Merge pull request #4523 from ahocevar/render-to-context

Allow rendering geometries to an arbitrary canvas

examples/render-geometry.html

@@ -0,0 +1,9 @@
+---
+layout: example.html
+title: Render geometries to a canvas
+shortdesc: Example of rendering geometries to an arbitrary canvas.
+docs: >
+  This example shows how to render geometries to an arbitrary canvas.
+tags: "render, geometry, canvas"
+---
+<canvas id="canvas"></canvas>

examples/render-geometry.js

@@ -0,0 +1,25 @@
+goog.require('ol.geom.LineString');
+goog.require('ol.geom.Point');
+goog.require('ol.geom.Polygon');
+goog.require('ol.render');
+goog.require('ol.style.Circle');
+goog.require('ol.style.Fill');
+goog.require('ol.style.Stroke');
+
+
+var canvas = document.getElementById('canvas');
+var render = ol.render.toContext(canvas.getContext('2d'), {size: [100, 100]});
+
+var fill = new ol.style.Fill({ color: 'blue' });
+var stroke = new ol.style.Stroke({ color: 'black' });
+render.setFillStrokeStyle(fill, stroke);
+render.setImageStyle(new ol.style.Circle({
+  radius: 10,
+  fill: fill,
+  stroke: stroke
+}));
+
+render.drawLineStringGeometry(new ol.geom.LineString([[10, 10], [90, 90]]));
+render.drawPolygonGeometry(
+    new ol.geom.Polygon([[[2, 2], [98, 2], [2, 98], [2, 2]]]));
+render.drawPointGeometry(new ol.geom.Point([88, 88]));