en/builder/src/echarts3/chart/line/poly.js

// Poly path support NaN point
import Path from 'zrender/src/graphic/Path';
import * as vec2 from 'zrender/src/core/vector';
import fixClipWithShadow from 'zrender/src/graphic/helper/fixClipWithShadow';
var vec2Min = vec2.min;
var vec2Max = vec2.max;
var scaleAndAdd = vec2.scaleAndAdd;
var v2Copy = vec2.copy; // Temporary variable

var v = [];
var cp0 = [];
var cp1 = [];

function isPointNull(p) {
  return isNaN(p[0]) || isNaN(p[1]);
}

function drawSegment(ctx, points, start, segLen, allLen, dir, smoothMin, smoothMax, smooth, smoothMonotone, connectNulls) {
  var prevIdx = 0;
  var idx = start;

  for (var k = 0; k < segLen; k++) {
    var p = points[idx];

    if (idx >= allLen || idx < 0) {
      break;
    }

    if (isPointNull(p)) {
      if (connectNulls) {
        idx += dir;
        continue;
      }

      break;
    }

    if (idx === start) {
      ctx[dir > 0 ? 'moveTo' : 'lineTo'](p[0], p[1]);
      v2Copy(cp0, p);
    } else {
      if (smooth > 0) {
        var nextIdx = idx + dir;
        var nextP = points[nextIdx];

        if (connectNulls) {
          // Find next point not null
          while (nextP && isPointNull(points[nextIdx])) {
            nextIdx += dir;
            nextP = points[nextIdx];
          }
        }

        var ratioNextSeg = 0.5;
        var prevP = points[prevIdx];
        var nextP = points[nextIdx]; // Last point

        if (!nextP || isPointNull(nextP)) {
          v2Copy(cp1, p);
        } else {
          // If next data is null in not connect case
          if (isPointNull(nextP) && !connectNulls) {
            nextP = p;
          }

          vec2.sub(v, nextP, prevP);
          var lenPrevSeg;
          var lenNextSeg;

          if (smoothMonotone === 'x' || smoothMonotone === 'y') {
            var dim = smoothMonotone === 'x' ? 0 : 1;
            lenPrevSeg = Math.abs(p[dim] - prevP[dim]);
            lenNextSeg = Math.abs(p[dim] - nextP[dim]);
          } else {
            lenPrevSeg = vec2.dist(p, prevP);
            lenNextSeg = vec2.dist(p, nextP);
          } // Use ratio of seg length


          ratioNextSeg = lenNextSeg / (lenNextSeg + lenPrevSeg);
          scaleAndAdd(cp1, p, v, -smooth * (1 - ratioNextSeg));
        } // Smooth constraint


        vec2Min(cp0, cp0, smoothMax);
        vec2Max(cp0, cp0, smoothMin);
        vec2Min(cp1, cp1, smoothMax);
        vec2Max(cp1, cp1, smoothMin);
        ctx.bezierCurveTo(cp0[0], cp0[1], cp1[0], cp1[1], p[0], p[1]); // cp0 of next segment

        scaleAndAdd(cp0, p, v, smooth * ratioNextSeg);
      } else {
        ctx.lineTo(p[0], p[1]);
      }
    }

    prevIdx = idx;
    idx += dir;
  }

  return k;
}

function getBoundingBox(points, smoothConstraint) {
  var ptMin = [Infinity, Infinity];
  var ptMax = [-Infinity, -Infinity];

  if (smoothConstraint) {
    for (var i = 0; i < points.length; i++) {
      var pt = points[i];

      if (pt[0] < ptMin[0]) {
        ptMin[0] = pt[0];
      }

      if (pt[1] < ptMin[1]) {
        ptMin[1] = pt[1];
      }

      if (pt[0] > ptMax[0]) {
        ptMax[0] = pt[0];
      }

      if (pt[1] > ptMax[1]) {
        ptMax[1] = pt[1];
      }
    }
  }

  return {
    min: smoothConstraint ? ptMin : ptMax,
    max: smoothConstraint ? ptMax : ptMin
  };
}

export var Polyline = Path.extend({
  type: 'ec-polyline',
  shape: {
    points: [],
    smooth: 0,
    smoothConstraint: true,
    smoothMonotone: null,
    connectNulls: false
  },
  style: {
    fill: null,
    stroke: '#000'
  },
  brush: fixClipWithShadow(Path.prototype.brush),
  buildPath: function (ctx, shape) {
    var points = shape.points;
    var i = 0;
    var len = points.length;
    var result = getBoundingBox(points, shape.smoothConstraint);

    if (shape.connectNulls) {
      // Must remove first and last null values avoid draw error in polygon
      for (; len > 0; len--) {
        if (!isPointNull(points[len - 1])) {
          break;
        }
      }

      for (; i < len; i++) {
        if (!isPointNull(points[i])) {
          break;
        }
      }
    }

    while (i < len) {
      i += drawSegment(ctx, points, i, len, len, 1, result.min, result.max, shape.smooth, shape.smoothMonotone, shape.connectNulls) + 1;
    }
  }
});
export var Polygon = Path.extend({
  type: 'ec-polygon',
  shape: {
    points: [],
    // Offset between stacked base points and points
    stackedOnPoints: [],
    smooth: 0,
    stackedOnSmooth: 0,
    smoothConstraint: true,
    smoothMonotone: null,
    connectNulls: false
  },
  brush: fixClipWithShadow(Path.prototype.brush),
  buildPath: function (ctx, shape) {
    var points = shape.points;
    var stackedOnPoints = shape.stackedOnPoints;
    var i = 0;
    var len = points.length;
    var smoothMonotone = shape.smoothMonotone;
    var bbox = getBoundingBox(points, shape.smoothConstraint);
    var stackedOnBBox = getBoundingBox(stackedOnPoints, shape.smoothConstraint);

    if (shape.connectNulls) {
      // Must remove first and last null values avoid draw error in polygon
      for (; len > 0; len--) {
        if (!isPointNull(points[len - 1])) {
          break;
        }
      }

      for (; i < len; i++) {
        if (!isPointNull(points[i])) {
          break;
        }
      }
    }

    while (i < len) {
      var k = drawSegment(ctx, points, i, len, len, 1, bbox.min, bbox.max, shape.smooth, smoothMonotone, shape.connectNulls);
      drawSegment(ctx, stackedOnPoints, i + k - 1, k, len, -1, stackedOnBBox.min, stackedOnBBox.max, shape.stackedOnSmooth, smoothMonotone, shape.connectNulls);
      i += k + 1;
      ctx.closePath();
    }
  }
});