import { MathUtil, PIXIRectangle, PIXIPoint } from "./MathUtil"; export class GeometryUtil { public static ComputeBoundingBox(points: { x: number, y: number }[], scale = 1, padding: number = 0): PIXIRectangle { let minX: number = Number.MAX_VALUE; let minY: number = Number.MAX_VALUE; let maxX: number = Number.MIN_VALUE; let maxY: number = Number.MIN_VALUE; for (const point of points) { if (point.x < minX) { minX = point.x; } if (point.y < minY) { minY = point.y; } if (point.x > maxX) { maxX = point.x; } if (point.y > maxY) { maxY = point.y; } } return new PIXIRectangle(minX * scale - padding, minY * scale - padding, (maxX - minX) * scale + padding * 2, (maxY - minY) * scale + padding * 2); } public static RectangleOverlap(rect1: PIXIRectangle, rect2: PIXIRectangle) { let x_overlap = Math.max(0, Math.min(rect1.right, rect2.right) - Math.max(rect1.left, rect2.left)); let y_overlap = Math.max(0, Math.min(rect1.bottom, rect2.bottom) - Math.max(rect1.top, rect2.top)); return x_overlap * y_overlap; } public static RotatePoints(center: { x: number, y: number }, points: { x: number, y: number }[], angle: number): PIXIPoint[] { const rotate = (cx: number, cy: number, x: number, y: number, angle: number) => { const radians = angle, cos = Math.cos(radians), sin = Math.sin(radians), nx = (cos * (x - cx)) + (sin * (y - cy)) + cx, ny = (cos * (y - cy)) - (sin * (x - cx)) + cy; return new PIXIPoint(nx, ny); }; return points.map(p => rotate(center.x, center.y, p.x, p.y, angle)); } public static LineByLeastSquares(points: { x: number, y: number }[]): PIXIPoint[] { let sum_x: number = 0; let sum_y: number = 0; let sum_xy: number = 0; let sum_xx: number = 0; let count: number = 0; let x: number = 0; let y: number = 0; if (points.length === 0) { return []; } for (const point of points) { x = point.x; y = point.y; sum_x += x; sum_y += y; sum_xx += x * x; sum_xy += x * y; count++; } let m = (count * sum_xy - sum_x * sum_y) / (count * sum_xx - sum_x * sum_x); let b = (sum_y / count) - (m * sum_x) / count; let result: PIXIPoint[] = new Array(); for (const point of points) { x = point.x; y = x * m + b; result.push(new PIXIPoint(x, y)); } return result; } // public static PointInsidePolygon(vs:Point[], x:number, y:number):boolean { // // ray-casting algorithm based on // // http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html // var inside = false; // for (var i = 0, j = vs.length - 1; i < vs.length; j = i++) { // var xi = vs[i].x, yi = vs[i].y; // var xj = vs[j].x, yj = vs[j].y; // var intersect = ((yi > y) !== (yj > y)) && (x < (xj - xi) * (y - yi) / (yj - yi) + xi); // if (intersect) // inside = !inside; // } // return inside; // }; public static IntersectLines(x1: number, y1: number, x2: number, y2: number, x3: number, y3: number, x4: number, y4: number): boolean { let a1: number, a2: number, b1: number, b2: number, c1: number, c2: number; let r1: number, r2: number, r3: number, r4: number; let denom: number, offset: number, num: number; a1 = y2 - y1; b1 = x1 - x2; c1 = (x2 * y1) - (x1 * y2); r3 = ((a1 * x3) + (b1 * y3) + c1); r4 = ((a1 * x4) + (b1 * y4) + c1); if ((r3 !== 0) && (r4 !== 0) && (MathUtil.Sign(r3) === MathUtil.Sign(r4))) { return false; } a2 = y4 - y3; b2 = x3 - x4; c2 = (x4 * y3) - (x3 * y4); r1 = (a2 * x1) + (b2 * y1) + c2; r2 = (a2 * x2) + (b2 * y2) + c2; if ((r1 !== 0) && (r2 !== 0) && (MathUtil.Sign(r1) === MathUtil.Sign(r2))) { return false; } denom = (a1 * b2) - (a2 * b1); if (denom === 0) { return false; } return true; } }