Provides multiple implementations of Android's SkBitmapRegionDecoder

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index f555b9fcbdba78f485e47b9baf4be67d2fa1d83c..62a5772931f9e77dd358f752d94a005a60f8ba49 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -64,6 +64,113 @@ void GMSrc::modifyGrContextOptions(GrContextOptions* options) const {
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
+BRDSrc::BRDSrc(Path path, SkBitmapRegionDecoder::Strategy strategy, Mode mode,
+        SkColorType dstColorType, uint32_t sampleSize)
+    : fPath(path)
+    , fStrategy(strategy)
+    , fMode(mode)
+    , fColorType(dstColorType)
+    , fSampleSize(sampleSize)
+{}
+
+bool BRDSrc::veto(SinkFlags flags) const {
+    // No need to test to non-raster or indirect backends.
+    return flags.type != SinkFlags::kRaster
+        || flags.approach != SinkFlags::kDirect;
+}
+
+Error BRDSrc::draw(SkCanvas* canvas) const {
+    if (kRGB_565_SkColorType == canvas->imageInfo().colorType()) {
+        return Error::Nonfatal("Testing to multiple backends is uninteresting.");
+    }
+
+    SkAutoTDelete<SkBitmapRegionDecoder> brd(
+            SkBitmapRegionDecoder::CreateBitmapRegionDecoder(
+                    SkNEW_ARGS(SkMemoryStream, (SkData::NewFromFileName(fPath.c_str()))),
+                    fStrategy));
+    if (NULL == brd.get()) {
+        return SkStringPrintf("Could not create brd for %s.", fPath.c_str());
+    }
+
+    switch (fMode) {
+        case kFullImage_Mode: {
+            SkAutoTDelete<SkBitmap> bitmap(brd->decodeRegion(0, 0, brd->width(),
+                    brd->height(), fSampleSize, fColorType));
+            if (NULL == bitmap.get() || fColorType != bitmap->colorType()) {
+                return Error::Nonfatal("Cannot convert to color type.\n");
+            }
+            canvas->drawBitmap(*bitmap, 0, 0);
+            return "";
+        }
+        case kDivisor_Mode: {
+            // Use a border to test what happens when we ask for subsets that extend outside the image
+            uint32_t scaledBorder = 5;
+            uint32_t unscaledBorder = 5 * fSampleSize;
+            uint32_t divisor = 2;
+            uint32_t width = brd->width();
+            uint32_t height = brd->height();
+            for (uint32_t x = 0; x < divisor; x++) {
+                for (uint32_t y = 0; y < divisor; y++) {
+                    // Calculate the subset dimensions
+                    uint32_t subsetWidth = width / divisor;
+                    uint32_t subsetHeight = height / divisor;
+                    int left = x * subsetWidth;
+                    int top = y * subsetHeight;
+
+                    // Increase the size of the last subset in each row or column, when the
+                    // divisor does not divide evenly into the image dimensions
+                    subsetWidth += (x + 1 == divisor) ? (width % divisor) : 0;
+                    subsetHeight += (y + 1 == divisor) ? (height % divisor) : 0;
+
+                    // Increase the size of the subset in order to have a border on each side
+                    int decodeLeft = left - unscaledBorder;
+                    int decodeTop = top - unscaledBorder;
+                    uint32_t decodeWidth = subsetWidth + unscaledBorder * 2;
+                    uint32_t decodeHeight = subsetHeight + unscaledBorder * 2;
+
+                    SkAutoTDelete<SkBitmap> bitmap(brd->decodeRegion(decodeLeft,
+                            decodeTop, decodeWidth, decodeHeight, fSampleSize, fColorType));
+                    if (NULL == bitmap.get() || fColorType != bitmap->colorType()) {
+                        return Error::Nonfatal("Cannot convert to color type.\n");
+                    }
+                    canvas->drawBitmapRect(*bitmap,
+                            SkRect::MakeXYWH(scaledBorder, scaledBorder,
+                                    subsetWidth / fSampleSize, subsetHeight / fSampleSize),
+                            SkRect::MakeXYWH(left / fSampleSize, top / fSampleSize,
+                                    subsetWidth / fSampleSize, subsetHeight / fSampleSize),
+                            NULL);
+                }
+            }
+            return "";
+        }
+        default:
+            SkASSERT(false);
+            return "Error: Should not be reached.\n";
+    }
+}
+
+SkISize BRDSrc::size() const {
+    SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(fPath.c_str()));
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded));
+    if (codec) {
+        return SkISize::Make(codec->getInfo().width() / fSampleSize,
+                codec->getInfo().height() / fSampleSize);
+    }
+    return SkISize::Make(0, 0);
+}
+
+Name BRDSrc::name() const {
+    // We will replicate the names used by CodecSrc so that images can
+    // be compared in Gold.
+    if (1.0f == fSampleSize) {
+        return SkOSPath::Basename(fPath.c_str());
+    }
+    float scale = 1.0f / fSampleSize;
+    return SkStringPrintf("%s_%.3f", SkOSPath::Basename(fPath.c_str()).c_str(), scale);
+}
+
+/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
 CodecSrc::CodecSrc(Path path, Mode mode, DstColorType dstColorType, float scale)
     : fPath(path)
     , fMode(mode)
@@ -447,20 +554,17 @@ Error CodecSrc::draw(SkCanvas* canvas) const {
 SkISize CodecSrc::size() const {
     SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(fPath.c_str()));
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded));
-    if (NULL != codec) {
-        SkISize size = codec->getScaledDimensions(fScale);
-        return size;
-    } else {
-        return SkISize::Make(0, 0);
+    if (codec) {
+        return codec->getScaledDimensions(fScale);
     }
+    return SkISize::Make(0, 0);
 }
 
 Name CodecSrc::name() const {
     if (1.0f == fScale) {
         return SkOSPath::Basename(fPath.c_str());
-    } else {
-        return SkStringPrintf("%s_%.3f", SkOSPath::Basename(fPath.c_str()).c_str(), fScale);
     }
+    return SkStringPrintf("%s_%.3f", SkOSPath::Basename(fPath.c_str()).c_str(), fScale);
 }
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/