Simplify flattening to just write enough to call the factory/public-constructor for the class. We want to *not* rely on private constructors, and not rely on calling through the inheritance hierarchy for either flattening or unflattening(CreateProc).

Refactoring pattern:

1. guard the existing constructor(readbuffer) with the legacy build-flag
2. If you are a instancable subclass, implement CreateProc(readbuffer) to create a new instances from the buffer params (or return NULL).

If you're a shader subclass
1. You must read/write the local matrix if your class accepts that in its factory/constructor, else ignore it.

R=robertphillips@google.com, mtklein@google.com, senorblanco@google.com, senorblanco@chromium.org, sugoi@chromium.org

Author: reed@google.com

Review URL: https://codereview.chromium.org/395603002

1 files changed, 41 insertions, 2 deletions

diff --git a/src/effects/gradients/SkTwoPointConicalGradient.cpp b/src/effects/gradients/SkTwoPointConicalGradient.cpp
index 91856c88a2..9284e7cb09 100644
--- a/src/effects/gradients/SkTwoPointConicalGradient.cpp
+++ b/src/effects/gradients/SkTwoPointConicalGradient.cpp
@@ -343,6 +343,7 @@ SkShader::GradientType SkTwoPointConicalGradient::asAGradient(
     return kConical_GradientType;
 }
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
 SkTwoPointConicalGradient::SkTwoPointConicalGradient(
     SkReadBuffer& buffer)
     : INHERITED(buffer),
@@ -366,9 +367,47 @@ SkTwoPointConicalGradient::SkTwoPointConicalGradient(
     }
     this->init();
 };
+#endif
+
+SkFlattenable* SkTwoPointConicalGradient::CreateProc(SkReadBuffer& buffer) {
+    DescriptorScope desc;
+    if (!desc.unflatten(buffer)) {
+        return NULL;
+    }
+    SkPoint c1 = buffer.readPoint();
+    SkPoint c2 = buffer.readPoint();
+    SkScalar r1 = buffer.readScalar();
+    SkScalar r2 = buffer.readScalar();
+
+    if (buffer.readBool()) {    // flipped
+        SkTSwap(c1, c2);
+        SkTSwap(r1, r2);
+
+        SkColor* colors = desc.mutableColors();
+        SkScalar* pos = desc.mutablePos();
+        const int last = desc.fCount - 1;
+        const int half = desc.fCount >> 1;
+        for (int i = 0; i < half; ++i) {
+            SkTSwap(colors[i], colors[last - i]);
+            if (pos) {
+                SkScalar tmp = pos[i];
+                pos[i] = SK_Scalar1 - pos[last - i];
+                pos[last - i] = SK_Scalar1 - tmp;
+            }
+        }
+        if (pos) {
+            if (desc.fCount & 1) {
+                pos[half] = SK_Scalar1 - pos[half];
+            }
+        }
+    }
+
+    return SkGradientShader::CreateTwoPointConical(c1, r1, c2, r2, desc.fColors, desc.fPos,
+                                                   desc.fCount, desc.fTileMode, desc.fGradFlags,
+                                                   desc.fLocalMatrix);
+}
 
-void SkTwoPointConicalGradient::flatten(
-    SkWriteBuffer& buffer) const {
+void SkTwoPointConicalGradient::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writePoint(fCenter1);
     buffer.writePoint(fCenter2);