1 files changed, 133 insertions, 0 deletions
diff --git a/source/blender/draw/engines/overlay/overlay_metaball.cc b/source/blender/draw/engines/overlay/overlay_metaball.cc
new file mode 100644
index 00000000000..dd0a862337e
--- /dev/null
+++ b/source/blender/draw/engines/overlay/overlay_metaball.cc
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2019 Blender Foundation. */
+
+/** \file
+ * \ingroup draw_engine
+ */
+
+#include "DRW_render.h"
+
+#include "DNA_meta_types.h"
+
+#include "BKE_object.h"
+
+#include "DEG_depsgraph_query.h"
+
+#include "ED_mball.h"
+
+#include "overlay_private.hh"
+
+void OVERLAY_metaball_cache_init(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+
+  OVERLAY_InstanceFormats *formats = OVERLAY_shader_instance_formats_get();
+
+#define BUF_INSTANCE DRW_shgroup_call_buffer_instance
+
+  for (int i = 0; i < 2; i++) {
+    DRWState infront_state = (DRW_state_is_select() && (i == 1)) ? DRW_STATE_IN_FRONT_SELECT :
+                                                                   DRWState(0);
+    DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL;
+    DRW_PASS_CREATE(psl->metaball_ps[i], state | pd->clipping_state | infront_state);
+
+    /* Reuse armature shader as it's perfect to outline ellipsoids. */
+    struct GPUVertFormat *format = formats->instance_bone;
+    struct GPUShader *sh = OVERLAY_shader_armature_sphere(true);
+    DRWShadingGroup *grp = DRW_shgroup_create(sh, psl->metaball_ps[i]);
+    DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
+    pd->mball.handle[i] = BUF_INSTANCE(grp, format, DRW_cache_bone_point_wire_outline_get());
+  }
+}
+
+static void metaball_instance_data_set(
+    BoneInstanceData *data, Object *ob, const float *pos, const float radius, const float color[4])
+{
+  /* Bone point radius is 0.05. Compensate for that. */
+  mul_v3_v3fl(data->mat[0], ob->object_to_world[0], radius / 0.05f);
+  mul_v3_v3fl(data->mat[1], ob->object_to_world[1], radius / 0.05f);
+  mul_v3_v3fl(data->mat[2], ob->object_to_world[2], radius / 0.05f);
+  mul_v3_m4v3(data->mat[3], ob->object_to_world, pos);
+  /* WATCH: Reminder, alpha is wire-size. */
+  OVERLAY_bone_instance_data_set_color(data, color);
+}
+
+void OVERLAY_edit_metaball_cache_populate(OVERLAY_Data *vedata, Object *ob)
+{
+  const bool do_in_front = (ob->dtx & OB_DRAW_IN_FRONT) != 0;
+  const bool is_select = DRW_state_is_select();
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+  MetaBall *mb = static_cast<MetaBall *>(ob->data);
+
+  const float *color;
+  const float *col_radius = G_draw.block.color_mball_radius;
+  const float *col_radius_select = G_draw.block.color_mball_radius_select;
+  const float *col_stiffness = G_draw.block.color_mball_stiffness;
+  const float *col_stiffness_select = G_draw.block.color_mball_stiffness_select;
+
+  int select_id = 0;
+  if (is_select) {
+    select_id = ob->runtime.select_id;
+  }
+
+  LISTBASE_FOREACH (MetaElem *, ml, mb->editelems) {
+    const bool is_selected = (ml->flag & SELECT) != 0;
+    const bool is_scale_radius = (ml->flag & MB_SCALE_RAD) != 0;
+    float stiffness_radius = ml->rad * atanf(ml->s) / float(M_PI_2);
+    BoneInstanceData instdata;
+
+    if (is_select) {
+      DRW_select_load_id(select_id | MBALLSEL_RADIUS);
+    }
+    color = (is_selected && is_scale_radius) ? col_radius_select : col_radius;
+    metaball_instance_data_set(&instdata, ob, &ml->x, ml->rad, color);
+    DRW_buffer_add_entry_struct(pd->mball.handle[do_in_front], &instdata);
+
+    if (is_select) {
+      DRW_select_load_id(select_id | MBALLSEL_STIFF);
+    }
+    color = (is_selected && !is_scale_radius) ? col_stiffness_select : col_stiffness;
+    metaball_instance_data_set(&instdata, ob, &ml->x, stiffness_radius, color);
+    DRW_buffer_add_entry_struct(pd->mball.handle[do_in_front], &instdata);
+
+    select_id += 0x10000;
+  }
+
+  /* Needed so object centers and geometry are not detected as meta-elements. */
+  if (is_select) {
+    DRW_select_load_id(-1);
+  }
+}
+
+void OVERLAY_metaball_cache_populate(OVERLAY_Data *vedata, Object *ob)
+{
+  const bool do_in_front = (ob->dtx & OB_DRAW_IN_FRONT) != 0;
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+  MetaBall *mb = static_cast<MetaBall *>(ob->data);
+  const DRWContextState *draw_ctx = DRW_context_state_get();
+
+  float *color;
+  DRW_object_wire_theme_get(ob, draw_ctx->view_layer, &color);
+
+  LISTBASE_FOREACH (MetaElem *, ml, &mb->elems) {
+    /* Draw radius only. */
+    BoneInstanceData instdata;
+    metaball_instance_data_set(&instdata, ob, &ml->x, ml->rad, color);
+    DRW_buffer_add_entry_struct(pd->mball.handle[do_in_front], &instdata);
+  }
+}
+
+void OVERLAY_metaball_draw(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+
+  DRW_draw_pass(psl->metaball_ps[0]);
+}
+
+void OVERLAY_metaball_in_front_draw(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+
+  DRW_draw_pass(psl->metaball_ps[1]);
+}