Add config option to skimage.

tools/skimage_main.cpp

Index: tools/skimage_main.cpp
diff --git a/tools/skimage_main.cpp b/tools/skimage_main.cpp
index ef5c133fc6ba55e8b1003efb5faa261e622cebc8..8a46210bb61d010bff6a57aed8ef74eb4de08336 100644
--- a/tools/skimage_main.cpp
+++ b/tools/skimage_main.cpp
@@ -22,6 +22,7 @@
 
 __SK_FORCE_IMAGE_DECODER_LINKING;
 
+DEFINE_string(config, "None", "Preferred config to decode into. [None|8888|565|A8]");
 DEFINE_string(createExpectationsPath, "", "Path to write JSON expectations.");
 DEFINE_string(mismatchPath, "", "Folder to write mismatched images to.");
 DEFINE_string2(readPath, r, "", "Folder(s) and files to decode images. Required.");
@@ -98,6 +99,8 @@ static SkTArray<SkString, false> gSuccessfulDecodes;
 static SkTArray<SkString, false> gSuccessfulSubsetDecodes;
 static SkTArray<SkString, false> gFailedSubsetDecodes;
 
+static SkBitmap::Config gPrefConfig(SkBitmap::kNo_Config);
+
 // Expections read from a file specified by readExpectationsPath. The expectations must have been
 // previously written using createExpectationsPath.
 SkAutoTUnref<skiagm::JsonExpectationsSource> gJsonExpectations;
@@ -316,7 +319,7 @@ static void decodeFileAndWrite(const char srcPath[], const SkString* writePath)
     SkString basename = SkOSPath::SkBasename(srcPath);
     const char* filename = basename.c_str();
 
-    if (!codec->decode(&stream, &bitmap, SkBitmap::kARGB_8888_Config,
+    if (!codec->decode(&stream, &bitmap, gPrefConfig,
                        SkImageDecoder::kDecodePixels_Mode)) {
         if (expect_to_fail(filename)) {
             gSuccessfulDecodes.push_back().appendf(
@@ -384,7 +387,7 @@ static void decodeFileAndWrite(const char srcPath[], const SkString* writePath)
                 SkIRect rect = generate_random_rect(&rand, width, height);
                 SkString subsetDim = SkStringPrintf("[%d,%d,%d,%d]", rect.fLeft, rect.fTop,
                                                     rect.fRight, rect.fBottom);
-                if (codec->decodeSubset(&bitmapFromDecodeSubset, rect, SkBitmap::kNo_Config)) {
+                if (codec->decodeSubset(&bitmapFromDecodeSubset, rect, gPrefConfig)) {
                     SkString subsetName = SkStringPrintf("%s_%s", filename, subsetDim.c_str());
                     if (compare_to_expectations_if_necessary(bitmapFromDecodeSubset,
                                                              subsetName.c_str(),
@@ -466,7 +469,7 @@ static void decodeFileAndWrite(const char srcPath[], const SkString* writePath)
         SkMemoryStream memStream(data);
         SkBitmap redecodedBitmap;
         SkImageDecoder::Format formatOnSecondDecode;
-        if (SkImageDecoder::DecodeStream(&memStream, &redecodedBitmap, SkBitmap::kNo_Config,
+        if (SkImageDecoder::DecodeStream(&memStream, &redecodedBitmap, gPrefConfig,
                                           SkImageDecoder::kDecodePixels_Mode,
                                           &formatOnSecondDecode)) {
             SkASSERT(format_to_type(formatOnSecondDecode) == type);
@@ -550,6 +553,21 @@ int tool_main(int argc, char** argv) {
         outDirPtr = NULL;
     }
 
+    if (FLAGS_config.count() == 1) {
+        // Only consider the first config specified on the command line.
+        const char* config = FLAGS_config[0];
+        if (0 == strcmp(config, "8888")) {
+            gPrefConfig = SkBitmap::kARGB_8888_Config;
+        } else if (0 == strcmp(config, "565")) {
+            gPrefConfig = SkBitmap::kRGB_565_Config;
+        } else if (0 == strcmp(config, "A8")) {
+            gPrefConfig = SkBitmap::kA8_Config;
+        } else if (0 != strcmp(config, "None")) {
+            SkDebugf("Invalid preferred config\n");
+            return -1;
+        }
+    }
+
     for (int i = 0; i < FLAGS_readPath.count(); i++) {
         const char* readPath = FLAGS_readPath[i];
         if (strlen(readPath) < 1) {