DM: Add support for reading a directory of images with --expectations (-r).

dm/DMWriteTask.cpp

Index: dm/DMWriteTask.cpp
diff --git a/dm/DMWriteTask.cpp b/dm/DMWriteTask.cpp
index c86381f78af12485fcd1bf4d1dcbc4cc08acb119..11b9fd3470738acaa865f0c2685d7c377cc87213 100644
--- a/dm/DMWriteTask.cpp
+++ b/dm/DMWriteTask.cpp
@@ -2,6 +2,7 @@
 
 #include "DMUtil.h"
 #include "SkCommandLineFlags.h"
+#include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkString.h"
 
@@ -9,18 +10,25 @@ DEFINE_string2(writePath, w, "", "If set, write GMs here as .pngs.");
 
 namespace DM {
 
-WriteTask::WriteTask(const Task& parent, SkBitmap bitmap) : Task(parent), fBitmap(bitmap) {
-    const int suffixes = parent.depth() + 1;
-    const char* name = parent.name().c_str();
+// Splits off the last N suffixes of name (splitting on _) and appends them to out.
+// Returns the total number of characters consumed.
+static int split_suffixes(int N, const char* name, SkTArray<SkString>* out) {
     SkTArray<SkString> split;
     SkStrSplit(name, "_", &split);
-    int totalSuffixLength = 0;
-    for (int i = 0; i < suffixes; i++) {
+    int consumed = 0;
+    for (int i = 0; i < N; i++) {
         // We're splitting off suffixes from the back to front.
-        fSuffixes.push_back(split[split.count()-i-1]);
-        totalSuffixLength += fSuffixes.back().size() + 1;
+        out->push_back(split[split.count()-i-1]);
+        consumed += out->back().size() + 1;  // Add one for the _.
     }
-    fGmName.set(name, strlen(name)-totalSuffixLength);
+    return consumed;
+}
+
+WriteTask::WriteTask(const Task& parent, SkBitmap bitmap) : Task(parent), fBitmap(bitmap) {
+    const int suffixes = parent.depth() + 1;
+    const SkString& name = parent.name();
+    const int totalSuffixLength = split_suffixes(suffixes, name.c_str(), &fSuffixes);
+    fGmName.set(name.c_str(), name.size()-totalSuffixLength);
 }
 
 void WriteTask::makeDirOrFail(SkString dir) {
@@ -36,7 +44,9 @@ void WriteTask::draw() {
         dir = SkOSPath::SkPathJoin(dir.c_str(), fSuffixes[i].c_str());
         this->makeDirOrFail(dir);
     }
-    if (!SkImageEncoder::EncodeFile(Png(SkOSPath::SkPathJoin(dir.c_str(), fGmName.c_str())).c_str(),
+    SkString path = SkOSPath::SkPathJoin(dir.c_str(), fGmName.c_str());
+    path.append(".png");
+    if (!SkImageEncoder::EncodeFile(path.c_str(),
                                     fBitmap,
                                     SkImageEncoder::kPNG_Type,
                                     100/*quality*/)) {
@@ -57,4 +67,44 @@ bool WriteTask::shouldSkip() const {
     return FLAGS_writePath.isEmpty();
 }
 
+static SkString path_to_expected_image(const char* root, const Task& task) {
+    SkString filename = task.name();
+
+    // We know that all names passed in here belong to top-level Tasks, which have a single suffix
+    // (8888, 565, gpu, etc.) indicating what subdirectory to look in.
+    SkTArray<SkString> suffixes;
+    const int suffixLength = split_suffixes(1, filename.c_str(), &suffixes);
+    SkASSERT(1 == suffixes.count());
+
+    // We'll look in root/suffix for images.
+    const SkString dir = SkOSPath::SkPathJoin(root, suffixes[0].c_str());
+
+    // Remove the suffix and tack on a .png.
+    filename.remove(filename.size() - suffixLength, suffixLength);
+    filename.append(".png");
+
+    //SkDebugf("dir %s, filename %s\n", dir.c_str(), filename.c_str());
+
+    return SkOSPath::SkPathJoin(dir.c_str(), filename.c_str());
+}
+
+bool WriteTask::Expectations::check(const Task& task, SkBitmap bitmap) const {
+    const SkString path = path_to_expected_image(fRoot, task);
+
+    SkBitmap expected;
+    if (SkImageDecoder::DecodeFile(path.c_str(), &expected)) {
+        if (expected.config() != bitmap.config()) {
+            SkBitmap converted;
+            SkAssertResult(expected.copyTo(&converted, bitmap.config()));
+            expected.swap(converted);
+        }
+        SkASSERT(expected.config() == bitmap.config());
+        return BitmapsEqual(expected, bitmap);
+    }
+
+    // Couldn't read the file, etc.
+    SkDebugf("Problem decoding %s to SkBitmap.\n", path.c_str());
+    return false;
+}
+
 }  // namespace DM