FlowDashedLineFlowMaterialProperty = "FlowDashedLineFlowMaterialProperty";
  Cesium.Material.FlowDashedLineMaterialType = "FlowDashedLineMaterialType";
  Cesium.Material.FlowDashedLineMaterialSource = `
      uniform vec4 color;
      uniform float speed;
      // uniform int uType;
      uniform float lineBackAlpha;

      czm_material czm_getMaterial(czm_materialInput materialInput)
        {
            czm_material material = czm_getDefaultMaterial(materialInput);
            vec2 st = materialInput.st;

            // 计算流动虚线
            float dashSize = 0.03;
            float gapSize = 0.01;
            float progress = fract(czm_frameNumber * 0.01); // 时间控制流动
            float pattern = fract(st.x / (dashSize + gapSize) + progress);
            float dash1 = step(0.1, pattern) - step(0.9, pattern);
            float dash2 = smoothstep(0.1, 0.3, pattern) - smoothstep(0.7, 0.9, pattern);
            float dash = (float(uType) != 1.0)?dash1:dash2;
            material.alpha = dash;
            material.diffuse = color.rgb;
            return material;
        }
       `;

  Cesium.Material._materialCache.addMaterial(
    Cesium.Material.FlowDashedLineMaterialType,
    {
      fabric: {
        type: Cesium.Material.FlowDashedLineMaterialType,
        uniforms: {
          color: new Cesium.Color(1.0, 1.0, 1.0, 1.0),
          speed: 0.1,
          uType: 1,
          lineBackAlpha: 0.05,
        },
        source: Cesium.Material.FlowDashedLineMaterialSource,
      },
      translucent: function (material) {
        return true;
      },
    }
  );
}

export { FlowDashedLine }