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, 69 insertions, 0 deletions

diff --git a/src/decoder/test/weight_infill_test.cc b/src/decoder/test/weight_infill_test.cc
new file mode 100644
index 0000000..79c7745
--- /dev/null
+++ b/src/decoder/test/weight_infill_test.cc
@@ -0,0 +1,69 @@
+// 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.
+
+#include "src/decoder/weight_infill.h"
+#include "src/decoder/footprint.h"
+
+#include <gtest/gtest.h>
+
+#include <vector>
+
+namespace astc_codec {
+
+namespace {
+
+// Make sure that the physical size of the bit representations for certain
+// dimensions of weight grids matches our expectations
+TEST(ASTCWeightInfillTest, TestGetBitCount) {
+  // Bit encodings
+  EXPECT_EQ(32, CountBitsForWeights(4, 4, 3));
+  EXPECT_EQ(48, CountBitsForWeights(4, 4, 7));
+  EXPECT_EQ(24, CountBitsForWeights(2, 4, 7));
+  EXPECT_EQ(8, CountBitsForWeights(2, 4, 1));
+
+  // Trit encodings
+  EXPECT_EQ(32, CountBitsForWeights(4, 5, 2));
+  EXPECT_EQ(26, CountBitsForWeights(4, 4, 2));
+  EXPECT_EQ(52, CountBitsForWeights(4, 5, 5));
+  EXPECT_EQ(42, CountBitsForWeights(4, 4, 5));
+
+  // Quint encodings
+  EXPECT_EQ(21, CountBitsForWeights(3, 3, 4));
+  EXPECT_EQ(38, CountBitsForWeights(4, 4, 4));
+  EXPECT_EQ(49, CountBitsForWeights(3, 7, 4));
+  EXPECT_EQ(52, CountBitsForWeights(4, 3, 19));
+  EXPECT_EQ(70, CountBitsForWeights(4, 4, 19));
+}
+
+// Make sure that we bilerp our weights properly
+TEST(ASTCWeightInfillTest, TestInfillBilerp) {
+  std::vector<int> weights = InfillWeights(
+      {{ 1, 3, 5, 3, 5, 7, 5, 7, 9 }}, Footprint::Get5x5(), 3, 3);
+
+  std::vector<int> expected_weights = {
+      1, 2, 3, 4, 5,
+      2, 3, 4, 5, 6,
+      3, 4, 5, 6, 7,
+      4, 5, 6, 7, 8,
+      5, 6, 7, 8, 9 };
+
+  ASSERT_EQ(weights.size(), expected_weights.size());
+  for (int i = 0; i < weights.size(); ++i) {
+    EXPECT_EQ(weights[i], expected_weights[i]);
+  }
+}
+
+}  // namespace
+
+}  // namespace astc_codec