Sculpt: Rewrite PBVH draw

Rewrite PBVH draw to allocate attributes into individual VBOs.
The old system tried to create a single VBO that could feed
every open viewport.  This required uploading every color and
UV attribute  to the viewport whether needed or not, often exceeding
the VBO limit.

This new system creates one VBO per attribute.  Each attribute layout is
given its own GPU batch which is cached inside the owning PBVH node.

Notes:

* This is a full C++ rewrite.  The old code is still there; ripping it out
can happen later.
* PBVH nodes now have a collection of batches, PBVHBatches, that keeps
track of all the batches inside the node.
* Batches are built exclusively from a list of attributes.
* Each attribute has its own VBO.
* Overlays, workbench and EEVEE can all have different attribute
  layouts, each of which will get its own batch.

Reviewed by: Clement Foucault
Differential Revision: https://developer.blender.org/D15428
Ref D15428

1 files changed, 113 insertions, 144 deletions

diff --git a/source/blender/blenkernel/intern/pbvh.c b/source/blender/blenkernel/intern/pbvh.c
index 1d65e958e1c..a1de8e40fe3 100644
--- a/source/blender/blenkernel/intern/pbvh.c
+++ b/source/blender/blenkernel/intern/pbvh.c
@@ -25,9 +25,9 @@
 #include "BKE_pbvh.h"
 #include "BKE_subdiv_ccg.h"
 
-#include "PIL_time.h"
+#include "DRW_pbvh.h"
 
-#include "GPU_buffers.h"
+#include "PIL_time.h"
 
 #include "bmesh.h"
 
@@ -513,6 +513,80 @@ static void pbvh_build(PBVH *pbvh, BB *cb, BBC *prim_bbc, int totprim)
   build_sub(pbvh, 0, cb, prim_bbc, 0, totprim);
 }
 
+static void pbvh_draw_args_init(PBVH *pbvh, PBVH_GPU_Args *args, PBVHNode *node)
+{
+  memset((void *)args, 0, sizeof(*args));
+
+  args->pbvh_type = pbvh->header.type;
+  args->mesh_verts_num = pbvh->totvert;
+  args->mesh_grids_num = pbvh->totgrid;
+  args->node = node;
+
+  BKE_pbvh_node_num_verts(pbvh, node, NULL, &args->node_verts_num);
+
+  args->grid_hidden = pbvh->grid_hidden;
+  args->face_sets_color_default = pbvh->face_sets_color_default;
+  args->face_sets_color_seed = pbvh->face_sets_color_seed;
+  args->mvert = pbvh->verts;
+  args->mloop = pbvh->mloop;
+  args->mpoly = pbvh->mpoly;
+  args->mlooptri = pbvh->looptri;
+
+  if (ELEM(pbvh->header.type, PBVH_FACES, PBVH_GRIDS)) {
+    args->hide_poly = pbvh->pdata ?
+                          CustomData_get_layer_named(pbvh->pdata, CD_PROP_BOOL, ".hide_poly") :
+                          NULL;
+  }
+
+  switch (pbvh->header.type) {
+    case PBVH_FACES:
+      args->mesh_faces_num = pbvh->mesh->totpoly;
+      args->vdata = pbvh->vdata;
+      args->ldata = pbvh->ldata;
+      args->pdata = pbvh->pdata;
+      args->totprim = node->totprim;
+      args->me = pbvh->mesh;
+      args->mpoly = pbvh->mpoly;
+      args->vert_normals = pbvh->vert_normals;
+
+      args->prim_indices = node->prim_indices;
+      args->face_sets = pbvh->face_sets;
+      break;
+    case PBVH_GRIDS:
+      args->vdata = pbvh->vdata;
+      args->ldata = pbvh->ldata;
+      args->pdata = pbvh->pdata;
+      args->ccg_key = pbvh->gridkey;
+      args->me = pbvh->mesh;
+      args->totprim = node->totprim;
+      args->grid_indices = node->prim_indices;
+      args->subdiv_ccg = pbvh->subdiv_ccg;
+      args->face_sets = pbvh->face_sets;
+      args->mpoly = pbvh->mpoly;
+
+      args->mesh_grids_num = pbvh->totgrid;
+      args->grids = pbvh->grids;
+      args->gridfaces = pbvh->gridfaces;
+      args->grid_flag_mats = pbvh->grid_flag_mats;
+      args->vert_normals = pbvh->vert_normals;
+
+      args->face_sets = pbvh->face_sets;
+      break;
+    case PBVH_BMESH:
+      args->bm = pbvh->header.bm;
+      args->vdata = &args->bm->vdata;
+      args->ldata = &args->bm->ldata;
+      args->pdata = &args->bm->pdata;
+      args->bm_faces = node->bm_faces;
+      args->bm_other_verts = node->bm_other_verts;
+      args->bm_unique_vert = node->bm_unique_verts;
+      args->totprim = BLI_gset_len(node->bm_faces);
+      args->cd_mask_layer = CustomData_get_offset(&pbvh->header.bm->vdata, CD_PAINT_MASK);
+
+      break;
+  }
+}
+
 void BKE_pbvh_build_mesh(PBVH *pbvh,
                          Mesh *mesh,
                          const MPoly *mpoly,
@@ -645,8 +719,8 @@ void BKE_pbvh_free(PBVH *pbvh)
     PBVHNode *node = &pbvh->nodes[i];
 
     if (node->flag & PBVH_Leaf) {
-      if (node->draw_buffers) {
-        GPU_pbvh_buffers_free(node->draw_buffers);
+      if (node->draw_batches) {
+        DRW_pbvh_node_free(node->draw_batches);
       }
       if (node->vert_indices) {
         MEM_freeN((void *)node->vert_indices);
@@ -693,10 +767,6 @@ void BKE_pbvh_free(PBVH *pbvh)
 
   MEM_SAFE_FREE(pbvh->vert_bitmap);
 
-  if (pbvh->vbo_id) {
-    GPU_pbvh_free_format(pbvh->vbo_id);
-  }
-
   MEM_freeN(pbvh);
 }
 
@@ -988,6 +1058,8 @@ typedef struct PBVHUpdateData {
   float (*vnors)[3];
   int flag;
   bool show_sculpt_face_sets;
+  PBVHAttrReq *attrs;
+  int attrs_num;
 } PBVHUpdateData;
 
 static void pbvh_update_normals_clear_task_cb(void *__restrict userdata,
@@ -1240,13 +1312,6 @@ void pbvh_update_BB_redraw(PBVH *pbvh, PBVHNode **nodes, int totnode, int flag)
   BLI_task_parallel_range(0, totnode, &data, pbvh_update_BB_redraw_task_cb, &settings);
 }
 
-static int pbvh_get_buffers_update_flags(PBVH *UNUSED(pbvh))
-{
-  int update_flags = GPU_PBVH_BUFFERS_SHOW_VCOL | GPU_PBVH_BUFFERS_SHOW_MASK |
-                     GPU_PBVH_BUFFERS_SHOW_SCULPT_FACE_SETS;
-  return update_flags;
-}
-
 bool BKE_pbvh_get_color_layer(const Mesh *me, CustomDataLayer **r_layer, eAttrDomain *r_attr)
 {
   CustomDataLayer *layer = BKE_id_attributes_active_color_get((ID *)me);
@@ -1283,128 +1348,29 @@ static void pbvh_update_draw_buffer_cb(void *__restrict userdata,
   PBVHNode *node = data->nodes[n];
 
   if (node->flag & PBVH_RebuildDrawBuffers) {
-    switch (pbvh->header.type) {
-      case PBVH_GRIDS: {
-        bool smooth = node->totprim > 0 ?
-                          pbvh->grid_flag_mats[node->prim_indices[0]].flag & ME_SMOOTH :
-                          false;
+    PBVH_GPU_Args args;
+    pbvh_draw_args_init(pbvh, &args, node);
 
-        node->draw_buffers = GPU_pbvh_grid_buffers_build(node->totprim, pbvh->grid_hidden, smooth);
-        break;
-      }
-      case PBVH_FACES:
-        node->draw_buffers = GPU_pbvh_mesh_buffers_build(
-            pbvh->mesh, pbvh->looptri, node->prim_indices, node->totprim);
-        break;
-      case PBVH_BMESH:
-        node->draw_buffers = GPU_pbvh_bmesh_buffers_build(pbvh->flags &
-                                                          PBVH_DYNTOPO_SMOOTH_SHADING);
-        break;
-    }
+    node->draw_batches = DRW_pbvh_node_create(&args);
   }
 
   if (node->flag & PBVH_UpdateDrawBuffers) {
     node->debug_draw_gen++;
 
-    const int update_flags = pbvh_get_buffers_update_flags(pbvh);
-    switch (pbvh->header.type) {
-      case PBVH_GRIDS:
-        GPU_pbvh_grid_buffers_update(pbvh->vbo_id,
-                                     node->draw_buffers,
-                                     pbvh->subdiv_ccg,
-                                     pbvh->grids,
-                                     pbvh->grid_flag_mats,
-                                     node->prim_indices,
-                                     node->totprim,
-                                     pbvh->face_sets,
-                                     pbvh->face_sets_color_seed,
-                                     pbvh->face_sets_color_default,
-                                     &pbvh->gridkey,
-                                     update_flags);
-        break;
-      case PBVH_FACES: {
-        /* Pass vertices separately because they may be not be the same as the mesh's vertices,
-         * and pass normals separately because they are managed by the PBVH. */
-        GPU_pbvh_mesh_buffers_update(
-            pbvh->vbo_id,
-            node->draw_buffers,
-            pbvh->mesh,
-            pbvh->verts,
-            CustomData_get_layer(pbvh->vdata, CD_PAINT_MASK),
-            CustomData_get_layer_named(pbvh->pdata, CD_PROP_INT32, ".sculpt_face_set"),
-            pbvh->face_sets_color_seed,
-            pbvh->face_sets_color_default,
-            update_flags,
-            pbvh->vert_normals);
-        break;
-      }
-      case PBVH_BMESH:
-        GPU_pbvh_bmesh_buffers_update(pbvh->vbo_id,
-                                      node->draw_buffers,
-                                      pbvh->header.bm,
-                                      node->bm_faces,
-                                      node->bm_unique_verts,
-                                      node->bm_other_verts,
-                                      update_flags);
-        break;
+    if (node->draw_batches) {
+      PBVH_GPU_Args args;
+
+      pbvh_draw_args_init(pbvh, &args, node);
+      DRW_pbvh_node_update(node->draw_batches, &args);
     }
   }
 }
 
 void pbvh_free_draw_buffers(PBVH *pbvh, PBVHNode *node)
 {
-  if (node->draw_buffers) {
-    pbvh->draw_cache_invalid = true;
-
-    GPU_pbvh_buffers_free(node->draw_buffers);
-    node->draw_buffers = NULL;
-  }
-}
-
-static void pbvh_check_draw_layout(PBVH *pbvh)
-{
-  const CustomData *vdata;
-  const CustomData *ldata;
-
-  if (!pbvh->vbo_id) {
-    pbvh->vbo_id = GPU_pbvh_make_format();
-  }
-
-  switch (pbvh->header.type) {
-    case PBVH_BMESH:
-      if (!pbvh->header.bm) {
-        /* BMesh hasn't been created yet */
-        return;
-      }
-
-      vdata = &pbvh->header.bm->vdata;
-      ldata = &pbvh->header.bm->ldata;
-      break;
-    case PBVH_FACES:
-      vdata = pbvh->vdata;
-      ldata = pbvh->ldata;
-      break;
-    case PBVH_GRIDS:
-      ldata = vdata = NULL;
-      break;
-  }
-
-  /* Rebuild all draw buffers if attribute layout changed.
-   *
-   * NOTE: The optimization where we only send active attributes
-   * to the GPU in workbench mode is disabled due to bugs
-   * (there's no guarantee there isn't another EEVEE viewport which would
-   *  free the draw buffers and corrupt the draw cache).
-   */
-  if (GPU_pbvh_attribute_names_update(pbvh->header.type, pbvh->vbo_id, vdata, ldata, false)) {
-    /* attribute layout changed; force rebuild */
-    for (int i = 0; i < pbvh->totnode; i++) {
-      PBVHNode *node = pbvh->nodes + i;
-
-      if (node->flag & PBVH_Leaf) {
-        node->flag |= PBVH_RebuildDrawBuffers | PBVH_UpdateDrawBuffers | PBVH_UpdateRedraw;
-      }
-    }
+  if (node->draw_batches) {
+    DRW_pbvh_node_free(node->draw_batches);
+    node->draw_batches = NULL;
   }
 }
 
@@ -1412,10 +1378,6 @@ static void pbvh_update_draw_buffers(PBVH *pbvh, PBVHNode **nodes, int totnode,
 {
   const CustomData *vdata;
 
-  if (!pbvh->vbo_id) {
-    pbvh->vbo_id = GPU_pbvh_make_format();
-  }
-
   switch (pbvh->header.type) {
     case PBVH_BMESH:
       if (!pbvh->header.bm) {
@@ -1441,14 +1403,11 @@ static void pbvh_update_draw_buffers(PBVH *pbvh, PBVHNode **nodes, int totnode,
       if (node->flag & PBVH_RebuildDrawBuffers) {
         pbvh_free_draw_buffers(pbvh, node);
       }
-      else if ((node->flag & PBVH_UpdateDrawBuffers) && node->draw_buffers) {
-        if (pbvh->header.type == PBVH_GRIDS) {
-          GPU_pbvh_grid_buffers_update_free(
-              node->draw_buffers, pbvh->grid_flag_mats, node->prim_indices);
-        }
-        else if (pbvh->header.type == PBVH_BMESH) {
-          GPU_pbvh_bmesh_buffers_update_free(node->draw_buffers);
-        }
+      else if ((node->flag & PBVH_UpdateDrawBuffers) && node->draw_batches) {
+        PBVH_GPU_Args args;
+
+        pbvh_draw_args_init(pbvh, &args, node);
+        DRW_pbvh_update_pre(node->draw_batches, &args);
       }
     }
   }
@@ -1468,7 +1427,10 @@ static void pbvh_update_draw_buffers(PBVH *pbvh, PBVHNode **nodes, int totnode,
 
     if (node->flag & PBVH_UpdateDrawBuffers) {
       /* Flush buffers uses OpenGL, so not in parallel. */
-      GPU_pbvh_buffers_update_flush(node->draw_buffers);
+
+      if (node->draw_batches) {
+        DRW_pbvh_node_gpu_flush(node->draw_batches);
+      }
     }
 
     node->flag &= ~(PBVH_RebuildDrawBuffers | PBVH_UpdateDrawBuffers);
@@ -2810,6 +2772,8 @@ void BKE_pbvh_face_sets_color_set(PBVH *pbvh, int seed, int color_default)
 typedef struct PBVHDrawSearchData {
   PBVHFrustumPlanes *frustum;
   int accum_update_flag;
+  PBVHAttrReq *attrs;
+  int attrs_num;
 } PBVHDrawSearchData;
 
 static bool pbvh_draw_search_cb(PBVHNode *node, void *data_v)
@@ -2827,9 +2791,11 @@ void BKE_pbvh_draw_cb(PBVH *pbvh,
                       bool update_only_visible,
                       PBVHFrustumPlanes *update_frustum,
                       PBVHFrustumPlanes *draw_frustum,
-                      void (*draw_fn)(void *user_data, GPU_PBVH_Buffers *buffers),
+                      void (*draw_fn)(void *user_data, PBVHBatches *batches, PBVH_GPU_Args *args),
                       void *user_data,
-                      bool UNUSED(full_render))
+                      bool UNUSED(full_render),
+                      PBVHAttrReq *attrs,
+                      int attrs_num)
 {
   PBVHNode **nodes;
   int totnode;
@@ -2840,7 +2806,8 @@ void BKE_pbvh_draw_cb(PBVH *pbvh,
   /* Search for nodes that need updates. */
   if (update_only_visible) {
     /* Get visible nodes with draw updates. */
-    PBVHDrawSearchData data = {.frustum = update_frustum, .accum_update_flag = 0};
+    PBVHDrawSearchData data = {
+        .frustum = update_frustum, .accum_update_flag = 0, attrs, attrs_num};
     BKE_pbvh_search_gather(pbvh, pbvh_draw_search_cb, &data, &nodes, &totnode);
     update_flag = data.accum_update_flag;
   }
@@ -2852,8 +2819,6 @@ void BKE_pbvh_draw_cb(PBVH *pbvh,
     update_flag = PBVH_RebuildDrawBuffers | PBVH_UpdateDrawBuffers;
   }
 
-  pbvh_check_draw_layout(pbvh);
-
   /* Update draw buffers. */
   if (totnode != 0 && (update_flag & (PBVH_RebuildDrawBuffers | PBVH_UpdateDrawBuffers))) {
     pbvh_update_draw_buffers(pbvh, nodes, totnode, update_flag);
@@ -2864,10 +2829,14 @@ void BKE_pbvh_draw_cb(PBVH *pbvh,
   PBVHDrawSearchData draw_data = {.frustum = draw_frustum, .accum_update_flag = 0};
   BKE_pbvh_search_gather(pbvh, pbvh_draw_search_cb, &draw_data, &nodes, &totnode);
 
+  PBVH_GPU_Args args;
+
   for (int i = 0; i < totnode; i++) {
     PBVHNode *node = nodes[i];
     if (!(node->flag & PBVH_FullyHidden)) {
-      draw_fn(user_data, node->draw_buffers);
+      pbvh_draw_args_init(pbvh, &args, node);
+
+      draw_fn(user_data, node->draw_batches, &args);
     }
   }