Use a host interface for CustomLayer instead of function pointers (#11553)

Use a host interface for CustomLayer instead of function pointers

Co-authored-by: Julian Rex <julian.rex@mapbox.com>

1 files changed, 13 insertions, 16 deletions

diff --git a/src/mbgl/renderer/layers/render_custom_layer.cpp b/src/mbgl/renderer/layers/render_custom_layer.cpp
index a429b8d82e..85ca5b074e 100644
--- a/src/mbgl/renderer/layers/render_custom_layer.cpp
+++ b/src/mbgl/renderer/layers/render_custom_layer.cpp
@@ -12,17 +12,17 @@ namespace mbgl {
 using namespace style;
 
 RenderCustomLayer::RenderCustomLayer(Immutable<style::CustomLayer::Impl> _impl)
-    : RenderLayer(LayerType::Custom, _impl) {
+    : RenderLayer(LayerType::Custom, _impl), host(_impl->host) {
+    assert(BackendScope::exists());
+    host->initialize();
 }
 
 RenderCustomLayer::~RenderCustomLayer() {
     assert(BackendScope::exists());
-    if (initialized) {
-        if (contextDestroyed && impl().contextLostFn ) {
-            impl().contextLostFn(impl().context);
-        } else if (!contextDestroyed && impl().deinitializeFn) {
-            impl().deinitializeFn(impl().context);
-        }
+    if (contextDestroyed) {
+        host->contextLost();
+    } else {
+        host->deinitialize();
     }
 }
 
@@ -44,15 +44,13 @@ std::unique_ptr<Bucket> RenderCustomLayer::createBucket(const BucketParameters&,
 }
 
 void RenderCustomLayer::render(PaintParameters& paintParameters, RenderSource*) {
-    if (context != impl().context || !initialized) {
+    if (host != impl().host) {
         //If the context changed, deinitialize the previous one before initializing the new one.
-        if (context && !contextDestroyed && impl().deinitializeFn) {
-            MBGL_CHECK_ERROR(impl().deinitializeFn(context));
+        if (host && !contextDestroyed) {
+            MBGL_CHECK_ERROR(host->deinitialize());
         }
-        context = impl().context;
-        assert(impl().initializeFn);
-        MBGL_CHECK_ERROR(impl().initializeFn(impl().context));
-        initialized = true;
+        host = impl().host;
+        MBGL_CHECK_ERROR(host->initialize());
     }
 
     gl::Context& glContext = paintParameters.context;
@@ -75,8 +73,7 @@ void RenderCustomLayer::render(PaintParameters& paintParameters, RenderSource*)
     parameters.pitch = state.getPitch();
     parameters.fieldOfView = state.getFieldOfView();
 
-    assert(impl().renderFn);
-    MBGL_CHECK_ERROR(impl().renderFn(context, parameters));
+    MBGL_CHECK_ERROR(host->render(parameters));
 
     // Reset the view back to our original one, just in case the CustomLayer changed
     // the viewport or Framebuffer.