Get OffsetImageFilter really working with SkSpecialImages

src/core/SkImageFilter.cpp

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImageFilter.h"
 #include "SkImageFilterCacheKey.h"
 
 #include "SkBitmap.h"
 #include "SkBitmapDevice.h"
 #include "SkChecksum.h"
 #include "SkDevice.h"
 #include "SkLocalMatrixImageFilter.h"
 #include "SkMatrixImageFilter.h"
 #include "SkOncePtr.h"
 #include "SkReadBuffer.h"
 #include "SkRect.h"
 #include "SkSpecialImage.h"
+#include "SkSpecialSurface.h"
 #include "SkTDynamicHash.h"
 #include "SkTInternalLList.h"
 #include "SkValidationUtils.h"
 #include "SkWriteBuffer.h"
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "GrDrawContext.h"
 #include "SkGrPixelRef.h"
 #include "SkGr.h"
 #endif
@@ skipping 175 matching lines @@
         SkImageFilter* input = this->getInput(i);
         buffer.writeBool(input != nullptr);
         if (input != nullptr) {
             buffer.writeFlattenable(input);
         }
     }
     buffer.writeRect(fCropRect.rect());
     buffer.writeUInt(fCropRect.flags());
 }
 
+SkSpecialImage* SkImageFilter::filterImage(SkSpecialImage* src, const Context& context,
+                                           SkIPoint* offset) const {
+    SkASSERT(src && offset);
+
+    uint32_t srcGenID = fUsesSrcInput ? src->uniqueID() : 0;
+    const SkIRect srcSubset = fUsesSrcInput ? src->subset() : SkIRect::MakeWH(0, 0);
+    Cache::Key key(fUniqueID, context.ctm(), context.clipBounds(), srcGenID, srcSubset);
+    if (context.cache()) {
+        SkSpecialImage* result = context.cache()->get(key, offset);
+        if (result) {
+            return SkRef(result);
+        }
+    }
+
+    SkSpecialImage* result = this->onFilterImage(src, context, offset);
+    if (result && context.cache()) {
+        context.cache()->set(key, result, *offset);
+    }
+
+    return result;
+}
+
 bool SkImageFilter::filterImageDeprecated(Proxy* proxy, const SkBitmap& src,
                                           const Context& context,
                                           SkBitmap* result, SkIPoint* offset) const {
     SkASSERT(result);
     SkASSERT(offset);
     uint32_t srcGenID = fUsesSrcInput ? src.getGenerationID() : 0;
     Cache::Key key(fUniqueID, context.ctm(), context.clipBounds(),
                    srcGenID, SkIRect::MakeWH(0, 0));
     if (context.cache()) {
         if (context.cache()->get(key, result, offset)) {
@@ skipping 74 matching lines @@
         }
     }
     return true;
 }
 
 bool SkImageFilter::onFilterImageDeprecated(Proxy*, const SkBitmap&, const Context&,
                                             SkBitmap*, SkIPoint*) const {
     return false;
 }
 
+SkSpecialImage* SkImageFilter::onFilterImage(SkSpecialImage* src, const Context& ctx,
+                                             SkIPoint* offset) const {
+    SkBitmap tmpSrc, result;
+
+    if (!src->internal_getBM(&tmpSrc)) {
+        return nullptr;
+    }
+
+    if (!this->filterImageDeprecated(src->internal_getProxy(), tmpSrc,
+                                     this->mapContext(ctx), &result, offset)) {
+        return nullptr;
+    }
+
+    return SkSpecialImage::internal_fromBM(src->internal_getProxy(), result);
+}
+
 bool SkImageFilter::canFilterImageGPU() const {
     return this->asFragmentProcessor(nullptr, nullptr, SkMatrix::I(), SkIRect());
 }
 
 bool SkImageFilter::filterImageGPUDeprecated(Proxy* proxy, const SkBitmap& src, const Context& ctx,
                                              SkBitmap* result, SkIPoint* offset) const {
 #if SK_SUPPORT_GPU
     SkBitmap input = src;
     SkASSERT(fInputCount == 1);
     SkIPoint srcOffset = SkIPoint::Make(0, 0);
@@ skipping 92 matching lines @@
         }
         SkCanvas canvas(device);
         canvas.clear(0x00000000);
         canvas.drawBitmap(src, srcOffset->x() - bounds->x(), srcOffset->y() - bounds->y());
         *srcOffset = SkIPoint::Make(bounds->x(), bounds->y());
         *dst = device->accessBitmap(false);
         return true;
     }
 }
 
+// Return a larger (newWidth x newHeight) copy of 'src' with black padding
+// around it.
+static SkSpecialImage* pad_image(SkSpecialImage* src,
+                                 int newWidth, int newHeight, int offX, int offY) {
+
+    SkImageInfo info = SkImageInfo::MakeN32Premul(newWidth, newHeight);
+    SkAutoTUnref<SkSpecialSurface> surf(src->newSurface(info));
+    if (!surf) {
+        return nullptr;
+    }
+
+    SkCanvas* canvas = surf->getCanvas();
+    if (!canvas) {
+        return nullptr;
+    }
+
+    canvas->clear(0x0);
+
+    src->draw(canvas, offX, offY, nullptr);
+
+    return surf->newImageSnapshot();
+}
+
+SkSpecialImage* SkImageFilter::applyCropRect(const Context& ctx,
+                                             SkSpecialImage* src,
+                                             SkIPoint* srcOffset,
+                                             SkIRect* bounds) const {
+    SkIRect srcBounds;
+    srcBounds = SkIRect::MakeXYWH(srcOffset->fX, srcOffset->fY, src->width(), src->height());
+
+    SkIRect dstBounds;
+    this->onFilterNodeBounds(srcBounds, ctx.ctm(), &dstBounds, kForward_MapDirection);
+    fCropRect.applyTo(dstBounds, ctx.ctm(), bounds);
+    if (!bounds->intersect(ctx.clipBounds())) {
+        return nullptr;
+    }
+
+    if (srcBounds.contains(*bounds)) {
+        return SkRef(src);
+    } else {
+        SkSpecialImage* img = pad_image(src,
+                                        bounds->width(), bounds->height(),
+                                        srcOffset->x() - bounds->x(),
+                                        srcOffset->y() - bounds->y());
+        *srcOffset = SkIPoint::Make(bounds->x(), bounds->y());
+        return img;
+    }
+}
+
 bool SkImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
                                    SkIRect* dst, MapDirection direction) const {
     if (fInputCount < 1) {
         *dst = src;
         return true;
     }
 
     SkIRect totalBounds;
     for (int i = 0; i < fInputCount; ++i) {
         SkImageFilter* filter = this->getInput(i);
@@ skipping 38 matching lines @@
     return SkMatrixImageFilter::Create(matrix, filterQuality, input);
 }
 
 SkImageFilter* SkImageFilter::newWithLocalMatrix(const SkMatrix& matrix) const {
     // SkLocalMatrixImageFilter takes SkImage* in its factory, but logically that parameter
     // is *always* treated as a const ptr. Hence the const-cast here.
     //
     return SkLocalMatrixImageFilter::Create(matrix, const_cast<SkImageFilter*>(this));
 }
 
+SkSpecialImage* SkImageFilter::filterInput(int index,
+                                           SkSpecialImage* src,
+                                           const Context& ctx,
+                                           SkIPoint* offset) const {
+    SkImageFilter* input = this->getInput(index);
+    if (!input) {
+        return SkRef(src);
+    }
+
+    return input->filterImage(src, this->mapContext(ctx), offset);
+}
+
 #if SK_SUPPORT_GPU
 
 bool SkImageFilter::filterInputGPUDeprecated(int index, SkImageFilter::Proxy* proxy,
                                              const SkBitmap& src, const Context& ctx,
                                              SkBitmap* result, SkIPoint* offset) const {
     SkImageFilter* input = this->getInput(index);
     if (!input) {
         return true;
     }
     // Ensure that GrContext calls under filterImage and filterImageGPU below will see an identity
@@ skipping 187 matching lines @@
     }
     return dev;
 }
 
 bool SkImageFilter::DeviceProxy::filterImage(const SkImageFilter* filter, const SkBitmap& src,
                                        const SkImageFilter::Context& ctx,
                                        SkBitmap* result, SkIPoint* offset) {
     return fDevice->filterImage(filter, src, ctx, result, offset);
 }