Revert of Revert of Fix SkTileImageFilter clipping/cropRect interaction issue (patchset #1 id:1 of https://codereview.chromium.org/1219193002/)

Reason for revert:
Blocking the roll

Original issue's description:
> Revert of Fix SkTileImageFilter clipping/cropRect interaction issue (patchset #2 id:30001 of https://codereview.chromium.org/1210053003/)
>
> Reason for revert:
> Perf regression: https://code.google.com/p/chromium/issues/detail?id=505564
>
> Original issue's description:
> > Fix SkTileImageFilter clipping/cropRect interaction issue
> >
> > BUG=499499
> >
> > Committed: https://skia.googlesource.com/skia/+/157bcd0840b578060dbc3365daafffc6837da391
>
> TBR=reed@google.com,senorblanco@google.com,senorblanco@chromium.org,robertphillips@google.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=499499
>
> Committed: https://skia.googlesource.com/skia/+/ebaf6a69bf604c85185e23aca3fb93308e747ff5

TBR=reed@google.com,senorblanco@google.com,senorblanco@chromium.org,robertphillips@google.com,reed@chromium.org,bsalomon@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=499499

Review URL: https://codereview.chromium.org/1207353004

6 files changed, 162 insertions, 12 deletions

diff --git a/gm/cropdisp.cpp b/gm/cropdisp.cpp
new file mode 100644
index 0000000000..6cc0d5fe96
--- /dev/null
+++ b/gm/cropdisp.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkBitmapSource.h"
+#include "SkColorFilter.h"
+#include "SkColorFilterImageFilter.h"
+#include "SkDisplacementMapEffect.h"
+#include "SkTileImageFilter.h"
+#include "SkXfermode.h"
+#include "gm.h"
+
+namespace skiagm {
+
+// This tests the image filter graph:
+//
+//    BitmapSource1 -- all red 512x512
+//        |
+//    ColorFilterImageFilter -- with a 64x64 crop rect - makes the pixels green
+//        |
+//    TileImageFilter -- which tiles the 64x64 green pixels across 512x512
+//        |
+//        |                BitmapSource1 -- all red 512x512
+//        | displacement   | color
+//        |                |
+//    DisplacementMapEffect -- this is only necessary to preserve the clip in the computed bounds
+//                             TileImageFilter by itself bloats the bounds to include the src
+//                             It has the TileImageFilter as the offset input.
+//
+// What was going on was that the clipRect being applied to the draw (64, 64, 512, 512)
+// was eliminating the "displacement" chain due to the crop rect.
+// This reproduces crbug/499499
+class CroppedDisplacementGM : public GM {
+public:
+    CroppedDisplacementGM() { }
+
+protected:
+
+    SkString onShortName() override {
+        return SkString("cropped-displacement");
+    }
+
+    SkISize onISize() override {
+        return SkISize::Make(kWidth, kHeight);
+    }
+
+    void onOnceBeforeDraw() override {
+        fRedBitmap.allocN32Pixels(kWidth, kHeight);
+        SkCanvas canvas(fRedBitmap);
+        canvas.clear(SK_ColorRED);
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+
+        SkPaint p;
+
+        const SkRect smRect = SkRect::MakeWH(SkIntToScalar(kSmallSize), SkIntToScalar(kSmallSize));
+        SkImageFilter::CropRect cr(smRect);
+
+        SkAutoTUnref<SkBitmapSource> bms(SkBitmapSource::Create(fRedBitmap));
+        SkAutoTUnref<SkColorFilter> cf(SkColorFilter::CreateModeFilter(SK_ColorGREEN,
+                                                                       SkXfermode::kSrc_Mode));
+        SkAutoTUnref<SkColorFilterImageFilter> cfif(SkColorFilterImageFilter::Create(cf, bms, &cr));
+
+        SkAutoTUnref<SkTileImageFilter> tif(SkTileImageFilter::Create(
+                        SkRect::MakeWH(SkIntToScalar(kSmallSize), SkIntToScalar(kSmallSize)),
+                        SkRect::MakeWH(SkIntToScalar(kWidth), SkIntToScalar(kHeight)),
+                        cfif));
+
+        static const SkScalar kScale = 20.0f;
+
+        SkAutoTUnref<SkDisplacementMapEffect> dif(SkDisplacementMapEffect::Create(
+            SkDisplacementMapEffect::kB_ChannelSelectorType,
+            SkDisplacementMapEffect::kB_ChannelSelectorType,
+            kScale,
+            tif, bms));
+
+        p.setImageFilter(dif);
+
+        canvas->clipRect(SkRect::MakeLTRB(kSmallSize+kScale/2.0f,
+                                          kSmallSize+kScale/2.0f, 
+                                          SkIntToScalar(kWidth), SkIntToScalar(kHeight)));
+        canvas->saveLayer(NULL, &p);
+        canvas->restore();
+    }
+
+private:
+    static const int kWidth = 512;
+    static const int kHeight = 512;
+    static const int kSmallSize = 64;
+
+    SkBitmap fRedBitmap;
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW(CroppedDisplacementGM); )
+
+}
diff --git a/include/core/SkImageFilter.h b/include/core/SkImageFilter.h
index 4125db3734..188905e5d7 100644
--- a/include/core/SkImageFilter.h
+++ b/include/core/SkImageFilter.h
@@ -44,6 +44,9 @@ public:
         explicit CropRect(const SkRect& rect, uint32_t flags = kHasAll_CropEdge) : fRect(rect), fFlags(flags) {}
         uint32_t flags() const { return fFlags; }
         const SkRect& rect() const { return fRect; }
+#ifndef SK_IGNORE_TO_STRING
+        void toString(SkString* str) const;
+#endif
     private:
         SkRect fRect;
         uint32_t fFlags;
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 7233ec6706..f63d1bf13b 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -32,6 +32,37 @@
   enum { kDefaultCacheSize = 128 * 1024 * 1024 };
 #endif 
 
+#ifndef SK_IGNORE_TO_STRING
+void SkImageFilter::CropRect::toString(SkString* str) const {
+    if (!fFlags) {
+        return;
+    }
+
+    str->appendf("cropRect (");
+    if (fFlags & CropRect::kHasLeft_CropEdge) {
+        str->appendf("%.2f, ", fRect.fLeft);
+    } else {
+        str->appendf("X, ");
+    }
+    if (fFlags & CropRect::kHasTop_CropEdge) {
+        str->appendf("%.2f, ", fRect.fTop);
+    } else {
+        str->appendf("X, ");
+    }
+    if (fFlags & CropRect::kHasRight_CropEdge) {
+        str->appendf("%.2f, ", fRect.fRight);
+    } else {
+        str->appendf("X, ");
+    }
+    if (fFlags & CropRect::kHasBottom_CropEdge) {
+        str->appendf("%.2f", fRect.fBottom);
+    } else {
+        str->appendf("X");
+    }
+    str->appendf(") ");
+}
+#endif
+
 static int32_t next_image_filter_unique_id() {
     static int32_t gImageFilterUniqueID;
 
diff --git a/src/effects/SkColorFilterImageFilter.cpp b/src/effects/SkColorFilterImageFilter.cpp
index 2eb720e5c4..d7a5ff848c 100755
--- a/src/effects/SkColorFilterImageFilter.cpp
+++ b/src/effects/SkColorFilterImageFilter.cpp
@@ -101,6 +101,7 @@ bool SkColorFilterImageFilter::onIsColorFilterNode(SkColorFilter** filter) const
 #ifndef SK_IGNORE_TO_STRING
 void SkColorFilterImageFilter::toString(SkString* str) const {
     str->appendf("SkColorFilterImageFilter: (");
+    this->getCropRect().toString(str);
 
     str->appendf("input: (");
 
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index d7d92c82b9..0eac80ff8a 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -269,7 +269,7 @@ void SkDisplacementMapEffect::computeFastBounds(const SkRect& src, SkRect* dst)
 }
 
 bool SkDisplacementMapEffect::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
-                                   SkIRect* dst) const {
+                                             SkIRect* dst) const {
     SkIRect bounds = src;
     SkVector scale = SkVector::Make(fScale, fScale);
     ctm.mapVectors(&scale, 1);
@@ -285,6 +285,7 @@ bool SkDisplacementMapEffect::onFilterBounds(const SkIRect& src, const SkMatrix&
 #ifndef SK_IGNORE_TO_STRING
 void SkDisplacementMapEffect::toString(SkString* str) const {
     str->appendf("SkDisplacementMapEffect: (");
+    this->getCropRect().toString(str);
     str->appendf("scale: %f ", fScale);
     str->appendf("displacement: (");
     if (this->getDisplacementInput()) {
diff --git a/src/effects/SkTileImageFilter.cpp b/src/effects/SkTileImageFilter.cpp
index 2b7ed940d2..64e9a43f5a 100644
--- a/src/effects/SkTileImageFilter.cpp
+++ b/src/effects/SkTileImageFilter.cpp
@@ -27,19 +27,27 @@ SkTileImageFilter* SkTileImageFilter::Create(const SkRect& srcRect, const SkRect
 bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
                                       const Context& ctx,
                                       SkBitmap* dst, SkIPoint* offset) const {
-    SkBitmap source = src;
-    SkImageFilter* input = getInput(0);
-    SkIPoint srcOffset = SkIPoint::Make(0, 0);
-    if (input && !input->filterImage(proxy, src, ctx, &source, &srcOffset)) {
-        return false;
-    }
 
     SkRect dstRect;
     ctx.ctm().mapRect(&dstRect, fDstRect);
     const SkIRect dstIRect = dstRect.roundOut();
-    int w = dstIRect.width();
-    int h = dstIRect.height();
-    if (!fSrcRect.width() || !fSrcRect.height() || !w || !h) {
+    if (fSrcRect.isEmpty() || dstIRect.isEmpty()) {
+        return false;
+    }
+
+    // TODO: the actual clip that needs to be applied to the src should be (roughly) determined by:
+    //  intersect ctx.clip and dstIRect
+    //  determine if that rect lies wholly inside fSrcRect
+    //      if so pass it on as the clip
+    //      if not pass the entire fSrcRect as the clip
+    // For now don't apply any clip to the source (since it is usually very small and all of it
+    // will be required anyway).
+    Context srcCtx(ctx.ctm(), SkIRect::MakeLargest(), ctx.cache());
+
+    SkBitmap source = src;
+    SkImageFilter* input = this->getInput(0);
+    SkIPoint srcOffset = SkIPoint::Make(0, 0);
+    if (input && !input->filterImage(proxy, src, srcCtx, &source, &srcOffset)) {
         return false;
     }
 
@@ -59,7 +67,7 @@ bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
         return false;
     }
 
-    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(w, h));
+    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(dstIRect.width(), dstIRect.height()));
     if (NULL == device.get()) {
         return false;
     }
@@ -116,12 +124,13 @@ void SkTileImageFilter::flatten(SkWriteBuffer& buffer) const {
 #ifndef SK_IGNORE_TO_STRING
 void SkTileImageFilter::toString(SkString* str) const {
     str->appendf("SkTileImageFilter: (");
+    this->getCropRect().toString(str);
     str->appendf("src: %.2f %.2f %.2f %.2f",
                  fSrcRect.fLeft, fSrcRect.fTop, fSrcRect.fRight, fSrcRect.fBottom);
     str->appendf(" dst: %.2f %.2f %.2f %.2f",
                  fDstRect.fLeft, fDstRect.fTop, fDstRect.fRight, fDstRect.fBottom);
     if (this->getInput(0)) {
-        str->appendf("input: (");
+        str->appendf(" input: (");
         this->getInput(0)->toString(str);
         str->appendf(")");
     }