Infrastructure changes to support pull-saveLayers-forward task

This is split out of (First pass at pre-rendering saveLayers for GPU - https://codereview.chromium.org/261663003/).

It mainly:

	Moves NeedsDeepCopy to somewhere more accessible (so GrPictureUtils.cpp can use it)
	Moves ComputeAccelDataKey somewhere more accessible (so GPUPicture test can use it)
	Adds unit test for picture saveLayer analysis (done in EXPERIMENTAL_optimize)
        Adds new fields to SaveLayerInfo that are needed to pull forward layers

R=bsalomon@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/266203003

git-svn-id: http://skia.googlecode.com/svn/trunk@14571 2bbb7eff-a529-9590-31e7-b0007b416f81

3 files changed, 64 insertions, 51 deletions

diff --git a/src/gpu/GrPictureUtils.cpp b/src/gpu/GrPictureUtils.cpp
index e8c3b504cf..d8e4161c9f 100644
--- a/src/gpu/GrPictureUtils.cpp
+++ b/src/gpu/GrPictureUtils.cpp
@@ -7,6 +7,8 @@
 
 #include "GrPictureUtils.h"
 #include "SkDevice.h"
+#include "SkDraw.h"
+#include "SkPaintPriv.h"
 
 // The GrGather device performs GPU-backend-specific preprocessing on
 // a picture. The results are stored in a GPUAccelData.
@@ -20,12 +22,17 @@ class GrGatherDevice : public SkBaseDevice {
 public:
     SK_DECLARE_INST_COUNT(GrGatherDevice)
 
-    GrGatherDevice(int width, int height, SkPicture* picture, GPUAccelData* accelData) {
+    GrGatherDevice(int width, int height, SkPicture* picture, GPUAccelData* accelData,
+                   int saveLayerDepth) {
         fPicture = picture;
+        fSaveLayerDepth = saveLayerDepth;
+        fInfo.fValid = true;
         fInfo.fSize.set(width, height);
+        fInfo.fPaint = NULL;
         fInfo.fSaveLayerOpID = fPicture->EXPERIMENTAL_curOpID();
         fInfo.fRestoreOpID = 0;
         fInfo.fHasNestedLayers = false;
+        fInfo.fIsNested = (2 == fSaveLayerDepth);
 
         fEmptyBitmap.setConfig(SkImageInfo::Make(fInfo.fSize.fWidth,
                                                  fInfo.fSize.fHeight,
@@ -110,7 +117,8 @@ protected:
                               const SkPaint& paint) SK_OVERRIDE {
     }
     virtual void drawDevice(const SkDraw& draw, SkBaseDevice* deviceIn, int x, int y,
-                            const SkPaint&) SK_OVERRIDE {
+                            const SkPaint& paint) SK_OVERRIDE {
+        // deviceIn is the one that is being "restored" back to its parent
         GrGatherDevice* device = static_cast<GrGatherDevice*>(deviceIn);
 
         if (device->fAlreadyDrawn) {
@@ -118,6 +126,29 @@ protected:
         }
 
         device->fInfo.fRestoreOpID = fPicture->EXPERIMENTAL_curOpID();
+        device->fInfo.fCTM = *draw.fMatrix;
+        device->fInfo.fCTM.postTranslate(SkIntToScalar(-device->getOrigin().fX),
+                                         SkIntToScalar(-device->getOrigin().fY));
+
+        // We need the x & y values that will yield 'getOrigin' when transformed
+        // by 'draw.fMatrix'.
+        device->fInfo.fOffset.iset(device->getOrigin());
+
+        SkMatrix invMatrix;
+        if (draw.fMatrix->invert(&invMatrix)) {
+            invMatrix.mapPoints(&device->fInfo.fOffset, 1);
+        } else {
+            device->fInfo.fValid = false;
+        }
+
+        if (NeedsDeepCopy(paint)) {
+            // This NULL acts as a signal that the paint was uncopyable (for now)
+            device->fInfo.fPaint = NULL;
+            device->fInfo.fValid = false;
+        } else {
+            device->fInfo.fPaint = SkNEW_ARGS(SkPaint, (paint));
+        }
+
         fAccelData->addSaveLayerInfo(device->fInfo);
         device->fAlreadyDrawn = true;
     }
@@ -158,6 +189,9 @@ private:
     // The information regarding the saveLayer call this device represents.
     GPUAccelData::SaveLayerInfo fInfo;
 
+    // The depth of this device in the saveLayer stack
+    int fSaveLayerDepth;
+
     virtual void replaceBitmapBackendForRasterSurface(const SkBitmap&) SK_OVERRIDE {
         NotSupported();
     }
@@ -167,7 +201,8 @@ private:
         SkASSERT(kSaveLayer_Usage == usage);
 
         fInfo.fHasNestedLayers = true;
-        return SkNEW_ARGS(GrGatherDevice, (info.width(), info.height(), fPicture, fAccelData));
+        return SkNEW_ARGS(GrGatherDevice, (info.width(), info.height(), fPicture, 
+                                           fAccelData, fSaveLayerDepth+1));
     }
 
     virtual void flush() SK_OVERRIDE {}
@@ -239,7 +274,7 @@ void GatherGPUInfo(SkPicture* pict, GPUAccelData* accelData) {
         return ;
     }
 
-    GrGatherDevice device(pict->width(), pict->height(), pict, accelData);
+    GrGatherDevice device(pict->width(), pict->height(), pict, accelData, 0);
     GrGatherCanvas canvas(&device, pict);
 
     canvas.gather();
diff --git a/src/gpu/GrPictureUtils.h b/src/gpu/GrPictureUtils.h
index 6b4d901cc1..5ca41320e3 100644
--- a/src/gpu/GrPictureUtils.h
+++ b/src/gpu/GrPictureUtils.h
@@ -17,8 +17,21 @@ class GPUAccelData : public SkPicture::AccelData {
 public:
     // Information about a given saveLayer in an SkPicture
     struct SaveLayerInfo {
+        // True if the SaveLayerInfo is valid. False if either 'fOffset' is
+        // invalid (due to a non-invertible CTM) or 'fPaint' is NULL (due
+        // to a non-copyable paint).
+        bool fValid;
         // The size of the saveLayer
         SkISize fSize;
+        // The CTM in which this layer's draws must occur. It already incorporates
+        // the translation needed to map the layer's top-left point to the origin.
+        SkMatrix fCTM;
+        // The offset that needs to be passed to drawBitmap to correctly
+        // position the pre-rendered layer.
+        SkPoint fOffset;
+        // The paint to use on restore. NULL if the paint was not copyable (and
+        // thus that this layer should not be pulled forward).
+        const SkPaint* fPaint;
         // The ID of this saveLayer in the picture. 0 is an invalid ID.
         size_t  fSaveLayerOpID;
         // The ID of the matching restore in the picture. 0 is an invalid ID.
@@ -26,6 +39,8 @@ public:
         // True if this saveLayer has at least one other saveLayer nested within it.
         // False otherwise.
         bool    fHasNestedLayers;
+        // True if this saveLayer is nested within another. False otherwise.
+        bool    fIsNested;
     };
 
     GPUAccelData(Key key) : INHERITED(key) { }
@@ -43,6 +58,14 @@ public:
         return fSaveLayerInfo[index];
     }
 
+    // We may, in the future, need to pass in the GPUDevice in order to
+    // incorporate the clip and matrix state into the key
+    static SkPicture::AccelData::Key ComputeAccelDataKey() {
+        static const SkPicture::AccelData::Key gGPUID = SkPicture::AccelData::GenerateDomain();
+
+        return gGPUID;
+    }
+
 protected:
     SkTDArray<SaveLayerInfo> fSaveLayerInfo;
 
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 714a6da65d..3119a9e7e3 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1910,16 +1910,8 @@ SkSurface* SkGpuDevice::newSurface(const SkImageInfo& info) {
     return SkSurface::NewRenderTarget(fContext, info, fRenderTarget->numSamples());
 }
 
-// In the future this may not be a static method if we need to incorporate the
-// clip and matrix state into the key
-SkPicture::AccelData::Key SkGpuDevice::ComputeAccelDataKey() {
-    static const SkPicture::AccelData::Key gGPUID = SkPicture::AccelData::GenerateDomain();
-
-    return gGPUID;
-}
-
 void SkGpuDevice::EXPERIMENTAL_optimize(SkPicture* picture) {
-    SkPicture::AccelData::Key key = ComputeAccelDataKey();
+    SkPicture::AccelData::Key key = GPUAccelData::ComputeAccelDataKey();
 
     GPUAccelData* data = SkNEW_ARGS(GPUAccelData, (key));
 
@@ -1934,7 +1926,7 @@ void SkGpuDevice::EXPERIMENTAL_purge(SkPicture* picture) {
 
 bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* canvas, SkPicture* picture) {
 
-    SkPicture::AccelData::Key key = ComputeAccelDataKey();
+    SkPicture::AccelData::Key key = GPUAccelData::ComputeAccelDataKey();
 
     const SkPicture::AccelData* data = picture->EXPERIMENTAL_getAccelData(key);
     if (NULL == data) {
@@ -1943,27 +1935,6 @@ bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* canvas, SkPicture* picture)
 
     const GPUAccelData *gpuData = static_cast<const GPUAccelData*>(data);
 
-//#define SK_PRINT_PULL_FORWARD_INFO 1
-
-#ifdef SK_PRINT_PULL_FORWARD_INFO
-    static bool gPrintedAccelData = false;
-
-    if (!gPrintedAccelData) {
-        for (int i = 0; i < gpuData->numSaveLayers(); ++i) {
-            const GPUAccelData::SaveLayerInfo& info = gpuData->saveLayerInfo(i);
-
-            SkDebugf("%d: Width: %d Height: %d SL: %d R: %d hasNestedLayers: %s\n",
-                                            i,
-                                            info.fSize.fWidth,
-                                            info.fSize.fHeight,
-                                            info.fSaveLayerOpID,
-                                            info.fRestoreOpID,
-                                            info.fHasNestedLayers ? "T" : "F");
-        }
-        gPrintedAccelData = true;
-    }
-#endif
-
     SkAutoTArray<bool> pullForward(gpuData->numSaveLayers());
     for (int i = 0; i < gpuData->numSaveLayers(); ++i) {
         pullForward[i] = false;
@@ -1984,10 +1955,6 @@ bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* canvas, SkPicture* picture)
 
     const SkPicture::OperationList& ops = picture->EXPERIMENTAL_getActiveOps(clip);
 
-#ifdef SK_PRINT_PULL_FORWARD_INFO
-    SkDebugf("rect: %d %d %d %d\n", clip.fLeft, clip.fTop, clip.fRight, clip.fBottom);
-#endif
-
     for (int i = 0; i < ops.numOps(); ++i) {
         for (int j = 0; j < gpuData->numSaveLayers(); ++j) {
             const GPUAccelData::SaveLayerInfo& info = gpuData->saveLayerInfo(j);
@@ -1998,17 +1965,5 @@ bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* canvas, SkPicture* picture)
         }
     }
 
-#ifdef SK_PRINT_PULL_FORWARD_INFO
-    SkDebugf("Need SaveLayers: ");
-    for (int i = 0; i < gpuData->numSaveLayers(); ++i) {
-        if (pullForward[i]) {
-            const GrCachedLayer* layer = fContext->getLayerCache()->findLayerOrCreate(picture, i);
-
-            SkDebugf("%d (%d), ", i, layer->layerID());
-        }
-    }
-    SkDebugf("\n");
-#endif
-
     return false;
 }