Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 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 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x | import { vec3 } from 'gl-matrix';
import { ActorSliceRange, Point3 } from '../types';
/**
* Given a number of frames, `deltaFrames`,
* move the `focalPoint` and camera `position` so that it moves forward/backwards
* `deltaFrames` in the camera's normal direction, and snaps to the nearest frame.
*
* @param focalPoint - The focal point to move.
* @param position - The camera position to move.
* @param sliceRange - The scroll range used to find the current
* position in the stack, as well as prevent scrolling past the extent of the volume.
* @param viewPlaneNormal - The normal direction of the camera.
* @param spacingInNormalDirection - The spacing of frames the normal direction of the camera.
* @param deltaFrames - The number of frames to jump.
*
* @returns The `newFocalPoint` and `newPosition` of the camera.
*/
export default function snapFocalPointToSlice(
focalPoint: Point3,
position: Point3,
sliceRange: ActorSliceRange,
viewPlaneNormal: Point3,
spacingInNormalDirection: number,
deltaFrames: number
): { newFocalPoint: Point3; newPosition: Point3 } {
const { min, max, current } = sliceRange;
// Get the current offset off the camera position so we can add it on at the end.
const posDiffFromFocalPoint = vec3.create();
vec3.sub(posDiffFromFocalPoint, <vec3>position, <vec3>focalPoint);
// Now we can see how many steps there are in this direction
const steps = Math.round((max - min) / spacingInNormalDirection);
// Find out current frameIndex
const fraction = (current - min) / (max - min);
const floatingStepNumber = fraction * steps;
let frameIndex = Math.round(floatingStepNumber);
// Dolly the focal point back to min slice focal point.
let newFocalPoint = <Point3>[
focalPoint[0] -
viewPlaneNormal[0] * floatingStepNumber * spacingInNormalDirection,
focalPoint[1] -
viewPlaneNormal[1] * floatingStepNumber * spacingInNormalDirection,
focalPoint[2] -
viewPlaneNormal[2] * floatingStepNumber * spacingInNormalDirection,
];
// Increment the slice number by deltaFrames.
frameIndex += deltaFrames;
// Clamp sliceNumber to volume.
Iif (frameIndex > steps) {
frameIndex = steps;
} else Iif (frameIndex < 0) {
frameIndex = 0;
}
// Dolly the focal towards to the correct frame focal point.
const newSlicePosFromMin = frameIndex * spacingInNormalDirection;
newFocalPoint = <Point3>[
newFocalPoint[0] + viewPlaneNormal[0] * newSlicePosFromMin,
newFocalPoint[1] + viewPlaneNormal[1] * newSlicePosFromMin,
newFocalPoint[2] + viewPlaneNormal[2] * newSlicePosFromMin,
];
const newPosition = <Point3>[
newFocalPoint[0] + posDiffFromFocalPoint[0],
newFocalPoint[1] + posDiffFromFocalPoint[1],
newFocalPoint[2] + posDiffFromFocalPoint[2],
];
return { newFocalPoint, newPosition };
}
|