1 files changed, 115 insertions, 0 deletions
diff --git a/source/blender/draw/intern/mesh_extractors/extract_mesh_vbo_orco.cc b/source/blender/draw/intern/mesh_extractors/extract_mesh_vbo_orco.cc
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+++ b/source/blender/draw/intern/mesh_extractors/extract_mesh_vbo_orco.cc
@@ -0,0 +1,115 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2021 by Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup draw
+ */
+
+#include "draw_cache_extract_mesh_private.h"
+
+namespace blender::draw {
+
+/* ---------------------------------------------------------------------- */
+/** \name Extract Orco
+ * \{ */
+
+struct MeshExtract_Orco_Data {
+  float (*vbo_data)[4];
+  float (*orco)[3];
+};
+
+static void extract_orco_init(const MeshRenderData *mr,
+                              struct MeshBatchCache *UNUSED(cache),
+                              void *buf,
+                              void *tls_data)
+{
+  GPUVertBuf *vbo = static_cast<GPUVertBuf *>(buf);
+  static GPUVertFormat format = {0};
+  if (format.attr_len == 0) {
+    /* FIXME(fclem): We use the last component as a way to differentiate from generic vertex
+     * attributes. This is a substantial waste of video-ram and should be done another way.
+     * Unfortunately, at the time of writing, I did not found any other "non disruptive"
+     * alternative. */
+    GPU_vertformat_attr_add(&format, "orco", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
+  }
+
+  GPU_vertbuf_init_with_format(vbo, &format);
+  GPU_vertbuf_data_alloc(vbo, mr->loop_len);
+
+  CustomData *cd_vdata = &mr->me->vdata;
+
+  MeshExtract_Orco_Data *data = static_cast<MeshExtract_Orco_Data *>(tls_data);
+  data->vbo_data = (float(*)[4])GPU_vertbuf_get_data(vbo);
+  data->orco = static_cast<float(*)[3]>(CustomData_get_layer(cd_vdata, CD_ORCO));
+  /* Make sure `orco` layer was requested only if needed! */
+  BLI_assert(data->orco);
+}
+
+static void extract_orco_iter_poly_bm(const MeshRenderData *UNUSED(mr),
+                                      const BMFace *f,
+                                      const int UNUSED(f_index),
+                                      void *data)
+{
+  MeshExtract_Orco_Data *orco_data = (MeshExtract_Orco_Data *)data;
+  BMLoop *l_iter, *l_first;
+  l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+  do {
+    const int l_index = BM_elem_index_get(l_iter);
+    float *loop_orco = orco_data->vbo_data[l_index];
+    copy_v3_v3(loop_orco, orco_data->orco[BM_elem_index_get(l_iter->v)]);
+    loop_orco[3] = 0.0; /* Tag as not a generic attribute. */
+  } while ((l_iter = l_iter->next) != l_first);
+}
+
+static void extract_orco_iter_poly_mesh(const MeshRenderData *mr,
+                                        const MPoly *mp,
+                                        const int UNUSED(mp_index),
+                                        void *data)
+{
+  const MLoop *mloop = mr->mloop;
+  const int ml_index_end = mp->loopstart + mp->totloop;
+  for (int ml_index = mp->loopstart; ml_index < ml_index_end; ml_index += 1) {
+    const MLoop *ml = &mloop[ml_index];
+    MeshExtract_Orco_Data *orco_data = (MeshExtract_Orco_Data *)data;
+    float *loop_orco = orco_data->vbo_data[ml_index];
+    copy_v3_v3(loop_orco, orco_data->orco[ml->v]);
+    loop_orco[3] = 0.0; /* Tag as not a generic attribute. */
+  }
+}
+
+constexpr MeshExtract create_extractor_orco()
+{
+  MeshExtract extractor = {nullptr};
+  extractor.init = extract_orco_init;
+  extractor.iter_poly_bm = extract_orco_iter_poly_bm;
+  extractor.iter_poly_mesh = extract_orco_iter_poly_mesh;
+  extractor.data_type = MR_DATA_NONE;
+  extractor.data_size = sizeof(MeshExtract_Orco_Data);
+  extractor.use_threading = true;
+  extractor.mesh_buffer_offset = offsetof(MeshBufferCache, vbo.orco);
+  return extractor;
+}
+
+/** \} */
+
+}  // namespace blender::draw
+
+extern "C" {
+const MeshExtract extract_orco = blender::draw::create_extractor_orco();
+}