Change SkDecodingImageGenerator API

tests/ImageDecodingTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 #include "TestClassDef.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkColor.h"
 #include "SkColorPriv.h"
 #include "SkData.h"
+#include "SkDecodingImageGenerator.h"
+#include "SkDiscardableMemoryPool.h"
 #include "SkForceLinking.h"
 #include "SkGradientShader.h"
 #include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
+#include "SkImageGenerator.h"
 #include "SkOSFile.h"
 #include "SkPoint.h"
 #include "SkShader.h"
 #include "SkStream.h"
 #include "SkString.h"
 
 __SK_FORCE_IMAGE_DECODER_LINKING;
 
 /**
  *  Interprets c as an unpremultiplied color, and returns the
@@ skipping 116 matching lines @@
     SkString resourcePath = skiatest::Test::GetResourcePath();
     if (resourcePath.isEmpty()) {
         SkDebugf("Could not run unpremul test because resourcePath not specified.");
         return;
     }
     SkOSFile::Iter iter(resourcePath.c_str());
     SkString basename;
     if (iter.next(&basename)) {
         do {
             SkString filename = SkOSPath::SkPathJoin(resourcePath.c_str(), basename.c_str());
-            //SkDebugf("about to decode \"%s\"\n", filename.c_str());
+            // SkDebugf("about to decode \"%s\"\n", filename.c_str());
             compare_unpremul(reporter, filename);
         } while (iter.next(&basename));
     } else {
         SkDebugf("Failed to find any files :(\n");
     }
 }
 
 #ifdef SK_DEBUG
 // Create a stream containing a bitmap encoded to Type type.
 static SkMemoryStream* create_image_stream(SkImageEncoder::Type type) {
@@ skipping 27 matching lines @@
 // Only runs in debug mode since we are testing for a crash.
 static void test_stream_life() {
     const SkImageEncoder::Type gTypes[] = {
 #ifdef SK_BUILD_FOR_ANDROID
         SkImageEncoder::kJPEG_Type,
         SkImageEncoder::kPNG_Type,
 #endif
         SkImageEncoder::kWEBP_Type,
     };
     for (size_t i = 0; i < SK_ARRAY_COUNT(gTypes); ++i) {
-        //SkDebugf("encoding to %i\n", i);
+        // SkDebugf("encoding to %i\n", i);
         SkAutoTUnref<SkMemoryStream> stream(create_image_stream(gTypes[i]));
         if (NULL == stream.get()) {
             SkDebugf("no stream\n");
             continue;
         }
         SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(stream));
         if (NULL == decoder.get()) {
             SkDebugf("no decoder\n");
             continue;
         }
         int width, height;
         if (!decoder->buildTileIndex(stream.get(), &width, &height)) {
             SkDebugf("could not build a tile index\n");
             continue;
         }
         // Now unref the stream to make sure it survives
         stream.reset(NULL);
         SkBitmap bm;
         decoder->decodeSubset(&bm, SkIRect::MakeWH(width, height),
                               SkBitmap::kARGB_8888_Config);
     }
 }
 
 // Test inside SkScaledBitmapSampler.cpp
 extern void test_row_proc_choice();
 
-#endif // SK_DEBUG
+#endif  // SK_DEBUG
 
 DEF_TEST(ImageDecoding, reporter) {
     test_unpremul(reporter);
 #ifdef SK_DEBUG
     test_stream_life();
     test_row_proc_choice();
 #endif
 }
+
+////////////////////////////////////////////////////////////////////////////////
+
+// example of how Android will do this inside their BitmapFactory
+static SkPixelRef* install_pixel_ref(SkBitmap* bitmap,
+                                     SkStreamRewindable* stream,
+                                     int sampleSize, bool ditherImage) {
+    SkASSERT(bitmap != NULL);
+    SkASSERT(stream != NULL);
+    SkASSERT(stream->rewind());
+    SkASSERT(stream->unique());
+    SkDecoderOptions opts(sampleSize, ditherImage, bitmap->config());
+    SkAutoTDelete<SkImageGenerator> gen(
+        SkNewDecodingImageGenerator(stream, opts));
+    SkImageInfo info;
+    if ((NULL == gen.get()) || !gen->getInfo(&info)) {
+        return NULL;
+    }
+    SkDiscardableMemory::Factory* factory = NULL;
+    if (SkBitmap::ComputeSize(info) < (32 * 1024)) {
+        // only use ashmem for large images, since mmaps come at a price
+        factory = SkGetGlobalDiscardableMemoryPool();
+    }
+    if (SkInstallDiscardablePixelRef(gen.detach(), bitmap, factory)) {
+        return bitmap->pixelRef();
+    }
+    return NULL;
+}
+/**
+ *  A test for the SkNewDecodingImageGenerator and
+ *  SkInstallDiscardablePixelRef functions.
+ */
+DEF_TEST(ImprovedBitmapFactory, reporter) {
+    SkString resourcePath = skiatest::Test::GetResourcePath();
+    SkString directory = SkOSPath::SkPathJoin(resourcePath.c_str(), "encoding");
+    SkString path = SkOSPath::SkPathJoin(directory.c_str(), "randPixels.png");
+    SkAutoTUnref<SkStreamRewindable> stream(
+        SkStream::NewFromFile(path.c_str()));
+    if (sk_exists(path.c_str())) {
+        SkBitmap bm;
+        SkAssertResult(bm.setConfig(SkBitmap::kARGB_8888_Config, 1, 1));
+        REPORTER_ASSERT(reporter,
+            NULL != install_pixel_ref(&bm, stream.detach(), 1, true));
+        SkAutoLockPixels alp(bm);
+        REPORTER_ASSERT(reporter, NULL != bm.getPixels());
+    }
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+
+
+static inline bool check_rounding(int value, int dividend, int divisor) {
+    // returns true if (dividend/divisor) rounds up OR down to value
+    return (((divisor * value) > (dividend - divisor))
+            && ((divisor * value) < (dividend + divisor)));
+}
+namespace {
+// expected output for 8x8 bitmap
+const int kExpectedWidth = 8;
+const int kExpectedHeight = 8;
+const SkColor kExpectedPixels[] = {
+    0xffbba570, 0xff395f5d, 0xffe25c39, 0xff197666,
+    0xff3cba27, 0xffdefcb0, 0xffc13874, 0xfffa0093,
+    0xffbda60e, 0xffc01db6, 0xff2bd688, 0xff9362d4,
+    0xffc641b2, 0xffa5cede, 0xff606eba, 0xff8f4bf3,
+    0xff3bf742, 0xff8f02a8, 0xff5509df, 0xffc7027e,
+    0xff24aa8a, 0xff886c96, 0xff625481, 0xff403689,
+    0xffc52152, 0xff78ccd6, 0xffdcb4ab, 0xff09d27d,
+    0xffca00f3, 0xff605d47, 0xff446fb2, 0xff576e46,
+    0xff273df9, 0xffb41a83, 0xfff812c3, 0xffccab67,
+    0xff034218, 0xff7db9a7, 0xff821048, 0xfffe4ab4,
+    0xff6fac98, 0xff941d27, 0xff5fe411, 0xfffbb283,
+    0xffd86e99, 0xff169162, 0xff71128c, 0xff39cab4,
+    0xffa7fe63, 0xff4c956b, 0xffbc22e0, 0xffb272e4,
+    0xff129f4a, 0xffe34513, 0xff3d3742, 0xffbd190a,
+    0xffb07222, 0xff2e23f8, 0xfff089d9, 0xffb35738,
+    0xffa86022, 0xff3340fe, 0xff95fe71, 0xff6a71df
+};
+SK_COMPILE_ASSERT((kExpectedWidth * kExpectedHeight)
+                  == SK_ARRAY_COUNT(kExpectedPixels), array_size_mismatch);
+}  // namespace
+
+/**
+ * Given either a SkStream or a SkData, try to decode the encoded
+ * image using the specified options and report errors.
+ */
+static void test_options(skiatest::Reporter* reporter,
+                         const SkDecoderOptions& opts,
+                         SkStreamRewindable* encodedStream,
+                         SkData* encodedData,
+                         bool useData,
+                         const SkString& path) {
+    SkBitmap bm;
+    bool success = false;
+    if (useData) {
+        if (NULL == encodedData) {
+            return;
+        }
+        success = SkInstallDiscardablePixelRef(
+            SkNewDecodingImageGenerator(encodedData, opts), &bm, NULL);
+    } else {
+        if (NULL == encodedStream) {
+            return;
+        }
+        success = SkInstallDiscardablePixelRef(
+            SkNewDecodingImageGenerator(encodedStream->duplicate(), opts),
+            &bm, NULL);
+    }
+
+    REPORTER_ASSERT(reporter, success
+                    || (SkBitmap::kARGB_4444_Config == opts.fRequestedConfig));
+    if (!success) {
+        return;
+    }
+    REPORTER_ASSERT(reporter, check_rounding(bm.height(), kExpectedHeight,
+                                             opts.fSampleSize));
+    REPORTER_ASSERT(reporter, check_rounding(bm.width(), kExpectedWidth,
+                                             opts.fSampleSize));
+
+    SkAutoLockPixels alp(bm);
+    REPORTER_ASSERT(reporter, bm.getPixels() != NULL);
+
+    REPORTER_ASSERT(reporter,
+                    (SkBitmap::kNo_Config == opts.fRequestedConfig)
+                    || (bm.config() == opts.fRequestedConfig));
+
+    // Condition under which we should check the decoding results:
+    if ((SkBitmap::kARGB_8888_Config == bm.config())
+        && (NULL != bm.getPixels())
+        && (!path.endsWith(".jpg"))  // lossy
+        && (!path.endsWith(".webp"))  // decoder error
+        && (opts.fSampleSize == 1)) {  // scaled
+        bool pixelError = false;
+        const SkColor* correctPixels = kExpectedPixels;
+        SkASSERT(bm.height() == kExpectedHeight);
+        SkASSERT(bm.width() == kExpectedWidth);
+        for (int y = 0; y < bm.height(); ++y) {
+            for (int x = 0; x < bm.width(); ++x) {
+                pixelError |= (*correctPixels != bm.getColor(x, y));
+                ++correctPixels;
+            }
+        }
+        REPORTER_ASSERT(reporter, !pixelError);
+    }
+}
+
+/**
+ *  SkDecodingImageGenerator has an Options struct which lets the
+ *  client of the generator set sample size, dithering, and bitmap
+ *  config.  This test loops through many possible options and tries
+ *  them on a set of 5 small encoded images (each in a different
+ *  format).  We test both SkData and SkStreamRewindable decoding.
+ */
+DEF_TEST(ImageDecoderOptions, reporter) {
+    const char* files[]  = {
+        "randPixels.bmp",
+        "randPixels.jpg",
+        "randPixels.png",
+        "randPixels.webp",
+        "randPixels.gif"
+    };
+
+    SkString resourceDir = skiatest::Test::GetResourcePath();
+    SkString directory = SkOSPath::SkPathJoin(resourceDir.c_str(), "encoding");
+    if (!sk_exists(directory.c_str())) {
+        return;
+    }
+
+    int scaleList[] = {1, 2, 3, 4};
+    bool ditherList[] = {true, false};
+    SkBitmap::Config configList[] = {
+        SkBitmap::kNo_Config,  // Use whatever the decoder prefers.
+        SkBitmap::kARGB_8888_Config,
+        SkBitmap::kRGB_565_Config,
+        SkBitmap::kA8_Config,
+        SkBitmap::kARGB_4444_Config,  // Most decoders will fail on 4444.
+        // Note that indexed color is left out of the list.  Lazy
+        // decoding doesn't do indexed color.
+    };
+    const bool useDataList[] = {true, false};
+
+    for (size_t fidx = 0; fidx < SK_ARRAY_COUNT(files); ++fidx) {
+        SkString path = SkOSPath::SkPathJoin(directory.c_str(), files[fidx]);
+        if (!sk_exists(path.c_str())) {
+            continue;
+        }
+
+        SkAutoDataUnref encodedData(SkData::NewFromFileName(path.c_str()));
+        REPORTER_ASSERT(reporter, encodedData.get() != NULL);
+        SkAutoTUnref<SkStreamRewindable> encodedStream(
+            SkStream::NewFromFile(path.c_str()));
+        REPORTER_ASSERT(reporter, encodedStream.get() != NULL);
+
+        for (size_t i = 0; i < SK_ARRAY_COUNT(scaleList); ++i) {
+            for (size_t j = 0; j < SK_ARRAY_COUNT(ditherList); ++j) {
+                for (size_t k = 0; k < SK_ARRAY_COUNT(configList); ++k) {
+                    SkDecoderOptions opts(scaleList[i], ditherList[j],
+                                          configList[k]);
+                    for (size_t m = 0; m < SK_ARRAY_COUNT(useDataList); ++m) {
+                        test_options(reporter, opts, encodedStream, encodedData,
+                                     useDataList[m], path);
+                    }
+                }
+            }
+        }
+    }
+}
+