refactor: draw coastline

This commit is contained in:
max 2022-07-16 15:14:13 +03:00
parent 1888b04d54
commit 4833a8ab35
8 changed files with 422 additions and 371 deletions

View file

@ -0,0 +1,50 @@
import * as d3 from "d3";
import {simplify} from "scripts/simplify";
import {clipPoly} from "utils/lineUtils";
import {round} from "utils/stringUtils";
export function drawCoastline(vertices: IGraphVertices, features: TPackFeatures) {
const landMask = defs.select("#land");
const waterMask = defs.select("#water");
const lineGen = d3.line().curve(d3.curveBasisClosed);
const SIMPLIFICATION_TOLERANCE = 0.5; // px
for (const feature of features) {
if (!feature) continue;
const points = clipPoly(feature.vertices.map(vertex => vertices.p[vertex]));
const simplifiedPoints = simplify(points, SIMPLIFICATION_TOLERANCE);
const path = round(lineGen(simplifiedPoints)!);
landMask
.append("path")
.attr("d", path)
.attr("fill", "black")
.attr("id", "land_" + feature.i);
if (feature.type === "lake") {
lakes
.select("#freshwater")
.append("path")
.attr("d", path)
.attr("id", "lake_" + feature.i)
.attr("data-f", feature.i);
} else {
waterMask
.append("path")
.attr("d", path)
.attr("fill", "black")
.attr("id", "water_" + feature.i);
const group = feature.group === "lake_island" ? "lake_island" : "sea_island";
coastline
.select("#" + group)
.append("path")
.attr("d", path)
.attr("id", "island_" + feature.i)
.attr("data-f", feature.i);
}
}
}

View file

@ -3,6 +3,7 @@ import {TIME} from "config/logging";
import {drawBiomes} from "./drawBiomes";
import {drawBorders} from "./drawBorders";
import {drawCells} from "./drawCells";
import {drawCoastline} from "./drawCoastline";
import {drawCoordinates} from "./drawCoordinates";
import {drawCultures} from "./drawCultures";
import {drawEmblems} from "./drawEmblems";
@ -23,6 +24,7 @@ const layerRenderersMap = {
biomes: drawBiomes,
borders: drawBorders,
cells: drawCells,
coastline: drawCoastline,
coordinates: drawCoordinates,
cultures: drawCultures,
emblems: drawEmblems,

View file

@ -1,141 +0,0 @@
import * as d3 from "d3";
import {ERROR, TIME} from "config/logging";
import {clipPoly} from "utils/lineUtils";
import {round} from "utils/stringUtils";
import {Ruler} from "modules/measurers";
// Detect and draw the coastline
export function drawCoastline(pack) {
TIME && console.time("drawCoastline");
const {cells, vertices, features} = pack;
const n = cells.i.length;
const used = new Uint8Array(features.length); // store connected features
const largestLand = d3.scan(
features.map(f => (f.land ? f.cells : 0)),
(a, b) => b - a
);
const landMask = defs.select("#land");
const waterMask = defs.select("#water");
const lineGen = d3.line().curve(d3.curveBasisClosed);
for (const i of cells.i) {
const startFromEdge = !i && cells.h[i] >= 20;
if (!startFromEdge && cells.t[i] !== -1 && cells.t[i] !== 1) continue; // non-edge cell
const f = cells.f[i];
if (used[f]) continue; // already connected
if (features[f].type === "ocean") continue; // ocean cell
const type = features[f].type === "lake" ? 1 : -1; // type value to search for
const start = findStart(i, type);
if (start === -1) continue; // cannot start here
let vchain = connectVertices(start, type);
if (features[f].type === "lake") relax(vchain, 1.2);
used[f] = 1;
let points = clipPoly(vchain.map(v => vertices.p[v]));
const area = d3.polygonArea(points); // area with lakes/islands
if (area > 0 && features[f].type === "lake") {
points = points.reverse();
vchain = vchain.reverse();
}
features[f].area = Math.abs(area);
features[f].vertices = vchain;
const path = round(lineGen(points));
if (features[f].type === "lake") {
landMask
.append("path")
.attr("d", path)
.attr("fill", "black")
.attr("id", "land_" + f);
// waterMask.append("path").attr("d", path).attr("fill", "white").attr("id", "water_"+id); // uncomment to show over lakes
lakes
.select("#freshwater")
.append("path")
.attr("d", path)
.attr("id", "lake_" + f)
.attr("data-f", f); // draw the lake
} else {
landMask
.append("path")
.attr("d", path)
.attr("fill", "white")
.attr("id", "land_" + f);
waterMask
.append("path")
.attr("d", path)
.attr("fill", "black")
.attr("id", "water_" + f);
const g = features[f].group === "lake_island" ? "lake_island" : "sea_island";
coastline
.select("#" + g)
.append("path")
.attr("d", path)
.attr("id", "island_" + f)
.attr("data-f", f); // draw the coastline
}
// draw ruler to cover the biggest land piece
if (f === largestLand) {
const from = points[d3.scan(points, (a, b) => a[0] - b[0])];
const to = points[d3.scan(points, (a, b) => b[0] - a[0])];
rulers.create(Ruler, [from, to]);
}
}
// find cell vertex to start path detection
function findStart(i, t) {
if (t === -1 && cells.b[i]) return cells.v[i].find(v => vertices.c[v].some(c => c >= n)); // map border cell
const filtered = cells.c[i].filter(c => cells.t[c] === t);
const index = cells.c[i].indexOf(d3.min(filtered));
return index === -1 ? index : cells.v[i][index];
}
// connect vertices to chain
function connectVertices(start, t) {
const chain = []; // vertices chain to form a path
for (let i = 0, current = start; i === 0 || (current !== start && i < 50000); i++) {
const prev = chain[chain.length - 1]; // previous vertex in chain
chain.push(current); // add current vertex to sequence
const c = vertices.c[current]; // cells adjacent to vertex
const v = vertices.v[current]; // neighboring vertices
const c0 = c[0] >= n || cells.t[c[0]] === t;
const c1 = c[1] >= n || cells.t[c[1]] === t;
const c2 = c[2] >= n || cells.t[c[2]] === t;
if (v[0] !== prev && c0 !== c1) current = v[0];
else if (v[1] !== prev && c1 !== c2) current = v[1];
else if (v[2] !== prev && c0 !== c2) current = v[2];
if (current === chain[chain.length - 1]) {
ERROR && console.error("Next vertex is not found");
break;
}
}
return chain;
}
// move vertices that are too close to already added ones
function relax(vchain, r) {
const p = vertices.p,
tree = d3.quadtree();
for (let i = 0; i < vchain.length; i++) {
const v = vchain[i];
let [x, y] = [p[v][0], p[v][1]];
if (i && vchain[i + 1] && tree.find(x, y, r) !== undefined) {
const v1 = vchain[i - 1];
const v2 = vchain[i + 1];
const [x1, y1] = [p[v1][0], p[v1][1]];
const [x2, y2] = [p[v2][0], p[v2][1]];
[x, y] = [(x1 + x2) / 2, (y1 + y2) / 2];
p[v] = [x, y];
}
tree.add([x, y]);
}
}
TIME && console.timeEnd("drawCoastline");
}

View file

@ -1,14 +1,11 @@
import * as d3 from "d3";
import {MIN_LAND_HEIGHT, DISTANCE_FIELD} from "config/generation";
import {ERROR, TIME} from "config/logging";
import {TIME} from "config/logging";
import {INT8_MAX} from "constants";
// @ts-expect-error js module
import {aleaPRNG} from "scripts/aleaPRNG";
import {createTypedArray} from "utils/arrayUtils";
import {dist2, pick} from "utils/functionUtils";
import {getColors} from "utils/colorUtils";
import {clipPoly} from "utils/lineUtils";
import {dist2} from "utils/functionUtils";
import {getFeatureVertices} from "scripts/connectVertices";
const {UNMARKED, LAND_COAST, WATER_COAST, LANDLOCKED, DEEPER_WATER} = DISTANCE_FIELD;
@ -81,8 +78,8 @@ export function markupPackFeatures(
) {
TIME && console.time("markupPackFeatures");
const packCellsNumber = cells.h.length;
const gridCellsNumber = grid.cells.h.length;
const packCellsNumber = cells.c.length;
const features: TPackFeatures = [0];
const featureIds = new Uint16Array(packCellsNumber); // ids of features, starts from 1
@ -99,73 +96,6 @@ export function markupPackFeatures(
harbor[cellId] = waterCells.length;
};
const OCEAN_MIN_SIZE = gridCellsNumber / 25;
const SEA_MIN_SIZE = gridCellsNumber / 1000;
const CONTINENT_MIN_SIZE = gridCellsNumber / 10;
const ISLAND_MIN_SIZE = gridCellsNumber / 1000;
function defineOceanGroup(cellsNumber: number) {
if (cellsNumber > OCEAN_MIN_SIZE) return "ocean";
if (cellsNumber > SEA_MIN_SIZE) return "sea";
return "gulf";
}
function defineIslandGroup(firstCell: number, cellsNumber: number) {
const prevCellFeature = features[featureIds[firstCell - 1]];
if (prevCellFeature && prevCellFeature.type === "lake") return "lake_island";
if (cellsNumber > CONTINENT_MIN_SIZE) return "continent";
if (cellsNumber > ISLAND_MIN_SIZE) return "island";
return "isle";
}
function addIsland(featureId: number, border: boolean, firstCell: number, cells: number, vertices: number[]) {
const group = defineIslandGroup(firstCell, cells);
const feature: IPackFeatureIsland = {
i: featureId,
type: "island",
group,
land: true,
border,
cells,
firstCell,
vertices
};
features.push(feature);
}
function addOcean(featureId: number, firstCell: number, cells: number, vertices: number[]) {
const group = defineOceanGroup(cells);
const feature: IPackFeatureOcean = {
i: featureId,
type: "ocean",
group,
land: false,
border: false,
cells,
firstCell,
vertices
};
features.push(feature);
}
function addLake(featureId: number, firstCell: number, cells: number, vertices: number[]) {
const group = "freshwater"; // temp, to be defined later
const name = ""; // temp, to be defined later
const feature: IPackFeatureLake = {
i: featureId,
type: "lake",
group,
name,
land: false,
border: false,
cells,
firstCell,
vertices
};
features.push(feature);
}
const queue = [0];
for (let featureId = 1; queue[0] !== -1; featureId++) {
const firstCell = queue[0];
@ -175,8 +105,6 @@ export function markupPackFeatures(
let border = false; // true if feature touches map border
let cellNumber = 1; // count cells in a feature
const featureCells = [firstCell];
while (queue.length) {
const cellId = queue.pop()!;
if (cells.b[cellId]) border = true;
@ -199,59 +127,30 @@ export function markupPackFeatures(
queue.push(neighborId);
featureIds[neighborId] = featureId;
cellNumber++;
featureCells.push(neighborId);
}
}
}
cells.v[firstCell]
.map(v => vertices.p[v])
.forEach(([x, y]) => {
d3.select("#debug").append("circle").attr("cx", x).attr("cy", y).attr("r", 0.2).attr("fill", "yellow");
});
const featureVertices = getFeatureVertices({firstCell, vertices, cells, featureIds, featureId});
const startingCell = findStartingCell({firstCell, featureIds, featureId, vertices, cells, packCellsNumber});
// let points = clipPoly(vchain.map(v => vertices.p[v]));
// const area = d3.polygonArea(points); // area with lakes/islands
// if (area > 0 && features[f].type === "lake") {
// points = points.reverse();
// vchain = vchain.reverse();
// }
const isOuterCell = (cellId: number) => cellId >= packCellsNumber;
const startingVertex = findStartingVertex({
startingCell,
const feature = addFeature({
features,
firstCell,
land,
border,
featureIds,
featureVertices,
featureId,
vertices,
cells,
isOuterCell
cellNumber,
gridCellsNumber
});
if (startingVertex === undefined || startingVertex > vertices.p.length) {
throw new Error("Starting vertex not found");
}
const color = featureId === 1 ? "#2274cc" : getColors(12)[featureId % 12];
const paths: TPoint[][] = featureCells.map(i => cells.v[i].map(v => vertices.p[v]));
d3.select("#cells")
.append("path")
.attr("d", "M" + paths.join("M"))
.attr("fill", color)
.attr("fill-opacity", 0.5)
.attr("stroke", "#333")
.attr("stroke-width", "0.1");
const [x, y] = cells.p[firstCell];
d3.select("#debug").append("circle").attr("cx", x).attr("cy", y).attr("r", 1).attr("fill", "blue");
const [cx, cy] = vertices.p[startingVertex];
d3.select("#debug").append("circle").attr("cx", cx).attr("cy", cy).attr("r", 1.5).attr("fill", "red");
const featureVertices = connectVertices({vertices, startingVertex, featureIds, featureId});
const lineGen = d3.line();
const points = clipPoly(featureVertices.map(v => vertices.p[v]));
const path = lineGen(points)!;
d3.select("#sea_island").attr("stroke", "black").append("path").attr("d", path);
if (land) addIsland(featureId, border, firstCell, cellNumber, []);
else if (border) addOcean(featureId, firstCell, cellNumber, []);
else addLake(featureId, firstCell, cellNumber, []);
features.push(feature);
queue[0] = featureIds.findIndex(f => f === UNMARKED); // find unmarked cell
}
@ -264,6 +163,97 @@ export function markupPackFeatures(
return {features, featureIds, distanceField: dfLandMarked, haven, harbor};
}
function addFeature({
features,
firstCell,
land,
border,
featureVertices,
featureId,
cellNumber,
gridCellsNumber
}: {
features: TPackFeatures;
firstCell: number;
land: boolean;
border: boolean;
featureVertices: number[];
featureId: number;
cellNumber: number;
gridCellsNumber: number;
}) {
const OCEAN_MIN_SIZE = gridCellsNumber / 25;
const SEA_MIN_SIZE = gridCellsNumber / 1000;
const CONTINENT_MIN_SIZE = gridCellsNumber / 10;
const ISLAND_MIN_SIZE = gridCellsNumber / 1000;
if (land) return addIsland();
if (border) return addOcean();
return addLake();
function addIsland() {
const group = defineIslandGroup();
const feature: IPackFeatureIsland = {
i: featureId,
type: "island",
group,
land: true,
border,
cells: cellNumber,
firstCell,
vertices: featureVertices
};
return feature;
}
function addOcean() {
const group = defineOceanGroup();
const feature: IPackFeatureOcean = {
i: featureId,
type: "ocean",
group,
land: false,
border: false,
cells: cellNumber,
firstCell,
vertices: featureVertices
};
return feature;
}
function addLake() {
const group = "freshwater"; // temp, to be defined later
const name = ""; // temp, to be defined later
const feature: IPackFeatureLake = {
i: featureId,
type: "lake",
group,
name,
land: false,
border: false,
cells: cellNumber,
firstCell,
vertices: featureVertices
};
return feature;
}
function defineOceanGroup() {
if (cellNumber > OCEAN_MIN_SIZE) return "ocean";
if (cellNumber > SEA_MIN_SIZE) return "sea";
return "gulf";
}
function defineIslandGroup() {
const prevFeature = features.at(-1);
if (prevFeature && prevFeature.type === "lake") return "lake_island";
if (cellNumber > CONTINENT_MIN_SIZE) return "continent";
if (cellNumber > ISLAND_MIN_SIZE) return "island";
return "isle";
}
}
// calculate distance to coast for every cell
function markup({
distanceField,
@ -294,111 +284,3 @@ function markup({
return distanceField;
}
function findStartingCell({
firstCell,
featureIds,
featureId,
vertices,
cells,
packCellsNumber
}: {
firstCell: number;
featureIds: Uint16Array;
featureId: number;
vertices: IGraphVertices;
cells: Pick<IPack["cells"], "c" | "v">;
packCellsNumber: number;
}) {
const bordersOtherFeature = cells.c[firstCell].some(neighbor => featureIds[neighbor] !== featureId);
if (bordersOtherFeature) return firstCell;
const neibCells = cells.c[firstCell].sort((a, b) => a - b);
for (const neibCell of neibCells) {
const cellVertices = cells.v[neibCell];
const edgingVertex = cellVertices.findIndex(vertex => vertices.c[vertex].some(cellId => cellId >= packCellsNumber));
if (edgingVertex !== -1) {
const engingCell = cells.c[neibCell];
return engingCell[edgingVertex];
}
}
throw new Error(`Markup: firstCell ${firstCell} of feature ${featureId} has no neighbors of other features`);
}
function findStartingVertex({
startingCell,
border,
featureIds,
featureId,
vertices,
cells,
isOuterCell
}: {
startingCell: number;
border: boolean;
featureIds: Uint16Array;
featureId: number;
vertices: IGraphVertices;
cells: Pick<IPack["cells"], "c" | "v">;
isOuterCell: (cellId: number) => boolean;
}) {
const neibCells = cells.c[startingCell];
const cellVertices = cells.v[startingCell];
if (border) {
const externalVertex = cellVertices.find(vertex => {
const [x, y] = vertices.p[vertex];
if (x < 0 || y < 0) return true;
return vertices.c[vertex].some(isOuterCell);
});
if (externalVertex !== undefined) return externalVertex;
}
const otherFeatureNeibs = neibCells.filter(neibCell => featureIds[neibCell] !== featureId);
if (!otherFeatureNeibs.length) {
throw new Error(`Markup: firstCell ${startingCell} of feature ${featureId} has no neighbors of other features`);
}
const index = neibCells.indexOf(d3.min(otherFeatureNeibs)!);
return cellVertices[index];
}
const CONNECT_VERTICES_MAX_ITERATIONS = 50000;
// connect vertices around feature
function connectVertices({
vertices,
startingVertex,
featureIds,
featureId
}: {
vertices: IGraphVertices;
startingVertex: number;
featureIds: Uint16Array;
featureId: number;
}) {
const ofSameType = (cellId: number) => featureIds[cellId] === featureId;
const chain: number[] = []; // vertices chain to form a path
let next = startingVertex;
for (let i = 0; i === 0 || (next !== startingVertex && i < CONNECT_VERTICES_MAX_ITERATIONS); i++) {
const previous = chain.at(-1);
const current = next;
chain.push(current);
const [c1, c2, c3] = vertices.c[current].map(ofSameType);
const [v1, v2, v3] = vertices.v[current];
if (v1 !== previous && c1 !== c2) next = v1;
else if (v2 !== previous && c2 !== c3) next = v2;
else if (v3 !== previous && c1 !== c3) next = v3;
if (next === current) {
ERROR && console.error("Next vertex is not found");
break;
}
}
return chain;
}

View file

@ -0,0 +1,150 @@
import * as d3 from "d3";
import {ERROR} from "config/logging";
import {clipPoly} from "utils/lineUtils";
export function getFeatureVertices({
firstCell,
vertices,
cells,
featureIds,
featureId
}: {
firstCell: number;
vertices: IGraphVertices;
cells: Pick<IPack["cells"], "c" | "v">;
featureIds: Uint16Array;
featureId: number;
}) {
const packCellsNumber = cells.c.length;
const startingCell = findStartingCell({firstCell, featureIds, featureId, vertices, cells, packCellsNumber});
const startingVertex = findStartingVertex({startingCell, featureIds, featureId, vertices, cells, packCellsNumber});
const featureVertices = connectVertices({vertices, startingVertex, featureIds, featureId});
// temp: draw feature vertices
cells.v[firstCell]
.map(v => vertices.p[v])
.forEach(([x, y]) => {
d3.select("#debug").append("circle").attr("cx", x).attr("cy", y).attr("r", 0.2).attr("fill", "yellow");
});
const [cx, cy] = vertices.p[startingVertex];
d3.select("#debug").append("circle").attr("cx", cx).attr("cy", cy).attr("r", 1.5).attr("fill", "red");
const lineGen = d3.line();
const points = clipPoly(featureVertices.map(v => vertices.p[v]));
const path = lineGen(points)!;
d3.select("#debug")
.attr("fill", "none")
.attr("stroke", "black")
.attr("stroke-width", 0.1)
.append("path")
.attr("d", path);
return featureVertices;
}
function findStartingCell({
firstCell,
featureIds,
featureId,
vertices,
cells,
packCellsNumber
}: {
firstCell: number;
featureIds: Uint16Array;
featureId: number;
vertices: IGraphVertices;
cells: Pick<IPack["cells"], "c" | "v">;
packCellsNumber: number;
}) {
const bordersOtherFeature = cells.c[firstCell].some(neighbor => featureIds[neighbor] !== featureId);
if (bordersOtherFeature) return firstCell;
const neibCells = cells.c[firstCell].sort((a, b) => a - b);
for (const neibCell of neibCells) {
const cellVertices = cells.v[neibCell];
const edgingVertex = cellVertices.findIndex(vertex => vertices.c[vertex].some(cellId => cellId >= packCellsNumber));
if (edgingVertex !== -1) {
const engingCell = cells.c[neibCell];
return engingCell[edgingVertex];
}
}
throw new Error(`Markup: firstCell ${firstCell} of feature ${featureId} has no neighbors of other features`);
}
function findStartingVertex({
startingCell,
featureIds,
featureId,
vertices,
cells,
packCellsNumber
}: {
startingCell: number;
featureIds: Uint16Array;
featureId: number;
vertices: IGraphVertices;
cells: Pick<IPack["cells"], "c" | "v">;
packCellsNumber: number;
}) {
const neibCells = cells.c[startingCell];
const cellVertices = cells.v[startingCell];
const externalVertex = cellVertices.find(vertex => {
const [x, y] = vertices.p[vertex];
if (x < 0 || y < 0) return true;
return vertices.c[vertex].some((cellId: number) => cellId >= packCellsNumber);
});
if (externalVertex !== undefined) return externalVertex;
const otherFeatureNeibs = neibCells.filter(neibCell => featureIds[neibCell] !== featureId);
if (!otherFeatureNeibs.length) {
throw new Error(`Markup: firstCell ${startingCell} of feature ${featureId} has no neighbors of other features`);
}
const index = neibCells.indexOf(d3.min(otherFeatureNeibs)!);
return cellVertices[index];
}
const CONNECT_VERTICES_MAX_ITERATIONS = 50000;
// connect vertices around feature
function connectVertices({
vertices,
startingVertex,
featureIds,
featureId
}: {
vertices: IGraphVertices;
startingVertex: number;
featureIds: Uint16Array;
featureId: number;
}) {
const ofSameType = (cellId: number) => featureIds[cellId] === featureId;
const chain: number[] = []; // vertices chain to form a path
let next = startingVertex;
for (let i = 0; i === 0 || (next !== startingVertex && i < CONNECT_VERTICES_MAX_ITERATIONS); i++) {
const previous = chain.at(-1);
const current = next;
chain.push(current);
const [c1, c2, c3] = vertices.c[current].map(ofSameType);
const [v1, v2, v3] = vertices.v[current];
if (v1 !== previous && c1 !== c2) next = v1;
else if (v2 !== previous && c2 !== c3) next = v2;
else if (v3 !== previous && c1 !== c3) next = v3;
if (next === current) {
ERROR && console.error("Next vertex is not found");
break;
}
}
return chain;
}

View file

@ -5,7 +5,7 @@ import {closeDialogs} from "dialogs/utils";
import {openDialog} from "dialogs";
import {initLayers, restoreLayers} from "layers";
// @ts-expect-error js module
import {drawCoastline} from "modules/coastline";
import {drawCoastline} from "layers/renderers/drawCoastline";
// @ts-expect-error js module
import {drawScaleBar, Rulers} from "modules/measurers";
// @ts-expect-error js module
@ -29,6 +29,7 @@ import {showStatistics} from "../statistics";
import {createGrid} from "./grid";
import {createPack} from "./pack";
import {getInputValue, setInputValue} from "utils/nodeUtils";
// import {Ruler} from "modules/measurers";
const {Zoom, ThreeD} = window;
@ -56,6 +57,8 @@ async function generate(options?: IGenerationOptions) {
const newGrid = await createGrid(grid, precreatedGraph);
const newPack = createPack(newGrid);
// TODO: draw default ruler
// redefine global grid and pack
grid = newGrid;
pack = newPack;

View file

@ -2,7 +2,7 @@ import * as d3 from "d3";
import {renderLayer} from "layers";
// @ts-expect-error js module
import {drawCoastline} from "modules/coastline";
import {drawCoastline} from "layers/renderers/drawCoastline";
import {markupPackFeatures} from "modules/markup";
// @ts-expect-error js module
import {drawScaleBar} from "modules/measurers";
@ -24,6 +24,8 @@ export function createPack(grid: IGrid): IPack {
const markup = markupPackFeatures(grid, vertices, pick(cells, "v", "c", "b", "p", "h"));
renderLayer("coastline", vertices, markup.features);
// drawCoastline({vertices, cells}); // split into vertices definition and rendering
// Rivers.generate(newPack, grid);
@ -131,3 +133,6 @@ function repackGrid(grid: IGrid) {
TIME && console.timeEnd("repackGrid");
return pack;
}
function drawLayer(arg0: string, vertices: IGraphVertices, features: TPackFeatures) {
throw new Error("Function not implemented.");
}

100
src/scripts/simplify.ts Normal file
View file

@ -0,0 +1,100 @@
/*
(c) 2017, Vladimir Agafonkin
Simplify.js, a high-performance JS polyline simplification library
mourner.github.io/simplify-js
*/
// square distance between 2 points
function getSqDist([x1, y1]: TPoint, [x2, y2]: TPoint) {
const dx = x1 - x2;
const dy = y1 - y2;
return dx * dx + dy * dy;
}
// square distance from a point to a segment
function getSqSegDist([x1, y1]: TPoint, [x, y]: TPoint, [x2, y2]: TPoint) {
let dx = x2 - x;
let dy = y2 - y;
if (dx !== 0 || dy !== 0) {
const t = ((x1 - x) * dx + (y1 - y) * dy) / (dx * dx + dy * dy);
if (t > 1) {
x = x2;
y = y2;
} else if (t > 0) {
x += dx * t;
y += dy * t;
}
}
dx = x1 - x;
dy = y1 - y;
return dx * dx + dy * dy;
}
// rest of the code doesn't care about point format
// basic distance-based simplification
function simplifyRadialDist(points: TPoints, sqTolerance: number) {
let prevPoint = points[0];
const newPoints = [prevPoint];
let point;
for (let i = 1, len = points.length; i < len; i++) {
point = points[i];
if (getSqDist(point, prevPoint) > sqTolerance) {
newPoints.push(point);
prevPoint = point;
}
}
if (point && prevPoint !== point) newPoints.push(point);
return newPoints;
}
function simplifyDPStep(points: TPoints, first: number, last: number, sqTolerance: number, simplified: TPoints) {
let maxSqDist = sqTolerance;
let index = first;
for (let i = first + 1; i < last; i++) {
const sqDist = getSqSegDist(points[i], points[first], points[last]);
if (sqDist > maxSqDist) {
index = i;
maxSqDist = sqDist;
}
}
if (maxSqDist > sqTolerance) {
if (index - first > 1) simplifyDPStep(points, first, index, sqTolerance, simplified);
simplified.push(points[index]);
if (last - index > 1) simplifyDPStep(points, index, last, sqTolerance, simplified);
}
}
// simplification using Ramer-Douglas-Peucker algorithm
function simplifyDouglasPeucker(points: TPoints, sqTolerance: number) {
const last = points.length - 1;
const simplified = [points[0]];
simplifyDPStep(points, 0, last, sqTolerance, simplified);
simplified.push(points[last]);
return simplified;
}
// both algorithms combined for awesome performance
export function simplify(points: TPoints, tolerance: number, highestQuality = false) {
if (points.length <= 2) return points;
const sqTolerance = tolerance * tolerance;
points = highestQuality ? points : simplifyRadialDist(points, sqTolerance);
points = simplifyDouglasPeucker(points, sqTolerance);
return points;
}