Files
vue-flow/packages/pathfinding-edge/src/edge/pointConversion.ts
2022-10-08 23:25:34 +02:00

96 lines
2.5 KiB
TypeScript

import type { XYPosition } from '@vue-flow/core'
const gridRatio = 10
/**
* Each bounding box is a collection of X/Y points in a graph, and we
* need to convert them to "occupied" cells in a 2D grid representation.
*
* The top most position of the grid (grid[0][0]) needs to be equivalent
* to the top most point in the graph (the graph.topLeft point).
*
* Since the top most point can have X/Y values different than zero,
* and each cell in a grid represents a 10x10 pixel area in the grid,
* there's need to be a conversion between a point in a graph to a point
* in the grid.
*
* We do this conversion by dividing a graph point X/Y values by 10, and
* "shifting" their values up or down, depending on the values of the top most
* point in the graph. The top most point in the graph will have the smallest
* values for X and Y.
*
* We avoid setting nodes in the border of the grid (x=0 or y=0), so there's
* always a "walkable" area around the grid.
*/
export const graphToGridPoint = (graphPoint: XYPosition, smallestX: number, smallestY: number): XYPosition => {
let x = graphPoint.x / gridRatio
let y = graphPoint.y / gridRatio
let referenceX = smallestX / gridRatio
let referenceY = smallestY / gridRatio
if (referenceX < 1) {
while (referenceX !== 1) {
referenceX++
x++
}
} else if (referenceX > 1) {
while (referenceX !== 1) {
referenceX--
x--
}
}
if (referenceY < 1) {
while (referenceY !== 1) {
referenceY++
y++
}
} else if (referenceY > 1) {
while (referenceY !== 1) {
referenceY--
y--
}
}
return { x, y }
}
/**
* Converts a grid point back to a graph point, using the reverse logic of
* graphToGridPoint.
*/
export const gridToGraphPoint = (gridPoint: XYPosition, smallestX: number, smallestY: number): XYPosition => {
let x = gridPoint.x * gridRatio
let y = gridPoint.y * gridRatio
let referenceX = smallestX
let referenceY = smallestY
if (referenceX < gridRatio) {
while (referenceX !== gridRatio) {
referenceX = referenceX + gridRatio
x = x - gridRatio
}
} else if (referenceX > gridRatio) {
while (referenceX !== gridRatio) {
referenceX = referenceX - gridRatio
x = x + gridRatio
}
}
if (referenceY < gridRatio) {
while (referenceY !== gridRatio) {
referenceY = referenceY + gridRatio
y = y - gridRatio
}
} else if (referenceY > gridRatio) {
while (referenceY !== gridRatio) {
referenceY = referenceY - gridRatio
y = y + gridRatio
}
}
return { x, y }
}