1 files changed, 54 insertions, 0 deletions
diff --git a/test/example/sparse_square_matrix.cpp b/test/example/sparse_square_matrix.cpp
new file mode 100644
index 000000000..ad1f71ade
--- /dev/null
+++ b/test/example/sparse_square_matrix.cpp
@@ -0,0 +1,54 @@
+#include <iostream>
+
+#include "support/sparse_square_matrix.h"
+
+int main() {
+  sparse_square_matrix<uint32_t> m;
+
+  // New matrix should initialize to 0x0 size.
+  assert(m.width() == 0);
+
+  // Recreating should resize the matrix.
+  m.recreate(100);
+  assert(m.width() == 100);
+
+  // Small matrices should use dense storage.
+  assert(m.usingDenseStorage());
+
+  // Setting and getting element values in dense storage should work.
+  for (int y = 0; y < 100; ++y)
+    for (int x = 0; x < 100; ++x)
+      m.set(y, x, y * 100 + x);
+  for (int y = 0; y < 100; ++y)
+    for (int x = 0; x < 100; ++x)
+      assert(m.get(y, x) == y * 100 + x);
+
+  // Recreating should clear the matrix elements to zero,
+  // even if recreating to same size as before.
+  assert(m.width() == 100);
+  m.recreate(100);
+  for (int y = 0; y < 100; ++y)
+    for (int x = 0; x < 100; ++x)
+      assert(m.get(y, x) == 0);
+
+  // Large matrices should use sparse storage.
+  m.recreate(m.DenseLimit);
+  assert(!m.usingDenseStorage());
+
+  // Setting and getting element values in sparse storage should work.
+  for (int y = 0; y < m.DenseLimit; y += 128)
+    for (int x = 0; x < m.DenseLimit; x += 128)
+      m.set(y, x, y * m.DenseLimit + x);
+  for (int y = 0; y < m.DenseLimit; y += 128)
+    for (int x = 0; x < m.DenseLimit; x += 128)
+      assert(m.get(y, x) == y * m.DenseLimit + x);
+
+  // Recreating matrix in sparse mode should reset values in sparse
+  // storage to zero.
+  m.recreate(m.DenseLimit + 1);
+  for (int y = 0; y < m.width(); y += 128)
+    for (int x = 0; x < m.width(); x += 128)
+      assert(m.get(y, x) == 0);
+
+  std::cout << "ok.\n";
+}