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

/*
 * @Description: 流动线
 */
function LineTexture() {
  class LineTextureMaterialProperty {
    constructor(options) {
      this._definitionChanged = new Cesium.Event();
      this._image = undefined;
      this._color = undefined;
      this._speed = undefined;
      this._repeat = undefined;
      this.image = options.image || "";
      this.color = new Cesium.Color.fromCssColorString(options.color || "rgba(255,255,255,1)");
      this.speed = options.speed != undefined ? options.speed : 1.0;
      this.repeat = options.repeat || 1.0;
    }

    get isConstant() {
      return false;
    }

    get definitionChanged() {
      return this._definitionChanged;
    }

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

    getValue(time, result) {
      if (!Cesium.defined(result)) {
        result = {};
      }
      result.image = Cesium.Property.getValueOrDefault(
        this._image,
        time,
        "",
        result.image
      );
      result.color = Cesium.Property.getValueOrDefault(
        this._color,
        time,
        Cesium.Color.RED,
        result.color
      );
      result.speed = Cesium.Property.getValueOrDefault(
        this._speed,
        time,
        1.0,
        result.speed
      );
      result.repeat = Cesium.Property.getValueOrDefault(
        this._repeat,
        time,
        1.0,
        result.repeat
      );
      result.frameNumber = Cesium.getTimestamp();
      return result;
    }

    equals(other) {
      return (
        this === other ||
        (other instanceof LineTextureMaterialProperty &&
          Cesium.Property.equals(this._image, other._image) &&
          Cesium.Property.equals(this._color, other._color) &&
          Cesium.Property.equals(this._imageW, other._imageW) &&
          Cesium.Property.equals(this._speed, other._speed))
      );
    }
  }

  Object.defineProperties(LineTextureMaterialProperty.prototype, {
    image: Cesium.createPropertyDescriptor("image"),
    color: Cesium.createPropertyDescriptor("color"),
    speed: Cesium.createPropertyDescriptor("speed"),
    repeat: Cesium.createPropertyDescriptor("repeat"),
  });

  Cesium.LineTextureMaterialProperty = LineTextureMaterialProperty;
  Cesium.Material.LineTextureMaterialProperty = "LineTextureMaterialProperty";
  Cesium.Material.LineTextureMaterialType = "LineTextureMaterialType";
  Cesium.Material.LineTextureMaterialSource = `
        uniform vec4 color;
        uniform sampler2D image;
        uniform float speed;
        uniform float repeat;
        czm_material czm_getMaterial(czm_materialInput materialInput)
        {
          czm_material material = czm_getDefaultMaterial(materialInput);
          vec2 st = materialInput.st;
          st.s *= repeat; // 关键：通过repeat控制纹理密度
          // vec4 colorImage = texture2D(image, vec2(fract(st.s + speed*czm_frameNumber* 0.01), st.t));
          vec4 colorImage = speed==0.0?texture2D(image, vec2(fract(st.s), st.t)):texture2D(image, vec2(fract(st.s + frameNumber / 1000.0 / speed * repeat ), st.t));
          material.alpha = colorImage.a * color.a;
          material.diffuse = color.rgb;
          return material;
        }
       `;
  Cesium.Material._materialCache.addMaterial(
    Cesium.Material.LineTextureMaterialType,
    {
      fabric: {
        type: Cesium.Material.LineTextureMaterialType,
        uniforms: {
          color: new Cesium.Color(1.0, 1.0, 1.0, 1.0),
          image: '',
          repeat: 1.0,
          speed: 1.0,
          frameNumber: Cesium.getTimestamp(),
          uTime: 1
        },
        source: Cesium.Material.LineTextureMaterialSource,
      },
      translucent: function (material) {
        return true;
      },
    }
  );
}

export { LineTexture }