1 files changed, 14 insertions, 4 deletions
diff --git a/platform/darwin/src/MGLOpenGLStyleLayer.mm b/platform/darwin/src/MGLOpenGLStyleLayer.mm
index 745eacbf4e..5d81eb85ea 100644
--- a/platform/darwin/src/MGLOpenGLStyleLayer.mm
+++ b/platform/darwin/src/MGLOpenGLStyleLayer.mm
@@ -4,6 +4,7 @@
 #import "MGLStyle_Private.h"
 #import "MGLStyleLayer_Private.h"
 
+#include <mbgl/map/map.hpp>
 #include <mbgl/style/layers/custom_layer.hpp>
 #include <mbgl/math/wrap.hpp>
 
@@ -52,10 +53,19 @@ void MGLFinishCustomStyleLayer(void *context) {
 }
 
 /**
- An `MGLOpenGLStyleLayer` is a style layer that is rendered by OpenGL code in
- Objective-C blocks or Swift closures that you specify. You may initialize a new
- OpenGL style layer to add to an `MGLStyle` or obtain one from an `MGLMapView`’s
- current style using the `-[MGLStyle layerWithIdentifier:]` method.
+ An `MGLOpenGLStyleLayer` is a style layer that is rendered by OpenGL code that
+ you provide.
+ 
+ By default, this class does nothing. You can subclass this class to provide
+ custom OpenGL drawing code that is run on each frame of the map. Your subclass
+ should override the `-didMoveToMapView:`, `-willMoveFromMapView:`, and
+ `-drawInMapView:withContext:` methods.
+ 
+ You can access an existing OpenGL style layer using the
+ `-[MGLStyle layerWithIdentifier:]` method if you know its identifier;
+ otherwise, find it using the `MGLStyle.layers` property. You can also create a
+ new OpenGL style layer and add it to the style using a method such as
+ `-[MGLStyle addLayer:]`.
  
  @warning This API is undocumented and therefore unsupported. It may change at
     any time without notice.