tools: Add codectest to make it easy to test attribute encoder

This is useful when trying to compress binary vertex data blobs as well
as to check the output data with a separate compressor using piping, so
we use stdin and stdout instead of named files.

Makefile

@@ -213,6 +213,9 @@ codecbench.wasm: tools/codecbench.cpp $(LIBRARY_SOURCES)
 codecbench-simd.wasm: tools/codecbench.cpp $(LIBRARY_SOURCES)
 	$(WASMCC) $^ -fno-exceptions --target=wasm32-wasi --sysroot=$(WASIROOT) -lc++ -lc++abi -O3 -g -DNDEBUG -msimd128 -o $@
 
+codectest: tools/codectest.cpp $(LIBRARY)
+	$(CXX) $^ $(CXXFLAGS) $(LDFLAGS) -o $@
+
 codecfuzz: tools/codecfuzz.cpp src/vertexcodec.cpp src/indexcodec.cpp
 	$(CXX) $^ -fsanitize=fuzzer,address,undefined -O1 -g -o $@
 

tools/codectest.cpp

@@ -0,0 +1,41 @@
+#include "../src/meshoptimizer.h"
+
+#include <vector>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef _WIN32
+#include <fcntl.h>
+#include <io.h>
+#endif
+
+int main(int argc, char** argv)
+{
+#ifdef _WIN32
+	_setmode(_fileno(stdin), _O_BINARY);
+	_setmode(_fileno(stdout), _O_BINARY);
+#endif
+
+	if (argc != 2 || atoi(argv[1]) <= 0)
+	{
+		fprintf(stderr, "Usage: %s <stride>\n", argv[0]);
+		return 1;
+	}
+
+	size_t stride = atoi(argv[1]);
+
+	std::vector<unsigned char> input;
+	unsigned char buffer[4096];
+	size_t bytes_read;
+
+	while ((bytes_read = fread(buffer, 1, sizeof(buffer), stdin)) > 0)
+		input.insert(input.end(), buffer, buffer + bytes_read);
+
+	size_t vertex_count = input.size() / stride;
+	std::vector<unsigned char> output(meshopt_encodeVertexBufferBound(vertex_count, stride));
+	size_t output_size = meshopt_encodeVertexBuffer(output.data(), output.size(), input.data(), vertex_count, stride);
+
+	fwrite(output.data(), 1, output_size, stdout);
+	return 0;
+}