1 files changed, 47 insertions, 0 deletions
diff --git a/source/blender/gpu/tests/gpu_index_buffer_test.cc b/source/blender/gpu/tests/gpu_index_buffer_test.cc
new file mode 100644
index 00000000000..ebc110056e3
--- /dev/null
+++ b/source/blender/gpu/tests/gpu_index_buffer_test.cc
@@ -0,0 +1,47 @@
+/* Apache License, Version 2.0 */
+
+#include "testing/testing.h"
+
+#include "MEM_guardedalloc.h"
+
+#include "GPU_index_buffer.h"
+
+#include "gpu_testing.hh"
+
+namespace blender::gpu::tests {
+
+TEST_F(GPUTest, gpu_index_buffer_subbuilders)
+{
+  const uint num_subbuilders = 10;
+  const uint verts_per_subbuilders = 100;
+  const uint vertex_len = num_subbuilders * verts_per_subbuilders;
+
+  GPUIndexBufBuilder builder;
+  GPU_indexbuf_init(&builder, GPU_PRIM_POINTS, vertex_len, vertex_len);
+
+  GPUIndexBufBuilder subbuilders[num_subbuilders];
+  for (int subbuilder_index = 0; subbuilder_index < num_subbuilders; subbuilder_index++) {
+    GPU_indexbuf_subbuilder_init(&builder, &subbuilders[subbuilder_index]);
+  }
+
+  for (int subbuilder_index = 0; subbuilder_index < num_subbuilders; subbuilder_index++) {
+    GPUIndexBufBuilder &subbuilder = subbuilders[subbuilder_index];
+    for (int subbuilder_vert_index = 0; subbuilder_vert_index < verts_per_subbuilders;
+         subbuilder_vert_index++) {
+      int vert_index_to_update = subbuilder_index * verts_per_subbuilders + subbuilder_vert_index;
+      GPU_indexbuf_set_point_vert(&subbuilder, vert_index_to_update, vert_index_to_update);
+    }
+  }
+
+  for (int subbuilder_index = 0; subbuilder_index < num_subbuilders; subbuilder_index++) {
+    EXPECT_EQ(builder.index_len, subbuilder_index * verts_per_subbuilders);
+    GPU_indexbuf_subbuilder_finish(&builder, &subbuilders[subbuilder_index]);
+    EXPECT_EQ(builder.index_len, (subbuilder_index + 1) * verts_per_subbuilders);
+  }
+
+  GPUIndexBuf *index_buffer = GPU_indexbuf_build(&builder);
+  EXPECT_NE(index_buffer, nullptr);
+  GPU_INDEXBUF_DISCARD_SAFE(index_buffer);
+}
+
+}  // namespace blender::gpu::tests