Reland "Hide SkEncodedInfo"

This partially reverts commit
1793e7bb46c1f9d430c1a699a1c3d3168159b659.

Hide SkEncodedInfo

Bug: skia:7353
Bug: skia:6839

This contains information that is not necessary for clients to know. The
Color enum tells the number of components in the input, but this is only
interesting internally (to the SkSwizzler).

Similarly, the Alpha enum differs from SkAlphaType in that it has
kBinary instead of kPremul. This is useful information only internally
for determining whether the SkColorSpaceXform needs to premultiply.

The bitsPerComponent is potentially useful for a client; Android (in
SkAndroidCodec) uses it to determine the SkColorType. Rather than
exposing bitsPerComponent, make SkAndroidCodec a friend so it can
access the SkEncodedInfo. A future change will change SkCodec to
recommend F16 for bitsPerComponent > 8, but that will be more involved;
it was the reason for the revert of this CL.

Switch conversionSupported to use an SkColorType, which is enough info.

Replace the SkEncodedInfo::Alpha field on SkCodec::FrameInfo with an
SkAlphaType.

SkCodec still needs an SkEncodedInfo, so move its header (which is
already not SK_API) to include/private.

TBR=mtklein@chromium.org,reed@google.com
Change-Id: I928b1f55317602cb37d29da63b53026c8d139cee
Reviewed-on: https://skia-review.googlesource.com/80860
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>

11 files changed, 31 insertions, 32 deletions

diff --git a/src/codec/SkAndroidCodec.cpp b/src/codec/SkAndroidCodec.cpp
index cd23680932..a694b4b916 100644
--- a/src/codec/SkAndroidCodec.cpp
+++ b/src/codec/SkAndroidCodec.cpp
@@ -64,10 +64,6 @@ SkAndroidCodec::SkAndroidCodec(SkCodec* codec)
 
 SkAndroidCodec::~SkAndroidCodec() {}
 
-const SkEncodedInfo& SkAndroidCodec::getEncodedInfo() const {
-    return fCodec->getEncodedInfo();
-}
-
 std::unique_ptr<SkAndroidCodec> SkAndroidCodec::MakeFromStream(std::unique_ptr<SkStream> stream, SkPngChunkReader* chunkReader) {
     auto codec = SkCodec::MakeFromStream(std::move(stream), nullptr, chunkReader);
     if (nullptr == codec) {
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index a0f1fb2706..7de083db3c 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -158,7 +158,7 @@ SkCodec::SkCodec(const SkEncodedInfo& info, const SkImageInfo& imageInfo,
 
 SkCodec::~SkCodec() {}
 
-bool SkCodec::conversionSupported(const SkImageInfo& dst, SkEncodedInfo::Color srcColor,
+bool SkCodec::conversionSupported(const SkImageInfo& dst, SkColorType srcColor,
                                   bool srcIsOpaque, const SkColorSpace* srcCS) const {
     if (!valid_alpha(dst.alphaType(), srcIsOpaque)) {
         return false;
@@ -173,7 +173,7 @@ bool SkCodec::conversionSupported(const SkImageInfo& dst, SkEncodedInfo::Color s
         case kRGB_565_SkColorType:
             return srcIsOpaque;
         case kGray_8_SkColorType:
-            return SkEncodedInfo::kGray_Color == srcColor && srcIsOpaque &&
+            return kGray_8_SkColorType == srcColor && srcIsOpaque &&
                    !needs_color_xform(dst, srcCS, false);
         case kAlpha_8_SkColorType:
             // conceptually we can convert anything into alpha_8, but we haven't actually coded
@@ -224,7 +224,7 @@ SkCodec::Result SkCodec::handleFrameIndex(const SkImageInfo& info, void* pixels,
                                           const Options& options) {
     const int index = options.fFrameIndex;
     if (0 == index) {
-        if (!this->conversionSupported(info, fEncodedInfo.color(), fEncodedInfo.opaque(),
+        if (!this->conversionSupported(info, fSrcInfo.colorType(), fEncodedInfo.opaque(),
                                       fSrcInfo.colorSpace())
             || !this->initializeColorXform(info, fEncodedInfo.alpha(), options.fPremulBehavior))
         {
@@ -253,7 +253,7 @@ SkCodec::Result SkCodec::handleFrameIndex(const SkImageInfo& info, void* pixels,
     const auto* frame = frameHolder->getFrame(index);
     SkASSERT(frame);
 
-    if (!this->conversionSupported(info, fEncodedInfo.color(), !frame->hasAlpha(),
+    if (!this->conversionSupported(info, fSrcInfo.colorType(), !frame->hasAlpha(),
                                    fSrcInfo.colorSpace())) {
         return kInvalidConversion;
     }
@@ -297,9 +297,7 @@ SkCodec::Result SkCodec::handleFrameIndex(const SkImageInfo& info, void* pixels,
         }
     }
 
-    FrameInfo frameInfo;
-    SkAssertResult(this->getFrameInfo(index, &frameInfo));
-    return this->initializeColorXform(info, frameInfo.fAlpha, options.fPremulBehavior)
+    return this->initializeColorXform(info, frame->reportedAlpha(), options.fPremulBehavior)
         ? kSuccess : kInvalidConversion;
 }
 
@@ -630,6 +628,10 @@ bool SkCodec::initializeColorXform(const SkImageInfo& dstInfo, SkEncodedInfo::Al
     if (!this->usesColorXform()) {
         return true;
     }
+    // FIXME: In SkWebpCodec, if a frame is blending with a prior frame, we don't need
+    // a colorXform to do a color correct premul, since the blend step will handle
+    // premultiplication. But there is no way to know whether we need to blend from
+    // inside this call.
     bool needsColorCorrectPremul = needs_premul(dstInfo.alphaType(), encodedAlpha) &&
                                    SkTransferFunctionBehavior::kRespect == premulBehavior;
     if (needs_color_xform(dstInfo, fSrcInfo.colorSpace(), needsColorCorrectPremul)) {
diff --git a/src/codec/SkFrameHolder.h b/src/codec/SkFrameHolder.h
index 29539ff908..ab308b39db 100644
--- a/src/codec/SkFrameHolder.h
+++ b/src/codec/SkFrameHolder.h
@@ -40,14 +40,14 @@ public:
     int frameId() const { return fId; }
 
     /**
-     *  Whether this frame reports alpha.
+     *  How this frame reports its alpha.
      *
      *  This only considers the rectangle of this frame, and
      *  considers it to have alpha even if it is opaque once
      *  blended with the frame behind it.
      */
-    bool reportsAlpha() const {
-        return this->onReportsAlpha();
+    SkEncodedInfo::Alpha reportedAlpha() const {
+        return this->onReportedAlpha();
     }
 
     /**
@@ -130,7 +130,7 @@ public:
     }
 
 protected:
-    virtual bool onReportsAlpha() const = 0;
+    virtual SkEncodedInfo::Alpha onReportedAlpha() const = 0;
 
 private:
     static constexpr int kUninitialized = -2;
@@ -166,7 +166,7 @@ public:
 
     /**
      *  Compute the opacity and required frame, based on
-     *  whether the frame reportsAlpha and how it blends
+     *  the frame's reportedAlpha and how it blends
      *  with prior frames.
      */
     void setAlphaAndRequiredFrame(SkFrame*);
diff --git a/src/codec/SkGifCodec.cpp b/src/codec/SkGifCodec.cpp
index 17c8617500..dff8136d75 100644
--- a/src/codec/SkGifCodec.cpp
+++ b/src/codec/SkGifCodec.cpp
@@ -144,8 +144,8 @@ bool SkGifCodec::onGetFrameInfo(int i, SkCodec::FrameInfo* frameInfo) const {
         frameInfo->fDuration = frameContext->getDuration();
         frameInfo->fRequiredFrame = frameContext->getRequiredFrame();
         frameInfo->fFullyReceived = frameContext->isComplete();
-        frameInfo->fAlpha = frameContext->hasAlpha() ? SkEncodedInfo::kBinary_Alpha
-                                                     : SkEncodedInfo::kOpaque_Alpha;
+        frameInfo->fAlphaType = frameContext->hasAlpha() ? kUnpremul_SkAlphaType
+                                                         : kOpaque_SkAlphaType;
         frameInfo->fDisposalMethod = frameContext->getDisposalMethod();
     }
     return true;
diff --git a/src/codec/SkHeifCodec.h b/src/codec/SkHeifCodec.h
index 6eb8e9c3b8..20bec6539e 100644
--- a/src/codec/SkHeifCodec.h
+++ b/src/codec/SkHeifCodec.h
@@ -47,7 +47,7 @@ protected:
         return SkEncodedImageFormat::kHEIF;
     }
 
-    bool conversionSupported(const SkImageInfo&, SkEncodedInfo::Color, bool,
+    bool conversionSupported(const SkImageInfo&, SkColorType, bool,
                              const SkColorSpace*) const override {
         // This class checks for conversion after creating colorXform.
         return true;
diff --git a/src/codec/SkIcoCodec.h b/src/codec/SkIcoCodec.h
index 06ddeba9b4..c43fcf8cc0 100644
--- a/src/codec/SkIcoCodec.h
+++ b/src/codec/SkIcoCodec.h
@@ -48,7 +48,7 @@ protected:
 
     SkScanlineOrder onGetScanlineOrder() const override;
 
-    bool conversionSupported(const SkImageInfo&, SkEncodedInfo::Color, bool,
+    bool conversionSupported(const SkImageInfo&, SkColorType, bool,
                              const SkColorSpace*) const override {
         // This will be checked by the embedded codec.
         return true;
diff --git a/src/codec/SkJpegCodec.h b/src/codec/SkJpegCodec.h
index 41814d2ead..7fab209b6e 100644
--- a/src/codec/SkJpegCodec.h
+++ b/src/codec/SkJpegCodec.h
@@ -58,7 +58,7 @@ protected:
 
     bool onDimensionsSupported(const SkISize&) override;
 
-    bool conversionSupported(const SkImageInfo&, SkEncodedInfo::Color, bool,
+    bool conversionSupported(const SkImageInfo&, SkColorType, bool,
                              const SkColorSpace*) const override {
         // This class checks for conversion after creating colorXform.
         return true;
diff --git a/src/codec/SkWbmpCodec.cpp b/src/codec/SkWbmpCodec.cpp
index 63380e109c..d8b10287f6 100644
--- a/src/codec/SkWbmpCodec.cpp
+++ b/src/codec/SkWbmpCodec.cpp
@@ -108,7 +108,7 @@ SkEncodedImageFormat SkWbmpCodec::onGetEncodedFormat() const {
     return SkEncodedImageFormat::kWBMP;
 }
 
-bool SkWbmpCodec::conversionSupported(const SkImageInfo& dst, SkEncodedInfo::Color srcColor,
+bool SkWbmpCodec::conversionSupported(const SkImageInfo& dst, SkColorType /*srcColor*/,
                                       bool srcIsOpaque, const SkColorSpace* srcCS) const {
     return valid_color_type(dst) && valid_alpha(dst.alphaType(), srcIsOpaque);
 }
diff --git a/src/codec/SkWbmpCodec.h b/src/codec/SkWbmpCodec.h
index 57efe21e3b..192189d1ec 100644
--- a/src/codec/SkWbmpCodec.h
+++ b/src/codec/SkWbmpCodec.h
@@ -28,7 +28,7 @@ protected:
     Result onGetPixels(const SkImageInfo&, void*, size_t,
                        const Options&, int*) override;
     bool onRewind() override;
-    bool conversionSupported(const SkImageInfo& dst, SkEncodedInfo::Color srcColor,
+    bool conversionSupported(const SkImageInfo& dst, SkColorType srcColor,
                              bool srcIsOpaque, const SkColorSpace* srcCS) const override;
     // No need to Xform; all pixels are either black or white.
     bool usesColorXform() const override { return false; }
diff --git a/src/codec/SkWebpCodec.cpp b/src/codec/SkWebpCodec.cpp
index d5614d6213..2ff4681337 100644
--- a/src/codec/SkWebpCodec.cpp
+++ b/src/codec/SkWebpCodec.cpp
@@ -192,7 +192,8 @@ static WEBP_CSP_MODE webp_decode_mode(SkColorType dstCT, bool premultiply) {
 
 SkWebpCodec::Frame* SkWebpCodec::FrameHolder::appendNewFrame(bool hasAlpha) {
     const int i = this->size();
-    fFrames.emplace_back(i, hasAlpha);
+    fFrames.emplace_back(i, hasAlpha ? SkEncodedInfo::kUnpremul_Alpha
+                                     : SkEncodedInfo::kOpaque_Alpha);
     return &fFrames[i];
 }
 
@@ -300,8 +301,8 @@ bool SkWebpCodec::onGetFrameInfo(int i, FrameInfo* frameInfo) const {
         // libwebp only reports fully received frames for an
         // animated image.
         frameInfo->fFullyReceived = true;
-        frameInfo->fAlpha = frame->hasAlpha() ? SkEncodedInfo::kUnpremul_Alpha
-                                              : SkEncodedInfo::kOpaque_Alpha;
+        frameInfo->fAlphaType = frame->hasAlpha() ? kUnpremul_SkAlphaType
+                                                  : kOpaque_SkAlphaType;
         frameInfo->fDisposalMethod = frame->getDisposalMethod();
     }
 
diff --git a/src/codec/SkWebpCodec.h b/src/codec/SkWebpCodec.h
index 134dafa3d5..010771bcff 100644
--- a/src/codec/SkWebpCodec.h
+++ b/src/codec/SkWebpCodec.h
@@ -58,22 +58,22 @@ private:
 
     class Frame : public SkFrame {
     public:
-        Frame(int i, bool alpha)
+        Frame(int i, SkEncodedInfo::Alpha alpha)
             : INHERITED(i)
-            , fReportsAlpha(alpha)
+            , fReportedAlpha(alpha)
         {}
         Frame(Frame&& other)
             : INHERITED(other.frameId())
-            , fReportsAlpha(other.fReportsAlpha)
+            , fReportedAlpha(other.fReportedAlpha)
         {}
 
     protected:
-        bool onReportsAlpha() const override {
-            return fReportsAlpha;
+        SkEncodedInfo::Alpha onReportedAlpha() const override {
+            return fReportedAlpha;
         }
 
     private:
-        const bool fReportsAlpha;
+        const SkEncodedInfo::Alpha fReportedAlpha;
 
         typedef SkFrame INHERITED;
     };