Adding a tool to get images from skps

tools/get_images_from_skps.cpp

Index: tools/get_images_from_skps.cpp
diff --git a/tools/get_images_from_skps.cpp b/tools/get_images_from_skps.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e57c3de8e7b6a73108b38a8f9ba2be3e531c0b3e
--- /dev/null
+++ b/tools/get_images_from_skps.cpp
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCanvas.h"
+#include "SkCodec.h"
+#include "SkCommandLineFlags.h"
+#include "SkData.h"
+#include "SkOSFile.h"
+#include "SkPicture.h"
+#include "SkStream.h"
+
+DEFINE_string2(skps, s, "", "A path to a directory of skps.");
+DEFINE_string2(out, o, "", "A path to an output directory.");
+
+static int gCtr = 0;
+static int gSuccessCtr = 0;
+static const char* gOutputDir;
+
+static void printUsage() {
+    SkDebugf("Usage: get_images_from_skps -s <dir of skps> -o <dir for output images>\n");

[scroggo, 2016/02/12 17:18:38]

SkCommandLineFlags has a method to specify usage (SetUsage), which gets printed
when you use -h/--help. Maybe we should add a method to print that usage, and
you can use that? Then this message will also be printed when you use -h.

[msarett, 2016/02/12 21:30:29]

Done.

+}
+
+void setup_output_dirs() {
+    const char* exts[] = { "jpg", "png", "gif", "webp", "bmp", "wbmp", "ico", "dng", "unknown" };
+    for (const char* ext : exts) {
+        SkString path(gOutputDir);
+        path.append("/");

[scroggo, 2016/02/12 17:18:38]

Should these use SkOSPath::Join so that it will work on Windows?

[msarett, 2016/02/12 21:30:29]

Done.

+        path.append(ext);
+        sk_mkdir(path.c_str());
+    }
+}
+
+bool store_encoded_to_file(const void* encoded, size_t length, SkBitmap* bitmap) {
+    // Silence warnings about empty bitmaps.
+    bitmap->allocN32Pixels(1, 1, true);
+
+    SkString path(gOutputDir);
+    SkAutoTUnref<SkData> data(SkData::NewWithoutCopy(encoded, length));
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(data));
+    if (codec) {
+        switch (codec->getEncodedFormat()) {
+            case SkEncodedFormat::kJPEG_SkEncodedFormat:
+                path.append("/jpg/");
+                path.appendS32(gCtr++);
+                path.append(".jpg");
+                break;
+            case SkEncodedFormat::kPNG_SkEncodedFormat:
+                path.append("/png/");
+                path.appendS32(gCtr++);
+                path.append(".png");
+                break;
+            case SkEncodedFormat::kGIF_SkEncodedFormat:
+                path.append("/gif/");
+                path.appendS32(gCtr++);
+                path.append(".gif");
+                break;
+            case SkEncodedFormat::kWEBP_SkEncodedFormat:
+                path.append("/webp/");
+                path.appendS32(gCtr++);
+                path.append(".webp");
+                break;
+            case SkEncodedFormat::kBMP_SkEncodedFormat:
+                path.append("/bmp/");
+                path.appendS32(gCtr++);
+                path.append(".bmp");
+                break;
+            case SkEncodedFormat::kWBMP_SkEncodedFormat:
+                path.append("/wbmp/");
+                path.appendS32(gCtr++);
+                path.append(".wbmp");
+                break;
+            case SkEncodedFormat::kICO_SkEncodedFormat:
+                path.append("/ico/");
+                path.appendS32(gCtr++);
+                path.append(".ico");
+                break;
+            case SkEncodedFormat::kRAW_SkEncodedFormat:
+                path.append("/dng/");
+                path.appendS32(gCtr++);
+                path.append(".dng");
+                break;
+            default:
+                path.append("/unknown/");
+                path.appendS32(gCtr++);
+                break;
+        }
+    } else {
+        path.append("/unknown/");
+        path.appendS32(gCtr++);
+    }
+
+    FILE* file = sk_fopen(path.c_str(), kWrite_SkFILE_Flag);
+    if (file) {
+        sk_fwrite(encoded, length, file);
+        sk_fclose(file);
+        gSuccessCtr++;
+        return true;
+    }
+
+    SkDebugf("Could not open %s\n", path.c_str());
+    return false;
+}
+
+int main(int argc, char** argv) {
+    SkCommandLineFlags::Parse(argc, argv);
+    if (FLAGS_skps.isEmpty() || FLAGS_out.isEmpty()) {
+        printUsage();
+        return 0;
+    }
+
+    const char* inputs = FLAGS_skps[0];
+    gOutputDir = FLAGS_out[0];
+    setup_output_dirs();
+    if (!sk_isdir(inputs) || !sk_isdir(gOutputDir)) {
+        printUsage();
+        return 0;
+    }
+
+    SkOSFile::Iter iter(inputs, "skp");
+    for (SkString file; iter.next(&file); ) {
+        SkAutoTDelete<SkStream> stream =
+                SkStream::NewFromFile(SkOSPath::Join(inputs, file.c_str()).c_str());
+
+        // Rather than passing in a function that actually decodes the encoded data,
+        // we pass in a function that saves the encoded data to a file.
+        SkAutoTUnref<SkPicture> picture(SkPicture::CreateFromStream(stream, store_encoded_to_file));

[msarett, 2016/02/12 16:33:49]

Originally, I wanted to write code that actually parsed the SkPicture.  But I
think this is a nice way to take advantage of the fact that someone has already
written that code :).

[scroggo, 2016/02/12 17:18:38]

Yep! This is similar to a feature we used to have in the long dead
render_pictures program, which was subsumed into DM. (Although I just did a git
grep of "render_pictures" and it turns out we have two python scripts that use
it, plus some documentation that refers to it. So we have more cleanups to do
there...)

Why not put this inside DM also?

[mtklein, 2016/02/12 17:21:41]

Unlike render_pictures, this program has multiple outputs per input, which
doesn't fit well into DM's model.  Let's just leave it stand-alone.

[scroggo, 2016/02/12 18:50:27]

sgtm

+
+        SkCanvas canvas;
+        canvas.drawPicture(picture);
+    }
+
+    SkDebugf("Saved %d images to %s\n", gSuccessCtr, gOutputDir);

[scroggo, 2016/02/12 17:18:38]

Should we also report the number of images that failed?

[msarett, 2016/02/12 21:30:29]

Yes that sounds good.

+    return 1;

[scroggo, 2016/02/12 17:18:38]

FWIW, I think our other testing tools return 0 and success and 1 on failure.

[msarett, 2016/02/12 21:30:29]

Haha yes.  Fixed.

+}