Make SkAndroidCodec support gif

Involves a few bug fixes in SkCodec_libgif and a bit more
complexity in SkSwizzler.

BUG=skia:4405

Review URL: https://codereview.chromium.org/1445313002

3 files changed, 3 insertions, 83 deletions

diff --git a/dm/DM.cpp b/dm/DM.cpp
index 0cbf9440db..8873dcabbe 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -230,9 +230,6 @@ static void push_codec_src(Path path, CodecSrc::Mode mode, CodecSrc::DstColorTyp
         case CodecSrc::kScanline_Mode:
             folder.append("scanline");
             break;
-        case CodecSrc::kScanline_Subset_Mode:
-            folder.append("scanline_subset");
-            break;
         case CodecSrc::kStripe_Mode:
             folder.append("stripe");
             break;
@@ -310,7 +307,7 @@ static void push_codec_srcs(Path path) {
     const float nativeScales[] = { 0.125f, 0.25f, 0.375f, 0.5f, 0.625f, 0.750f, 0.875f, 1.0f };
 
     const CodecSrc::Mode nativeModes[] = { CodecSrc::kCodec_Mode, CodecSrc::kScanline_Mode,
-            CodecSrc::kScanline_Subset_Mode, CodecSrc::kStripe_Mode, CodecSrc::kSubset_Mode };
+            CodecSrc::kStripe_Mode, CodecSrc::kSubset_Mode };
 
     CodecSrc::DstColorType colorTypes[3];
     uint32_t numColorTypes;
@@ -363,8 +360,8 @@ static void push_codec_srcs(Path path) {
     // The following image types are only supported by BitmapFactory,
     // so we only need to test full image decodes.
     static const char* fullExts[] = {
-        "wbmp", "bmp",
-        "WBMP", "BMP",
+        "wbmp", "bmp", "gif",
+        "WBMP", "BMP", "GIF",
     };
     for (const char* ext : fullExts) {
         if (path.endsWith(ext)) {
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index 75f954f453..af62dafdd4 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -372,82 +372,6 @@ Error CodecSrc::draw(SkCanvas* canvas) const {
             canvas->drawBitmap(bitmap, 0, 0);
             break;
         }
-        case kScanline_Subset_Mode: {
-            //this mode decodes the image in divisor*divisor subsets, using a scanline decoder
-            const int divisor = 2;
-            const int w = decodeInfo.width();
-            const int h = decodeInfo.height();
-            if (divisor > w || divisor > h) {
-                return Error::Nonfatal(SkStringPrintf("Cannot decode subset: divisor %d is too big"
-                        "for %s with dimensions (%d x %d)", divisor, fPath.c_str(), w, h));
-            }
-            const int subsetWidth = w/divisor;
-            const int subsetHeight = h/divisor;
-            // One of our subsets will be larger to contain any pixels that do not divide evenly.
-            const int extraX = w % divisor;
-            const int extraY = h % divisor;
-            /*
-            * if w or h are not evenly divided by divisor need to adjust width and height of end
-            * subsets to cover entire image.
-            * Add extraX and extraY to largestSubsetBm's width and height to adjust width
-            * and height of end subsets.
-            * subsetBm is extracted from largestSubsetBm.
-            * subsetBm's size is determined based on the current subset and may be larger for end
-            * subsets.
-            */
-            SkImageInfo largestSubsetDecodeInfo =
-                    decodeInfo.makeWH(subsetWidth + extraX, subsetHeight + extraY);
-            SkBitmap largestSubsetBm;
-            if (!largestSubsetBm.tryAllocPixels(largestSubsetDecodeInfo, nullptr,
-                    colorTable.get())) {
-                return SkStringPrintf("Image(%s) is too large (%d x %d)\n", fPath.c_str(),
-                        largestSubsetDecodeInfo.width(), largestSubsetDecodeInfo.height());
-            }
-            for (int col = 0; col < divisor; col++) {
-                //currentSubsetWidth may be larger than subsetWidth for rightmost subsets
-                const int currentSubsetWidth = (col + 1 == divisor) ?
-                        subsetWidth + extraX : subsetWidth;
-                const int x = col * subsetWidth;
-                for (int row = 0; row < divisor; row++) {
-                    //currentSubsetHeight may be larger than subsetHeight for bottom subsets
-                    const int currentSubsetHeight = (row + 1 == divisor) ?
-                            subsetHeight + extraY : subsetHeight;
-                    const int y = row * subsetHeight;
-                    //create scanline decoder for each subset
-                    SkCodec::Options options;
-                    SkIRect subset = SkIRect::MakeXYWH(x, 0, currentSubsetWidth, h);
-                    options.fSubset = &subset;
-                    // TODO (msarett): Support this mode for all scanline orderings.
-                    if (SkCodec::kSuccess != codec->startScanlineDecode(decodeInfo, &options,
-                            colorPtr, colorCountPtr) ||
-                            SkCodec::kTopDown_SkScanlineOrder != codec->getScanlineOrder()) {
-                        if (x == 0 && y == 0) {
-                            //first try, image may not be compatible
-                            return Error::Nonfatal("Could not start top-down scanline decoder");
-                        } else {
-                            return "Error scanline decoder is nullptr";
-                        }
-                    }
-                    // Skip to the first line of subset.  We ignore the result value here.
-                    // If the skip value fails, this will indicate an incomplete image.
-                    // This means that the call to getScanlines() will also fail, but it
-                    // will fill the buffer with a default value, so we can still draw the
-                    // image.
-                    codec->skipScanlines(y);
-
-                    //create and set size of subsetBm
-                    SkBitmap subsetBm;
-                    SkIRect bounds = SkIRect::MakeWH(currentSubsetWidth, currentSubsetHeight);
-                    SkAssertResult(largestSubsetBm.extractSubset(&subsetBm, bounds));
-                    SkAutoLockPixels autolock(subsetBm, true);
-                    codec->getScanlines(subsetBm.getAddr(0, 0), currentSubsetHeight,
-                            subsetBm.rowBytes());
-                    subsetBm.notifyPixelsChanged();
-                    canvas->drawBitmap(subsetBm, SkIntToScalar(x), SkIntToScalar(y));
-                }
-            }
-            break;
-        }
         case kStripe_Mode: {
             const int height = decodeInfo.height();
             // This value is chosen arbitrarily.  We exercise more cases by choosing a value that
diff --git a/dm/DMSrcSink.h b/dm/DMSrcSink.h
index 6371a9046f..e155508ac2 100644
--- a/dm/DMSrcSink.h
+++ b/dm/DMSrcSink.h
@@ -106,7 +106,6 @@ public:
     enum Mode {
         kCodec_Mode,
         kScanline_Mode,
-        kScanline_Subset_Mode,
         kStripe_Mode, // Tests the skipping of scanlines
         kSubset_Mode, // For codecs that support subsets directly.
     };