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| 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 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 | 1x 1440x 720x 240x 240x 240x 240x 240x 240x 1920x 240x 240x 240x 240x 240x 240x 1920x 1920x 480x 1920x 445x 240x | import vtkMatrixBuilder from '@kitware/vtk.js/Common/Core/MatrixBuilder';
import getVolumeActorCorners from './getVolumeActorCorners';
import type { VolumeActor, Point3, ActorSliceRange } from '../types';
import { EPSILON } from '../constants';
const SMALL_EPSILON = EPSILON * EPSILON;
const isOne = (v) => Math.abs(Math.abs(v) - 1) < SMALL_EPSILON;
const isUnit = (v, off) =>
isOne(v[off]) || isOne(v[off + 1]) || isOne(v[off + 2]);
const isOrthonormal = (v) => isUnit(v, 0) && isUnit(v, 3) && isUnit(v, 6);
/**
* Given a `vtkVolumeActor`, and a normal direction,
* calculate the range of slices in the focal normal direction that encapsulate
* the volume. Also project the `focalPoint` onto this range.
*
* @param volumeActor - The `vtkVolumeActor`.
* @param viewPlaneNormal - The normal to the camera view.
* @param focalPoint - The focal point of the camera.
*
* @returns an object containing the `min`, `max` and `current`
* positions in the normal direction.
*/
export default function getSliceRange(
volumeActor: VolumeActor,
viewPlaneNormal: Point3,
focalPoint: Point3
): ActorSliceRange {
const imageData = volumeActor.getMapper().getInputData();
let corners;
const direction = imageData.getDirection();
Eif (isOrthonormal(direction)) {
// This logic is only valid when the IJK vectors are unit vectors
corners = getVolumeActorCorners(volumeActor);
} else {
// This logic works for both unit and non-unit vectors, but is slower
const [dx, dy, dz] = imageData.getDimensions();
const cornersIdx = [
[0, 0, 0],
[dx - 1, 0, 0],
[0, dy - 1, 0],
[dx - 1, dy - 1, 0],
[0, 0, dz - 1],
[dx - 1, 0, dz - 1],
[0, dy - 1, dz - 1],
[dx - 1, dy - 1, dz - 1],
];
corners = cornersIdx.map((it) => imageData.indexToWorld(it));
}
// Get rotation matrix from normal to +X (since bounds is aligned to XYZ)
const transform = vtkMatrixBuilder
.buildFromDegree()
.identity()
.rotateFromDirections(viewPlaneNormal, [1, 0, 0]);
corners.forEach((pt) => transform.apply(pt));
const transformedFocalPoint = [...focalPoint];
transform.apply(transformedFocalPoint);
const currentSlice = transformedFocalPoint[0];
// range is now maximum X distance
let minX = Infinity;
let maxX = -Infinity;
for (let i = 0; i < 8; i++) {
const x = corners[i][0];
if (x > maxX) {
maxX = x;
}
if (x < minX) {
minX = x;
}
}
return {
min: minX,
max: maxX,
current: currentSlice,
actor: volumeActor,
viewPlaneNormal,
focalPoint,
};
}
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