Split assets atlas batches

Bug #10185769

The assets atlas contains assets that need to be blended and assets
that do not need to be blended. With a single merge id, currently
set to be the pointer to the atlas itself, draw ops merging could
generate batches of commands containing both opaque and translucent
assets. The blend state was chosen from only one of the assets in
the batch, leading either to inefficiencies (blending large opaque
assets) or incorrect behaviors (not blending translucent assets.)

This change introduces two new merge ids in the atlas: an opaque
key and a blend key. These keys are simple booleans set to false
and true respectively (the values do not matter really.) Their
memory addresses are used as the merge ids when createing draw ops
batches, allowing all opaque ops to be batched together and all
translucent ops to be batched together.

Change-Id: I114dba0533c44987e53864b471ccb28c811f2025

4 files changed, 21 insertions, 7 deletions

diff --git a/libs/hwui/AssetAtlas.cpp b/libs/hwui/AssetAtlas.cpp
index d98a538fe40d..eb8bb9fc1a69 100644
--- a/libs/hwui/AssetAtlas.cpp
+++ b/libs/hwui/AssetAtlas.cpp
@@ -100,6 +100,7 @@ struct DelegateTexture: public Texture {
             bool force = false, GLenum renderTarget = GL_TEXTURE_2D) {
         mDelegate->setFilterMinMag(min, mag, bindTexture, force, renderTarget);
     }
+
 private:
     Texture* const mDelegate;
 }; // struct DelegateTexture
@@ -125,12 +126,12 @@ void AssetAtlas::createEntries(Caches& caches, int* map, int count) {
                 y / height, (y + bitmap->height()) / height);
 
         Texture* texture = new DelegateTexture(caches, mTexture);
-        Entry* entry = new Entry(bitmap, x, y, rotated, texture, mapper, *this);
-
         texture->id = mTexture->id;
         texture->blend = !bitmap->isOpaque();
         texture->width = bitmap->width();
         texture->height = bitmap->height();
+
+        Entry* entry = new Entry(bitmap, x, y, rotated, texture, mapper, *this);
         texture->uvMapper = &entry->uvMapper;
 
         mEntries.add(entry->bitmap, entry);
diff --git a/libs/hwui/AssetAtlas.h b/libs/hwui/AssetAtlas.h
index 9afc54de6de2..a28efc62eef5 100644
--- a/libs/hwui/AssetAtlas.h
+++ b/libs/hwui/AssetAtlas.h
@@ -84,11 +84,20 @@ public:
          */
         const AssetAtlas& atlas;
 
+        /**
+         * Unique identifier used to merge bitmaps and 9-patches stored
+         * in the atlas.
+         */
+        const void* getMergeId() const {
+            return texture->blend ? &atlas.mBlendKey : &atlas.mOpaqueKey;
+        }
+
     private:
         Entry(SkBitmap* bitmap, int x, int y, bool rotated,
                 Texture* texture, const UvMapper& mapper, const AssetAtlas& atlas):
                 bitmap(bitmap), x(x), y(y), rotated(rotated),
-                texture(texture), uvMapper(mapper), atlas(atlas) { }
+                texture(texture), uvMapper(mapper), atlas(atlas) {
+        }
 
         ~Entry() {
             delete texture;
@@ -97,7 +106,8 @@ public:
         friend class AssetAtlas;
     };
 
-    AssetAtlas(): mTexture(NULL), mImage(NULL), mGenerationId(0) { }
+    AssetAtlas(): mTexture(NULL), mImage(NULL), mGenerationId(0),
+            mBlendKey(true), mOpaqueKey(false) { }
     ~AssetAtlas() { terminate(); }
 
     /**
@@ -173,6 +183,9 @@ private:
 
     uint32_t mGenerationId;
 
+    const bool mBlendKey;
+    const bool mOpaqueKey;
+
     KeyedVector<SkBitmap*, Entry*> mEntries;
 }; // class AssetAtlas
 
diff --git a/libs/hwui/DeferredDisplayList.h b/libs/hwui/DeferredDisplayList.h
index 6c5a84742a43..1ef01523a4fc 100644
--- a/libs/hwui/DeferredDisplayList.h
+++ b/libs/hwui/DeferredDisplayList.h
@@ -40,7 +40,7 @@ class Batch;
 class DrawBatch;
 class MergingDrawBatch;
 
-typedef void* mergeid_t;
+typedef const void* mergeid_t;
 
 class DeferredDisplayList {
 public:
diff --git a/libs/hwui/DisplayListOp.h b/libs/hwui/DisplayListOp.h
index 83de651ea6a0..1b52b65457c7 100644
--- a/libs/hwui/DisplayListOp.h
+++ b/libs/hwui/DisplayListOp.h
@@ -818,7 +818,7 @@ public:
 
     virtual void onDefer(OpenGLRenderer& renderer, DeferInfo& deferInfo) {
         deferInfo.batchId = DeferredDisplayList::kOpBatch_Bitmap;
-        deferInfo.mergeId = getAtlasEntry() ? (mergeid_t) &mEntry->atlas : (mergeid_t) mBitmap;
+        deferInfo.mergeId = getAtlasEntry() ? (mergeid_t) mEntry->getMergeId() : (mergeid_t) mBitmap;
 
         // Don't merge A8 bitmaps - the paint's color isn't compared by mergeId, or in
         // MergingDrawBatch::canMergeWith()
@@ -1071,7 +1071,7 @@ public:
 
     virtual void onDefer(OpenGLRenderer& renderer, DeferInfo& deferInfo) {
         deferInfo.batchId = DeferredDisplayList::kOpBatch_Patch;
-        deferInfo.mergeId = getAtlasEntry() ? (mergeid_t) &mEntry->atlas : (mergeid_t) mBitmap;
+        deferInfo.mergeId = getAtlasEntry() ? (mergeid_t) mEntry->getMergeId() : (mergeid_t) mBitmap;
         deferInfo.mergeable = state.mMatrix.isPureTranslate() &&
                 OpenGLRenderer::getXfermodeDirect(mPaint) == SkXfermode::kSrcOver_Mode;
         deferInfo.opaqueOverBounds = isOpaqueOverBounds() && mBitmap->isOpaque();