Deferred layer updates

Change-Id: I83d9e564fe274db658dcee9e0cc5bbf9223ebb49

2 files changed, 42 insertions, 0 deletions

diff --git a/libs/hwui/Layer.h b/libs/hwui/Layer.h
index ee6ef1a..f243177 100644
--- a/libs/hwui/Layer.h
+++ b/libs/hwui/Layer.h
@@ -37,6 +37,10 @@ namespace uirenderer {
 // Layers
 ///////////////////////////////////////////////////////////////////////////////
 
+// Forward declarations
+class OpenGLRenderer;
+class DisplayList;
+
 /**
  * A layer has dimensions and is backed by an OpenGL texture or FBO.
  */
@@ -51,6 +55,9 @@ struct Layer {
         texture.width = layerWidth;
         texture.height = layerHeight;
         colorFilter = NULL;
+        deferredUpdateScheduled = false;
+        renderer = NULL;
+        displayList = NULL;
     }
 
     ~Layer() {
@@ -77,6 +84,15 @@ struct Layer {
         regionRect.translate(layer.left, layer.top);
     }
 
+    void updateDeferred(OpenGLRenderer* renderer, DisplayList* displayList,
+            int left, int top, int right, int bottom) {
+        this->renderer = renderer;
+        this->displayList = displayList;
+        const Rect r(left, top, right, bottom);
+        dirtyRect.unionWith(r);
+        deferredUpdateScheduled = true;
+    }
+
     inline uint32_t getWidth() {
         return texture.width;
     }
@@ -234,6 +250,14 @@ struct Layer {
     uint16_t* meshIndices;
     GLsizei meshElementCount;
 
+    /**
+     * Used for deferred updates.
+     */
+    bool deferredUpdateScheduled;
+    OpenGLRenderer* renderer;
+    DisplayList* displayList;
+    Rect dirtyRect;
+
 private:
     /**
      * Name of the FBO used to render the layer. If the name is 0
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index e3148e8..339ae0a 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -2364,6 +2364,24 @@ void OpenGLRenderer::drawLayer(Layer* layer, float x, float y, SkPaint* paint) {
         return;
     }
 
+    if (layer->deferredUpdateScheduled && layer->renderer && layer->displayList) {
+        OpenGLRenderer* renderer = layer->renderer;
+        Rect& dirty = layer->dirtyRect;
+
+        interrupt();
+        renderer->setViewport(layer->layer.getWidth(), layer->layer.getHeight());
+        renderer->prepareDirty(dirty.left, dirty.top, dirty.right, dirty.bottom, !layer->isBlend());
+        renderer->drawDisplayList(layer->displayList, layer->getWidth(), layer->getHeight(),
+                dirty, DisplayList::kReplayFlag_ClipChildren);
+        renderer->finish();
+        resume();
+
+        dirty.setEmpty();
+        layer->deferredUpdateScheduled = false;
+        layer->renderer = NULL;
+        layer->displayList = NULL;
+    }
+
     mCaches.activeTexture(0);
 
     int alpha;