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Diffstat (limited to 'src/client/northstar/utils/GeometryUtil.ts')
| -rw-r--r-- | src/client/northstar/utils/GeometryUtil.ts | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/client/northstar/utils/GeometryUtil.ts b/src/client/northstar/utils/GeometryUtil.ts new file mode 100644 index 000000000..d5f3ba631 --- /dev/null +++ b/src/client/northstar/utils/GeometryUtil.ts @@ -0,0 +1,129 @@ +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 (var i = 0; i < points.length; i++) { + if (points[i].x < minX) + minX = points[i].x; + if (points[i].y < minY) + minY = points[i].y; + if (points[i].x > maxX) + maxX = points[i].x; + if (points[i].y > maxY) + maxY = points[i].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 (let v = 0; v < points.length; v++) { + x = points[v].x; + y = points[v].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<PIXIPoint>(); + + for (let v = 0; v < points.length; v++) { + x = points[v].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; + } +}
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