AAPT2: Refactor PngCrunching
PngCrunching now has a slightly better heuristic of choosing to encode
an image as a palette or RGB. For small images, RGB compresses much better
than a palette.
The original PNG is used as-is (minus some optional chunks being stripped)
if the resulting crunched PNG is larger than the original.
9-patch handling is abstracted away from PNGs, paving the way
for other 9-patches, like WebP.
TODO: handle PNGs with 9-patch chunks already present, which
should just be passed through. This will allow for 3rd party
tools to generate 9-patches.
TODO: implement cheap transparency: when one color is used to represent
transparent, and all other colors are opaque.
Bug:30053276
Change-Id: I5167f53b91d1efa462d9f03d6b9108d9b541c0c1
diff --git a/tools/aapt2/io/Io.cpp b/tools/aapt2/io/Io.cpp
new file mode 100644
index 0000000..963c21c
--- /dev/null
+++ b/tools/aapt2/io/Io.cpp
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "io/Io.h"
+
+#include <algorithm>
+#include <cstring>
+
+namespace aapt {
+namespace io {
+
+bool copy(OutputStream* out, InputStream* in) {
+ const void* inBuffer;
+ int inLen;
+ while (in->Next(&inBuffer, &inLen)) {
+ void* outBuffer;
+ int outLen;
+ if (!out->Next(&outBuffer, &outLen)) {
+ return !out->HadError();
+ }
+
+ const int bytesToCopy = std::min(inLen, outLen);
+ memcpy(outBuffer, inBuffer, bytesToCopy);
+ out->BackUp(outLen - bytesToCopy);
+ in->BackUp(inLen - bytesToCopy);
+ }
+ return !in->HadError();
+}
+
+} // namespace io
+} // namespace aapt