Change SkDecodingImageGenerator API

tests/ImageDecodingTest.cpp

Index: tests/ImageDecodingTest.cpp
diff --git a/tests/ImageDecodingTest.cpp b/tests/ImageDecodingTest.cpp
index be8626f0f6beb9dcc52b6065dfb028c58788e1a2..8fd96be7bf6062ef283f5cea2a457ea244c40ba0 100644
--- a/tests/ImageDecodingTest.cpp
+++ b/tests/ImageDecodingTest.cpp
@@ -10,10 +10,13 @@
 #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"
@@ -151,7 +154,7 @@ 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 {
@@ -199,7 +202,7 @@ 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");
@@ -226,7 +229,7 @@ static void test_stream_life() {
 // Test inside SkScaledBitmapSampler.cpp
 extern void test_row_proc_choice();
 
-#endif // SK_DEBUG
+#endif  // SK_DEBUG
 
 static void test_imageDecodingTests(skiatest::Reporter* reporter) {
     test_unpremul(reporter);
@@ -239,3 +242,222 @@ static void test_imageDecodingTests(skiatest::Reporter* reporter) {
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("ImageDecoding", ImageDecodingTestClass,
                  test_imageDecodingTests)
+
+////////////////////////////////////////////////////////////////////////////////
+
+// 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 checkrounding(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)));
+}
+/**
+ *  SkDecodingImageGenerator has an Options struct which lets the
+ *  client of the generator set sample size, dithering, prefer quality
+ *  over speed, and bitmap config.  This test loops through a list of
+ *  sets of options and tries them on a set of 5 small encoded images.
+ */
+DEF_TEST(ImageDecoderOptions, reporter) {
+    // expected output for 8x8 bitmap
+    const int expectedWidth = 8;
+    const int expectedHeight = 8;
+    const SkColor expectedPixels[] = {
+        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((expectedWidth * expectedHeight)
+                      == SK_ARRAY_COUNT(expectedPixels), array_size_mismatch);
+    const char* files[]  = {
+        "randPixels.bmp",
+        "randPixels.jpg",
+        "randPixels.png",
+        "randPixels.webp",
+        "randPixels.gif"
+    };
+
+    SkString resourcePath = skiatest::Test::GetResourcePath();
+    SkString directory = SkOSPath::SkPathJoin(resourcePath.c_str(), "encoding");
+    if (!sk_exists(directory.c_str())) {
+        return;
+    }
+
+    typedef SkDecoderOptions Options;
+    const Options optionList[] = {
+        Options(),
+        Options(1, true, SkBitmap::kNo_Config),

[scroggo, 2013/12/13 17:23:03]

Would it be better to generate this programmatically? Then if we decide to
modify Options in the future the change should be much simpler.

[hal.canary, 2013/12/18 15:39:07]

Done.

+        Options(2, true, SkBitmap::kNo_Config),
+        Options(3, true, SkBitmap::kNo_Config),
+        Options(4, true, SkBitmap::kNo_Config),
+        Options(1, false, SkBitmap::kNo_Config),
+        Options(2, false, SkBitmap::kNo_Config),
+        Options(3, false, SkBitmap::kNo_Config),
+        Options(4, false, SkBitmap::kNo_Config),
+        Options(1, true, SkBitmap::kARGB_8888_Config),
+        Options(2, true, SkBitmap::kARGB_8888_Config),
+        Options(3, true, SkBitmap::kARGB_8888_Config),
+        Options(4, true, SkBitmap::kARGB_8888_Config),
+        Options(1, true, SkBitmap::kRGB_565_Config),
+        Options(2, true, SkBitmap::kRGB_565_Config),
+        Options(3, true, SkBitmap::kRGB_565_Config),
+        Options(4, true, SkBitmap::kRGB_565_Config),
+        Options(1, false, SkBitmap::kRGB_565_Config),
+        Options(2, false, SkBitmap::kRGB_565_Config),
+        Options(3, false, SkBitmap::kRGB_565_Config),
+        Options(4, false, SkBitmap::kRGB_565_Config),
+        Options(1, true, SkBitmap::kA8_Config),
+        Options(2, true, SkBitmap::kA8_Config),
+        Options(3, true, SkBitmap::kA8_Config),
+        Options(4, true, SkBitmap::kA8_Config),
+        Options(1, false, SkBitmap::kA8_Config),
+        Options(2, false, SkBitmap::kA8_Config),
+        Options(3, false, SkBitmap::kA8_Config),
+        Options(4, false, SkBitmap::kA8_Config),
+        Options(1, true, SkBitmap::kARGB_4444_Config),
+        Options(2, true, SkBitmap::kARGB_4444_Config),
+        Options(3, true, SkBitmap::kARGB_4444_Config),
+        Options(4, true, SkBitmap::kARGB_4444_Config),
+        Options(1, false, SkBitmap::kARGB_4444_Config),
+        Options(2, false, SkBitmap::kARGB_4444_Config),
+        Options(3, false, SkBitmap::kARGB_4444_Config),
+        Options(4, false, SkBitmap::kARGB_4444_Config),
+    };
+
+    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 oidx = 0; oidx < SK_ARRAY_COUNT(optionList); ++oidx) {
+            // Test with NULL option pointer as well.
+            const Options& opts = optionList[oidx];
+
+            SkBitmap bm;
+            bool success = false;
+            for (int inputType = 0; inputType < 2; ++inputType) {
+                if (0 == inputType) {
+                    if (NULL == encodedData.get()) {
+                        continue;
+                    }
+                    success = SkInstallDiscardablePixelRef(
+                        SkNewDecodingImageGenerator(encodedData, opts),
+                        &bm, NULL);
+                } else {
+                    if (NULL == encodedStream.get()) {
+                        continue;
+                    }
+                    success = SkInstallDiscardablePixelRef(
+                        SkNewDecodingImageGenerator(encodedStream->duplicate(),
+                                                    opts),
+                        &bm, NULL);
+                }
+                REPORTER_ASSERT(reporter, success
+                                || (SkBitmap::kARGB_4444_Config
+                                    == opts.fRequestedConfig));
+                if (!success) {
+                    continue;
+                }
+                REPORTER_ASSERT(reporter,
+                                checkrounding(bm.height(), expectedHeight,
+                                              opts.fSampleSize));
+                REPORTER_ASSERT(reporter,
+                                checkrounding(bm.width(), expectedWidth,
+                                              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 = expectedPixels;
+                    SkASSERT(bm.height() == expectedHeight);
+                    SkASSERT(bm.width() == expectedWidth);
+                    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);
+                }
+            }
+        }
+    }
+}