SkScaledCodec should implement onRewind()

tests/CodexTest.cpp

 /*
  * 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"
@@ skipping 56 matching lines @@
     do {
         rect.fLeft = rand->nextRangeU(0, w);
         rect.fTop = rand->nextRangeU(0, h);
         rect.fRight = rand->nextRangeU(0, w);
         rect.fBottom = rand->nextRangeU(0, h);
         rect.sort();
     } while (rect.isEmpty());
     return rect;
 }
 
-static void check(skiatest::Reporter* r,
-                  const char path[],
-                  SkISize size,
-                  bool supportsScanlineDecoding,
-                  bool supportsSubsetDecoding,
-                  bool supports565 = true) {
-    SkAutoTDelete<SkStream> stream(resource(path));
-    if (!stream) {
-        SkDebugf("Missing resource '%s'\n", path);
-        return;
-    }
-    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
-    if (!codec) {
-        ERRORF(r, "Unable to decode '%s'", path);
-        return;
-    }
-
-    // This test is used primarily to verify rewinding works properly.  Using kN32 allows
-    // us to test this without the added overhead of creating different bitmaps depending
-    // on the color type (ex: building a color table for kIndex8).  DM is where we test
-    // decodes to all possible destination color types.
-    SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
+static void test_codec(skiatest::Reporter* r, SkCodec* codec, SkBitmap& bm, const SkImageInfo& info,
+        const SkISize& size, bool supports565, SkMD5::Digest* digest,
+        const SkMD5::Digest* goodDigest) {
     REPORTER_ASSERT(r, info.dimensions() == size);
-
-    SkBitmap bm;
     bm.allocPixels(info);
     SkAutoLockPixels autoLockPixels(bm);
-    SkCodec::Result result =
-        codec->getPixels(info, bm.getPixels(), bm.rowBytes(), nullptr, nullptr, nullptr);
+
+    SkCodec::Result result = codec->getPixels(info, bm.getPixels(), bm.rowBytes());
     REPORTER_ASSERT(r, result == SkCodec::kSuccess);
 
-    SkMD5::Digest digest;
-    md5(bm, &digest);
+    md5(bm, digest);
+    if (goodDigest) {
+        REPORTER_ASSERT(r, *digest == *goodDigest);
+    }
 
     {
         // Test decoding to 565
         SkImageInfo info565 = info.makeColorType(kRGB_565_SkColorType);
         SkCodec::Result expected = (supports565 && info.alphaType() == kOpaque_SkAlphaType) ?
                 SkCodec::kSuccess : SkCodec::kInvalidConversion;
         test_info(r, codec, info565, expected, nullptr);
     }
 
     // Verify that re-decoding gives the same result.  It is interesting to check this after
     // a decode to 565, since choosing to decode to 565 may result in some of the decode
     // options being modified.  These options should return to their defaults on another
     // decode to kN32, so the new digest should match the old digest.
-    test_info(r, codec, info, SkCodec::kSuccess, &digest);
+    test_info(r, codec, info, SkCodec::kSuccess, digest);
 
     {
         // Check alpha type conversions
         if (info.alphaType() == kOpaque_SkAlphaType) {
             test_info(r, codec, info.makeAlphaType(kUnpremul_SkAlphaType),
                       SkCodec::kInvalidConversion, nullptr);
             test_info(r, codec, info.makeAlphaType(kPremul_SkAlphaType),
                       SkCodec::kInvalidConversion, nullptr);
         } else {
             // Decoding to opaque should fail
             test_info(r, codec, info.makeAlphaType(kOpaque_SkAlphaType),
                       SkCodec::kInvalidConversion, nullptr);
             SkAlphaType otherAt = info.alphaType();
             if (kPremul_SkAlphaType == otherAt) {
                 otherAt = kUnpremul_SkAlphaType;
             } else {
                 otherAt = kPremul_SkAlphaType;
             }
             // The other non-opaque alpha type should always succeed, but not match.
             test_info(r, codec, info.makeAlphaType(otherAt), SkCodec::kSuccess, nullptr);
         }
     }
+}
+
+static void check(skiatest::Reporter* r,
+                  const char path[],
+                  SkISize size,
+                  bool supportsScanlineDecoding,
+                  bool supportsSubsetDecoding,
+                  bool supports565 = true) {
+
+    SkAutoTDelete<SkStream> stream(resource(path));
+    if (!stream) {
+        SkDebugf("Missing resource '%s'\n", path);
+        return;
+    }
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
+    if (!codec) {
+        ERRORF(r, "Unable to decode '%s'", path);
+        return;
+    }
+
+    // Test full image decodes with SkCodec
+    SkMD5::Digest codecDigest;
+    SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
+    SkBitmap bm;
+    test_codec(r, codec, bm, info, size, supports565, &codecDigest, nullptr);
 
     // Scanline decoding follows.
-
-    // Need to call start() first.
+    // Need to call startScanlineDecode() first.
     REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
             == SkCodec::kScanlineDecodingNotStarted);
     REPORTER_ASSERT(r, codec->skipScanlines(1)
             == SkCodec::kScanlineDecodingNotStarted);
 
     const SkCodec::Result startResult = codec->startScanlineDecode(info);
     if (supportsScanlineDecoding) {
         bm.eraseColor(SK_ColorYELLOW);
 
         REPORTER_ASSERT(r, startResult == SkCodec::kSuccess);
 
         for (int y = 0; y < info.height(); y++) {
-            result = codec->getScanlines(bm.getAddr(0, y), 1, 0);
+            SkCodec::Result result = codec->getScanlines(bm.getAddr(0, y), 1, 0);
             REPORTER_ASSERT(r, result == SkCodec::kSuccess);
         }
         // verify that scanline decoding gives the same result.
         if (SkCodec::kTopDown_SkScanlineOrder == codec->getScanlineOrder()) {
-            compare_to_good_digest(r, digest, bm);
+            compare_to_good_digest(r, codecDigest, bm);
         }
 
         // Cannot continue to decode scanlines beyond the end
         REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
                 == SkCodec::kInvalidParameters);
 
         // Interrupting a scanline decode with a full decode starts from
         // scratch
         REPORTER_ASSERT(r, codec->startScanlineDecode(info) == SkCodec::kSuccess);
         REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
@@ skipping 35 matching lines @@
         if (supportsSubsetDecoding) {
             REPORTER_ASSERT(r, result == SkCodec::kSuccess);
             // Webp is the only codec that supports subsets, and it will have modified the subset
             // to have even left/top.
             REPORTER_ASSERT(r, SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
         } else {
             // No subsets will work.
             REPORTER_ASSERT(r, result == SkCodec::kUnimplemented);
         }
     }
+
+    // SkScaledCodec tests
+    if (supportsScanlineDecoding || supportsSubsetDecoding){
+        SkAutoTDelete<SkStream> stream(resource(path));
+        if (!stream) {
+            SkDebugf("Missing resource '%s'\n", path);
+            return;
+        }
+        SkAutoTDelete<SkCodec> codec(SkScaledCodec::NewFromStream(stream.detach()));
+        if (!codec) {
+            ERRORF(r, "Unable to decode '%s'", path);
+            return;
+        }
+
+        SkBitmap bm;
+        SkMD5::Digest scaledCodecDigest;
+        test_codec(r, codec, bm, info, size, supports565, &scaledCodecDigest, &codecDigest);
+    }
 }
 
 DEF_TEST(Codec, r) {
     // WBMP
     check(r, "mandrill.wbmp", SkISize::Make(512, 512), true, false);
 
     // WEBP
     check(r, "baby_tux.webp", SkISize::Make(386, 395), false, true);
     check(r, "color_wheel.webp", SkISize::Make(128, 128), false, true);
     check(r, "yellow_rose.webp", SkISize::Make(400, 301), false, true);
@@ skipping 266 matching lines @@
     REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
     result = decoder->startScanlineDecode(
         decoder->getInfo().makeColorType(kIndex_8_SkColorType));
     REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
 }
 
 DEF_TEST(Codec_Params, r) {
     test_invalid_parameters(r, "index8.png");
     test_invalid_parameters(r, "mandrill.wbmp");
 }