Add GM to test out blurmaskfilter occluders

src/effects/SkBlurMaskFilter.cpp

 /*
  * Copyright 2006 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 "SkBlurMaskFilter.h"
 #include "SkBlurMask.h"
 #include "SkGpuBlurUtils.h"
@@ skipping 20 matching lines @@
 #include "glsl/GrGLSLSampler.h"
 #include "glsl/GrGLSLUniformHandler.h"
 #endif
 
 SkScalar SkBlurMaskFilter::ConvertRadiusToSigma(SkScalar radius) {
     return SkBlurMask::ConvertRadiusToSigma(radius);
 }
 
 class SkBlurMaskFilterImpl : public SkMaskFilter {
 public:
-    SkBlurMaskFilterImpl(SkScalar sigma, SkBlurStyle, uint32_t flags);
+    SkBlurMaskFilterImpl(SkScalar sigma, SkBlurStyle, const SkRect& occluder, uint32_t flags);
 
     // overrides from SkMaskFilter
     SkMask::Format getFormat() const override;
     bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix&,
                     SkIPoint* margin) const override;
 
 #if SK_SUPPORT_GPU
     bool canFilterMaskGPU(const SkRRect& devRRect,
                           const SkIRect& clipBounds,
                           const SkMatrix& ctm,
@@ skipping 37 matching lines @@
                         SkIPoint* margin, SkMask::CreateMode createMode) const;
     bool filterRRectMask(SkMask* dstM, const SkRRect& r, const SkMatrix& matrix,
                         SkIPoint* margin, SkMask::CreateMode createMode) const;
 
 private:
     // To avoid unseemly allocation requests (esp. for finite platforms like
     // handset) we limit the radius so something manageable. (as opposed to
     // a request like 10,000)
     static const SkScalar kMAX_BLUR_SIGMA;
 
+    // This flag should never escape from serialization
+    static const int kInternalFlag_HasOccluder = 0x08;
+
     SkScalar    fSigma;
     SkBlurStyle fBlurStyle;
+    SkRect      fOccluder;
     uint32_t    fBlurFlags;
 
     SkBlurQuality getQuality() const {
         return (fBlurFlags & SkBlurMaskFilter::kHighQuality_BlurFlag) ?
                 kHigh_SkBlurQuality : kLow_SkBlurQuality;
     }
 
     SkBlurMaskFilterImpl(SkReadBuffer&);
     void flatten(SkWriteBuffer&) const override;
 
     SkScalar computeXformedSigma(const SkMatrix& ctm) const {
         bool ignoreTransform = SkToBool(fBlurFlags & SkBlurMaskFilter::kIgnoreTransform_BlurFlag);
 
         SkScalar xformedSigma = ignoreTransform ? fSigma : ctm.mapRadius(fSigma);
         return SkMinScalar(xformedSigma, kMAX_BLUR_SIGMA);
     }
 
     friend class SkBlurMaskFilter;
 
     typedef SkMaskFilter INHERITED;
 };
 
 const SkScalar SkBlurMaskFilterImpl::kMAX_BLUR_SIGMA = SkIntToScalar(128);
 
-sk_sp<SkMaskFilter> SkBlurMaskFilter::Make(SkBlurStyle style, SkScalar sigma, uint32_t flags) {
+sk_sp<SkMaskFilter> SkBlurMaskFilter::Make(SkBlurStyle style, SkScalar sigma, 
+                                           const SkRect& occluder, uint32_t flags) {
     if (!SkScalarIsFinite(sigma) || sigma <= 0) {
         return nullptr;
     }
     if ((unsigned)style > (unsigned)kLastEnum_SkBlurStyle) {
         return nullptr;
     }
-    if (flags > SkBlurMaskFilter::kAll_BlurFlag) {
-        return nullptr;
-    }
-    return sk_sp<SkMaskFilter>(new SkBlurMaskFilterImpl(sigma, style, flags));
+    SkASSERT(flags <= SkBlurMaskFilter::kAll_BlurFlag);
+    flags &= SkBlurMaskFilter::kAll_BlurFlag;
+
+    return sk_sp<SkMaskFilter>(new SkBlurMaskFilterImpl(sigma, style, occluder, flags));
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-SkBlurMaskFilterImpl::SkBlurMaskFilterImpl(SkScalar sigma, SkBlurStyle style, uint32_t flags)
+SkBlurMaskFilterImpl::SkBlurMaskFilterImpl(SkScalar sigma, SkBlurStyle style,
+                                           const SkRect& occluder, uint32_t flags)
     : fSigma(sigma)
     , fBlurStyle(style)
+    , fOccluder(occluder)
     , fBlurFlags(flags) {
     SkASSERT(fSigma > 0);
     SkASSERT((unsigned)style <= kLastEnum_SkBlurStyle);
+    fOccluder.sort();
     SkASSERT(flags <= SkBlurMaskFilter::kAll_BlurFlag);
 }
 
 SkMask::Format SkBlurMaskFilterImpl::getFormat() const {
     return SkMask::kA8_Format;
 }
 
 bool SkBlurMaskFilterImpl::asABlur(BlurRec* rec) const {
     if (fBlurFlags & SkBlurMaskFilter::kIgnoreTransform_BlurFlag) {
         return false;
@@ skipping 421 matching lines @@
     SkScalar pad = 3.0f * fSigma;
 
     dst->set(src.fLeft  - pad, src.fTop    - pad,
              src.fRight + pad, src.fBottom + pad);
 }
 
 sk_sp<SkFlattenable> SkBlurMaskFilterImpl::CreateProc(SkReadBuffer& buffer) {
     const SkScalar sigma = buffer.readScalar();
     const unsigned style = buffer.readUInt();
     const unsigned flags = buffer.readUInt();
+
+    SkRect occluder;
+    if (flags & kInternalFlag_HasOccluder) {
+        buffer.readRect(&occluder);
+    } else {
+        occluder.setEmpty();
+    }
+
     if (style <= kLastEnum_SkBlurStyle) {
-        return SkBlurMaskFilter::Make((SkBlurStyle)style, sigma, flags);
+        return SkBlurMaskFilter::Make((SkBlurStyle)style, sigma, occluder,
+                                      flags & ~kInternalFlag_HasOccluder);
     }
     return nullptr;
 }
 
 void SkBlurMaskFilterImpl::flatten(SkWriteBuffer& buffer) const {
     buffer.writeScalar(fSigma);
     buffer.writeUInt(fBlurStyle);
-    buffer.writeUInt(fBlurFlags);
+
+    SkASSERT(!(fBlurFlags & kInternalFlag_HasOccluder));
+    buffer.writeUInt(fBlurFlags | kInternalFlag_HasOccluder);
+
+    buffer.writeRect(fOccluder);
 }
 
 #if SK_SUPPORT_GPU
 
 class GrGLRectBlurEffect;
 
 class GrRectBlurEffect : public GrFragmentProcessor {
 public:
     ~GrRectBlurEffect() override { }
 
@@ skipping 702 matching lines @@
     } else {
         str->append("None");
     }
     str->append("))");
 }
 #endif
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkBlurMaskFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBlurMaskFilterImpl)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END