1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
|
/*
* 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.
*/
#include <mutex>
#include "BLI_float4x4.hh"
#include "BLI_map.hh"
#include "BLI_rand.hh"
#include "BLI_set.hh"
#include "BLI_span.hh"
#include "BLI_task.hh"
#include "BLI_vector.hh"
#include "DNA_collection_types.h"
#include "BKE_geometry_set.hh"
#include "BKE_geometry_set_instances.hh"
#include "attribute_access_intern.hh"
using blender::float4x4;
using blender::Map;
using blender::MutableSpan;
using blender::Set;
using blender::Span;
using blender::VectorSet;
/* -------------------------------------------------------------------- */
/** \name Geometry Component Implementation
* \{ */
InstancesComponent::InstancesComponent() : GeometryComponent(GEO_COMPONENT_TYPE_INSTANCES)
{
}
GeometryComponent *InstancesComponent::copy() const
{
InstancesComponent *new_component = new InstancesComponent();
new_component->instance_reference_handles_ = instance_reference_handles_;
new_component->instance_transforms_ = instance_transforms_;
new_component->instance_ids_ = instance_ids_;
new_component->references_ = references_;
return new_component;
}
void InstancesComponent::reserve(int min_capacity)
{
instance_reference_handles_.reserve(min_capacity);
instance_transforms_.reserve(min_capacity);
if (!instance_ids_.is_empty()) {
this->instance_ids_ensure();
}
}
/**
* Resize the transform, handles, and ID vectors to the specified capacity.
*
* \note This function should be used carefully, only when it's guaranteed
* that the data will be filled.
*/
void InstancesComponent::resize(int capacity)
{
instance_reference_handles_.resize(capacity);
instance_transforms_.resize(capacity);
if (!instance_ids_.is_empty()) {
this->instance_ids_ensure();
}
}
void InstancesComponent::clear()
{
instance_reference_handles_.clear();
instance_transforms_.clear();
instance_ids_.clear();
references_.clear();
}
void InstancesComponent::add_instance(const int instance_handle, const float4x4 &transform)
{
BLI_assert(instance_handle >= 0);
BLI_assert(instance_handle < references_.size());
instance_reference_handles_.append(instance_handle);
instance_transforms_.append(transform);
if (!instance_ids_.is_empty()) {
this->instance_ids_ensure();
}
}
blender::Span<int> InstancesComponent::instance_reference_handles() const
{
return instance_reference_handles_;
}
blender::MutableSpan<int> InstancesComponent::instance_reference_handles()
{
return instance_reference_handles_;
}
blender::MutableSpan<blender::float4x4> InstancesComponent::instance_transforms()
{
return instance_transforms_;
}
blender::Span<blender::float4x4> InstancesComponent::instance_transforms() const
{
return instance_transforms_;
}
blender::MutableSpan<int> InstancesComponent::instance_ids()
{
return instance_ids_;
}
blender::Span<int> InstancesComponent::instance_ids() const
{
return instance_ids_;
}
/**
* Make sure the ID storage size matches the number of instances. By directly resizing the
* component's vectors internally, it is possible to be in a situation where the IDs are not
* empty but they do not have the correct size; this function resolves that.
*/
blender::MutableSpan<int> InstancesComponent::instance_ids_ensure()
{
instance_ids_.append_n_times(0, this->instances_amount() - instance_ids_.size());
return instance_ids_;
}
void InstancesComponent::instance_ids_clear()
{
instance_ids_.clear_and_make_inline();
}
/**
* With write access to the instances component, the data in the instanced geometry sets can be
* changed. This is a function on the component rather than each reference to ensure `const`
* correctness for that reason.
*/
GeometrySet &InstancesComponent::geometry_set_from_reference(const int reference_index)
{
/* If this assert fails, it means #ensure_geometry_instances must be called first or that the
* reference can't be converted to a geometry set. */
BLI_assert(references_[reference_index].type() == InstanceReference::Type::GeometrySet);
/* The const cast is okay because the instance's hash in the set
* is not changed by adjusting the data inside the geometry set. */
return const_cast<GeometrySet &>(references_[reference_index].geometry_set());
}
/**
* Returns a handle for the given reference.
* If the reference exists already, the handle of the existing reference is returned.
* Otherwise a new handle is added.
*/
int InstancesComponent::add_reference(const InstanceReference &reference)
{
return references_.index_of_or_add_as(reference);
}
blender::Span<InstanceReference> InstancesComponent::references() const
{
return references_;
}
void InstancesComponent::remove_unused_references()
{
using namespace blender;
using namespace blender::bke;
const int tot_instances = this->instances_amount();
const int tot_references_before = references_.size();
if (tot_instances == 0) {
/* If there are no instances, no reference is needed. */
references_.clear();
return;
}
if (tot_references_before == 1) {
/* There is only one reference and at least one instance. So the only existing reference is
* used. Nothing to do here. */
return;
}
Array<bool> usage_by_handle(tot_references_before, false);
std::mutex mutex;
/* Loop over all instances to see which references are used. */
threading::parallel_for(IndexRange(tot_instances), 1000, [&](IndexRange range) {
/* Use local counter to avoid lock contention. */
Array<bool> local_usage_by_handle(tot_references_before, false);
for (const int i : range) {
const int handle = instance_reference_handles_[i];
BLI_assert(handle >= 0 && handle < tot_references_before);
local_usage_by_handle[handle] = true;
}
std::lock_guard lock{mutex};
for (const int i : IndexRange(tot_references_before)) {
usage_by_handle[i] |= local_usage_by_handle[i];
}
});
if (!usage_by_handle.as_span().contains(false)) {
/* All references are used. */
return;
}
/* Create new references and a mapping for the handles. */
Vector<int> handle_mapping;
VectorSet<InstanceReference> new_references;
int next_new_handle = 0;
bool handles_have_to_be_updated = false;
for (const int old_handle : IndexRange(tot_references_before)) {
if (!usage_by_handle[old_handle]) {
/* Add some dummy value. It won't be read again. */
handle_mapping.append(-1);
}
else {
const InstanceReference &reference = references_[old_handle];
handle_mapping.append(next_new_handle);
new_references.add_new(reference);
if (old_handle != next_new_handle) {
handles_have_to_be_updated = true;
}
next_new_handle++;
}
}
references_ = new_references;
if (!handles_have_to_be_updated) {
/* All remaining handles are the same as before, so they don't have to be updated. This happens
* when unused handles are only at the end. */
return;
}
/* Update handles of instances. */
threading::parallel_for(IndexRange(tot_instances), 1000, [&](IndexRange range) {
for (const int i : range) {
instance_reference_handles_[i] = handle_mapping[instance_reference_handles_[i]];
}
});
}
int InstancesComponent::instances_amount() const
{
return instance_transforms_.size();
}
int InstancesComponent::references_amount() const
{
return references_.size();
}
bool InstancesComponent::is_empty() const
{
return this->instance_reference_handles_.size() == 0;
}
bool InstancesComponent::owns_direct_data() const
{
for (const InstanceReference &reference : references_) {
if (!reference.owns_direct_data()) {
return false;
}
}
return true;
}
void InstancesComponent::ensure_owns_direct_data()
{
BLI_assert(this->is_mutable());
for (const InstanceReference &const_reference : references_) {
/* Const cast is fine because we are not changing anything that would change the hash of the
* reference. */
InstanceReference &reference = const_cast<InstanceReference &>(const_reference);
reference.ensure_owns_direct_data();
}
}
static blender::Array<int> generate_unique_instance_ids(Span<int> original_ids)
{
using namespace blender;
Array<int> unique_ids(original_ids.size());
Set<int> used_unique_ids;
used_unique_ids.reserve(original_ids.size());
Vector<int> instances_with_id_collision;
for (const int instance_index : original_ids.index_range()) {
const int original_id = original_ids[instance_index];
if (used_unique_ids.add(original_id)) {
/* The original id has not been used by another instance yet. */
unique_ids[instance_index] = original_id;
}
else {
/* The original id of this instance collided with a previous instance, it needs to be looked
* at again in a second pass. Don't generate a new random id here, because this might collide
* with other existing ids. */
instances_with_id_collision.append(instance_index);
}
}
Map<int, RandomNumberGenerator> generator_by_original_id;
for (const int instance_index : instances_with_id_collision) {
const int original_id = original_ids[instance_index];
RandomNumberGenerator &rng = generator_by_original_id.lookup_or_add_cb(original_id, [&]() {
RandomNumberGenerator rng;
rng.seed_random(original_id);
return rng;
});
const int max_iteration = 100;
for (int iteration = 0;; iteration++) {
/* Try generating random numbers until an unused one has been found. */
const int random_id = rng.get_int32();
if (used_unique_ids.add(random_id)) {
/* This random id is not used by another instance. */
unique_ids[instance_index] = random_id;
break;
}
if (iteration == max_iteration) {
/* It seems to be very unlikely that we ever run into this case (assuming there are less
* than 2^30 instances). However, if that happens, it's better to use an id that is not
* unique than to be stuck in an infinite loop. */
unique_ids[instance_index] = original_id;
break;
}
}
}
return unique_ids;
}
blender::Span<int> InstancesComponent::almost_unique_ids() const
{
std::lock_guard lock(almost_unique_ids_mutex_);
if (instance_ids().is_empty()) {
almost_unique_ids_.reinitialize(this->instances_amount());
for (const int i : almost_unique_ids_.index_range()) {
almost_unique_ids_[i] = i;
}
}
else {
if (almost_unique_ids_.size() != instance_ids_.size()) {
almost_unique_ids_ = generate_unique_instance_ids(instance_ids_);
}
}
return almost_unique_ids_;
}
int InstancesComponent::attribute_domain_size(const AttributeDomain domain) const
{
if (domain != ATTR_DOMAIN_POINT) {
return 0;
}
return this->instances_amount();
}
namespace blender::bke {
static float3 get_transform_position(const float4x4 &transform)
{
return transform.translation();
}
static void set_transform_position(float4x4 &transform, const float3 position)
{
copy_v3_v3(transform.values[3], position);
}
class InstancePositionAttributeProvider final : public BuiltinAttributeProvider {
public:
InstancePositionAttributeProvider()
: BuiltinAttributeProvider(
"position", ATTR_DOMAIN_POINT, CD_PROP_FLOAT3, NonCreatable, Writable, NonDeletable)
{
}
GVArrayPtr try_get_for_read(const GeometryComponent &component) const final
{
const InstancesComponent &instances_component = static_cast<const InstancesComponent &>(
component);
Span<float4x4> transforms = instances_component.instance_transforms();
return std::make_unique<fn::GVArray_For_DerivedSpan<float4x4, float3, get_transform_position>>(
transforms);
}
GVMutableArrayPtr try_get_for_write(GeometryComponent &component) const final
{
InstancesComponent &instances_component = static_cast<InstancesComponent &>(component);
MutableSpan<float4x4> transforms = instances_component.instance_transforms();
return std::make_unique<fn::GVMutableArray_For_DerivedSpan<float4x4,
float3,
get_transform_position,
set_transform_position>>(
transforms);
}
bool try_delete(GeometryComponent &UNUSED(component)) const final
{
return false;
}
bool try_create(GeometryComponent &UNUSED(component),
const AttributeInit &UNUSED(initializer)) const final
{
return false;
}
bool exists(const GeometryComponent &UNUSED(component)) const final
{
return true;
}
};
class InstanceIDAttributeProvider final : public BuiltinAttributeProvider {
public:
InstanceIDAttributeProvider()
: BuiltinAttributeProvider(
"id", ATTR_DOMAIN_POINT, CD_PROP_INT32, Creatable, Writable, Deletable)
{
}
GVArrayPtr try_get_for_read(const GeometryComponent &component) const final
{
const InstancesComponent &instances = static_cast<const InstancesComponent &>(component);
if (instances.instance_ids().is_empty()) {
return {};
}
return std::make_unique<fn::GVArray_For_Span<int>>(instances.instance_ids());
}
GVMutableArrayPtr try_get_for_write(GeometryComponent &component) const final
{
InstancesComponent &instances = static_cast<InstancesComponent &>(component);
if (instances.instance_ids().is_empty()) {
return {};
}
return std::make_unique<fn::GVMutableArray_For_MutableSpan<int>>(instances.instance_ids());
}
bool try_delete(GeometryComponent &component) const final
{
InstancesComponent &instances = static_cast<InstancesComponent &>(component);
if (instances.instance_ids().is_empty()) {
return false;
}
instances.instance_ids_clear();
return true;
}
bool try_create(GeometryComponent &component, const AttributeInit &initializer) const final
{
InstancesComponent &instances = static_cast<InstancesComponent &>(component);
if (instances.instances_amount() == 0) {
return false;
}
MutableSpan<int> ids = instances.instance_ids_ensure();
switch (initializer.type) {
case AttributeInit::Type::Default: {
ids.fill(0);
break;
}
case AttributeInit::Type::VArray: {
const GVArray *varray = static_cast<const AttributeInitVArray &>(initializer).varray;
varray->materialize_to_uninitialized(IndexRange(varray->size()), ids.data());
break;
}
case AttributeInit::Type::MoveArray: {
void *source_data = static_cast<const AttributeInitMove &>(initializer).data;
ids.copy_from({static_cast<int *>(source_data), instances.instances_amount()});
MEM_freeN(source_data);
break;
}
}
return true;
}
bool exists(const GeometryComponent &component) const final
{
const InstancesComponent &instances = static_cast<const InstancesComponent &>(component);
return !instances.instance_ids().is_empty();
}
};
static ComponentAttributeProviders create_attribute_providers_for_instances()
{
static InstancePositionAttributeProvider position;
static InstanceIDAttributeProvider id;
return ComponentAttributeProviders({&position, &id}, {});
}
} // namespace blender::bke
const blender::bke::ComponentAttributeProviders *InstancesComponent::get_attribute_providers()
const
{
static blender::bke::ComponentAttributeProviders providers =
blender::bke::create_attribute_providers_for_instances();
return &providers;
}
/** \} */
|