Files
test/source/blender/modifiers/intern/MOD_build.cc
Hans Goudey 7966cd16d6 Mesh: Replace MPoly struct with offset indices
Implements #95967.

Currently the `MPoly` struct is 12 bytes, and stores the index of a
face's first corner and the number of corners/verts/edges. Polygons
and corners are always created in order by Blender, meaning each
face's corners will be after the previous face's corners. We can take
advantage of this fact and eliminate the redundancy in mesh face
storage by only storing a single integer corner offset for each face.
The size of the face is then encoded by the offset of the next face.
The size of a single integer is 4 bytes, so this reduces memory
usage by 3 times.

The same method is used for `CurvesGeometry`, so Blender already has
an abstraction to simplify using these offsets called `OffsetIndices`.
This class is used to easily retrieve a range of corner indices for
each face. This also gives the opportunity for sharing some logic with
curves.

Another benefit of the change is that the offsets and sizes stored in
`MPoly` can no longer disagree with each other. Storing faces in the
order of their corners can simplify some code too.

Face/polygon variables now use the `IndexRange` type, which comes with
quite a few utilities that can simplify code.

Some:
- The offset integer array has to be one longer than the face count to
  avoid a branch for every face, which means the data is no longer part
  of the mesh's `CustomData`.
- We lose the ability to "reference" an original mesh's offset array
  until more reusable CoW from #104478 is committed. That will be added
  in a separate commit.
- Since they aren't part of `CustomData`, poly offsets often have to be
  copied manually.
- To simplify using `OffsetIndices` in many places, some functions and
  structs in headers were moved to only compile in C++.
- All meshes created by Blender use the same order for faces and face
  corners, but just in case, meshes with mismatched order are fixed by
  versioning code.
- `MeshPolygon.totloop` is no longer editable in RNA. This API break is
  necessary here unfortunately. It should be worth it in 3.6, since
  that's the best way to allow loading meshes from 4.0, which is
  important for an LTS version.

Pull Request: https://projects.blender.org/blender/blender/pulls/105938
2023-04-04 20:39:28 +02:00

329 lines
10 KiB
C++

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright 2005 Blender Foundation */
/** \file
* \ingroup modifiers
*/
#include "MEM_guardedalloc.h"
#include "BLI_utildefines.h"
#include "BLI_ghash.h"
#include "BLI_math_vector.h"
#include "BLI_rand.h"
#include "BLT_translation.h"
#include "DNA_defaults.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_object_types.h"
#include "DNA_screen_types.h"
#include "DEG_depsgraph_query.h"
#include "BKE_context.h"
#include "BKE_mesh.hh"
#include "BKE_modifier.h"
#include "BKE_particle.h"
#include "BKE_scene.h"
#include "BKE_screen.h"
#include "UI_interface.h"
#include "UI_resources.h"
#include "RNA_access.h"
#include "RNA_prototypes.h"
#include "MOD_modifiertypes.h"
#include "MOD_ui_common.h"
static void initData(ModifierData *md)
{
BuildModifierData *bmd = (BuildModifierData *)md;
BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(bmd, modifier));
MEMCPY_STRUCT_AFTER(bmd, DNA_struct_default_get(BuildModifierData), modifier);
}
static bool dependsOnTime(Scene * /*scene*/, ModifierData * /*md*/)
{
return true;
}
static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mesh)
{
Mesh *result;
BuildModifierData *bmd = (BuildModifierData *)md;
int i, j, k;
int faces_dst_num, edges_dst_num, loops_dst_num = 0;
float frac;
GHashIterator gh_iter;
/* maps vert indices in old mesh to indices in new mesh */
GHash *vertHash = BLI_ghash_int_new("build ve apply gh");
/* maps edge indices in new mesh to indices in old mesh */
GHash *edgeHash = BLI_ghash_int_new("build ed apply gh");
/* maps edge indices in old mesh to indices in new mesh */
GHash *edgeHash2 = BLI_ghash_int_new("build ed apply gh");
const int vert_src_num = mesh->totvert;
const blender::Span<MEdge> edges_src = mesh->edges();
const blender::OffsetIndices polys_src = mesh->polys();
const blender::Span<int> corner_verts_src = mesh->corner_verts();
const blender::Span<int> corner_edges_src = mesh->corner_edges();
int *vertMap = static_cast<int *>(MEM_malloc_arrayN(vert_src_num, sizeof(int), __func__));
int *edgeMap = static_cast<int *>(MEM_malloc_arrayN(edges_src.size(), sizeof(int), __func__));
int *faceMap = static_cast<int *>(MEM_malloc_arrayN(polys_src.size(), sizeof(int), __func__));
range_vn_i(vertMap, vert_src_num, 0);
range_vn_i(edgeMap, edges_src.size(), 0);
range_vn_i(faceMap, polys_src.size(), 0);
Scene *scene = DEG_get_input_scene(ctx->depsgraph);
frac = (BKE_scene_ctime_get(scene) - bmd->start) / bmd->length;
CLAMP(frac, 0.0f, 1.0f);
if (bmd->flag & MOD_BUILD_FLAG_REVERSE) {
frac = 1.0f - frac;
}
faces_dst_num = polys_src.size() * frac;
edges_dst_num = edges_src.size() * frac;
/* if there's at least one face, build based on faces */
if (faces_dst_num) {
uintptr_t hash_num, hash_num_alt;
if (bmd->flag & MOD_BUILD_FLAG_RANDOMIZE) {
BLI_array_randomize(faceMap, sizeof(*faceMap), polys_src.size(), bmd->seed);
}
/* get the set of all vert indices that will be in the final mesh,
* mapped to the new indices
*/
hash_num = 0;
for (i = 0; i < faces_dst_num; i++) {
const blender::IndexRange poly = polys_src[faceMap[i]];
for (j = 0; j < poly.size(); j++) {
const int vert_i = corner_verts_src[poly[j]];
void **val_p;
if (!BLI_ghash_ensure_p(vertHash, POINTER_FROM_INT(vert_i), &val_p)) {
*val_p = (void *)hash_num;
hash_num++;
}
}
loops_dst_num += poly.size();
}
BLI_assert(hash_num == BLI_ghash_len(vertHash));
/* get the set of edges that will be in the new mesh (i.e. all edges
* that have both verts in the new mesh)
*/
hash_num = 0;
hash_num_alt = 0;
for (i = 0; i < edges_src.size(); i++, hash_num_alt++) {
const MEdge *edge = edges_src.data() + i;
if (BLI_ghash_haskey(vertHash, POINTER_FROM_INT(edge->v1)) &&
BLI_ghash_haskey(vertHash, POINTER_FROM_INT(edge->v2))) {
BLI_ghash_insert(edgeHash, (void *)hash_num, (void *)hash_num_alt);
BLI_ghash_insert(edgeHash2, (void *)hash_num_alt, (void *)hash_num);
hash_num++;
}
}
BLI_assert(hash_num == BLI_ghash_len(edgeHash));
}
else if (edges_dst_num) {
const MEdge *edge;
uintptr_t hash_num;
if (bmd->flag & MOD_BUILD_FLAG_RANDOMIZE) {
BLI_array_randomize(edgeMap, sizeof(*edgeMap), edges_src.size(), bmd->seed);
}
/* get the set of all vert indices that will be in the final mesh,
* mapped to the new indices
*/
const MEdge *edges = edges_src.data();
hash_num = 0;
BLI_assert(hash_num == BLI_ghash_len(vertHash));
for (i = 0; i < edges_dst_num; i++) {
void **val_p;
edge = edges + edgeMap[i];
if (!BLI_ghash_ensure_p(vertHash, POINTER_FROM_INT(edge->v1), &val_p)) {
*val_p = (void *)hash_num;
hash_num++;
}
if (!BLI_ghash_ensure_p(vertHash, POINTER_FROM_INT(edge->v2), &val_p)) {
*val_p = (void *)hash_num;
hash_num++;
}
}
BLI_assert(hash_num == BLI_ghash_len(vertHash));
/* get the set of edges that will be in the new mesh */
for (i = 0; i < edges_dst_num; i++) {
j = BLI_ghash_len(edgeHash);
BLI_ghash_insert(edgeHash, POINTER_FROM_INT(j), POINTER_FROM_INT(edgeMap[i]));
BLI_ghash_insert(edgeHash2, POINTER_FROM_INT(edgeMap[i]), POINTER_FROM_INT(j));
}
}
else {
int verts_num = vert_src_num * frac;
if (bmd->flag & MOD_BUILD_FLAG_RANDOMIZE) {
BLI_array_randomize(vertMap, sizeof(*vertMap), vert_src_num, bmd->seed);
}
/* get the set of all vert indices that will be in the final mesh,
* mapped to the new indices
*/
for (i = 0; i < verts_num; i++) {
BLI_ghash_insert(vertHash, POINTER_FROM_INT(vertMap[i]), POINTER_FROM_INT(i));
}
}
/* now we know the number of verts, edges and faces, we can create the mesh. */
result = BKE_mesh_new_nomain_from_template(
mesh, BLI_ghash_len(vertHash), BLI_ghash_len(edgeHash), loops_dst_num, faces_dst_num);
blender::MutableSpan<MEdge> result_edges = result->edges_for_write();
blender::MutableSpan<int> result_poly_offsets = result->poly_offsets_for_write();
blender::MutableSpan<int> result_corner_verts = result->corner_verts_for_write();
blender::MutableSpan<int> result_corner_edges = result->corner_edges_for_write();
/* copy the vertices across */
GHASH_ITER (gh_iter, vertHash) {
int oldIndex = POINTER_AS_INT(BLI_ghashIterator_getKey(&gh_iter));
int newIndex = POINTER_AS_INT(BLI_ghashIterator_getValue(&gh_iter));
CustomData_copy_data(&mesh->vdata, &result->vdata, oldIndex, newIndex, 1);
}
/* copy the edges across, remapping indices */
for (i = 0; i < BLI_ghash_len(edgeHash); i++) {
MEdge source;
MEdge *dest;
int oldIndex = POINTER_AS_INT(BLI_ghash_lookup(edgeHash, POINTER_FROM_INT(i)));
source = edges_src[oldIndex];
dest = &result_edges[i];
source.v1 = POINTER_AS_INT(BLI_ghash_lookup(vertHash, POINTER_FROM_INT(source.v1)));
source.v2 = POINTER_AS_INT(BLI_ghash_lookup(vertHash, POINTER_FROM_INT(source.v2)));
CustomData_copy_data(&mesh->edata, &result->edata, oldIndex, i, 1);
*dest = source;
}
/* copy the faces across, remapping indices */
k = 0;
for (i = 0; i < faces_dst_num; i++) {
const blender::IndexRange src_poly = polys_src[faceMap[i]];
result_poly_offsets[i] = k;
CustomData_copy_data(&mesh->pdata, &result->pdata, faceMap[i], i, 1);
CustomData_copy_data(&mesh->ldata, &result->ldata, src_poly.start(), k, src_poly.size());
for (j = 0; j < src_poly.size(); j++, k++) {
const int vert_src = corner_verts_src[src_poly[j]];
const int edge_src = corner_edges_src[src_poly[j]];
result_corner_verts[k] = POINTER_AS_INT(
BLI_ghash_lookup(vertHash, POINTER_FROM_INT(vert_src)));
result_corner_edges[k] = POINTER_AS_INT(
BLI_ghash_lookup(edgeHash2, POINTER_FROM_INT(edge_src)));
}
}
BLI_ghash_free(vertHash, nullptr, nullptr);
BLI_ghash_free(edgeHash, nullptr, nullptr);
BLI_ghash_free(edgeHash2, nullptr, nullptr);
MEM_freeN(vertMap);
MEM_freeN(edgeMap);
MEM_freeN(faceMap);
/* TODO(sybren): also copy flags & tags? */
return result;
}
static void panel_draw(const bContext * /*C*/, Panel *panel)
{
uiLayout *layout = panel->layout;
PointerRNA *ptr = modifier_panel_get_property_pointers(panel, nullptr);
uiLayoutSetPropSep(layout, true);
uiItemR(layout, ptr, "frame_start", 0, nullptr, ICON_NONE);
uiItemR(layout, ptr, "frame_duration", 0, nullptr, ICON_NONE);
uiItemR(layout, ptr, "use_reverse", 0, nullptr, ICON_NONE);
modifier_panel_end(layout, ptr);
}
static void random_panel_header_draw(const bContext * /*C*/, Panel *panel)
{
uiLayout *layout = panel->layout;
PointerRNA *ptr = modifier_panel_get_property_pointers(panel, nullptr);
uiItemR(layout, ptr, "use_random_order", 0, nullptr, ICON_NONE);
}
static void random_panel_draw(const bContext * /*C*/, Panel *panel)
{
uiLayout *layout = panel->layout;
PointerRNA *ptr = modifier_panel_get_property_pointers(panel, nullptr);
uiLayoutSetPropSep(layout, true);
uiLayoutSetActive(layout, RNA_boolean_get(ptr, "use_random_order"));
uiItemR(layout, ptr, "seed", 0, nullptr, ICON_NONE);
}
static void panelRegister(ARegionType *region_type)
{
PanelType *panel_type = modifier_panel_register(region_type, eModifierType_Build, panel_draw);
modifier_subpanel_register(
region_type, "randomize", "", random_panel_header_draw, random_panel_draw, panel_type);
}
ModifierTypeInfo modifierType_Build = {
/*name*/ N_("Build"),
/*structName*/ "BuildModifierData",
/*structSize*/ sizeof(BuildModifierData),
/*srna*/ &RNA_BuildModifier,
/*type*/ eModifierTypeType_Nonconstructive,
/*flags*/ eModifierTypeFlag_AcceptsMesh | eModifierTypeFlag_AcceptsCVs,
/*icon*/ ICON_MOD_BUILD,
/*copyData*/ BKE_modifier_copydata_generic,
/*deformVerts*/ nullptr,
/*deformMatrices*/ nullptr,
/*deformVertsEM*/ nullptr,
/*deformMatricesEM*/ nullptr,
/*modifyMesh*/ modifyMesh,
/*modifyGeometrySet*/ nullptr,
/*initData*/ initData,
/*requiredDataMask*/ nullptr,
/*freeData*/ nullptr,
/*isDisabled*/ nullptr,
/*updateDepsgraph*/ nullptr,
/*dependsOnTime*/ dependsOnTime,
/*dependsOnNormals*/ nullptr,
/*foreachIDLink*/ nullptr,
/*foreachTexLink*/ nullptr,
/*freeRuntimeData*/ nullptr,
/*panelRegister*/ panelRegister,
/*blendWrite*/ nullptr,
/*blendRead*/ nullptr,
};