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Function to get UV points from 3D coordinate in cubemap images
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| export interface Vector3 { | |
| x: number; | |
| y: number; | |
| z: number; | |
| } | |
| export function get3DPointFromSphere(phi: number, theta: number) { | |
| const coordinates = {x: 0, y: 0, z: 0}; | |
| coordinates.x = Math.sin(theta) * Math.cos(phi); | |
| coordinates.y = Math.sin(theta) * Math.sin(phi); | |
| coordinates.z = Math.cos(theta); | |
| return coordinates; | |
| } | |
| export function getParallelVector(coordinates: Vector3) { | |
| const maximumSegment = Math.max(Math.abs(coordinates.x), Math.abs(coordinates.y), Math.abs(coordinates.z)); | |
| return { | |
| x: coordinates.x / maximumSegment, | |
| y: coordinates.y / maximumSegment, | |
| z: coordinates.z / maximumSegment | |
| } | |
| } | |
| interface Pixels { | |
| x: number; | |
| y: number; | |
| } | |
| const directionsMapper = { | |
| RIGHT: ({ x }: Vector3) => x === 1, | |
| LEFT: ({ x }: Vector3) => x === -1, | |
| TOP: ({ y }: Vector3) => y === 1, | |
| DOWN: ({ y }: Vector3) => y === -1, | |
| FRONT: ({ z }: Vector3) => z === 1, | |
| BACK: ({ z }: Vector3) => z === -1, | |
| } | |
| const uvMapper = { | |
| RIGHT: ({ y, z }: Vector3, cubemapSize: number, tileSize: number ) => ({ | |
| xPixel: Math.ceil( ( ( z + 1 ) / 2 ) - 1 ) * cubemapSize, | |
| yPixel: Math.ceil( ( y + 1 ) / 2 ) * cubemapSize, | |
| xOffset: 2 * tileSize, | |
| yOffset: tileSize, | |
| }), | |
| LEFT: ({ y, z }: Vector3, cubemapSize: number, tileSize: number ) => ({ | |
| xPixel: Math.ceil( ( z + 1 ) / 2 ) * cubemapSize, | |
| yPixel: Math.ceil( ( y + 1 ) / 2 ) * cubemapSize, | |
| xOffset: 0, | |
| yOffset: tileSize, | |
| }), | |
| TOP: ({ x, z }: Vector3, cubemapSize: number, tileSize: number ) => ({ | |
| xPixel: Math.ceil( ( x + 1 ) / 2 ) * cubemapSize, | |
| yPixel: Math.ceil( ( ( z + 1 ) / 2 ) - 1 ) * cubemapSize, | |
| xOffset: tileSize, | |
| yOffset: 2 * tileSize, | |
| }), | |
| DOWN: ({ x, z }: Vector3, cubemapSize: number, tileSize: number ) => ({ | |
| xPixel: Math.ceil( ( x + 1 ) / 2 ) * cubemapSize, | |
| yPixel: Math.ceil( ( z + 1 ) / 2 ) * cubemapSize, | |
| xOffset: tileSize, | |
| yOffset: 0, | |
| }), | |
| FRONT: ({ x, y }: Vector3, cubemapSize: number, tileSize: number ) => ({ | |
| xPixel: Math.ceil( ( x + 1 ) / 2 ) * cubemapSize, | |
| yPixel: Math.ceil( ( y + 1 ) / 2 ) * cubemapSize, | |
| xOffset: 3 * tileSize, | |
| yOffset: tileSize, | |
| }), | |
| BACK: ({ x, y }: Vector3, cubemapSize: number, tileSize: number ) => ({ | |
| xPixel: Math.ceil( ( ( x + 1 ) / 2 ) - 1 ) * cubemapSize, | |
| yPixel: Math.ceil( ( y + 1 ) / 2 ) * cubemapSize, | |
| xOffset: 3 * tileSize, | |
| yOffset: tileSize, | |
| }), | |
| } | |
| export function getPixelsFromCoordinates( | |
| coordinate: Vector3, | |
| cubemapSize: number, | |
| cubemapTileSize: number | |
| ): Pixels { | |
| const [ direction ] = Object | |
| .entries(directionsMapper) | |
| .find(([, validator ]) => { | |
| return validator(coordinate); | |
| })!; | |
| const points = uvMapper[direction as keyof typeof uvMapper](coordinate, cubemapSize, cubemapTileSize); | |
| const pixels = { | |
| x: Math.abs(points.xPixel) + points.xOffset, | |
| y: Math.abs(points.yPixel) + points.yOffset, | |
| }; | |
| return pixels; | |
| } |
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