From 811c1302415d33813b57a51f76995bf5c7182314 Mon Sep 17 00:00:00 2001
From: changqing <changqingom@outlook.com>
Date: Tue, 15 Dec 2020 15:38:23 +0800
Subject: [PATCH]  Implement custom circle render

---
 src/ol/render/canvas/Builder.js  | 20 ++++++++++++++++++++
 src/ol/render/canvas/Executor.js |  8 +++++---
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/ol/render/canvas/Builder.js b/src/ol/render/canvas/Builder.js
index 1b710a74a9..8b1b0c53e3 100644
--- a/src/ol/render/canvas/Builder.js
+++ b/src/ol/render/canvas/Builder.js
@@ -345,6 +345,26 @@ class CanvasBuilder extends VectorContext {
         geometry,
         renderer,
       ]);
+    } else if (type == GeometryType.CIRCLE) {
+      const flatCoordinates = geometry.getFlatCoordinates();
+      this.appendFlatLineCoordinates(
+        flatCoordinates,
+        0,
+        flatCoordinates.length,
+        stride,
+        false,
+        false
+      );
+      builderEnd = this.coordinates.length;
+      this.instructions.push([
+        CanvasInstruction.CUSTOM,
+        builderBegin,
+        builderEnd,
+        geometry,
+        renderer,
+        undefined,
+        4,
+      ]);
     }
     this.endGeometry(feature);
   }
diff --git a/src/ol/render/canvas/Executor.js b/src/ol/render/canvas/Executor.js
index 058961edaf..bf7b6c465b 100644
--- a/src/ol/render/canvas/Executor.js
+++ b/src/ol/render/canvas/Executor.js
@@ -731,6 +731,7 @@ class Executor {
           const geometry = /** @type {import("../../geom/SimpleGeometry.js").default} */ (instruction[3]);
           const renderer = instruction[4];
           const fn = instruction.length == 6 ? instruction[5] : undefined;
+          const coordsLength = instruction.length >= 7 ? instruction[6] : 2;
           state.geometry = geometry;
           state.feature = feature;
           if (!(i in coordinateCache)) {
@@ -740,9 +741,10 @@ class Executor {
           if (fn) {
             fn(pixelCoordinates, d, dd, 2, coords);
           } else {
-            coords[0] = pixelCoordinates[d];
-            coords[1] = pixelCoordinates[d + 1];
-            coords.length = 2;
+            for (let index = 0; index < coordsLength; index++) {
+              coords[index] = pixelCoordinates[d + index];
+            }
+            coords.length = coordsLength;
           }
           renderer(coords, state);
           ++i;