<template>
  <div ref="myEchart" style="width: 100%; height: 180px"></div>
</template>

<script>
import * as echarts from "echarts";
import "echarts-gl";
export default {
  data() {
    return {
      pieChart: [
        {
          name: "a",
          value: 25,
          itemStyle: {
            color: "#00d8ff",
          },
        },
        {
          name: "b",
          value: 5,
          itemStyle: {
            color: "#018ef1",
          },
        },
        {
          name: "c",
          value: 4,
          itemStyle: {
            color: "#f8bc87",
          },
        },
        {
          name: "d",
          value: 3,
          itemStyle: {
            color: "#ffa130",
          },
        },
        {
          name: "e",
          value: 2,
          itemStyle: {
            color: "#c23531",
          },
        },
        {
          name: "f",
          value: 1,
          itemStyle: {
            color: "#fd5d48",
          },
        },
      ],
    };
  },
  mounted() {
    // this.getPie3D(this.pieChart, 0.59);
    this.myMap = echarts.init(this.$refs.myEchart);
    this.myMap.setOption(this.getPie3D(this.pieChart, 0.71));
  },
  methods: {
    // 生成扇形的曲面参数方程，用于 series-surface.parametricEquation
    getParametricEquation(startRatio, endRatio, isSelected, isHovered, k) {
      // 计算
      let midRatio = (startRatio + endRatio) / 2;

      let startRadian = startRatio * Math.PI * 2;
      let endRadian = endRatio * Math.PI * 2;
      let midRadian = midRatio * Math.PI * 2;

      // 如果只有一个扇形，则不实现选中效果。
      if (startRatio === 0 && endRatio === 1) {
        isSelected = false;
      }

      // 通过扇形内径/外径的值，换算出辅助参数 k（默认值 1/3）
      k = typeof k !== "undefined" ? k : 1 / 3;

      // 计算选中效果分别在 x 轴、y 轴方向上的位移（未选中，则位移均为 0）
      let offsetX = isSelected ? Math.cos(midRadian) * 0.1 : 0;
      let offsetY = isSelected ? Math.sin(midRadian) * 0.1 : 0;

      // 计算高亮效果的放大比例（未高亮，则比例为 1）
      let hoverRate = isHovered ? 1.05 : 1;

      // 返回曲面参数方程
      return {
        u: {
          min: -Math.PI,
          max: Math.PI * 3,
          step: Math.PI / 32,
        },

        v: {
          min: 0,
          max: Math.PI * 2,
          step: Math.PI / 20,
        },

        x: function (u, v) {
          if (u < startRadian) {
            return (
              offsetX +
              Math.cos(startRadian) * (1 + Math.cos(v) * k) * hoverRate
            );
          }
          if (u > endRadian) {
            return (
              offsetX + Math.cos(endRadian) * (1 + Math.cos(v) * k) * hoverRate
            );
          }
          return offsetX + Math.cos(u) * (1 + Math.cos(v) * k) * hoverRate;
        },

        y: function (u, v) {
          if (u < startRadian) {
            return (
              offsetY +
              Math.sin(startRadian) * (1 + Math.cos(v) * k) * hoverRate
            );
          }
          if (u > endRadian) {
            return (
              offsetY + Math.sin(endRadian) * (1 + Math.cos(v) * k) * hoverRate
            );
          }
          return offsetY + Math.sin(u) * (1 + Math.cos(v) * k) * hoverRate;
        },

        z: function (u, v) {
          if (u < -Math.PI * 0.5) {
            return Math.sin(u);
          }
          if (u > Math.PI * 2.5) {
            return Math.sin(u);
          }
          return Math.sin(v) > 0 ? 1 : -1;
        },
      };
    },

    // 生成模拟 3D 饼图的配置项
    getPie3D(pieData, internalDiameterRatio) {
      let series = [];
      let sumValue = 0;
      let startValue = 0;
      let endValue = 0;
      let legendData = [];
      let k =
        typeof internalDiameterRatio !== "undefined"
          ? (1 - internalDiameterRatio) / (1 + internalDiameterRatio)
          : 1 / 3;

      // 为每一个饼图数据，生成一个 series-surface 配置
      for (let i = 0; i < pieData.length; i++) {
        sumValue += pieData[i].value;

        let seriesItem = {
          name:
            typeof pieData[i].name === "undefined"
              ? `series${i}`
              : pieData[i].name,
          type: "surface",
          parametric: true,
          wireframe: {
            show: false,
          },
          pieData: pieData[i],
          pieStatus: {
            selected: false,
            hovered: false,
            k: k,
          },
        };

        if (typeof pieData[i].itemStyle != "undefined") {
          let itemStyle = {};

          typeof pieData[i].itemStyle.color != "undefined"
            ? (itemStyle.color = pieData[i].itemStyle.color)
            : null;
          typeof pieData[i].itemStyle.opacity != "undefined"
            ? (itemStyle.opacity = pieData[i].itemStyle.opacity)
            : null;

          seriesItem.itemStyle = itemStyle;
        }
        series.push(seriesItem);
      }

      // 使用上一次遍历时，计算出的数据和 sumValue，调用 getParametricEquation 函数，
      // 向每个 series-surface 传入不同的参数方程 series-surface.parametricEquation，也就是实现每一个扇形。
      for (let i = 0; i < series.length; i++) {
        endValue = startValue + series[i].pieData.value;

        series[i].pieData.startRatio = startValue / sumValue;
        series[i].pieData.endRatio = endValue / sumValue;
        series[i].parametricEquation = this.getParametricEquation(
          series[i].pieData.startRatio,
          series[i].pieData.endRatio,
          true,
          false,
          1
        );

        startValue = endValue;

        legendData.push(series[i].name);
      }

      // 补充一个透明的圆环，用于支撑高亮功能的近似实现。
      series.push({
        name: "mouseoutSeries",
        type: "surface",
        parametric: true,
        wireframe: {
          show: false,
        },
        itemStyle: {
          opacity: 1,
          color: "rgba(18,236,252,.5)",
        },
        parametricEquation: {
          u: {
            min: 0,
            max: Math.PI * 2,
            step: Math.PI / 20,
          },
          v: {
            min: 0,
            max: Math.PI,
            step: Math.PI / 1.4,
          },
          x: function (u, v) {
            return Math.sin(v) * Math.sin(u) + Math.sin(u);
          },
          y: function (u, v) {
            return Math.sin(v) * Math.cos(u) + Math.cos(u);
          },
          z: function (u, v) {
            return Math.cos(v) > 0 ? 0.1 : -0.1;
          },
        },
      });

      // 准备待返回的配置项，把准备好的 legendData、series 传入。
      let option = {
        //animation: false,
        legend: {
          show: true,
          data: legendData,
        },
        tooltip: {
          formatter: (params) => {
            if (params.seriesName !== "mouseoutSeries") {
              return `${
                params.seriesName
              }<br/><span style="display:inline-block;margin-right:5px;border-radius:10px;width:10px;height:10px;background-color:${
                params.color
              };"></span>${option.series[params.seriesIndex].pieData.value}`;
            }
          },
        },
        xAxis3D: {
          min: -1.3,
          max: 1.3,
        },
        yAxis3D: {
          min: -1.3,
          max: 1.3,
        },
        zAxis3D: {
          min: -1.3,
          max: 1.3,
        },
        grid3D: {
          show: false,
          boxHeight: 10,
          // top: '30%',
          left: "0",
          bottom: "50%",
          viewControl: {
            //3d效果可以放大、旋转等，请自己去查看官方配置
            alpha: 20,
            // beta: 40,
            rotateSensitivity: 0,
            zoomSensitivity: 0,
            panSensitivity: 0,
            autoRotate: true,
            //   autoRotateSpeed: 5,
            //   autoRotateAfterStill: 10
          },
        },
        series: series,
      };
      return option;
    },
  },
  // 传入数据生成 option
};
</script>

<style lang="scss" scoped></style>
