4 files changed, 49 insertions, 0 deletions
diff --git a/source/blender/gpu/GPU_vertex_buffer.h b/source/blender/gpu/GPU_vertex_buffer.h
index fe45ec7b78b..f9bdf726930 100644
--- a/source/blender/gpu/GPU_vertex_buffer.h
+++ b/source/blender/gpu/GPU_vertex_buffer.h
@@ -80,6 +80,8 @@ void GPU_vertbuf_init_with_format_ex(GPUVertBuf *, const GPUVertFormat *, GPUUsa
 #define GPU_vertbuf_init_with_format(verts, format) \
   GPU_vertbuf_init_with_format_ex(verts, format, GPU_USAGE_STATIC)
 
+GPUVertBuf *GPU_vertbuf_duplicate(GPUVertBuf *verts);
+
 uint GPU_vertbuf_size_get(const GPUVertBuf *);
 void GPU_vertbuf_data_alloc(GPUVertBuf *, uint v_len);
 void GPU_vertbuf_data_resize(GPUVertBuf *, uint v_len);
diff --git a/source/blender/gpu/GPU_vertex_format.h b/source/blender/gpu/GPU_vertex_format.h
index 61b14a4c5c0..34bfbb27823 100644
--- a/source/blender/gpu/GPU_vertex_format.h
+++ b/source/blender/gpu/GPU_vertex_format.h
@@ -124,6 +124,10 @@ BLI_INLINE const char *GPU_vertformat_attr_name_get(const GPUVertFormat *format,
   return format->names + attr->names[n_idx];
 }
 
+/* WARNING: Can only rename using a string with same character count.
+ * WARNING: This removes all other aliases of this attrib */
+void GPU_vertformat_attr_rename(GPUVertFormat *format, int attr, const char *new_name);
+
 void GPU_vertformat_safe_attr_name(const char *attr_name, char *r_safe_name, uint max_len);
 
 /* format conversion */
diff --git a/source/blender/gpu/intern/gpu_vertex_buffer.c b/source/blender/gpu/intern/gpu_vertex_buffer.c
index 25daabe601d..3b4d469542c 100644
--- a/source/blender/gpu/intern/gpu_vertex_buffer.c
+++ b/source/blender/gpu/intern/gpu_vertex_buffer.c
@@ -85,6 +85,35 @@ void GPU_vertbuf_init_with_format_ex(GPUVertBuf *verts,
   }
 }
 
+GPUVertBuf *GPU_vertbuf_duplicate(GPUVertBuf *verts)
+{
+  GPUVertBuf *verts_dst = GPU_vertbuf_create(GPU_USAGE_STATIC);
+  /* Full copy. */
+  *verts_dst = *verts;
+  GPU_vertformat_copy(&verts_dst->format, &verts->format);
+
+  if (verts->vbo_id) {
+    uint buffer_sz = GPU_vertbuf_size_get(verts);
+
+    verts_dst->vbo_id = GPU_buf_alloc();
+
+    glBindBuffer(GL_COPY_READ_BUFFER, verts->vbo_id);
+    glBindBuffer(GL_COPY_WRITE_BUFFER, verts_dst->vbo_id);
+
+    glBufferData(GL_COPY_WRITE_BUFFER, buffer_sz, NULL, convert_usage_type_to_gl(verts->usage));
+
+    glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, 0, 0, buffer_sz);
+#if VRAM_USAGE
+    vbo_memory_usage += GPU_vertbuf_size_get(verts);
+#endif
+  }
+
+  if (verts->data) {
+    verts_dst->data = MEM_dupallocN(verts->data);
+  }
+  return verts_dst;
+}
+
 /** Same as discard but does not free. */
 void GPU_vertbuf_clear(GPUVertBuf *verts)
 {
diff --git a/source/blender/gpu/intern/gpu_vertex_format.c b/source/blender/gpu/intern/gpu_vertex_format.c
index b84a7e0f554..585a22277b2 100644
--- a/source/blender/gpu/intern/gpu_vertex_format.c
+++ b/source/blender/gpu/intern/gpu_vertex_format.c
@@ -262,6 +262,20 @@ int GPU_vertformat_attr_id_get(const GPUVertFormat *format, const char *name)
   return -1;
 }
 
+void GPU_vertformat_attr_rename(GPUVertFormat *format, int attr_id, const char *new_name)
+{
+  BLI_assert(attr_id > -1 && attr_id < format->attr_len);
+  GPUVertAttr *attr = &format->attrs[attr_id];
+  char *attr_name = (char *)GPU_vertformat_attr_name_get(format, attr, 0);
+  BLI_assert(strlen(attr_name) == strlen(new_name));
+  int i = 0;
+  while (attr_name[i] != '\0') {
+    attr_name[i] = new_name[i];
+    i++;
+  }
+  attr->name_len = 1;
+}
+
 /* Encode 8 original bytes into 11 safe bytes. */
 static void safe_bytes(char out[11], const char data[8])
 {