Differential D1615 Diff 6869 binaries/data/mods/public/maps/random/rmgen/placer/noncentered/PolygonPlacer.js

Changeset View

Standalone View

binaries/data/mods/public/maps/random/rmgen/placer/noncentered/PolygonPlacer.js

				/*
				*Fills the inside of any polygon given 3 or more points - filling also works with overlapping sections
				*Algorithm: https://en.wikipedia.org/wiki/Point_in_polygon
				*/
				function PolygonPlacer(points)
				{
				this.points = points;

				this.horiLine = function(point1, point2)
				{
				const dy = point2.y - point1.y;
				if (dy != 0)
				{
				this.minx = Math.min(point1.x, point2.x);
				this.miny = Math.min(point1.y, point2.y);
				this.maxy = Math.max(point1.y, point2.y);
				this.val1 = (point2.x - point1.x) / dy;
				this.val2 = point1.x - this.val1 * point1.y;
				this.doesCross = (point) => this._cross(point);
				}
				else
				{
				lyvUnsubmitted Not Done Inline Actions Wat? lyv: Wat?
				this.doesCross = (point) => false;
				}
				}

				this.horiLine.prototype._cross = function(point)
				lyvUnsubmitted Not Done Inline Actions Why not inline this? Looks kinda out if place. lyv: Why not inline this? Looks kinda out if place.
				naniAuthorUnsubmitted Not Done Inline Actions a named function gives information for what it does nani: a named function gives information for what it does
				{
				//most probable cases
				if (point.y > this.maxy) return false;
				if (point.y <= this.miny) return false;
				//line segment side check
				return point.x >= this.val2 + this.val1 * point.y;
				}

				this.horiLine.prototype.cross = function(point)
				{
				return this.doesCross(point);
				}

				//bounding box
				const plength = this.points.length;
				const xlist = this.points.map((v) => v.x).sort((a, b) => a - b);
				const ylist = this.points.map((v) => v.y).sort((a, b) => a - b);
				this.minx = Math.floor(xlist[0]);
				this.miny = Math.floor(ylist[0]);
				this.maxx = Math.ceil(xlist[plength - 1]);
				this.maxy = Math.ceil(ylist[plength - 1]);
				//create lines and sort from min to max for this.minx
				this.lines = this.points.map((point, index, arr) => new this.horiLine(point, arr[(index + 1) % plength])).sort((a, b) => a.minx - b.minx)
				};

				PolygonPlacer.prototype.isInside = function(lines, point)
				{
				// % 2 returns wheter the number is odd or not
				return lines.filter((line) => line.cross(point)).length % 2;
				}

				PolygonPlacer.prototype.place = function(constraint)
				{
				//check every possible point
				let points = [];
				//upper right index of lines array
				let ix = 0;
				const length = this.lines.length;
				let lines = [];
				for (let x = this.minx; x < this.maxx; x++)
				{
				//only test for segments positioned to the left of x
				for (let i = ix; i < length; ++i)
				{
				if (this.lines[i].minx > x)
				{
				ix = i;
				lines = this.lines.slice(0, i);
				break;
				}
				}
				for (let y = this.miny; y < this.maxy; y++)
				{
				const point = new Vector2D(x, y);
				if (constraint.allows(point))
				{
				if (this.isInside(lines, point))
				{
				points.push(point);
				}
				}
				}
				}

				return points;
				};
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