Use separate subset directories in skimage.

tools/skimage_main.cpp

Index: tools/skimage_main.cpp
diff --git a/tools/skimage_main.cpp b/tools/skimage_main.cpp
index 2041f7bbcc5a4991fc81791519b65f4de86ea068..cb69e1e81ac81e9fdd66c4393ba58a8f92306268 100644
--- a/tools/skimage_main.cpp
+++ b/tools/skimage_main.cpp
@@ -299,21 +299,33 @@ static void decodeFileAndWrite(const char srcPath[], const SkString* writePath)
                     write_expectations(bitmapFromDecodeSubset, subsetName.c_str());
 
                     if (writePath != NULL) {
-                        // Write the region to a file whose name includes the dimensions.
-                        SkString suffix = SkStringPrintf("_%s.png", subsetDim.c_str());
-                        SkString outPath;
-                        make_outname(&outPath, writePath->c_str(), srcPath, suffix.c_str());
-                        SkDEBUGCODE(bool success =)
-                        write_bitmap(outPath.c_str(), &bitmapFromDecodeSubset);
-                        SkASSERT(success);
-                        gSuccessfulSubsetDecodes.push_back().printf("\twrote %s", outPath.c_str());
-                        // Also use extractSubset from the original for visual comparison.
-                        SkBitmap extractedSubset;
-                        if (bitmap.extractSubset(&extractedSubset, rect)) {
-                            suffix.printf("_%s_extracted.png", subsetDim.c_str());
-                            make_outname(&outPath, writePath->c_str(), srcPath, suffix.c_str());
-                            SkDEBUGCODE(success =) write_bitmap(outPath.c_str(), &extractedSubset);
+                        // Create a subdirectory to hold the results of decodeSubset.
+                        SkString dir(*writePath);
+                        dir.appendf("%s%c", "subsets", SkPATH_SEPARATOR);
+                        if (sk_mkdir(dir.c_str())) {

[epoger, 2013/05/09 17:45:40]

What happens if the mkdir fails?  Does it pretend to have completed
successfully?

[scroggo, 2013/05/13 17:34:12]

Now it will provide an error.

+                            // Write the subset to a file whose name includes the dimensions.
+                            SkString suffix = SkStringPrintf("_%s.png", subsetDim.c_str());
+                            SkString outPath;
+                            make_outname(&outPath, dir.c_str(), srcPath, suffix.c_str());
+                            SkDEBUGCODE(bool success =)
+                            write_bitmap(outPath.c_str(), &bitmapFromDecodeSubset);

[epoger, 2013/05/09 17:45:40]

Instead of the 3 lines, I think you can do it like this:

SkAssertResult(write_bitmap(outPath.c_str(), &bitmapFromDecodeSubset));

See
https://code.google.com/p/skia/source/browse/trunk/include/core/SkTypes.h?r=8...

[scroggo, 2013/05/13 17:34:12]

Done.

                             SkASSERT(success);
+                            gSuccessfulSubsetDecodes.push_back().printf("\twrote %s",
+                                                                        outPath.c_str());
+                            // Also use extractSubset from the original for visual comparison.
+                            // Write the result to a file in a separate subdirectory.
+                            SkBitmap extractedSubset;
+                            if (bitmap.extractSubset(&extractedSubset, rect)) {
+                                SkString dirExtracted(*writePath);
+                                dirExtracted.appendf("%s%c", "extracted", SkPATH_SEPARATOR);
+                                if (sk_mkdir(dirExtracted.c_str())) {
+                                    make_outname(&outPath, dirExtracted.c_str(), srcPath,
+                                                 suffix.c_str());
+                                    SkDEBUGCODE(success =)
+                                    write_bitmap(outPath.c_str(), &extractedSubset);
+                                    SkASSERT(success);
+                                }
+                            }
                         }
                     }
                 } else {