SkScaledCodec class

dm/DM.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 "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
@@ skipping 194 matching lines @@
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded));
     if (NULL == codec.get()) {
         SkDebugf("Couldn't create codec for %s.", path.c_str());
         return;
     }
 
     // Choose scales for scaling tests.
     // TODO (msarett): Add more scaling tests as we implement more flexible scaling.
     // TODO (msarett): Implement scaling tests for SkImageDecoder in order to compare with these
     //                 tests.  SkImageDecoder supports downscales by integer factors.
-    const float scales[] = { 0.125f, 0.25f, 0.375f, 0.5f, 0.625f, 0.750f, 0.875f, 1.0f };
+    const float scales[] = { 0.1f, 0.125f, 0.16666666f, 0.2f, 0.25f, 0.3f, 0.375f, 0.4f, 0.5f, 0.6f,

[scroggo, 2015/08/04 20:05:21]

Could you add comments explaining why we chose these particular scale values?

[emmaleer, 2015/08/05 14:47:51]

Before we were only testing scaled values that Jpeg natively supports. 
I wanted to test values that it didn't natively support, to test the partial
scaling. 
I think it's good to leave them, so we test the sampling functionality for jpeg
and don't always use the native scaling method.  

+                             0.625f, 0.7f, 0.750f, 0.8f, 0.875f, 0.9f, 1.0f };
 
     for (float scale : scales) {
         if (scale != 1.0f && (path.endsWith(".webp") || path.endsWith(".WEBP"))) {
             // FIXME: skbug.com/4038 Scaling webp seems to leave some pixels uninitialized/
             // compute their colors based on uninitialized values.
             continue;
         }
         // Build additional test cases for images that decode natively to non-canvas types
         switch(codec->getInfo().colorType()) {
             case kGray_8_SkColorType:
@@ skipping 617 matching lines @@
     }
     return 0;
 }
 
 #if !defined(SK_BUILD_FOR_IOS)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif