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

3 files changed, 115 insertions, 0 deletions

diff --git a/source/blender/draw/engines/overlay/overlay_pointcloud.c b/source/blender/draw/engines/overlay/overlay_pointcloud.c
new file mode 100644
index 00000000000..a0de7aac1f1
--- /dev/null
+++ b/source/blender/draw/engines/overlay/overlay_pointcloud.c
@@ -0,0 +1,72 @@
+/*
+ * 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.
+ *
+ * Copyright 2020, Blender Foundation.
+ */
+
+/** \file
+ * \ingroup draw_engine
+ */
+
+#include "DRW_render.h"
+
+#include "DEG_depsgraph_query.h"
+
+#include "DNA_pointcloud_types.h"
+
+#include "BKE_pointcache.h"
+
+#include "overlay_private.h"
+
+/* -------------------------------------------------------------------- */
+/** \name PointCloud
+ * \{ */
+
+void OVERLAY_pointcloud_cache_init(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+  GPUShader *sh;
+  DRWShadingGroup *grp;
+
+  DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL;
+  DRW_PASS_CREATE(psl->pointcloud_ps, state | pd->clipping_state);
+
+  sh = OVERLAY_shader_pointcloud_dot();
+  pd->pointcloud_dots_grp = grp = DRW_shgroup_create(sh, psl->pointcloud_ps);
+  DRW_shgroup_uniform_block_persistent(grp, "globalsBlock", G_draw.block_ubo);
+}
+
+void OVERLAY_pointcloud_cache_populate(OVERLAY_Data *vedata, Object *ob)
+{
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+
+  struct GPUBatch *geom = DRW_cache_pointcloud_get_dots(ob);
+
+  const float color[4] = {0.0f, 0.0f, 0.0f, 1.0f};
+
+  DRWShadingGroup *grp = DRW_shgroup_create_sub(pd->pointcloud_dots_grp);
+  DRW_shgroup_uniform_vec4_copy(grp, "color", color);
+  DRW_shgroup_call(grp, geom, ob);
+}
+
+void OVERLAY_pointcloud_draw(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+
+  DRW_draw_pass(psl->pointcloud_ps);
+}
+
+/** \} */
diff --git a/source/blender/draw/engines/overlay/shaders/pointcloud_frag.glsl b/source/blender/draw/engines/overlay/shaders/pointcloud_frag.glsl
new file mode 100644
index 00000000000..36928d0c776
--- /dev/null
+++ b/source/blender/draw/engines/overlay/shaders/pointcloud_frag.glsl
@@ -0,0 +1,16 @@
+
+in vec4 finalColor;
+
+out vec4 fragColor;
+
+void main()
+{
+  float dist = length(gl_PointCoord - vec2(0.5));
+
+  if (dist > 0.5) {
+    discard;
+  }
+  /* Nice sphere falloff. */
+  float intensity = sqrt(1.0 - dist * 2.0) * 0.5 + 0.5;
+  fragColor = finalColor * vec4(intensity, intensity, intensity, 1.0);
+}
diff --git a/source/blender/draw/engines/overlay/shaders/pointcloud_vert.glsl b/source/blender/draw/engines/overlay/shaders/pointcloud_vert.glsl
new file mode 100644
index 00000000000..d71ccee5159
--- /dev/null
+++ b/source/blender/draw/engines/overlay/shaders/pointcloud_vert.glsl
@@ -0,0 +1,27 @@
+
+uniform vec4 color;
+
+/* ---- Per instance Attrs ---- */
+in vec3 pointcloud_pos;
+in vec3 pointcloud_radius;
+
+out vec4 finalColor;
+
+void main()
+{
+  vec3 world_pos = point_object_to_world(pointcloud_pos);
+
+  vec3 world_size = abs(mat3(ModelMatrix) * vec3(pointcloud_radius));
+  float world_radius = (world_size.x + world_size.y + world_size.z) / 3.0;
+
+  gl_Position = point_world_to_ndc(world_pos);
+  /* World sized points. */
+  gl_PointSize = sizePixel * world_radius * ProjectionMatrix[1][1] * sizeViewport.y /
+                 gl_Position.w;
+
+  finalColor = color;
+
+#ifdef USE_WORLD_CLIP_PLANES
+  world_clip_planes_calc_clip_distance(world_pos);
+#endif
+}