From 88bbb8c1ae64f52ac526bb87100fc9d772d3850e Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Thu, 24 Oct 2019 13:52:59 +0200
Subject: [PATCH] Clamp the weight value between 0 and 1

---
 src/ol/layer/Heatmap.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/ol/layer/Heatmap.js b/src/ol/layer/Heatmap.js
index 4cbcf0a6ce..646777a0d3 100644
--- a/src/ol/layer/Heatmap.js
+++ b/src/ol/layer/Heatmap.js
@@ -4,6 +4,7 @@
 import {getChangeEventType} from '../Object.js';
 import {createCanvasContext2D} from '../dom.js';
 import VectorLayer from './Vector.js';
+import {clamp} from '../math.js';
 import {assign} from '../obj.js';
 import WebGLPointsLayerRenderer from '../renderer/webgl/PointsLayer.js';
 
@@ -180,7 +181,10 @@ class Heatmap extends VectorLayer {
       attributes: [
         {
           name: 'weight',
-          callback: this.weightFunction_
+          callback: function(feature) {
+            const weight = this.weightFunction_(feature);
+            return weight !== undefined ? clamp(weight, 0, 1) : 1;
+          }.bind(this)
         }
       ],
       vertexShader: `