OpenLayers v4.0.1 API - Namespace: render

# Namespace: render

This documentation is for OpenLayers v4.0.1. The latest is v.

## ol.render

### Classes

Event
Feature
VectorContext

### Namespaces

canvas
webgl

### Methods

#### ol.render.toContext(context, opt_options){ol.render.canvas.Immediate}

src/ol/render.js, line 28

  Binds a Canvas Immediate API to a canvas context, to allow drawing geometries to the context's canvas.

  The units for geometry coordinates are css pixels relative to the top left corner of the canvas element.

      var canvas = document.createElement('canvas');
      var render = ol.render.toContext(canvas.getContext('2d'),
          { size: [100, 100] });
      render.setFillStrokeStyle(new ol.style.Fill({ color: blue }));
      render.drawPolygon(
          new ol.geom.Polygon([[[0, 0], [100, 100], [100, 0], [0, 0]]]));

  Name | Type | Description
  --- | --- | ---
  `context` | CanvasRenderingContext2D | Canvas context.

  `options`

  Options.

  Name | Type | Description
  --- | --- | ---
  `size` | ol.Size | undefined | Desired size of the canvas in css pixels. When provided, both canvas and css size will be set according to the `pixelRatio`. If not provided, the current canvas and css sizes will not be altered.
  `pixelRatio` | number | undefined | Pixel ratio (canvas pixel to css pixel ratio) for the canvas. Default is the detected device pixel ratio.

  ##### Returns:

  Canvas Immediate.