Added VWDictionary tests and doc. Fixed LSH not working (fix from https://github.com/flann-lib/flann/pull/472

corelib/test/test_visualword.cpp

@@ -0,0 +1,82 @@
+#include <gtest/gtest.h>
+#include <opencv2/core.hpp>
+#include "rtabmap/core/VisualWord.h"
+#include <map>
+
+using namespace rtabmap;
+
+TEST(VisualWordTest, ConstructorAndAccessors)
+{
+    cv::Mat descriptor = (cv::Mat_<float>(1, 3) << 1.0, 2.0, 3.0);
+    int wordId = 123;
+    int signatureId = 10;
+
+    VisualWord word(wordId, descriptor, signatureId);
+
+    EXPECT_EQ(word.id(), wordId);
+    EXPECT_EQ(word.getTotalReferences(), 1);
+    EXPECT_EQ(word.getDescriptor().cols, descriptor.cols);
+    EXPECT_EQ(word.getDescriptor().rows, descriptor.rows);
+
+    auto refs = word.getReferences();
+    ASSERT_EQ(refs.size(), 1);
+    EXPECT_EQ(refs.at(signatureId), 1);
+}
+
+TEST(VisualWordTest, AddMultipleReferences)
+{
+    VisualWord word(1, cv::Mat::ones(1, 5, CV_32F));
+
+    word.addRef(100);
+    word.addRef(100); // same signature
+    word.addRef(200);
+
+    EXPECT_EQ(word.getTotalReferences(), 3);
+
+    auto refs = word.getReferences();
+    EXPECT_EQ(refs.size(), 2);
+    EXPECT_EQ(refs.at(100), 2);
+    EXPECT_EQ(refs.at(200), 1);
+}
+
+TEST(VisualWordTest, RemoveReferences)
+{
+    VisualWord word(1, cv::Mat::zeros(1, 3, CV_8U));
+    word.addRef(10);
+    word.addRef(10);
+    word.addRef(20);
+
+    EXPECT_EQ(word.getTotalReferences(), 3);
+
+    int removed = word.removeAllRef(10);
+    EXPECT_EQ(removed, 2);
+    EXPECT_EQ(word.getTotalReferences(), 1);
+
+    auto refs = word.getReferences();
+    EXPECT_EQ(refs.size(), 1);
+    EXPECT_TRUE(refs.find(10) == refs.end());
+    EXPECT_EQ(refs.at(20), 1);
+}
+
+TEST(VisualWordTest, SavedFlagBehavior)
+{
+    VisualWord word(1, cv::Mat());
+    EXPECT_FALSE(word.isSaved());
+
+    word.setSaved(true);
+    EXPECT_TRUE(word.isSaved());
+
+    word.setSaved(false);
+    EXPECT_FALSE(word.isSaved());
+}
+
+TEST(VisualWordTest, MemoryUsedEstimation)
+{
+    cv::Mat descriptor = cv::Mat::ones(1, 128, CV_32FC1); // simulate SIFT descriptor
+    VisualWord word(42, descriptor);
+
+    unsigned long mem = word.getMemoryUsed();
+
+    // Should be at least size of descriptor
+    EXPECT_GE(mem, 128ul*sizeof(float));
+}