All files / packages/tools/src/utilities/math/polyline projectTo2D.ts

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
 
 
 
1x
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
import { utilities } from '@cornerstonejs/core';
import type { Types } from '@cornerstonejs/core';
 
const epsilon = 1e-6;
 
/**
 * Projects a polyline from 3D to 2D by reducing one dimension.
 *
 * @param polyline - The polyline to be projected.
 * @returns An object containing the shared dimension index and the projected polyline in 2D.
 * @throws Error if a shared dimension index cannot be found for the polyline.
 */
export function projectTo2D(polyline: Types.Point3[]) {
  // We need to reduce one dimension to 2D, so basically
  // we need to find the dimension index that is shared by all points
  // Use the first three points, two is enough but three is more robust
  let sharedDimensionIndex;
 
  const testPoints = utilities.getRandomSampleFromArray(polyline, 50);
 
  for (let i = 0; i < 3; i++) {
    if (
      testPoints.every(
        (point, index, array) => Math.abs(point[i] - array[0][i]) < epsilon
      )
    ) {
      sharedDimensionIndex = i;
      break;
    }
  }
 
  if (sharedDimensionIndex === undefined) {
    throw new Error(
      'Cannot find a shared dimension index for polyline, probably oblique plane'
    );
  }
 
  // convert polyline list and point to 2D
  const points2D = [] as Types.Point2[];
 
  const firstDim = (sharedDimensionIndex + 1) % 3;
  const secondDim = (sharedDimensionIndex + 2) % 3;
 
  for (let i = 0; i < polyline.length; i++) {
    points2D.push([polyline[i][firstDim], polyline[i][secondDim]]);
  }
 
  return {
    sharedDimensionIndex,
    projectedPolyline: points2D,
  };
}