Cleanup: Move extract tris in own compile unit.

1 files changed, 175 insertions, 0 deletions

diff --git a/source/blender/draw/intern/mesh_extractors/extract_mesh_ibo_tris.cc b/source/blender/draw/intern/mesh_extractors/extract_mesh_ibo_tris.cc
new file mode 100644
index 00000000000..688f04450e9
--- /dev/null
+++ b/source/blender/draw/intern/mesh_extractors/extract_mesh_ibo_tris.cc
@@ -0,0 +1,175 @@
+/*
+ * 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"
+
+#include "MEM_guardedalloc.h"
+
+namespace blender::draw {
+
+/* ---------------------------------------------------------------------- */
+/** \name Extract Triangles Indices
+ * \{ */
+
+struct MeshExtract_Tri_Data {
+  GPUIndexBufBuilder elb;
+  int *tri_mat_start;
+  int *tri_mat_end;
+};
+
+static void *extract_tris_init(const MeshRenderData *mr,
+                               struct MeshBatchCache *UNUSED(cache),
+                               void *UNUSED(ibo))
+{
+  MeshExtract_Tri_Data *data = static_cast<MeshExtract_Tri_Data *>(
+      MEM_callocN(sizeof(*data), __func__));
+
+  size_t mat_tri_idx_size = sizeof(int) * mr->mat_len;
+  data->tri_mat_start = static_cast<int *>(MEM_callocN(mat_tri_idx_size, __func__));
+  data->tri_mat_end = static_cast<int *>(MEM_callocN(mat_tri_idx_size, __func__));
+
+  int *mat_tri_len = data->tri_mat_start;
+  /* Count how many triangle for each material. */
+  if (mr->extract_type == MR_EXTRACT_BMESH) {
+    BMIter iter;
+    BMFace *efa;
+    BM_ITER_MESH (efa, &iter, mr->bm, BM_FACES_OF_MESH) {
+      if (!BM_elem_flag_test(efa, BM_ELEM_HIDDEN)) {
+        int mat = min_ii(efa->mat_nr, mr->mat_len - 1);
+        mat_tri_len[mat] += efa->len - 2;
+      }
+    }
+  }
+  else {
+    const MPoly *mp = mr->mpoly;
+    for (int mp_index = 0; mp_index < mr->poly_len; mp_index++, mp++) {
+      if (!(mr->use_hide && (mp->flag & ME_HIDE))) {
+        int mat = min_ii(mp->mat_nr, mr->mat_len - 1);
+        mat_tri_len[mat] += mp->totloop - 2;
+      }
+    }
+  }
+  /* Accumulate triangle lengths per material to have correct offsets. */
+  int ofs = mat_tri_len[0];
+  mat_tri_len[0] = 0;
+  for (int i = 1; i < mr->mat_len; i++) {
+    int tmp = mat_tri_len[i];
+    mat_tri_len[i] = ofs;
+    ofs += tmp;
+  }
+
+  memcpy(data->tri_mat_end, mat_tri_len, mat_tri_idx_size);
+
+  int visible_tri_tot = ofs;
+  GPU_indexbuf_init(&data->elb, GPU_PRIM_TRIS, visible_tri_tot, mr->loop_len);
+
+  return data;
+}
+
+static void extract_tris_iter_looptri_bm(const MeshRenderData *mr,
+                                         BMLoop **elt,
+                                         const int UNUSED(elt_index),
+                                         void *_data)
+{
+  MeshExtract_Tri_Data *data = static_cast<MeshExtract_Tri_Data *>(_data);
+  const int mat_last = mr->mat_len - 1;
+
+  if (!BM_elem_flag_test(elt[0]->f, BM_ELEM_HIDDEN)) {
+    int *mat_tri_ofs = data->tri_mat_end;
+    const int mat = min_ii(elt[0]->f->mat_nr, mat_last);
+    GPU_indexbuf_set_tri_verts(&data->elb,
+                               mat_tri_ofs[mat]++,
+                               BM_elem_index_get(elt[0]),
+                               BM_elem_index_get(elt[1]),
+                               BM_elem_index_get(elt[2]));
+  }
+}
+
+static void extract_tris_iter_looptri_mesh(const MeshRenderData *mr,
+                                           const MLoopTri *mlt,
+                                           const int UNUSED(elt_index),
+                                           void *_data)
+{
+  MeshExtract_Tri_Data *data = static_cast<MeshExtract_Tri_Data *>(_data);
+  const int mat_last = mr->mat_len - 1;
+  const MPoly *mp = &mr->mpoly[mlt->poly];
+  if (!(mr->use_hide && (mp->flag & ME_HIDE))) {
+    int *mat_tri_ofs = data->tri_mat_end;
+    const int mat = min_ii(mp->mat_nr, mat_last);
+    GPU_indexbuf_set_tri_verts(
+        &data->elb, mat_tri_ofs[mat]++, mlt->tri[0], mlt->tri[1], mlt->tri[2]);
+  }
+}
+
+static void extract_tris_finish(const MeshRenderData *mr,
+                                struct MeshBatchCache *cache,
+                                void *buf,
+                                void *_data)
+{
+  GPUIndexBuf *ibo = static_cast<GPUIndexBuf *>(buf);
+  MeshExtract_Tri_Data *data = static_cast<MeshExtract_Tri_Data *>(_data);
+  GPU_indexbuf_build_in_place(&data->elb, ibo);
+
+  /* Create ibo sub-ranges. Always do this to avoid error when the standard surface batch
+   * is created before the surfaces-per-material. */
+  if (mr->use_final_mesh && cache->final.tris_per_mat) {
+    MeshBufferCache *mbc_final = &cache->final;
+    for (int i = 0; i < mr->mat_len; i++) {
+      /* These IBOs have not been queried yet but we create them just in case they are needed
+       * later since they are not tracked by mesh_buffer_cache_create_requested(). */
+      if (mbc_final->tris_per_mat[i] == NULL) {
+        mbc_final->tris_per_mat[i] = GPU_indexbuf_calloc();
+      }
+      /* Multiply by 3 because these are triangle indices. */
+      const int mat_start = data->tri_mat_start[i];
+      const int mat_end = data->tri_mat_end[i];
+      const int start = mat_start * 3;
+      const int len = (mat_end - mat_start) * 3;
+      GPU_indexbuf_create_subrange_in_place(mbc_final->tris_per_mat[i], ibo, start, len);
+    }
+  }
+  MEM_freeN(data->tri_mat_start);
+  MEM_freeN(data->tri_mat_end);
+  MEM_freeN(data);
+}
+
+constexpr MeshExtract create_extractor_tris()
+{
+  MeshExtract extractor = {0};
+  extractor.init = extract_tris_init;
+  extractor.iter_looptri_bm = extract_tris_iter_looptri_bm;
+  extractor.iter_looptri_mesh = extract_tris_iter_looptri_mesh;
+  extractor.finish = extract_tris_finish;
+  extractor.data_type = MR_DATA_NONE;
+  extractor.use_threading = false;
+  extractor.mesh_buffer_offset = offsetof(MeshBufferCache, ibo.tris);
+  return extractor;
+}
+
+/** \} */
+
+}  // namespace blender::draw
+
+extern "C" {
+const MeshExtract extract_tris = blender::draw::create_extractor_tris();
+}