Simplify flattening to just write enough to call the factory

src/effects/SkMatrixConvolutionImageFilter.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 "SkMatrixConvolutionImageFilter.h"
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkRect.h"
 #include "SkUnPreMultiply.h"
 
 #if SK_SUPPORT_GPU
 #include "effects/GrMatrixConvolutionEffect.h"
 #endif
 
-static bool tile_mode_is_valid(SkMatrixConvolutionImageFilter::TileMode tileMode) {
-    switch (tileMode) {
-    case SkMatrixConvolutionImageFilter::kClamp_TileMode:
-    case SkMatrixConvolutionImageFilter::kRepeat_TileMode:
-    case SkMatrixConvolutionImageFilter::kClampToBlack_TileMode:
-        return true;
-    default:
-        break;
-    }
-    return false;
-}
-
 SkMatrixConvolutionImageFilter::SkMatrixConvolutionImageFilter(
     const SkISize& kernelSize,
     const SkScalar* kernel,
     SkScalar gain,
     SkScalar bias,
     const SkIPoint& kernelOffset,
     TileMode tileMode,
     bool convolveAlpha,
     SkImageFilter* input,
     const CropRect* cropRect)
   : INHERITED(1, &input, cropRect),
     fKernelSize(kernelSize),
     fGain(gain),
     fBias(bias),
     fKernelOffset(kernelOffset),
     fTileMode(tileMode),
     fConvolveAlpha(convolveAlpha) {
     uint32_t size = fKernelSize.fWidth * fKernelSize.fHeight;
     fKernel = SkNEW_ARRAY(SkScalar, size);
     memcpy(fKernel, kernel, size * sizeof(SkScalar));
     SkASSERT(kernelSize.fWidth >= 1 && kernelSize.fHeight >= 1);
     SkASSERT(kernelOffset.fX >= 0 && kernelOffset.fX < kernelSize.fWidth);
     SkASSERT(kernelOffset.fY >= 0 && kernelOffset.fY < kernelSize.fHeight);
 }
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+static bool tile_mode_is_valid(SkMatrixConvolutionImageFilter::TileMode tileMode) {
+    switch (tileMode) {
+        case SkMatrixConvolutionImageFilter::kClamp_TileMode:
+        case SkMatrixConvolutionImageFilter::kRepeat_TileMode:
+        case SkMatrixConvolutionImageFilter::kClampToBlack_TileMode:
+            return true;
+        default:
+            break;
+    }
+    return false;
+}
+
 SkMatrixConvolutionImageFilter::SkMatrixConvolutionImageFilter(SkReadBuffer& buffer)
     : INHERITED(1, buffer) {
     // We need to be able to read at most SK_MaxS32 bytes, so divide that
     // by the size of a scalar to know how many scalars we can read.
     static const int32_t kMaxSize = SK_MaxS32 / sizeof(SkScalar);
     fKernelSize.fWidth = buffer.readInt();
     fKernelSize.fHeight = buffer.readInt();
     if ((fKernelSize.fWidth >= 1) && (fKernelSize.fHeight >= 1) &&
         // Make sure size won't be larger than a signed int,
         // which would still be extremely large for a kernel,
@@ skipping 12 matching lines @@
     fKernelOffset.fY = buffer.readInt();
     fTileMode = (TileMode) buffer.readInt();
     fConvolveAlpha = buffer.readBool();
     buffer.validate((fKernel != 0) &&
                     SkScalarIsFinite(fGain) &&
                     SkScalarIsFinite(fBias) &&
                     tile_mode_is_valid(fTileMode) &&
                     (fKernelOffset.fX >= 0) && (fKernelOffset.fX < fKernelSize.fWidth) &&
                     (fKernelOffset.fY >= 0) && (fKernelOffset.fY < fKernelSize.fHeight));
 }
+#endif
+
+SkFlattenable* SkMatrixConvolutionImageFilter::CreateProc(SkReadBuffer& buffer) {
+    SK_IMAGEFILTER_UNFLATTEN_COMMON(1);
+    SkISize kernelSize;
+    kernelSize.fWidth = buffer.readInt();
+    kernelSize.fHeight = buffer.readInt();
+    const int count = buffer.getArrayCount();
+    if (!buffer.validate(kernelSize.width() * kernelSize.height() == count)) {

[Stephen White, 2014/08/18 18:17:26]

Alexis should look at this. It looks like there's a potential for int 
overflow here, from which the old code above protected us.

[reed1, 2014/08/18 22:39:16]

Done.

+        return NULL;
+    }
+    SkAutoSTArray<16, SkScalar> kernel(count);
+    if (!buffer.readScalarArray(kernel.get(), count)) {
+        return NULL;
+    }
+    SkScalar gain = buffer.readScalar();
+    SkScalar bias = buffer.readScalar();
+    SkIPoint kernelOffset;
+    kernelOffset.fX = buffer.readInt();
+    kernelOffset.fY = buffer.readInt();
+    TileMode tileMode = (TileMode)buffer.readInt();
+    bool convolveAlpha = buffer.readBool();
+    return Create(kernelSize, kernel.get(), gain, bias, kernelOffset, tileMode, convolveAlpha,
+                  common.inputAt(0), &common.cropRect());
+}
 
 void SkMatrixConvolutionImageFilter::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeInt(fKernelSize.fWidth);
     buffer.writeInt(fKernelSize.fHeight);
     buffer.writeScalarArray(fKernel, fKernelSize.fWidth * fKernelSize.fHeight);
     buffer.writeScalar(fGain);
     buffer.writeScalar(fBias);
     buffer.writeInt(fKernelOffset.fX);
     buffer.writeInt(fKernelOffset.fY);
@@ skipping 248 matching lines @@
                                                 fKernelSize,
                                                 fKernel,
                                                 fGain,
                                                 fBias,
                                                 fKernelOffset,
                                                 convert_tilemodes(fTileMode),
                                                 fConvolveAlpha);
     return true;
 }
 #endif