Change SkDecodingImageGenerator API

tests/ImageDecodingTest.cpp

Index: tests/ImageDecodingTest.cpp
diff --git a/tests/ImageDecodingTest.cpp b/tests/ImageDecodingTest.cpp
index f840129b1c41c56f43fd1b35e2f1bd938b865b8b..163db8bc03f07bb3caf0ef7241c6b9040c70e56d 100644
--- a/tests/ImageDecodingTest.cpp
+++ b/tests/ImageDecodingTest.cpp
@@ -12,10 +12,14 @@
 #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 "SkImagePriv.h"
 #include "SkOSFile.h"
 #include "SkPoint.h"
 #include "SkShader.h"
@@ -152,7 +156,7 @@ static void test_unpremul(skiatest::Reporter* reporter) {
     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 {
@@ -200,7 +204,7 @@ static void test_stream_life() {
         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");
@@ -227,7 +231,7 @@ static void test_stream_life() {
 // Test inside SkScaledBitmapSampler.cpp
 extern void test_row_proc_choice();
 
-#endif // SK_DEBUG
+#endif  // SK_DEBUG
 
 DEF_TEST(ImageDecoding, reporter) {
     test_unpremul(reporter);
@@ -236,3 +240,223 @@ DEF_TEST(ImageDecoding, reporter) {
     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());
+    SkColorType colorType;
+    if (!SkBitmapConfigToColorType(bitmap->config(), &colorType)) {
+        return NULL;
+    }
+    SkDecodingImageGenerator::Options opts(sampleSize, ditherImage, colorType);
+    SkAutoTDelete<SkImageGenerator> gen(
+        SkDecodingImageGenerator::Create(stream, opts));
+    SkImageInfo info;
+    if ((NULL == gen.get()) || !gen->getInfo(&info)) {
+        return NULL;
+    }
+    SkDiscardableMemory::Factory* factory = NULL;
+    if (info.getSafeSize(info.minRowBytes()) < (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 SkDecodingImageGenerator::Create 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 SkDecodingImageGenerator::Options& opts,
+                         SkStreamRewindable* encodedStream,
+                         SkData* encodedData,
+                         bool useData,
+                         const SkString& path) {
+    SkBitmap bm;
+    bool success = false;
+    if (useData) {
+        if (NULL == encodedData) {
+            return;
+        }
+        success = SkInstallDiscardablePixelRef(
+            SkDecodingImageGenerator::Create(encodedData, opts), &bm, NULL);
+    } else {
+        if (NULL == encodedStream) {
+            return;
+        }
+        success = SkInstallDiscardablePixelRef(
+            SkDecodingImageGenerator::Create(encodedStream->duplicate(), opts),
+            &bm, NULL);
+    }
+
+    REPORTER_ASSERT(reporter, success
+                    || (kARGB_4444_SkColorType == opts.fRequestedColorType));
+    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);
+
+    SkBitmap::Config requestedConfig
+        = SkColorTypeToBitmapConfig(opts.fRequestedColorType);
+    REPORTER_ASSERT(reporter,
+                    (!opts.fUseRequestedColorType)
+                    || (bm.config() == requestedConfig));
+
+    // 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};
+    SkColorType colorList[] = {
+        kAlpha_8_SkColorType,
+        kRGB_565_SkColorType,
+        kARGB_4444_SkColorType,  // Most decoders will fail on 4444.
+        kPMColor_SkColorType
+        // 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 m = 0; m < SK_ARRAY_COUNT(useDataList); ++m) {
+                    for (size_t k = 0; k < SK_ARRAY_COUNT(colorList); ++k) {
+                        SkDecodingImageGenerator::Options opts(scaleList[i],
+                                                               ditherList[j],
+                                                               colorList[k]);
+                        test_options(reporter, opts, encodedStream, encodedData,
+                                     useDataList[m], path);
+
+                    }
+                    SkDecodingImageGenerator::Options options(scaleList[i],
+                                                              ditherList[j]);
+                    test_options(reporter, options, encodedStream, encodedData,
+                                 useDataList[m], path);
+                }
+            }
+        }
+    }
+}
+