Revert of Begin atlasing

src/gpu/GrLayerCache.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAtlas.h"
 #include "GrGpu.h"
 #include "GrLayerCache.h"
@@ skipping 24 matching lines @@
     static bool Equals(const GrCachedLayer& layer, const PictureLayerKey& key) {
         return layer.pictureID() == key.pictureID() && layer.layerID() == key.layerID();
     }
 
 private:
     uint32_t fPictureID;
     int      fLayerID;
 };
 
 GrLayerCache::GrLayerCache(GrContext* context)
-    : fContext(context) {
-    this->initAtlas();
+    : fContext(context)
+    , fLayerPool(16) {      // TODO: may need to increase this later
 }
 
 GrLayerCache::~GrLayerCache() {
 }
 
-void GrLayerCache::initAtlas() {
+void GrLayerCache::init() {
     static const int kAtlasTextureWidth = 1024;
     static const int kAtlasTextureHeight = 1024;
 
     SkASSERT(NULL == fAtlas.get());
 
     // The layer cache only gets 1 plot
     SkISize textureSize = SkISize::Make(kAtlasTextureWidth, kAtlasTextureHeight);
     fAtlas.reset(SkNEW_ARGS(GrAtlas, (fContext->getGpu(), kSkia8888_GrPixelConfig,
-                                      kRenderTarget_GrTextureFlagBit,
                                       textureSize, 1, 1, false)));
 }
 
 void GrLayerCache::freeAll() {
-    SkTDArray<GrCachedLayer*>& layerArray = fLayerHash.getArray();
-    for (int i = 0; i < fLayerHash.count(); ++i) {
-        this->unlock(layerArray[i]);
-    }
-
     fLayerHash.deleteAll();
-
-    // The atlas only lets go of its texture when the atlas is deleted. 
     fAtlas.free();
-    // GrLayerCache always assumes an atlas exists so recreate it. The atlas 
-    // lazily allocates a replacement texture so reallocating a new 
-    // atlas here won't disrupt a GrContext::contextDestroyed or freeGpuResources.
-    // TODO: Make GrLayerCache lazily allocate the atlas manager?
-    this->initAtlas();
 }
 
 GrCachedLayer* GrLayerCache::createLayer(const SkPicture* picture, int layerID) {
+    GrCachedLayer* layer = fLayerPool.alloc();
+
     SkASSERT(picture->uniqueID() != SK_InvalidGenID);
-
-    GrCachedLayer* layer = SkNEW_ARGS(GrCachedLayer, (picture->uniqueID(), layerID));
+    layer->init(picture->uniqueID(), layerID);
     fLayerHash.insert(PictureLayerKey(picture->uniqueID(), layerID), layer);
     return layer;
 }
 
 GrCachedLayer* GrLayerCache::findLayer(const SkPicture* picture, int layerID) {
     SkASSERT(picture->uniqueID() != SK_InvalidGenID);
     return fLayerHash.find(PictureLayerKey(picture->uniqueID(), layerID));
 }
 
 GrCachedLayer* GrLayerCache::findLayerOrCreate(const SkPicture* picture, int layerID) {
     SkASSERT(picture->uniqueID() != SK_InvalidGenID);
     GrCachedLayer* layer = fLayerHash.find(PictureLayerKey(picture->uniqueID(), layerID));
     if (NULL == layer) {
         layer = this->createLayer(picture, layerID);
     }
 
     return layer;
 }
 
 bool GrLayerCache::lock(GrCachedLayer* layer, const GrTextureDesc& desc) {
+    SkASSERT(NULL == layer->getTexture());
 
-    if (NULL != layer->texture()) {
-        // This layer is already locked
-#ifdef SK_DEBUG
-        if (!layer->rect().isEmpty()) {
-            // It claims to be atlased
-            SkASSERT(layer->rect().width() == desc.fWidth);
-            SkASSERT(layer->rect().height() == desc.fHeight);
-        }
-#endif
-        return true;
-    }
-
-#if USE_ATLAS
-    SkIPoint16 loc;
-    GrPlot* plot = fAtlas->addToAtlas(&fPlotUsage, desc.fWidth, desc.fHeight, NULL, &loc);
-    if (NULL != plot) {
-        GrIRect16 bounds = GrIRect16::MakeXYWH(loc.fX, loc.fY, 
-                                               SkToS16(desc.fWidth), SkToS16(desc.fHeight));
-        layer->setTexture(fAtlas->getTexture(), bounds);
-        return false;
-    }
-#endif
-
-    // This path always uses a new scratch texture and (thus) doesn't cache anything.
+    // This just uses scratch textures and doesn't cache the texture.
     // This can yield a lot of re-rendering
-    layer->setTexture(fContext->lockAndRefScratchTexture(desc, GrContext::kApprox_ScratchTexMatch),
-                      GrIRect16::MakeEmpty());
+    layer->setTexture(fContext->lockAndRefScratchTexture(desc, GrContext::kApprox_ScratchTexMatch));
     return false;
 }
 
 void GrLayerCache::unlock(GrCachedLayer* layer) {
-    if (NULL == layer || NULL == layer->texture()) {
+    if (NULL == layer || NULL == layer->getTexture()) {
         return;
     }
 
-    // The atlas doesn't currently use a scratch texture (and we would have
-    // to free up space differently anyways)
-    // TODO: unlock atlas space when a recycling rectanizer is available
-    if (layer->texture() != fAtlas->getTexture()) {
-        fContext->unlockScratchTexture(layer->texture());
-        layer->setTexture(NULL, GrIRect16::MakeEmpty());
-    }
+    fContext->unlockScratchTexture(layer->getTexture());
+    layer->setTexture(NULL);
 }
-
-void GrLayerCache::purge(const SkPicture* picture) {
-    // This is somewhat of an abuse of GrTHashTable. We need to find all the
-    // layers associated with 'picture' but the usual hash calls only look for
-    // exact key matches. This code peeks into the hash table's innards to
-    // find all the 'picture'-related layers.
-    // TODO: use a different data structure for the layer hash?
-    SkTDArray<GrCachedLayer*> toBeRemoved;
-
-    const SkTDArray<GrCachedLayer*>& layerArray = fLayerHash.getArray();
-    for (int i = 0; i < fLayerHash.count(); ++i) {
-        if (picture->uniqueID() == layerArray[i]->pictureID()) {
-            *toBeRemoved.append() = layerArray[i];
-        }
-    }
-
-    for (int i = 0; i < toBeRemoved.count(); ++i) {
-        this->unlock(toBeRemoved[i]);
-
-        PictureLayerKey key(picture->uniqueID(), toBeRemoved[i]->layerID());
-        fLayerHash.remove(key, toBeRemoved[i]);
-    }
-}