Revert of Refactor GrLayerHoister::FindLayersToHoist to prep for adding clip to cache key

src/gpu/GrLayerHoister.cpp

Index: src/gpu/GrLayerHoister.cpp
diff --git a/src/gpu/GrLayerHoister.cpp b/src/gpu/GrLayerHoister.cpp
index 6c5398b9021e80686876d69afe432e27e70f50f0..8b0079369d8afd76374bd5dbadf55fc94de66bc2 100644
--- a/src/gpu/GrLayerHoister.cpp
+++ b/src/gpu/GrLayerHoister.cpp
@@ -13,53 +13,6 @@
 #include "SkGrPixelRef.h"
 #include "SkSurface.h"
 
-// Create the layer information for the hoisted layer and secure the
-// required texture/render target resources.
-static void prepare_for_hoisting(GrLayerCache* layerCache, 
-                             const SkPicture* topLevelPicture,
-                             const GrAccelData::SaveLayerInfo& info,
-                             SkTDArray<GrHoistedLayer>* atlased,
-                             SkTDArray<GrHoistedLayer>* nonAtlased,
-                             SkTDArray<GrHoistedLayer>* recycled) {
-    const SkPicture* pict = info.fPicture ? info.fPicture : topLevelPicture;
-
-    GrCachedLayer* layer = layerCache->findLayerOrCreate(pict->uniqueID(),
-                                                         info.fSaveLayerOpID,
-                                                         info.fRestoreOpID,
-                                                         info.fOriginXform,
-                                                         info.fPaint);
-
-    GrTextureDesc desc;
-    desc.fFlags = kRenderTarget_GrTextureFlagBit;
-    desc.fWidth = info.fSize.fWidth;
-    desc.fHeight = info.fSize.fHeight;
-    desc.fConfig = kSkia8888_GrPixelConfig;
-    // TODO: need to deal with sample count
-
-    bool needsRendering = layerCache->lock(layer, desc, info.fHasNestedLayers || info.fIsNested);
-    if (NULL == layer->texture()) {
-        // GPU resources could not be secured for the hoisting of this layer
-        return;
-    }
-
-    GrHoistedLayer* hl;
-
-    if (needsRendering) {
-        if (layer->isAtlased()) {
-            hl = atlased->append();
-        } else {
-            hl = nonAtlased->append();
-        }
-    } else {
-        hl = recycled->append();
-    }
-    
-    hl->fLayer = layer;
-    hl->fPicture = pict;
-    hl->fOffset = info.fOffset;
-    hl->fCTM = info.fOriginXform;
-}
-
 // Return true if any layers are suitable for hoisting
 bool GrLayerHoister::FindLayersToHoist(GrContext* context,
                                        const SkPicture* topLevelPicture,
@@ -67,6 +20,7 @@
                                        SkTDArray<GrHoistedLayer>* atlased,
                                        SkTDArray<GrHoistedLayer>* nonAtlased,
                                        SkTDArray<GrHoistedLayer>* recycled) {
+    bool anyHoisted = false;
 
     GrLayerCache* layerCache = context->getLayerCache();
 
@@ -75,7 +29,7 @@
     SkPicture::AccelData::Key key = GrAccelData::ComputeAccelDataKey();
 
     const SkPicture::AccelData* topLevelData = topLevelPicture->EXPERIMENTAL_getAccelData(key);
-    if (!topLevelData) {
+    if (NULL == topLevelData) {
         return false;
     }
 
@@ -84,20 +38,17 @@
         return false;
     }
 
-    bool anyHoisted = false;
-
-    // The layer hoisting code will pre-render and cache an entire layer if most
-    // of it is being used (~70%) and it will fit in a texture. This is to allow
-    // such layers to be re-used for different clips/tiles. 
-    // Small layers will additionally be atlased.
-    // The only limitation right now is that nested layers are currently not hoisted.
-    // Parent layers are hoisted but are never atlased (so that we never swap
-    // away from the atlas rendertarget when generating the hoisted layers).
-
-    atlased->setReserve(atlased->count() + topLevelGPUData->numSaveLayers());
-
-    // Find and prepare for hoisting all the layers that intersect the query rect
+    // Layer hoisting pre-renders the entire layer since it will be cached and potentially
+    // reused with different clips (e.g., in different tiles). Because of this the
+    // clip will not be limiting the size of the pre-rendered layer. kSaveLayerMaxSize
+    // is used to limit which clips are pre-rendered.
+    static const int kSaveLayerMaxSize = 256;
+
+    SkAutoTArray<bool> pullForward(topLevelGPUData->numSaveLayers());
+
+    // Pre-render all the layers that intersect the query rect
     for (int i = 0; i < topLevelGPUData->numSaveLayers(); ++i) {
+        pullForward[i] = false;
 
         const GrAccelData::SaveLayerInfo& info = topLevelGPUData->saveLayerInfo(i);
 
@@ -113,12 +64,65 @@
         // TODO: ignore perspective projected layers here!
         // TODO: once this code is more stable unsuitable layers can
         // just be omitted during the optimization stage
-        if (!info.fValid || info.fIsNested) {
+        if (!info.fValid ||
+            kSaveLayerMaxSize < info.fSize.fWidth ||
+            kSaveLayerMaxSize < info.fSize.fHeight ||
+            info.fIsNested) {
             continue;
         }
 
-        prepare_for_hoisting(layerCache, topLevelPicture, info, atlased, nonAtlased, recycled);
+        pullForward[i] = true;
         anyHoisted = true;
+    }
+
+    if (!anyHoisted) {
+        return false;
+    }
+
+    atlased->setReserve(atlased->reserved() + topLevelGPUData->numSaveLayers());
+
+    // Generate the layer and/or ensure it is locked
+    for (int i = 0; i < topLevelGPUData->numSaveLayers(); ++i) {
+        if (pullForward[i]) {
+            const GrAccelData::SaveLayerInfo& info = topLevelGPUData->saveLayerInfo(i);
+            const SkPicture* pict = info.fPicture ? info.fPicture : topLevelPicture;
+
+            GrCachedLayer* layer = layerCache->findLayerOrCreate(pict->uniqueID(),
+                                                                 info.fSaveLayerOpID,
+                                                                 info.fRestoreOpID,
+                                                                 info.fOriginXform,
+                                                                 info.fPaint);
+
+            GrTextureDesc desc;
+            desc.fFlags = kRenderTarget_GrTextureFlagBit;
+            desc.fWidth = info.fSize.fWidth;
+            desc.fHeight = info.fSize.fHeight;
+            desc.fConfig = kSkia8888_GrPixelConfig;
+            // TODO: need to deal with sample count
+
+            bool needsRendering = layerCache->lock(layer, desc,
+                                                   info.fHasNestedLayers || info.fIsNested);
+            if (NULL == layer->texture()) {
+                continue;
+            }
+
+            GrHoistedLayer* hl;
+
+            if (needsRendering) {
+                if (layer->isAtlased()) {
+                    hl = atlased->append();
+                } else {
+                    hl = nonAtlased->append();
+                }
+            } else {
+                hl = recycled->append();
+            }
+        
+            hl->fLayer = layer;
+            hl->fPicture = pict;
+            hl->fOffset = info.fOffset;
+            hl->fCTM = info.fOriginXform;
+        }
     }
 
     return anyHoisted;