1 files changed, 46 insertions, 0 deletions
diff --git a/source/blender/blenlib/tests/BLI_bitmap_test.cc b/source/blender/blenlib/tests/BLI_bitmap_test.cc
new file mode 100644
index 00000000000..fb9e03e3136
--- /dev/null
+++ b/source/blender/blenlib/tests/BLI_bitmap_test.cc
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+
+#include "BLI_bitmap.h"
+#include "testing/testing.h"
+
+namespace blender::tests {
+
+TEST(bitmap, empty_is_all_unset)
+{
+  BLI_BITMAP_DECLARE(bitmap, 10);
+  for (int i = 0; i < 10; ++i) {
+    EXPECT_FALSE(BLI_BITMAP_TEST_BOOL(bitmap, i));
+  }
+}
+
+TEST(bitmap, find_first_unset_empty)
+{
+  BLI_BITMAP_DECLARE(bitmap, 10);
+  EXPECT_EQ(0, BLI_bitmap_find_first_unset(bitmap, 10));
+}
+
+TEST(bitmap, find_first_unset_full)
+{
+  BLI_BITMAP_DECLARE(bitmap, 10);
+  BLI_bitmap_flip_all(bitmap, 10);
+  EXPECT_EQ(-1, BLI_bitmap_find_first_unset(bitmap, 10));
+}
+
+TEST(bitmap, find_first_unset_middle)
+{
+  BLI_BITMAP_DECLARE(bitmap, 100);
+  BLI_bitmap_flip_all(bitmap, 100);
+  /* Turn some bits off */
+  BLI_BITMAP_DISABLE(bitmap, 53);
+  BLI_BITMAP_DISABLE(bitmap, 81);
+  BLI_BITMAP_DISABLE(bitmap, 85);
+  BLI_BITMAP_DISABLE(bitmap, 86);
+
+  /* Find lowest unset bit, and set it. */
+  EXPECT_EQ(53, BLI_bitmap_find_first_unset(bitmap, 100));
+  BLI_BITMAP_ENABLE(bitmap, 53);
+  /* Now should find the next lowest bit. */
+  EXPECT_EQ(81, BLI_bitmap_find_first_unset(bitmap, 100));
+}
+
+}  // namespace blender::tests