Moving 4 SkImageFilter derived classes from blink to skia

src/effects/SkOffsetImageFilter.cpp

Index: src/effects/SkOffsetImageFilter.cpp
diff --git a/src/effects/SkOffsetImageFilter.cpp b/src/effects/SkOffsetImageFilter.cpp
index ad5e49d776256b8e0c54deb17ca73ed9681dd056..3b98160841bbef6840f2b837592811eb92ad343a 100644
--- a/src/effects/SkOffsetImageFilter.cpp
+++ b/src/effects/SkOffsetImageFilter.cpp
@@ -7,24 +7,51 @@
 
 #include "SkOffsetImageFilter.h"
 #include "SkBitmap.h"
-#include "SkMatrix.h"
+#include "SkCanvas.h"
+#include "SkDevice.h"
 #include "SkFlattenableBuffers.h"
+#include "SkMatrix.h"
+#include "SkPaint.h"
 
 bool SkOffsetImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source,
                                         const SkMatrix& matrix,
                                         SkBitmap* result,
                                         SkIPoint* loc) {
+    SkImageFilter* input = getInput(0);
     SkBitmap src = source;
-    if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, loc)) {
-        return false;
-    }
+    if (cropRect().isLargest()) {
+        if (input && !input->filterImage(proxy, source, matrix, &src, loc)) {
+            return false;
+        }
 
-    SkVector vec;
-    matrix.mapVectors(&vec, &fOffset, 1);
+        SkVector vec;
+        matrix.mapVectors(&vec, &fOffset, 1);
 
-    loc->fX += SkScalarRoundToInt(vec.fX);
-    loc->fY += SkScalarRoundToInt(vec.fY);
-    *result = src;
+        loc->fX += SkScalarRoundToInt(vec.fX);
+        loc->fY += SkScalarRoundToInt(vec.fY);
+        *result = src;
+    } else {
+        SkIPoint srcOffset = SkIPoint::Make(0, 0);

[sugoi1, 2013/09/23 18:37:30]

@senorblanco : Was there a reason here why we aren't using "loc" directly and
provide a (0,0) point instead ?

[Stephen White, 2013/09/24 01:13:19]

Since this path draws its input into a buffer, it's applying the upstream offset
at draw time. We don't want to return it via the outparam, since that would
cause it to be applied twice. Note that other compositing filters (e.g.,
SkXfermodeImageFilter, SkMergeImageFilter) do the same.

[sugoi1, 2013/09/24 11:39:50]

Thanks for the explanation, I wanted to make sure this was desired and not
something on a TODO list :)

+        if (input && !input->filterImage(proxy, source, matrix, &src, &srcOffset)) {
+            return false;
+        }
+
+        SkIRect bounds;
+        src.getBounds(&bounds);
+
+        if (!applyCropRect(&bounds, matrix)) {
+            return false;
+        }
+
+        SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
+        SkCanvas canvas(device);
+        SkPaint paint;
+        paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+        canvas.drawBitmap(src, fOffset.fX - bounds.left(), fOffset.fY - bounds.top(), &paint);
+        *result = device->accessBitmap(false);
+        loc->fX += bounds.left();
+        loc->fY += bounds.top();
+    }
     return true;
 }
 
@@ -43,8 +70,8 @@ void SkOffsetImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     buffer.writePoint(fOffset);
 }
 
-SkOffsetImageFilter::SkOffsetImageFilter(SkScalar dx, SkScalar dy,
-                                         SkImageFilter* input) : INHERITED(input) {
+SkOffsetImageFilter::SkOffsetImageFilter(SkScalar dx, SkScalar dy, SkImageFilter* input,
+                                         const SkIRect* cropRect) : INHERITED(input, cropRect) {
     fOffset.set(dx, dy);
 }