Reorganize Layer Hoisting code

src/gpu/SkGpuDevice.cpp

Index: src/gpu/SkGpuDevice.cpp
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index f02529756eb266e8eb4420593a09a990181ad9c3..d26d4f8ed28831265feaea6f9978570c68a723d5 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -16,6 +16,7 @@
 #include "GrBitmapTextContext.h"
 #include "GrDistanceFieldTextContext.h"
 #include "GrLayerCache.h"
+#include "GrLayerHoister.h"
 #include "GrPictureUtils.h"
 #include "GrStrokeInfo.h"
 #include "GrTracing.h"
@@ -1839,85 +1840,6 @@ static void wrap_texture(GrTexture* texture, int width, int height, SkBitmap* re
     result->setPixelRef(SkNEW_ARGS(SkGrPixelRef, (info, texture)))->unref();
 }
 
-// Return true if any layers are suitable for hoisting
-bool SkGpuDevice::FindLayersToHoist(const GrAccelData *gpuData,
-                                    const SkPicture::OperationList* ops,
-                                    const SkRect& query,
-                                    bool* pullForward) {
-    bool anyHoisted = false;
-
-    // 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;
-
-    if (NULL != ops) {
-        // In this case the picture has been generated with a BBH so we use
-        // the BBH to limit the pre-rendering to just the layers needed to cover
-        // the region being drawn
-        for (int i = 0; i < ops->numOps(); ++i) {
-            uint32_t offset = ops->offset(i);
-
-            // For now we're saving all the layers in the GrAccelData so they
-            // can be nested. Additionally, the nested layers appear before
-            // their parent in the list.
-            for (int j = 0; j < gpuData->numSaveLayers(); ++j) {
-                const GrAccelData::SaveLayerInfo& info = gpuData->saveLayerInfo(j);
-
-                if (pullForward[j]) {
-                    continue;            // already pulling forward
-                }
-
-                if (offset < info.fSaveLayerOpID || offset > info.fRestoreOpID) {
-                    continue;            // the op isn't in this range
-                }
-
-                // TODO: once this code is more stable unsuitable layers can
-                // just be omitted during the optimization stage
-                if (!info.fValid ||
-                    kSaveLayerMaxSize < info.fSize.fWidth ||
-                    kSaveLayerMaxSize < info.fSize.fHeight ||
-                    info.fIsNested) {
-                    continue;            // this layer is unsuitable
-                }
-
-                pullForward[j] = true;
-                anyHoisted = true;
-            }
-        }
-    } else {
-        // In this case there is no BBH associated with the picture. Pre-render
-        // all the layers that intersect the drawn region
-        for (int j = 0; j < gpuData->numSaveLayers(); ++j) {
-            const GrAccelData::SaveLayerInfo& info = gpuData->saveLayerInfo(j);
-
-            SkRect layerRect = SkRect::MakeXYWH(SkIntToScalar(info.fOffset.fX),
-                                                SkIntToScalar(info.fOffset.fY),
-                                                SkIntToScalar(info.fSize.fWidth),
-                                                SkIntToScalar(info.fSize.fHeight));
-
-            if (!SkRect::Intersects(query, layerRect)) {
-                continue;
-            }
-
-            // TODO: once this code is more stable unsuitable layers can
-            // just be omitted during the optimization stage
-            if (!info.fValid ||
-                kSaveLayerMaxSize < info.fSize.fWidth ||
-                kSaveLayerMaxSize < info.fSize.fHeight ||
-                info.fIsNested) {
-                continue;
-            }
-
-            pullForward[j] = true;
-            anyHoisted = true;
-        }
-    }
-
-    return anyHoisted;
-}
-
 bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* mainCanvas, const SkPicture* picture,
                                            const SkMatrix* matrix, const SkPaint* paint) {
     // todo: should handle these natively
@@ -1941,9 +1863,6 @@ bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* mainCanvas, const SkPicture
     }
 
     SkAutoTArray<bool> pullForward(gpuData->numSaveLayers());
-    for (int i = 0; i < gpuData->numSaveLayers(); ++i) {
-        pullForward[i] = false;
-    }
 
     SkRect clipBounds;
     if (!mainCanvas->getClipBounds(&clipBounds)) {
@@ -1953,7 +1872,7 @@ bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* mainCanvas, const SkPicture
     SkAutoTDelete<const SkPicture::OperationList> ops(
             picture->EXPERIMENTAL_getActiveOps(clipBounds));
 
-    if (!FindLayersToHoist(gpuData, ops.get(), clipBounds, pullForward.get())) {
+    if (!GrLayerHoister::FindLayersToHoist(gpuData, ops.get(), clipBounds, pullForward.get())) {
         return false;
     }
 
@@ -2015,133 +1934,18 @@ bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* mainCanvas, const SkPicture
         }
     }
 
-    this->drawLayers(picture, atlased, nonAtlased);
+    GrLayerHoister::DrawLayers(picture, atlased, nonAtlased);
 
     // Render the entire picture using new layers
     SkPictureReplacementPlayback playback(picture, &replacements, ops.get());
 
     playback.draw(mainCanvas, NULL);
 
-    this->unlockLayers(picture);
+    GrLayerHoister::UnlockLayers(fContext->getLayerCache(), picture);
 
     return true;
 }
 
-void SkGpuDevice::drawLayers(const SkPicture* picture,
-                             const SkTDArray<GrCachedLayer*>& atlased,
-                             const SkTDArray<GrCachedLayer*>& nonAtlased) {
-    // Render the atlased layers that require it
-    if (atlased.count() > 0) {
-        // All the atlased layers are rendered into the same GrTexture
-        SkAutoTUnref<SkSurface> surface(SkSurface::NewRenderTargetDirect(
-                                            atlased[0]->texture()->asRenderTarget(),
-                                            SkSurface::kStandard_TextRenderMode,
-                                            SkSurface::kDontClear_RenderTargetFlag));
-
-        SkCanvas* atlasCanvas = surface->getCanvas();
-
-        SkPaint paint;
-        paint.setColor(SK_ColorTRANSPARENT);
-        paint.setXfermode(SkXfermode::Create(SkXfermode::kSrc_Mode))->unref();
-
-        for (int i = 0; i < atlased.count(); ++i) {
-            GrCachedLayer* layer = atlased[i];
-
-            atlasCanvas->save();
-
-            // Add a rect clip to make sure the rendering doesn't
-            // extend beyond the boundaries of the atlased sub-rect
-            SkRect bound = SkRect::MakeXYWH(SkIntToScalar(layer->rect().fLeft),
-                                            SkIntToScalar(layer->rect().fTop),
-                                            SkIntToScalar(layer->rect().width()),
-                                            SkIntToScalar(layer->rect().height()));
-            atlasCanvas->clipRect(bound);
-
-            // Since 'clear' doesn't respect the clip we need to draw a rect
-            // TODO: ensure none of the atlased layers contain a clear call!
-            atlasCanvas->drawRect(bound, paint);
-
-            // info.fCTM maps the layer's top/left to the origin.
-            // Since this layer is atlased, the top/left corner needs
-            // to be offset to the correct location in the backing texture.
-            atlasCanvas->translate(bound.fLeft, bound.fTop);
-            atlasCanvas->concat(layer->ctm());
-
-            SkPictureRangePlayback rangePlayback(picture,
-                                                 layer->start(),
-                                                 layer->stop());
-            rangePlayback.draw(atlasCanvas, NULL);
-
-            atlasCanvas->restore();
-        }
-
-        atlasCanvas->flush();
-    }
-
-    // Render the non-atlased layers that require it
-    for (int i = 0; i < nonAtlased.count(); ++i) {
-        GrCachedLayer* layer = nonAtlased[i];
-
-        // Each non-atlased layer has its own GrTexture
-        SkAutoTUnref<SkSurface> surface(SkSurface::NewRenderTargetDirect(
-                                            layer->texture()->asRenderTarget(),
-                                            SkSurface::kStandard_TextRenderMode,
-                                            SkSurface::kDontClear_RenderTargetFlag));
-
-        SkCanvas* layerCanvas = surface->getCanvas();
-
-        // Add a rect clip to make sure the rendering doesn't
-        // extend beyond the boundaries of the atlased sub-rect
-        SkRect bound = SkRect::MakeXYWH(SkIntToScalar(layer->rect().fLeft),
-                                        SkIntToScalar(layer->rect().fTop),
-                                        SkIntToScalar(layer->rect().width()),
-                                        SkIntToScalar(layer->rect().height()));
-
-        layerCanvas->clipRect(bound); // TODO: still useful?
-
-        layerCanvas->clear(SK_ColorTRANSPARENT);
-
-        layerCanvas->concat(layer->ctm());
-
-        SkPictureRangePlayback rangePlayback(picture,
-                                             layer->start(),
-                                             layer->stop());
-        rangePlayback.draw(layerCanvas, NULL);
-
-        layerCanvas->flush();
-    }
-}
-
-void SkGpuDevice::unlockLayers(const SkPicture* picture) {
-    SkPicture::AccelData::Key key = GrAccelData::ComputeAccelDataKey();
-
-    const SkPicture::AccelData* data = picture->EXPERIMENTAL_getAccelData(key);
-    SkASSERT(NULL != data);
-
-    const GrAccelData *gpuData = static_cast<const GrAccelData*>(data);
-    SkASSERT(0 != gpuData->numSaveLayers());
-
-    // unlock the layers
-    for (int i = 0; i < gpuData->numSaveLayers(); ++i) {
-        const GrAccelData::SaveLayerInfo& info = gpuData->saveLayerInfo(i);
-
-        GrCachedLayer* layer = fContext->getLayerCache()->findLayer(picture->uniqueID(),
-                                                                    info.fSaveLayerOpID,
-                                                                    info.fRestoreOpID,
-                                                                    info.fOriginXform);
-        fContext->getLayerCache()->unlock(layer);
-    }
-
-#if DISABLE_CACHING
-    // This code completely clears out the atlas. It is required when
-    // caching is disabled so the atlas doesn't fill up and force more
-    // free floating layers
-    fContext->getLayerCache()->purge(picture->uniqueID());
-
-    fContext->getLayerCache()->purgeAll();
-#endif
-}
-
 SkImageFilter::Cache* SkGpuDevice::getImageFilterCache() {
     // We always return a transient cache, so it is freed after each
     // filter traversal.