Objects: add Volume object type, and prototypes for Hair and PointCloud

Only the volume object is exposed in the user interface. It is based on OpenVDB
internally. Drawing and rendering code will follow in another commit.
https://wiki.blender.org/wiki/Source/Objects/Volume
https://wiki.blender.org/wiki/Reference/Release_Notes/2.83/Volumes

Hair and PointCloud object types are hidden behind a WITH_NEW_OBJECT_TYPES
build option. These are unfinished, and included only to make it easier to
cooperate on development in the future and avoid tricky merges.
https://wiki.blender.org/wiki/Source/Objects/New_Object_Types

Ref T73201, T68981

Differential Revision: https://developer.blender.org/D6945

1 files changed, 297 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_volume.c b/source/blender/draw/intern/draw_cache_impl_volume.c
new file mode 100644
index 00000000000..cdac8b33fba
--- /dev/null
+++ b/source/blender/draw/intern/draw_cache_impl_volume.c
@@ -0,0 +1,297 @@
+/*
+ * 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) 2017 by Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup draw
+ *
+ * \brief Volume API for render engines
+ */
+
+#include <string.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math_base.h"
+#include "BLI_math_vector.h"
+#include "BLI_utildefines.h"
+
+#include "DNA_object_types.h"
+#include "DNA_volume_types.h"
+
+#include "BKE_global.h"
+#include "BKE_volume.h"
+#include "BKE_volume_render.h"
+
+#include "GPU_batch.h"
+#include "GPU_texture.h"
+
+#include "DRW_render.h"
+
+#include "draw_cache.h"      /* own include */
+#include "draw_cache_impl.h" /* own include */
+
+static void volume_batch_cache_clear(Volume *volume);
+
+/* ---------------------------------------------------------------------- */
+/* Volume GPUBatch Cache */
+
+typedef struct VolumeBatchCache {
+  /* 3D textures */
+  ListBase grids;
+
+  /* Wireframe */
+  struct {
+    GPUVertBuf *pos_nor_in_order;
+    GPUBatch *batch;
+  } face_wire;
+
+  /* settings to determine if cache is invalid */
+  bool is_dirty;
+} VolumeBatchCache;
+
+/* GPUBatch cache management. */
+
+static bool volume_batch_cache_valid(Volume *volume)
+{
+  VolumeBatchCache *cache = volume->batch_cache;
+  return (cache && cache->is_dirty == false);
+}
+
+static void volume_batch_cache_init(Volume *volume)
+{
+  VolumeBatchCache *cache = volume->batch_cache;
+
+  if (!cache) {
+    cache = volume->batch_cache = MEM_callocN(sizeof(*cache), __func__);
+  }
+  else {
+    memset(cache, 0, sizeof(*cache));
+  }
+
+  cache->is_dirty = false;
+}
+
+void DRW_volume_batch_cache_validate(Volume *volume)
+{
+  if (!volume_batch_cache_valid(volume)) {
+    volume_batch_cache_clear(volume);
+    volume_batch_cache_init(volume);
+  }
+}
+
+static VolumeBatchCache *volume_batch_cache_get(Volume *volume)
+{
+  DRW_volume_batch_cache_validate(volume);
+  return volume->batch_cache;
+}
+
+void DRW_volume_batch_cache_dirty_tag(Volume *volume, int mode)
+{
+  VolumeBatchCache *cache = volume->batch_cache;
+  if (cache == NULL) {
+    return;
+  }
+  switch (mode) {
+    case BKE_VOLUME_BATCH_DIRTY_ALL:
+      cache->is_dirty = true;
+      break;
+    default:
+      BLI_assert(0);
+  }
+}
+
+static void volume_batch_cache_clear(Volume *volume)
+{
+  VolumeBatchCache *cache = volume->batch_cache;
+  if (!cache) {
+    return;
+  }
+
+  for (DRWVolumeGrid *grid = cache->grids.first; grid; grid = grid->next) {
+    MEM_SAFE_FREE(grid->name);
+    DRW_TEXTURE_FREE_SAFE(grid->texture);
+  }
+  BLI_freelistN(&cache->grids);
+
+  GPU_VERTBUF_DISCARD_SAFE(cache->face_wire.pos_nor_in_order);
+  GPU_BATCH_DISCARD_SAFE(cache->face_wire.batch);
+}
+
+void DRW_volume_batch_cache_free(Volume *volume)
+{
+  volume_batch_cache_clear(volume);
+  MEM_SAFE_FREE(volume->batch_cache);
+}
+
+static void drw_volume_wireframe_cb(
+    void *userdata, float (*verts)[3], int (*edges)[2], int totvert, int totedge)
+{
+  Volume *volume = userdata;
+  VolumeBatchCache *cache = volume->batch_cache;
+
+  /* Create vertex buffer. */
+  static GPUVertFormat format = {0};
+  static uint pos_id, nor_id;
+  if (format.attr_len == 0) {
+    pos_id = GPU_vertformat_attr_add(&format, "pos", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
+    nor_id = GPU_vertformat_attr_add(&format, "nor", GPU_COMP_I10, 4, GPU_FETCH_INT_TO_FLOAT_UNIT);
+  }
+
+  static float normal[3] = {1.0f, 0.0f, 0.0f};
+  GPUPackedNormal packed_normal = GPU_normal_convert_i10_v3(normal);
+
+  cache->face_wire.pos_nor_in_order = GPU_vertbuf_create_with_format(&format);
+  GPU_vertbuf_data_alloc(cache->face_wire.pos_nor_in_order, totvert);
+  GPU_vertbuf_attr_fill(cache->face_wire.pos_nor_in_order, pos_id, verts);
+  GPU_vertbuf_attr_fill_stride(cache->face_wire.pos_nor_in_order, nor_id, 0, &packed_normal);
+
+  /* Create wiredata. */
+  GPUVertBuf *vbo_wiredata = MEM_callocN(sizeof(GPUVertBuf), __func__);
+  DRW_vertbuf_create_wiredata(vbo_wiredata, totvert);
+
+  if (volume->display.wireframe_type == VOLUME_WIREFRAME_POINTS) {
+    /* Create batch. */
+    cache->face_wire.batch = GPU_batch_create(
+        GPU_PRIM_POINTS, cache->face_wire.pos_nor_in_order, NULL);
+  }
+  else {
+    /* Create edge index buffer. */
+    GPUIndexBufBuilder elb;
+    GPU_indexbuf_init(&elb, GPU_PRIM_LINES, totedge, totvert);
+    for (int i = 0; i < totedge; i++) {
+      GPU_indexbuf_add_line_verts(&elb, edges[i][0], edges[i][1]);
+    }
+    GPUIndexBuf *ibo = GPU_indexbuf_build(&elb);
+
+    /* Create batch. */
+    cache->face_wire.batch = GPU_batch_create_ex(
+        GPU_PRIM_LINES, cache->face_wire.pos_nor_in_order, ibo, GPU_BATCH_OWNS_INDEX);
+  }
+
+  GPU_batch_vertbuf_add_ex(cache->face_wire.batch, vbo_wiredata, true);
+}
+
+GPUBatch *DRW_volume_batch_cache_get_wireframes_face(Volume *volume)
+{
+  if (volume->display.wireframe_type == VOLUME_WIREFRAME_NONE) {
+    return NULL;
+  }
+
+  VolumeBatchCache *cache = volume_batch_cache_get(volume);
+
+  if (cache->face_wire.batch == NULL) {
+    VolumeGrid *volume_grid = BKE_volume_grid_active_get(volume);
+    if (volume_grid == NULL) {
+      return NULL;
+    }
+
+    /* Create wireframe from OpenVDB tree. */
+    BKE_volume_grid_wireframe(volume, volume_grid, drw_volume_wireframe_cb, volume);
+  }
+
+  return cache->face_wire.batch;
+}
+
+static DRWVolumeGrid *volume_grid_cache_get(Volume *volume,
+                                            VolumeGrid *grid,
+                                            VolumeBatchCache *cache)
+{
+  const char *name = BKE_volume_grid_name(grid);
+
+  /* Return cached grid. */
+  DRWVolumeGrid *cache_grid;
+  for (cache_grid = cache->grids.first; cache_grid; cache_grid = cache_grid->next) {
+    if (STREQ(cache_grid->name, name)) {
+      return cache_grid;
+    }
+  }
+
+  /* Allocate new grid. */
+  cache_grid = MEM_callocN(sizeof(DRWVolumeGrid), __func__);
+  cache_grid->name = BLI_strdup(name);
+  BLI_addtail(&cache->grids, cache_grid);
+
+  /* TODO: can we load this earlier, avoid accessing the global and take
+   * advantage of dependency graph multithreading? */
+  BKE_volume_load(volume, G.main);
+
+  /* Test if we support textures with the number of channels. */
+  size_t channels = BKE_volume_grid_channels(grid);
+  if (!ELEM(channels, 1, 3)) {
+    return cache_grid;
+  }
+
+  /* Load grid tree into memory, if not loaded already. */
+  const bool was_loaded = BKE_volume_grid_is_loaded(grid);
+  BKE_volume_grid_load(volume, grid);
+
+  /* Compute dense voxel grid size. */
+  int64_t dense_min[3], dense_max[3], resolution[3] = {0};
+  if (BKE_volume_grid_dense_bounds(volume, grid, dense_min, dense_max)) {
+    resolution[0] = dense_max[0] - dense_min[0];
+    resolution[1] = dense_max[1] - dense_min[1];
+    resolution[2] = dense_max[2] - dense_min[2];
+  }
+  size_t num_voxels = resolution[0] * resolution[1] * resolution[2];
+  size_t elem_size = sizeof(float) * channels;
+
+  /* Allocate and load voxels. */
+  float *voxels = (num_voxels > 0) ? MEM_malloc_arrayN(num_voxels, elem_size, __func__) : NULL;
+  if (voxels != NULL) {
+    BKE_volume_grid_dense_voxels(volume, grid, dense_min, dense_max, voxels);
+
+    /* Create GPU texture. */
+    cache_grid->texture = GPU_texture_create_3d(resolution[0],
+                                                resolution[1],
+                                                resolution[2],
+                                                (channels == 3) ? GPU_RGB16F : GPU_R16F,
+                                                voxels,
+                                                NULL);
+
+    GPU_texture_bind(cache_grid->texture, 0);
+    GPU_texture_swizzle_channel_auto(cache_grid->texture, channels);
+    GPU_texture_unbind(cache_grid->texture);
+
+    MEM_freeN(voxels);
+
+    /* Compute transform matrices. */
+    BKE_volume_grid_dense_transform_matrix(
+        grid, dense_min, dense_max, cache_grid->texture_to_object);
+    invert_m4_m4(cache_grid->object_to_texture, cache_grid->texture_to_object);
+  }
+
+  /* Free grid from memory if it wasn't previously loaded. */
+  if (!was_loaded) {
+    BKE_volume_grid_unload(volume, grid);
+  }
+
+  return cache_grid;
+}
+
+DRWVolumeGrid *DRW_volume_batch_cache_get_grid(Volume *volume, VolumeGrid *volume_grid)
+{
+  VolumeBatchCache *cache = volume_batch_cache_get(volume);
+  DRWVolumeGrid *grid = volume_grid_cache_get(volume, volume_grid, cache);
+  return (grid->texture != NULL) ? grid : NULL;
+}
+
+int DRW_volume_material_count_get(Volume *volume)
+{
+  return max_ii(1, volume->totcol);
+}