Add F16, SkColorSpaceXform support to SkGifCodec

BUG=skia:4895

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4396

Change-Id: I7c521760891852daf4f3933ecf02dc08acec64c0
Reviewed-on: https://skia-review.googlesource.com/4396
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

7 files changed, 80 insertions, 46 deletions

diff --git a/infra/bots/assets/skimage/VERSION b/infra/bots/assets/skimage/VERSION
index 9a037142aa..b4de394767 100644
--- a/infra/bots/assets/skimage/VERSION
+++ b/infra/bots/assets/skimage/VERSION
@@ -1 +1 @@
-10
\ No newline at end of file
+11
diff --git a/infra/bots/tasks.json b/infra/bots/tasks.json
index 0f4f3162cb..06600aa6f4 100644
--- a/infra/bots/tasks.json
+++ b/infra/bots/tasks.json
@@ -172,7 +172,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:10"
+          "version": "version:11"
         },
         {
           "name": "skia/bots/skp",
@@ -219,7 +219,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:10"
+          "version": "version:11"
         },
         {
           "name": "skia/bots/skp",
@@ -265,7 +265,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:10"
+          "version": "version:11"
         },
         {
           "name": "skia/bots/skp",
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index 2673d2ea9f..739c9cd673 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -472,7 +472,8 @@ void SkCodec::fillIncompleteImage(const SkImageInfo& info, void* dst, size_t row
 
 bool SkCodec::initializeColorXform(const SkImageInfo& dstInfo) {
     fColorXform = nullptr;
-    if (needs_color_xform(dstInfo, fSrcInfo)) {
+    bool needsPremul = needs_premul(dstInfo, fEncodedInfo);
+    if (needs_color_xform(dstInfo, fSrcInfo, needsPremul)) {
         fColorXform = SkColorSpaceXform::New(fSrcInfo.colorSpace(), dstInfo.colorSpace());
         if (!fColorXform) {
             return false;
diff --git a/src/codec/SkCodecPriv.h b/src/codec/SkCodecPriv.h
index a13cdbba92..bf3ab291e2 100644
--- a/src/codec/SkCodecPriv.h
+++ b/src/codec/SkCodecPriv.h
@@ -344,15 +344,13 @@ static inline PackColorProc choose_pack_color_proc(bool isPremul, SkColorType co
     }
 }
 
-static inline bool needs_premul(const SkImageInfo& dstInfo, const SkImageInfo& srcInfo) {
+static inline bool needs_premul(const SkImageInfo& dstInfo, const SkEncodedInfo& encodedInfo) {
     return kPremul_SkAlphaType == dstInfo.alphaType() &&
-           kUnpremul_SkAlphaType == srcInfo.alphaType();
+           SkEncodedInfo::kUnpremul_Alpha == encodedInfo.alpha();
 }
 
-static inline bool needs_color_xform(const SkImageInfo& dstInfo, const SkImageInfo& srcInfo) {
-    // Color xform is necessary in order to correctly perform premultiply in linear space.
-    bool needsPremul = needs_premul(dstInfo, srcInfo);
-
+static inline bool needs_color_xform(const SkImageInfo& dstInfo, const SkImageInfo& srcInfo,
+                                     bool needsPremul) {
     // F16 is by definition a linear space, so we always must perform a color xform.
     bool isF16 = kRGBA_F16_SkColorType == dstInfo.colorType();
 
@@ -402,10 +400,10 @@ static inline bool conversion_possible(const SkImageInfo& dst, const SkImageInfo
         case kIndex_8_SkColorType:
             return kIndex_8_SkColorType == src.colorType();
         case kRGB_565_SkColorType:
-            return kOpaque_SkAlphaType == src.alphaType() && !needs_color_xform(dst, src);
+            return kOpaque_SkAlphaType == src.alphaType() && !needs_color_xform(dst, src, false);
         case kGray_8_SkColorType:
             return kGray_8_SkColorType == src.colorType() &&
-                   kOpaque_SkAlphaType == src.alphaType() && !needs_color_xform(dst, src);
+                   kOpaque_SkAlphaType == src.alphaType() && !needs_color_xform(dst, src, false);
         default:
             return false;
     }
diff --git a/src/codec/SkGifCodec.cpp b/src/codec/SkGifCodec.cpp
index 277da03191..e773ed71e9 100644
--- a/src/codec/SkGifCodec.cpp
+++ b/src/codec/SkGifCodec.cpp
@@ -145,12 +145,29 @@ int SkGifCodec::onGetRepetitionCount() {
 }
 
 void SkGifCodec::initializeColorTable(const SkImageInfo& dstInfo, size_t frameIndex) {
-    fCurrColorTable = fReader->getColorTable(dstInfo.colorType(), frameIndex);
-    fCurrColorTableIsReal = fCurrColorTable;
-    if (!fCurrColorTable) {
+    SkColorType colorTableColorType = dstInfo.colorType();
+    if (this->colorXform()) {
+        colorTableColorType = kRGBA_8888_SkColorType;
+    }
+
+    sk_sp<SkColorTable> currColorTable = fReader->getColorTable(colorTableColorType, frameIndex);
+    fCurrColorTableIsReal = currColorTable;
+    if (!fCurrColorTableIsReal) {
         // This is possible for an empty frame. Create a dummy with one value (transparent).
         SkPMColor color = SK_ColorTRANSPARENT;
         fCurrColorTable.reset(new SkColorTable(&color, 1));
+    } else if (this->colorXform() && !fXformOnDecode) {
+        SkPMColor dstColors[256];
+        SkColorSpaceXform::ColorFormat dstFormat = select_xform_format(dstInfo.colorType());
+        SkColorSpaceXform::ColorFormat srcFormat = SkColorSpaceXform::kRGBA_8888_ColorFormat;
+        SkAlphaType xformAlphaType = select_xform_alpha(dstInfo.alphaType(),
+                                                        this->getInfo().alphaType());
+        SkAssertResult(this->colorXform()->apply(dstFormat, dstColors, srcFormat,
+                                                 currColorTable->readColors(),
+                                                 currColorTable->count(), xformAlphaType));
+        fCurrColorTable.reset(new SkColorTable(dstColors, currColorTable->count()));
+    } else {
+        fCurrColorTable = std::move(currColorTable);
     }
 }
 
@@ -158,13 +175,17 @@ void SkGifCodec::initializeColorTable(const SkImageInfo& dstInfo, size_t frameIn
 SkCodec::Result SkGifCodec::prepareToDecode(const SkImageInfo& dstInfo, SkPMColor* inputColorPtr,
         int* inputColorCount, const Options& opts) {
     // Check for valid input parameters
-    if (!conversion_possible_ignore_color_space(dstInfo, this->getInfo())) {
+    if (!conversion_possible(dstInfo, this->getInfo()) || !this->initializeColorXform(dstInfo)) {
         return gif_error("Cannot convert input type to output type.\n", kInvalidConversion);
     }
 
-    if (dstInfo.colorType() == kRGBA_F16_SkColorType) {
-        // FIXME: This should be supported.
-        return gif_error("GIF does not yet support F16.\n", kInvalidConversion);
+    fXformOnDecode = false;
+    if (this->colorXform()) {
+        fXformOnDecode = apply_xform_on_decode(dstInfo.colorType(), this->getEncodedInfo().color());
+        if (fXformOnDecode) {
+            fXformBuffer.reset(new uint32_t[dstInfo.width()]);
+            sk_bzero(fXformBuffer.get(), dstInfo.width() * sizeof(uint32_t));
+        }
     }
 
     if (opts.fSubset) {
@@ -238,6 +259,14 @@ void SkGifCodec::initializeSwizzler(const SkImageInfo& dstInfo, size_t frameInde
     // frameRect, since it might extend beyond the edge of the frame.
     SkIRect swizzleRect = SkIRect::MakeLTRB(xBegin, 0, xEnd, 0);
 
+    SkImageInfo swizzlerInfo = dstInfo;
+    if (this->colorXform()) {
+        swizzlerInfo = swizzlerInfo.makeColorType(kRGBA_8888_SkColorType);
+        if (kPremul_SkAlphaType == dstInfo.alphaType()) {
+            swizzlerInfo = swizzlerInfo.makeAlphaType(kUnpremul_SkAlphaType);
+        }
+    }
+
     // The default Options should be fine:
     // - we'll ignore if the memory is zero initialized - unless we're the first frame, this won't
     //   matter anyway.
@@ -246,7 +275,7 @@ void SkGifCodec::initializeSwizzler(const SkImageInfo& dstInfo, size_t frameInde
     // We may not be able to use the real Options anyway, since getPixels does not store it (due to
     // a bug).
     fSwizzler.reset(SkSwizzler::CreateSwizzler(this->getEncodedInfo(),
-                    fCurrColorTable->readColors(), dstInfo, Options(), &swizzleRect));
+                    fCurrColorTable->readColors(), swizzlerInfo, Options(), &swizzleRect));
     SkASSERT(fSwizzler.get());
 }
 
@@ -436,6 +465,22 @@ uint64_t SkGifCodec::onGetFillValue(const SkImageInfo& dstInfo) const {
     return SK_ColorTRANSPARENT;
 }
 
+void SkGifCodec::applyXformRow(const SkImageInfo& dstInfo, void* dst, const uint8_t* src) const {
+    if (this->colorXform() && fXformOnDecode) {
+        fSwizzler->swizzle(fXformBuffer.get(), src);
+
+        const SkColorSpaceXform::ColorFormat dstFormat = select_xform_format(dstInfo.colorType());
+        const SkColorSpaceXform::ColorFormat srcFormat = SkColorSpaceXform::kRGBA_8888_ColorFormat;
+        const SkAlphaType xformAlphaType = select_xform_alpha(dstInfo.alphaType(),
+                                                              this->getInfo().alphaType());
+        const int xformWidth = get_scaled_dimension(dstInfo.width(), fSwizzler->sampleX());
+        SkAssertResult(this->colorXform()->apply(dstFormat, dst, srcFormat, fXformBuffer.get(),
+                                                 xformWidth, xformAlphaType));
+    } else {
+        fSwizzler->swizzle(dst, src);
+    }
+}
+
 bool SkGifCodec::haveDecodedRow(size_t frameIndex, const unsigned char* rowBegin,
                                 size_t rowNumber, unsigned repeatCount, bool writeTransparentPixels)
 {
@@ -524,27 +569,10 @@ bool SkGifCodec::haveDecodedRow(size_t frameIndex, const unsigned char* rowBegin
     // will "show through" the later ones.
     const auto dstInfo = this->dstInfo();
     if (writeTransparentPixels) {
-        fSwizzler->swizzle(dstLine, rowBegin);
+        this->applyXformRow(dstInfo, dstLine, rowBegin);
     } else {
-        // We cannot swizzle directly into the dst, since that will write the transparent pixels.
-        // Instead, swizzle into a temporary buffer, and copy that into the dst.
-        {
-            void* const memsetDst = fTmpBuffer.get();
-            // Although onGetFillValue returns a uint64_t, we only use the low eight bits. The
-            // return value is either an 8 bit index (for index8) or SK_ColorTRANSPARENT, which is
-            // all zeroes.
-            const int fillValue = (uint8_t) this->onGetFillValue(dstInfo);
-            const size_t rb = dstInfo.minRowBytes();
-            if (fillValue == 0) {
-                // FIXME: This special case should be unnecessary, and in fact sk_bzero just calls
-                // memset. But without it, the compiler thinks this is trying to pass a zero length
-                // to memset, causing an error.
-                sk_bzero(memsetDst, rb);
-            } else {
-                memset(memsetDst, fillValue, rb);
-            }
-        }
-        fSwizzler->swizzle(fTmpBuffer.get(), rowBegin);
+        sk_bzero(fTmpBuffer.get(), dstInfo.minRowBytes());
+        this->applyXformRow(dstInfo, fTmpBuffer.get(), rowBegin);
 
         const size_t offsetBytes = fSwizzler->swizzleOffsetBytes();
         switch (dstInfo.colorType()) {
@@ -564,11 +592,11 @@ bool SkGifCodec::haveDecodedRow(size_t frameIndex, const unsigned char* rowBegin
                 }
                 break;
             }
-            case kIndex_8_SkColorType: {
-                uint8_t* dstPixel = SkTAddOffset<uint8_t>(dstLine, offsetBytes);
-                uint8_t* srcPixel = SkTAddOffset<uint8_t>(fTmpBuffer.get(), offsetBytes);
+            case kRGBA_F16_SkColorType: {
+                uint64_t* dstPixel = SkTAddOffset<uint64_t>(dstLine, offsetBytes);
+                uint64_t* srcPixel = SkTAddOffset<uint64_t>(fTmpBuffer.get(), offsetBytes);
                 for (int i = 0; i < fSwizzler->swizzleWidth(); i++) {
-                    if (*srcPixel != frameContext->transparentPixel()) {
+                    if (*srcPixel != 0) {
                         *dstPixel = *srcPixel;
                     }
                     dstPixel++;
diff --git a/src/codec/SkGifCodec.h b/src/codec/SkGifCodec.h
index 5793766204..8e93730bcd 100644
--- a/src/codec/SkGifCodec.h
+++ b/src/codec/SkGifCodec.h
@@ -115,6 +115,11 @@ private:
     Result decodeFrame(bool firstAttempt, const Options& opts, int* rowsDecoded);
 
     /*
+     *  Swizzles and color xforms (if necessary) into dst.
+     */
+    void applyXformRow(const SkImageInfo& dstInfo, void* dst, const uint8_t* src) const;
+
+    /*
      * Creates an instance of the decoder
      * Called only by NewFromStream
      * Takes ownership of the SkGifImageReader
@@ -142,6 +147,8 @@ private:
     // Updated inside haveDecodedRow when rows are decoded, unless we filled
     // the background, in which case it is set once and left alone.
     int                                 fRowsDecoded;
+    std::unique_ptr<uint32_t[]>         fXformBuffer;
+    bool                                fXformOnDecode;
 
     typedef SkCodec INHERITED;
 };
diff --git a/src/codec/SkPngCodec.cpp b/src/codec/SkPngCodec.cpp
index a7359ee848..8297dd49be 100644
--- a/src/codec/SkPngCodec.cpp
+++ b/src/codec/SkPngCodec.cpp
@@ -231,7 +231,7 @@ bool SkPngCodec::createColorTable(const SkImageInfo& dstInfo, int* ctableCount)
     if (png_get_tRNS(fPng_ptr, fInfo_ptr, &alphas, &numColorsWithAlpha, nullptr)) {
         // If we are performing a color xform, it will handle the premultiply.  Otherwise,
         // we'll do it here.
-        bool premultiply = !this->colorXform() && needs_premul(dstInfo, this->getInfo());
+        bool premultiply = !this->colorXform() && needs_premul(dstInfo, this->getEncodedInfo());
 
         // Choose which function to use to create the color table. If the final destination's
         // colortype is unpremultiplied, the color table will store unpremultiplied colors.