PixiJS: Bounds.ts

import { Rectangle } from '@pixi/math';

import type { IPointData, Transform, Matrix } from '@pixi/math';

/**
 * 'Builder' pattern for bounds rectangles.
 *
 * This could be called an Axis-Aligned Bounding Box.
 * It is not an actual shape. It is a mutable thing; no 'EMPTY' or those kind of problems.
 * @memberof PIXI
 */
export class Bounds
{
    /** @default Infinity */
    public minX: number;

    /** @default Infinity */
    public minY: number;

    /** @default -Infinity */
    public maxX: number;

    /** @default -Infinity */
    public maxY: number;

    public rect: Rectangle;

    /**
     * It is updated to _boundsID of corresponding object to keep bounds in sync with content.
     * Updated from outside, thus public modifier.
     */
    public updateID: number;

    constructor()
    {
        this.minX = Infinity;
        this.minY = Infinity;
        this.maxX = -Infinity;
        this.maxY = -Infinity;

        this.rect = null;
        this.updateID = -1;
    }

    /**
     * Checks if bounds are empty.
     * @returns - True if empty.
     */
    isEmpty(): boolean
    {
        return this.minX > this.maxX || this.minY > this.maxY;
    }

    /** Clears the bounds and resets. */
    clear(): void
    {
        this.minX = Infinity;
        this.minY = Infinity;
        this.maxX = -Infinity;
        this.maxY = -Infinity;
    }

    /**
     * Can return Rectangle.EMPTY constant, either construct new rectangle, either use your rectangle
     * It is not guaranteed that it will return tempRect
     * @param rect - Temporary object will be used if AABB is not empty
     * @returns - A rectangle of the bounds
     */
    getRectangle(rect?: Rectangle): Rectangle
    {
        if (this.minX > this.maxX || this.minY > this.maxY)
        {
            return Rectangle.EMPTY;
        }

        rect = rect || new Rectangle(0, 0, 1, 1);

        rect.x = this.minX;
        rect.y = this.minY;
        rect.width = this.maxX - this.minX;
        rect.height = this.maxY - this.minY;

        return rect;
    }

    /**
     * This function should be inlined when its possible.
     * @param point - The point to add.
     */
    addPoint(point: IPointData): void
    {
        this.minX = Math.min(this.minX, point.x);
        this.maxX = Math.max(this.maxX, point.x);
        this.minY = Math.min(this.minY, point.y);
        this.maxY = Math.max(this.maxY, point.y);
    }

    /**
     * Adds a point, after transformed. This should be inlined when its possible.
     * @param matrix
     * @param point
     */
    addPointMatrix(matrix: Matrix, point: IPointData): void
    {
        const { a, b, c, d, tx, ty } = matrix;

        const x = (a * point.x) + (c * point.y) + tx;
        const y = (b * point.x) + (d * point.y) + ty;

        this.minX = Math.min(this.minX, x);
        this.maxX = Math.max(this.maxX, x);
        this.minY = Math.min(this.minY, y);
        this.maxY = Math.max(this.maxY, y);
    }

    /**
     * Adds a quad, not transformed
     * @param vertices - The verts to add.
     */
    addQuad(vertices: Float32Array): void
    {
        let minX = this.minX;
        let minY = this.minY;
        let maxX = this.maxX;
        let maxY = this.maxY;

        let x = vertices[0];
        let y = vertices[1];

        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        x = vertices[2];
        y = vertices[3];
        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        x = vertices[4];
        y = vertices[5];
        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        x = vertices[6];
        y = vertices[7];
        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        this.minX = minX;
        this.minY = minY;
        this.maxX = maxX;
        this.maxY = maxY;
    }

    /**
     * Adds sprite frame, transformed.
     * @param transform - transform to apply
     * @param x0 - left X of frame
     * @param y0 - top Y of frame
     * @param x1 - right X of frame
     * @param y1 - bottom Y of frame
     */
    addFrame(transform: Transform, x0: number, y0: number, x1: number, y1: number): void
    {
        this.addFrameMatrix(transform.worldTransform, x0, y0, x1, y1);
    }

    /**
     * Adds sprite frame, multiplied by matrix
     * @param matrix - matrix to apply
     * @param x0 - left X of frame
     * @param y0 - top Y of frame
     * @param x1 - right X of frame
     * @param y1 - bottom Y of frame
     */
    addFrameMatrix(matrix: Matrix, x0: number, y0: number, x1: number, y1: number): void
    {
        const a = matrix.a;
        const b = matrix.b;
        const c = matrix.c;
        const d = matrix.d;
        const tx = matrix.tx;
        const ty = matrix.ty;

        let minX = this.minX;
        let minY = this.minY;
        let maxX = this.maxX;
        let maxY = this.maxY;

        let x = (a * x0) + (c * y0) + tx;
        let y = (b * x0) + (d * y0) + ty;

        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        x = (a * x1) + (c * y0) + tx;
        y = (b * x1) + (d * y0) + ty;
        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        x = (a * x0) + (c * y1) + tx;
        y = (b * x0) + (d * y1) + ty;
        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        x = (a * x1) + (c * y1) + tx;
        y = (b * x1) + (d * y1) + ty;
        minX = x < minX ? x : minX;
        minY = y < minY ? y : minY;
        maxX = x > maxX ? x : maxX;
        maxY = y > maxY ? y : maxY;

        this.minX = minX;
        this.minY = minY;
        this.maxX = maxX;
        this.maxY = maxY;
    }

    /**
     * Adds screen vertices from array
     * @param vertexData - calculated vertices
     * @param beginOffset - begin offset
     * @param endOffset - end offset, excluded
     */
    addVertexData(vertexData: Float32Array, beginOffset: number, endOffset: number): void
    {
        let minX = this.minX;
        let minY = this.minY;
        let maxX = this.maxX;
        let maxY = this.maxY;

        for (let i = beginOffset; i < endOffset; i += 2)
        {
            const x = vertexData[i];
            const y = vertexData[i + 1];

            minX = x < minX ? x : minX;
            minY = y < minY ? y : minY;
            maxX = x > maxX ? x : maxX;
            maxY = y > maxY ? y : maxY;
        }

        this.minX = minX;
        this.minY = minY;
        this.maxX = maxX;
        this.maxY = maxY;
    }

    /**
     * Add an array of mesh vertices
     * @param transform - mesh transform
     * @param vertices - mesh coordinates in array
     * @param beginOffset - begin offset
     * @param endOffset - end offset, excluded
     */
    addVertices(transform: Transform, vertices: Float32Array, beginOffset: number, endOffset: number): void
    {
        this.addVerticesMatrix(transform.worldTransform, vertices, beginOffset, endOffset);
    }

    /**
     * Add an array of mesh vertices.
     * @param matrix - mesh matrix
     * @param vertices - mesh coordinates in array
     * @param beginOffset - begin offset
     * @param endOffset - end offset, excluded
     * @param padX - x padding
     * @param padY - y padding
     */
    addVerticesMatrix(matrix: Matrix, vertices: Float32Array, beginOffset: number,
        endOffset: number, padX = 0, padY = padX): void
    {
        const a = matrix.a;
        const b = matrix.b;
        const c = matrix.c;
        const d = matrix.d;
        const tx = matrix.tx;
        const ty = matrix.ty;

        let minX = this.minX;
        let minY = this.minY;
        let maxX = this.maxX;
        let maxY = this.maxY;

        for (let i = beginOffset; i < endOffset; i += 2)
        {
            const rawX = vertices[i];
            const rawY = vertices[i + 1];
            const x = (a * rawX) + (c * rawY) + tx;
            const y = (d * rawY) + (b * rawX) + ty;

            minX = Math.min(minX, x - padX);
            maxX = Math.max(maxX, x + padX);
            minY = Math.min(minY, y - padY);
            maxY = Math.max(maxY, y + padY);
        }

        this.minX = minX;
        this.minY = minY;
        this.maxX = maxX;
        this.maxY = maxY;
    }

    /**
     * Adds other {@link Bounds}.
     * @param bounds - The Bounds to be added
     */
    addBounds(bounds: Bounds): void
    {
        const minX = this.minX;
        const minY = this.minY;
        const maxX = this.maxX;
        const maxY = this.maxY;

        this.minX = bounds.minX < minX ? bounds.minX : minX;
        this.minY = bounds.minY < minY ? bounds.minY : minY;
        this.maxX = bounds.maxX > maxX ? bounds.maxX : maxX;
        this.maxY = bounds.maxY > maxY ? bounds.maxY : maxY;
    }

    /**
     * Adds other Bounds, masked with Bounds.
     * @param bounds - The Bounds to be added.
     * @param mask - TODO
     */
    addBoundsMask(bounds: Bounds, mask: Bounds): void
    {
        const _minX = bounds.minX > mask.minX ? bounds.minX : mask.minX;
        const _minY = bounds.minY > mask.minY ? bounds.minY : mask.minY;
        const _maxX = bounds.maxX < mask.maxX ? bounds.maxX : mask.maxX;
        const _maxY = bounds.maxY < mask.maxY ? bounds.maxY : mask.maxY;

        if (_minX <= _maxX && _minY <= _maxY)
        {
            const minX = this.minX;
            const minY = this.minY;
            const maxX = this.maxX;
            const maxY = this.maxY;

            this.minX = _minX < minX ? _minX : minX;
            this.minY = _minY < minY ? _minY : minY;
            this.maxX = _maxX > maxX ? _maxX : maxX;
            this.maxY = _maxY > maxY ? _maxY : maxY;
        }
    }

    /**
     * Adds other Bounds, multiplied by matrix. Bounds shouldn't be empty.
     * @param bounds - other bounds
     * @param matrix - multiplicator
     */
    addBoundsMatrix(bounds: Bounds, matrix: Matrix): void
    {
        this.addFrameMatrix(matrix, bounds.minX, bounds.minY, bounds.maxX, bounds.maxY);
    }

    /**
     * Adds other Bounds, masked with Rectangle.
     * @param bounds - TODO
     * @param area - TODO
     */
    addBoundsArea(bounds: Bounds, area: Rectangle): void
    {
        const _minX = bounds.minX > area.x ? bounds.minX : area.x;
        const _minY = bounds.minY > area.y ? bounds.minY : area.y;
        const _maxX = bounds.maxX < area.x + area.width ? bounds.maxX : (area.x + area.width);
        const _maxY = bounds.maxY < area.y + area.height ? bounds.maxY : (area.y + area.height);

        if (_minX <= _maxX && _minY <= _maxY)
        {
            const minX = this.minX;
            const minY = this.minY;
            const maxX = this.maxX;
            const maxY = this.maxY;

            this.minX = _minX < minX ? _minX : minX;
            this.minY = _minY < minY ? _minY : minY;
            this.maxX = _maxX > maxX ? _maxX : maxX;
            this.maxY = _maxY > maxY ? _maxY : maxY;
        }
    }

    /**
     * Pads bounds object, making it grow in all directions.
     * If paddingY is omitted, both paddingX and paddingY will be set to paddingX.
     * @param paddingX - The horizontal padding amount.
     * @param paddingY - The vertical padding amount.
     */
    pad(paddingX = 0, paddingY = paddingX): void
    {
        if (!this.isEmpty())
        {
            this.minX -= paddingX;
            this.maxX += paddingX;
            this.minY -= paddingY;
            this.maxY += paddingY;
        }
    }

    /**
     * Adds padded frame. (x0, y0) should be strictly less than (x1, y1)
     * @param x0 - left X of frame
     * @param y0 - top Y of frame
     * @param x1 - right X of frame
     * @param y1 - bottom Y of frame
     * @param padX - padding X
     * @param padY - padding Y
     */
    addFramePad(x0: number, y0: number, x1: number, y1: number, padX: number, padY: number): void
    {
        x0 -= padX;
        y0 -= padY;
        x1 += padX;
        y1 += padY;

        this.minX = this.minX < x0 ? this.minX : x0;
        this.maxX = this.maxX > x1 ? this.maxX : x1;
        this.minY = this.minY < y0 ? this.minY : y0;
        this.maxY = this.maxY > y1 ? this.maxY : y1;
    }
}