Deno lint fixes, Polygon implementation

.changeset/poor-phones-laugh.md

@@ -0,0 +1,5 @@
+---
+"shp-kit": minor
+---
+
+Implemented Polygon write and read

.gitignore

@@ -1,2 +1,3 @@
 node_modules
-dist
+dist
+.DS_Store

README.md

@@ -10,15 +10,15 @@ The following table outlines the current support for different types of shapefil
 | -------------- | ---- | ----- |
 | Point          | ✅   | ✅    |
 | PolyLine       | ✅   | ✅    |
-| Polygon        | ❌   | ❌    |
+| Polygon        | ✅   | ✅    |
 | MultiPoint     | ❌   | ❌    |
 | PointZ         | ✅   | ✅    |
 | PolyLineZ      | ✅   | ✅    |
-| PolygonZ       | ❌   | ❌    |
+| PolygonZ       | ✅   | ✅    |
 | MultiPointZ    | ❌   | ❌    |
 | PointM         | ✅   | ✅    |
 | ⚠ PolyLineM    | ✅   | ✅    |
-| ⚠ PolygonM     | ❌   | ❌    |
+| ⚠ PolygonM     | ✅   | ✅    |
 | ⚠ MultiPointM  | ❌   | ❌    |
 | MultiPatch     | ❌   | ❌    |
 

package.json

@@ -35,6 +35,8 @@
     "vitest": "^0.34.6"
   },
   "dependencies": {
+    "@turf/helpers": "^7.1.0",
+    "@turf/turf": "^7.1.0",
     "buffer": "^6.0.3",
     "jszip": "^3.10.1",
     "proj4": "^2.10.0"

src/private/readers/Polygon.ts

@@ -0,0 +1,112 @@
+import { Feature } from "geojson";
+import { ShapefileTypesString } from "../helpers/shapefileTypes";
+import { Options } from "../../public/shpRead";
+
+const getOptionalViewFloat64 = (view: DataView, target: number, lastValidByte: number, little: boolean) => {
+  if (target > view.byteLength - 1 || target > lastValidByte) return 0;
+  return view.getFloat64(target, little);
+};
+
+const Polygon = (
+  shpView: DataView,
+  o: Options,
+  currByteIndex: number,
+  recordLength: number,
+  shpType: ShapefileTypesString,
+  properties: {
+    [key: string]: any;
+  }
+) => {
+  const recordEndByte = currByteIndex + recordLength;
+  //significant header information
+  const partsLength = shpView.getInt32(currByteIndex + 36, true);
+  const pointsLength = shpView.getInt32(currByteIndex + 40, true);
+  currByteIndex += 44;
+  const partsSeparators = [...Array(partsLength)].map((_, i) => shpView.getInt32(currByteIndex + 4 * i, true));
+  partsSeparators.push(pointsLength);
+
+  currByteIndex += 4 * partsLength;
+
+  let points = [...Array(pointsLength)].map((_, i) => {
+    return [shpView.getFloat64(currByteIndex + 16 * i, true), shpView.getFloat64(currByteIndex + 16 * i + 8, true)];
+  });
+
+  currByteIndex += 16 * pointsLength;
+
+  let mValues: number[] | null = null;
+  let zValues: number[] | null = null;
+  if (shpType === "PolygonM") {
+    currByteIndex += 32; // min-max
+    mValues = [...Array(pointsLength)].map((_, i) => {
+      return shpView.getFloat64(currByteIndex + 8 * i, true);
+    });
+  }
+  if (shpType === "PolygonZ") {
+    currByteIndex += 16; // min-max
+    zValues = [...Array(pointsLength)].map((_, i) => {
+      return getOptionalViewFloat64(shpView, currByteIndex + 8 * i, recordEndByte, true);
+    });
+    currByteIndex += pointsLength * 8 + 16;
+    mValues = [...Array(pointsLength)].map((_, i) => {
+      return getOptionalViewFloat64(shpView, currByteIndex + 8 * i, recordEndByte, true);
+    });
+
+    if (!o.elevationPropertyKey) {
+      points = points.map((pt, i) => [pt[0] as number, pt[1] as number, (zValues as number[])[i] as number]);
+    }
+  }
+
+  const coordinates = partsSeparators.reduce(
+    (list, v, i, a) =>
+      i === 0 ? list : [...list, [...Array(v - (a[i - 1] as number))].map((_, j) => points[(a[i - 1] as number) + j])],
+    [] as any[]
+  );
+
+  const output = {
+    type: "Feature",
+    geometry: {
+      type: "Polygon",
+      coordinates,
+    },
+    properties: {
+      ...properties,
+      ...(o.elevationPropertyKey && zValues
+        ? {
+            [o.elevationPropertyKey]:
+              zValues && [...new Set(zValues)].length === 1
+                ? zValues[0]
+                : partsSeparators.reduce(
+                    (list, v, i, a) =>
+                      i === 0
+                        ? list
+                        : [
+                            ...list,
+                            [...Array(v - (a[i - 1] as number))].map((_, j) => zValues[(a[i - 1] as number) + j]),
+                          ],
+                    [] as any[]
+                  ),
+          }
+        : {}),
+      ...(o.measurePropertyKey && mValues
+        ? {
+            [o.measurePropertyKey]:
+              mValues && [...new Set(mValues)].length === 1
+                ? mValues[0]
+                : partsSeparators.reduce(
+                    (list, v, i, a) =>
+                      i === 0
+                        ? list
+                        : [
+                            ...list,
+                            [...Array(v - (a[i - 1] as number))].map((_, j) => mValues[(a[i - 1] as number) + j]),
+                          ],
+                    [] as any[]
+                  ),
+          }
+        : {}),
+    },
+  } as Feature;
+  return output as Feature;
+};
+
+export default Polygon;

src/private/readers/index.ts

@@ -1,19 +1,20 @@
 import PolyLineReader from "./PolyLine";
+import PolygonReader from "./Polygon";
 import PointReader from "./Point";
 
 const readers = {
   // 0 : "Null Shape",
   1: PointReader, // "Point",
   3: PolyLineReader, // "PolyLine",
-  // 5: "Polygon",
+  5: PolygonReader, // "Polygon",
   // 8: "MultiPoint",
   11: PointReader, // "PointZ",
   13: PolyLineReader, // "PolyLineZ",
-  // 15: "PolygonZ",
+  15: PolygonReader, //"PolygonZ",
   // 18: "MultiPointZ",
   21: PointReader, // "PointM",
   23: PolyLineReader, // "PolyLineM",
-  // 25: "PolygonM",
+  25: PolygonReader, // "PolygonM",
   // 28: "MultiPointM",
   // 31 : "MultiPatch",
 } as const;