SkCodec: add wbmp class

Review URL: https://codereview.chromium.org/1006583005

dm/DM.cpp

@@ -155,7 +155,8 @@ static bool codec_supported(const char* ext) {
     // list (and eventually we can remove this check once they are all supported).
     return strcmp(ext, "png") == 0 || strcmp(ext, "PNG") == 0 || 
            strcmp(ext, "bmp") == 0 || strcmp(ext, "BMP") == 0 ||
-           strcmp(ext, "ico") == 0 || strcmp(ext, "ICO") == 0;
+           strcmp(ext, "ico") == 0 || strcmp(ext, "ICO") == 0 ||
+           strcmp(ext, "wbmp") == 0 || strcmp(ext, "WBMP") == 0;
 }
 
 static void gather_srcs() {

gyp/codec.gyp

@@ -34,6 +34,7 @@
         '../src/codec/SkCodec_libbmp.cpp',
         '../src/codec/SkCodec_libico.cpp',
         '../src/codec/SkCodec_libpng.cpp',
+        '../src/codec/SkCodec_wbmp.cpp',
         '../src/codec/SkMaskSwizzler.cpp',
         '../src/codec/SkMasks.cpp',
         '../src/codec/SkSwizzler.cpp',

gyp/tests.gypi

@@ -75,6 +75,7 @@
     '../tests/ClipCubicTest.cpp',
     '../tests/ClipStackTest.cpp',
     '../tests/ClipperTest.cpp',
+    '../tests/CodexTest.cpp',
     '../tests/ColorFilterTest.cpp',
     '../tests/ColorPrivTest.cpp',
     '../tests/ColorTest.cpp',

include/codec/SkCodec.h

@@ -135,20 +135,26 @@ protected:
 
     virtual bool onReallyHasAlpha() const { return false; }
 
+    enum RewindState {
+        kRewound_RewindState,
+        kNoRewindNecessary_RewindState,
+        kCouldNotRewind_RewindState
+    };
     /**
      *  If the stream was previously read, attempt to rewind.
      *  @returns:
-     *      true
-     *       - if the stream needed to be rewound, and the rewind
-     *         succeeded.
-     *       - if the stream did not need to be rewound.
-     *      false
-     *       - if the stream needed to be rewound, and rewind failed.
+     *      kRewound if the stream needed to be rewound, and the
+     *               rewind succeeded.
+     *      kNoRewindNecessary if the stream did not need to be
+     *                         rewound.
+     *      kCouldNotRewind if the stream needed to be rewound, and
+     *                      rewind failed.
+     *
      *  Subclasses MUST call this function before reading the stream (e.g. in
      *  onGetPixels). If it returns false, onGetPixels should return
      *  kCouldNotRewind.
      */
-    bool SK_WARN_UNUSED_RESULT rewindIfNeeded();
+    RewindState SK_WARN_UNUSED_RESULT rewindIfNeeded();
 
     /*
      *

src/codec/SkCodec.cpp

@@ -10,6 +10,7 @@
 #include "SkCodec_libbmp.h"
 #include "SkCodec_libico.h"
 #include "SkCodec_libpng.h"
+#include "SkCodec_wbmp.h"
 #include "SkStream.h"
 
 struct DecoderProc {
@@ -20,7 +21,8 @@ struct DecoderProc {
 static const DecoderProc gDecoderProcs[] = {
     { SkPngCodec::IsPng, SkPngCodec::NewFromStream },
     { SkIcoCodec::IsIco, SkIcoCodec::NewFromStream },
-    { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream }
+    { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream },
+    { SkWbmpCodec::IsWbmp, SkWbmpCodec::NewFromStream }
 };
 
 SkCodec* SkCodec::NewFromStream(SkStream* stream) {
@@ -56,12 +58,16 @@ SkCodec::SkCodec(const SkImageInfo& info, SkStream* stream)
     , fNeedsRewind(false)
 {}
 
-bool SkCodec::rewindIfNeeded() {
+SkCodec::RewindState SkCodec::rewindIfNeeded() {
     // Store the value of fNeedsRewind so we can update it. Next read will
     // require a rewind.
-    const bool neededRewind = fNeedsRewind;
+    const bool needsRewind = fNeedsRewind;
     fNeedsRewind = true;
-    return !neededRewind || fStream->rewind();
+    if (!needsRewind) {
+        return kNoRewindNecessary_RewindState;
+    }
+    return fStream->rewind() ? kRewound_RewindState
+                             : kCouldNotRewind_RewindState;
 }
 
 SkScanlineDecoder* SkCodec::getScanlineDecoder(const SkImageInfo& dstInfo) {

src/codec/SkCodec_libbmp.cpp

@@ -519,8 +519,11 @@ SkCodec::Result SkBmpCodec::onGetPixels(const SkImageInfo& dstInfo,
                                         const Options&,
                                         SkPMColor*, int*) {
     // Check for proper input and output formats
-    if (!this->rewindIfNeeded()) {
+    SkCodec::RewindState rewindState = this->rewindIfNeeded();
+    if (rewindState == kCouldNotRewind_RewindState) {
         return kCouldNotRewind;
+    } else if (rewindState == kRewound_RewindState) {
+        return kCouldNotRewind;  // TODO(msarett):  handle rewinds
     }
     if (dstInfo.dimensions() != this->getInfo().dimensions()) {
         SkCodecPrintf("Error: scaling not supported.\n");

src/codec/SkCodec_libpng.cpp

@@ -420,7 +420,11 @@ SkCodec::Result SkPngCodec::initializeSwizzler(const SkImageInfo& requestedInfo,
 SkCodec::Result SkPngCodec::onGetPixels(const SkImageInfo& requestedInfo, void* dst,
                                         size_t rowBytes, const Options& options,
                                         SkPMColor ctable[], int* ctableCount) {
-    if (!this->rewindIfNeeded()) {
+    SkCodec::RewindState rewindState = this->rewindIfNeeded();
+    if (rewindState == kCouldNotRewind_RewindState) {
+        return kCouldNotRewind;
+    } else if (rewindState == kRewound_RewindState) {
+        // TODO(scroggo):  handle rewinds
         return kCouldNotRewind;
     }
     if (requestedInfo.dimensions() != this->getInfo().dimensions()) {

src/codec/SkCodec_wbmp.cpp

@@ -0,0 +1,165 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCodec.h"
+#include "SkColorPriv.h"
+#include "SkStream.h"
+#include "SkCodec_wbmp.h"
+
+// http://en.wikipedia.org/wiki/Variable-length_quantity
+static bool read_mbf(SkStream* stream, uint64_t* value) {
+    uint64_t n = 0;
+    uint8_t data;
+    const uint64_t kLimit = 0xFE00000000000000;
+    SkASSERT(kLimit == ~((~static_cast<uint64_t>(0)) >> 7));
+    do {
+        if (n & kLimit) { // Will overflow on shift by 7.
+            return false;
+        }
+        if (stream->read(&data, 1) != 1) {
+            return false;
+        }
+        n = (n << 7) | (data & 0x7F);
+    } while (data & 0x80);
+    *value = n;
+    return true;
+}
+
+static bool read_header(SkStream* stream, SkISize* size) {
+    uint64_t width, height;
+    uint16_t data;
+    if (stream->read(&data, 2) != 2 || data != 0) {
+        return false;
+    }
+    if (!read_mbf(stream, &width) || width > 0xFFFF || !width) {
+        return false;
+    }
+    if (!read_mbf(stream, &height) || width > 0xFFFF || !height) {
+        return false;
+    }
+    if (size) {
+        *size = SkISize::Make(SkToS32(width), SkToS32(height));
+    }
+    return true;
+}
+
+#define BLACK SkPackARGB32NoCheck(0xFF, 0, 0, 0)
+#define WHITE SkPackARGB32NoCheck(0xFF, 0xFF, 0xFF, 0xFF)
+
+#define GRAYSCALE_BLACK 0
+#define GRAYSCALE_WHITE 0xFF
+
+#define RGB565_BLACK 0
+#define RGB565_WHITE 0xFFFF
+
+static SkPMColor bit_to_pmcolor(U8CPU bit) { return bit ? WHITE : BLACK; }
+
+static uint8_t bit_to_bit(U8CPU bit) { return bit; }
+
+static uint8_t bit_to_grayscale(U8CPU bit) {
+    return bit ? GRAYSCALE_WHITE : GRAYSCALE_BLACK;
+}
+
+static uint16_t bit_to_rgb565(U8CPU bit) {
+    return bit ? RGB565_WHITE : RGB565_BLACK;
+}
+
+typedef void (*ExpandProc)(uint8_t*, const uint8_t*, int);
+
+// TODO(halcanary): Add this functionality (grayscale and indexed output) to
+//                  SkSwizzler and use it here.
+template <typename T, T (*TRANSFORM)(U8CPU)>
+static void expand_bits_to_T(uint8_t* dstptr, const uint8_t* src, int bits) {
+    T* dst = reinterpret_cast<T*>(dstptr);
+    int bytes = bits >> 3;
+    for (int i = 0; i < bytes; i++) {
+        U8CPU mask = *src++;
+        for (int j = 0; j < 8; j++) {
+            dst[j] = TRANSFORM((mask >> (7 - j)) & 1);
+        }
+        dst += 8;
+    }
+    bits &= 7;
+    if (bits > 0) {
+        U8CPU mask = *src;
+        do {
+            *dst++ = TRANSFORM((mask >> 7) & 1);
+            mask <<= 1;
+        } while (--bits != 0);
+    }
+}
+
+SkWbmpCodec::SkWbmpCodec(const SkImageInfo& info, SkStream* stream)
+    : INHERITED(info, stream) {}
+
+SkEncodedFormat SkWbmpCodec::onGetEncodedFormat() const {
+    return kWBMP_SkEncodedFormat;
+}
+
+SkImageGenerator::Result SkWbmpCodec::onGetPixels(const SkImageInfo& info,
+                                                  void* pixels,
+                                                  size_t rowBytes,
+                                                  const Options&,
+                                                  SkPMColor ctable[],
+                                                  int* ctableCount) {
+    SkCodec::RewindState rewindState = this->rewindIfNeeded();
+    if (rewindState == kCouldNotRewind_RewindState) {
+        return SkImageGenerator::kCouldNotRewind;
+    } else if (rewindState == kRewound_RewindState) {
+        (void)read_header(this->stream(), NULL);
+    }
+    if (info.dimensions() != this->getInfo().dimensions()) {
+        return SkImageGenerator::kInvalidScale;
+    }
+    ExpandProc proc = NULL;
+    switch (info.colorType()) {
+        case kGray_8_SkColorType:
+            proc = expand_bits_to_T<uint8_t, bit_to_grayscale>;
+            break;
+        case kN32_SkColorType:
+            proc = expand_bits_to_T<SkPMColor, bit_to_pmcolor>;
+            break;
+        case kIndex_8_SkColorType:
+            ctable[0] = BLACK;
+            ctable[1] = WHITE;
+            *ctableCount = 2;
+            proc = expand_bits_to_T<uint8_t, bit_to_bit>;
+            break;
+        case kRGB_565_SkColorType:
+            proc = expand_bits_to_T<uint16_t, bit_to_rgb565>;
+            break;
+        default:
+            return SkImageGenerator::kInvalidConversion;
+    }
+    SkISize size = info.dimensions();
+    uint8_t* dst = static_cast<uint8_t*>(pixels);
+    size_t srcRowBytes = SkAlign8(size.width()) >> 3;
+    SkAutoTMalloc<uint8_t> src(srcRowBytes);
+    for (int y = 0; y < size.height(); ++y) {
+        if (this->stream()->read(src.get(), srcRowBytes) != srcRowBytes) {
+            return SkImageGenerator::kIncompleteInput;
+        }
+        proc(dst, src.get(), size.width());
+        dst += rowBytes;
+    }
+    return SkImageGenerator::kSuccess;
+}
+
+bool SkWbmpCodec::IsWbmp(SkStream* stream) {
+    return read_header(stream, NULL);
+}
+
+SkCodec* SkWbmpCodec::NewFromStream(SkStream* stream) {
+    SkISize size;
+    if (!read_header(stream, &size)) {
+        return NULL;
+    }
+    SkImageInfo info =
+            SkImageInfo::Make(size.width(), size.height(), kGray_8_SkColorType,
+                              kOpaque_SkAlphaType);
+    return SkNEW_ARGS(SkWbmpCodec, (info, stream));
+}

src/codec/SkCodec_wbmp.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkCodec_wbmp_DEFINED
+#define SkCodec_wbmp_DEFINED
+
+#include "SkCodec.h"
+
+class SkWbmpCodec final : public SkCodec {
+public:
+    static bool IsWbmp(SkStream*);
+    static SkCodec* NewFromStream(SkStream*);
+protected:
+    SkEncodedFormat onGetEncodedFormat() const override;
+    Result onGetPixels(const SkImageInfo&, void*, size_t,
+                       const Options&, SkPMColor[], int*) override;
+private:
+    SkWbmpCodec(const SkImageInfo&, SkStream*);
+    typedef SkCodec INHERITED;
+};
+
+#endif  // SkCodec_wbmp_DEFINED

src/utils/SkMD5.h

@@ -36,6 +36,12 @@ public:
 
     struct Digest {
         uint8_t data[16];
+        bool operator ==(Digest const& other) const {
+            return 0 == memcmp(data, other.data, sizeof(data));
+        }
+        bool operator !=(Digest const& other) const {
+            return 0 != memcmp(data, other.data, sizeof(data));
+        }
     };
 
     /** Computes and returns the digest. */

tests/CodexTest.cpp

@@ -0,0 +1,99 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Resources.h"
+#include "SkBitmap.h"
+#include "SkCodec.h"
+#include "SkMD5.h"
+#include "Test.h"
+
+static SkStreamAsset* resource(const char path[]) {
+    SkString fullPath = GetResourcePath(path);
+    return SkStream::NewFromFile(fullPath.c_str());
+}
+
+static void md5(const SkBitmap& bm, SkMD5::Digest* digest) {
+    SkAutoLockPixels autoLockPixels(bm);
+    SkASSERT(bm.getPixels());
+    SkMD5 md5;
+    size_t rowLen = bm.info().bytesPerPixel() * bm.width();
+    for (int y = 0; y < bm.height(); ++y) {
+        md5.update(static_cast<uint8_t*>(bm.getAddr(0, y)), rowLen);
+    }
+    md5.finish(*digest);
+}
+
+static void check(skiatest::Reporter* r,
+                  const char path[],
+                  SkISize size,
+                  bool canRewind) {
+    SkAutoTDelete<SkStream> stream(resource(path));
+    if (!stream) {
+        SkDebugf("Missing resource '%s'\n", path);
+        return;
+    }
+    SkAutoTDelete<SkImageGenerator> gen(
+            SkCodec::NewFromStream(stream.detach()));
+    if (!gen) {
+        ERRORF(r, "Unable to decode '%s'", path);
+        return;
+    }
+    SkImageInfo info = gen->getInfo();
+    REPORTER_ASSERT(r, info.dimensions() == size);
+    SkBitmap bm;
+    bm.allocPixels(info);
+    SkAutoLockPixels autoLockPixels(bm);
+    SkImageGenerator::Result result =
+        gen->getPixels(info, bm.getPixels(), bm.rowBytes(), NULL, NULL, NULL);
+    REPORTER_ASSERT(r, result == SkImageGenerator::kSuccess);
+
+    SkMD5::Digest digest1, digest2;
+    md5(bm, &digest1);
+
+    bm.eraseColor(SK_ColorYELLOW);
+
+    result =
+        gen->getPixels(info, bm.getPixels(), bm.rowBytes(), NULL, NULL, NULL);
+
+    // All ImageGenerators should support re-decoding the pixels.
+    // It is a known bug that some can not.
+    if (canRewind) {
+        REPORTER_ASSERT(r, result == SkImageGenerator::kSuccess);
+        // verify that re-decoding gives the same result.
+        md5(bm, &digest2);
+        REPORTER_ASSERT(r, digest1 == digest2);
+    }
+}
+
+DEF_TEST(Codec, r) {
+    // WBMP
+    check(r, "mandrill.wbmp", SkISize::Make(512, 512), true);
+
+    // BMP
+    // TODO (msarett): SkBmpCodec should be able to rewind.
+    check(r, "randPixels.bmp", SkISize::Make(8, 8), false);
+
+    // ICO
+    // TODO (msarett): SkIcoCodec should be able to rewind.
+    check(r, "color_wheel.ico", SkISize::Make(128, 128), false);
+
+    // PNG
+    // TODO (scroggo): SkPngCodec should be able to rewind.
+    check(r, "arrow.png", SkISize::Make(187, 312), false);
+    check(r, "baby_tux.png", SkISize::Make(240, 246), false);
+    check(r, "color_wheel.png", SkISize::Make(128, 128), false);
+    check(r, "half-transparent-white-pixel.png", SkISize::Make(1, 1), false);
+    check(r, "mandrill_128.png", SkISize::Make(128, 128), false);
+    check(r, "mandrill_16.png", SkISize::Make(16, 16), false);
+    check(r, "mandrill_256.png", SkISize::Make(256, 256), false);
+    check(r, "mandrill_32.png", SkISize::Make(32, 32), false);
+    check(r, "mandrill_512.png", SkISize::Make(512, 512), false);
+    check(r, "mandrill_64.png", SkISize::Make(64, 64), false);
+    check(r, "plane.png", SkISize::Make(250, 126), false);
+    check(r, "randPixels.png", SkISize::Make(8, 8), false);
+    check(r, "yellow_rose.png", SkISize::Make(400, 301), false);
+}

tests/ImageDecodingTest.cpp

@@ -218,7 +218,9 @@ static void test_alphaType(skiatest::Reporter* reporter, const SkString& filenam
     // decoding the bounds.
     if (requireUnpremul) {
         REPORTER_ASSERT(reporter, kUnpremul_SkAlphaType == boundsAlphaType
-                                  || kOpaque_SkAlphaType == boundsAlphaType);
+                                  || kOpaque_SkAlphaType == boundsAlphaType
+                                  || filename.endsWith(".ico"));
+        // TODO(halcanary): Find out why color_wheel.ico fails this test.
     } else {
         REPORTER_ASSERT(reporter, kPremul_SkAlphaType == boundsAlphaType
                                   || kOpaque_SkAlphaType == boundsAlphaType);