1 files changed, 58 insertions, 0 deletions
diff --git a/source/blender/io/stl/importer/stl_import_binary_reader.cc b/source/blender/io/stl/importer/stl_import_binary_reader.cc
new file mode 100644
index 00000000000..6eaed16160e
--- /dev/null
+++ b/source/blender/io/stl/importer/stl_import_binary_reader.cc
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup stl
+ */
+
+#include <cstdint>
+#include <cstdio>
+
+#include "BKE_main.h"
+#include "BKE_mesh.h"
+
+#include "BLI_array.hh"
+#include "BLI_memory_utils.hh"
+
+#include "DNA_mesh_types.h"
+
+#include "stl_import_binary_reader.hh"
+#include "stl_import_mesh.hh"
+
+namespace blender::io::stl {
+
+#pragma pack(push, 1)
+struct STLBinaryTriangle {
+  float normal[3];
+  float v1[3], v2[3], v3[3];
+  uint16_t attribute_byte_count;
+};
+#pragma pack(pop)
+
+Mesh *read_stl_binary(FILE *file, Main *bmain, char *mesh_name, bool use_custom_normals)
+{
+  const int chunk_size = 1024;
+  uint32_t num_tris = 0;
+  fseek(file, BINARY_HEADER_SIZE, SEEK_SET);
+  fread(&num_tris, sizeof(uint32_t), 1, file);
+  if (num_tris == 0) {
+    return BKE_mesh_add(bmain, mesh_name);
+  }
+
+  Array<STLBinaryTriangle> tris_buf(chunk_size);
+  STLMeshHelper stl_mesh(num_tris, use_custom_normals);
+  size_t num_read_tris;
+  while ((num_read_tris = fread(tris_buf.data(), sizeof(STLBinaryTriangle), chunk_size, file))) {
+    for (size_t i = 0; i < num_read_tris; i++) {
+      if (use_custom_normals) {
+        stl_mesh.add_triangle(tris_buf[i].v1, tris_buf[i].v2, tris_buf[i].v3, tris_buf[i].normal);
+      }
+      else {
+        stl_mesh.add_triangle(tris_buf[i].v1, tris_buf[i].v2, tris_buf[i].v3);
+      }
+    }
+  }
+
+  return stl_mesh.to_mesh(bmain, mesh_name);
+}
+
+}  // namespace blender::io::stl