Initial version of astc-codec for open source release

Contains an implementation of an ASTC decoder that is able to pass the
dEQP ASTC LDR tests.

astc-codec has no external dependencies for the main library, only for
test code, and is licensed under the Apache license.

Components:

include/ - Public API that can decode ASTC LDR data into a RGBA UNORM8
buffer.

src/base/ - Base library with common functionality not directly related
to ASTC decoding.  Contains a uint128 implementation, BitStream for
reading/writing bits with a primitive (or uint128 type), Optional
implementation (to not take a dependency on C++17), and more.

src/decoder/ - Internal implementation of the ASTC decoder.

src/base/test/, src/decoder/test/ - Unit tests (and a fuzzing test) for
the astc decoder.

src/decoder/testdata/ - Sample ASTC images and golden image results for
testing.

src/decoder/tools/ - A tool to inspect contents of an ASTC file.

third_party/ - Third party libraries, only used for tests.

Change-Id: Ia98e5a7dc847daa3d3a48c5e62d94b8fb1cb98bd

1 files changed, 68 insertions, 0 deletions

diff --git a/src/base/string_utils.h b/src/base/string_utils.h
new file mode 100644
index 0000000..c450b27
--- /dev/null
+++ b/src/base/string_utils.h
@@ -0,0 +1,68 @@
+// Copyright 2018 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#ifndef ASTC_CODEC_BASE_STRING_UTILS_H_
+#define ASTC_CODEC_BASE_STRING_UTILS_H_
+
+#include <limits>
+#include <string>
+
+namespace astc_codec {
+namespace base {
+
+// Iterates over a string's parts using |splitBy| as a delimiter.
+// |splitBy| must be a nonempty string well, or it's a no-op.
+// Otherwise, |func| is called on each of the splits, excluding the
+// characters that are part of |splitBy|.  If two |splitBy|'s occur in a row,
+// |func| will be called on a StringView("") in between. See
+// StringUtils_unittest.cpp for the full story.
+template<class Func>
+void Split(const std::string& str, const std::string& splitBy, Func func) {
+  if (splitBy.empty()) {
+    return;
+  }
+
+  size_t splitSize = splitBy.size();
+  size_t begin = 0;
+  size_t end = str.find(splitBy);
+
+  while (true) {
+    func(str.substr(begin, end - begin));
+    if (end == std::string::npos) {
+      return;
+    }
+
+    begin = end + splitSize;
+    end = str.find(splitBy, begin);
+  }
+}
+
+static int32_t ParseInt32(const char* str, int32_t deflt) {
+  using std::numeric_limits;
+
+  char* error = nullptr;
+  int64_t value = strtol(str, &error, 0);
+  // Limit long values to int32 min/max.  Needed for lp64; no-op on 32 bits.
+  if (value > std::numeric_limits<int32_t>::max()) {
+    value = std::numeric_limits<int32_t>::max();
+  } else if (value < std::numeric_limits<int32_t>::min()) {
+    value = std::numeric_limits<int32_t>::min();
+  }
+  return (error == str) ? deflt : static_cast<int32_t>(value);
+}
+
+}  // namespace base
+}  // namespace astc_codec
+
+#endif  // ASTC_CODEC_BASE_STRING_UTILS_H_