ds-heightmap - npm Package Compare versions

Comparing version 1.2.2 to 1.2.4

lib/index.js

@@ -10,2 +10,60 @@ "use strict";
 };
+// A simple implement of beta distribution: https://stackoverflow.com/a/13569020
+function beta(alpha, beta) {
+    const SG_MAGICCONST = 1 + Math.log(4.5);
+    const alpha_gamma = gamma(alpha, 1);
+    return alpha_gamma / (alpha_gamma + gamma(beta, 1));
+    function gamma(alpha, beta) {
+        if (alpha > 1) {
+            const ainv = Math.sqrt(2.0 * alpha - 1.0);
+            const bbb = alpha - Math.log(4.0);
+            const ccc = alpha + ainv;
+            while (true) {
+                const u1 = Math.random();
+                if (!(1e-7 < u1 && u1 < 0.9999999)) {
+                    continue;
+                }
+                const u2 = 1.0 - Math.random();
+                const v = Math.log(u1 / (1.0 - u1)) / ainv;
+                const x = alpha * Math.exp(v);
+                const z = u1 * u1 * u2;
+                const r = bbb + ccc * v - x;
+                if (r + SG_MAGICCONST - 4.5 * z >= 0.0 || r >= Math.log(z)) {
+                    return x * beta;
+                }
+            }
+        }
+        else if (alpha == 1.0) {
+            let u = Math.random();
+            while (u <= 1e-7) {
+                u = Math.random();
+            }
+            return -Math.log(u) * beta;
+        }
+        else {
+            let x = 0;
+            while (true) {
+                const u3 = Math.random();
+                const b = (Math.E + alpha) / Math.E;
+                const p = b * u3;
+                if (p <= 1.0) {
+                    x = Math.pow(p, 1.0 / alpha);
+                }
+                else {
+                    x = -Math.log((b - p) / alpha);
+                }
+                const u4 = Math.random();
+                if (p > 1.0) {
+                    if (u4 <= Math.pow(x, alpha - 1.0)) {
+                        break;
+                    }
+                }
+                else if (u4 <= Math.exp(-x)) {
+                    break;
+                }
+            }
+            return x * beta;
+        }
+    }
+}
 function ds(config = DEFAULT_CONFIG) {
@@ -38,14 +96,14 @@ const conf = {
     const p = side - 1;
-    data[0][0] = Math.random() * depth;
-    data[0][p] = Math.random() * depth;
-    data[p][0] = Math.random() * depth;
-    data[p][p] = Math.random() * depth;
+    data[0][0] = beta(3, 3) * depth;
+    data[0][p] = beta(3, 3) * depth;
+    data[p][0] = beta(3, 3) * depth;
+    data[p][p] = beta(3, 3) * depth;
     shape(side, side);
     const output = { data, max, min };
-    if (side !== width) {
-        data.length = width;
+    if (data.length !== width) {
+        data.splice(width);
     }
-    if (side !== height) {
+    if (data[0].length !== height) {
         for (const col of data) {
-            col.length = height;
+            col.splice(height);
         }
@@ -70,3 +128,3 @@ }
         }
-        let n = randomize(corners.reduce((p, c) => p + c, 0) / corners.length, halfW + halfH);
+        const n = randomize(corners.reduce((p, c) => p + c, 0) / corners.length, halfW + halfH);
         if (x < width && y < height) {
@@ -89,11 +147,3 @@ if (n < min)
             return randomizer(base, range);
-        const n = base +
-            ((((Math.random() - base / depth) *
-                Math.max(base, depth - base) *
-                range) /
-                (side + side)) *
-                rough *
-                base) /
-                depth;
-        return n > depth ? depth : n < 0 ? 0 : n;
+        return base + (Math.random() - base / depth) * range * rough;
     }
@@ -126,3 +176,3 @@ function shape(sizeW, sizeH) {
             return;
-        let n = randomize((data[x - halfW][y - halfH] +
+        const n = randomize((data[x - halfW][y - halfH] +
             data[x + halfW][y - halfH] +
@@ -129,0 +179,0 @@ data[x + halfW][y + halfH] +

package.json

 {
   "name": "ds-heightmap",
-  "version": "1.2.2",
+  "version": "1.2.4",
   "description": "Use diamond-square algorithm to generate heightmaps.",
@@ -5,0 +5,0 @@ "main": "lib/index.js",

wasm/package.json

@@ -7,3 +7,3 @@ {
   "description": "Using diamond-square algorithm to generate heightmaps which stored in a 2D-array.",
-  "version": "0.1.0",
+  "version": "0.1.2",
   "license": "MIT",
@@ -17,3 +17,2 @@ "repository": {
     "ds_heightmap.js",
-    "ds_heightmap_bg.js",
     "ds_heightmap.d.ts"
@@ -24,7 +23,3 @@ ],
   "types": "ds_heightmap.d.ts",
-  "sideEffects": false,
-  "keywords": [
-    "diamond-square",
-    "heightmap"
-  ]
+  "sideEffects": false
 }

No alert changes

Improved metrics

Total package byte prevSize

74339

increased by8.45%

Lines of code

465

increased by12.05%

No dependency changes