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// Copyright 2017 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "draco/attributes/attribute_quantization_transform.h"
#include "draco/attributes/attribute_transform_type.h"
#include "draco/core/quantization_utils.h"
namespace draco {
bool AttributeQuantizationTransform::InitFromAttribute(
const PointAttribute &attribute) {
const AttributeTransformData *const transform_data =
attribute.GetAttributeTransformData();
if (!transform_data ||
transform_data->transform_type() != ATTRIBUTE_QUANTIZATION_TRANSFORM) {
return false; // Wrong transform type.
}
int32_t byte_offset = 0;
quantization_bits_ = transform_data->GetParameterValue<int32_t>(byte_offset);
byte_offset += 4;
min_values_.resize(attribute.num_components());
for (int i = 0; i < attribute.num_components(); ++i) {
min_values_[i] = transform_data->GetParameterValue<float>(byte_offset);
byte_offset += 4;
}
range_ = transform_data->GetParameterValue<float>(byte_offset);
return true;
}
// Copy parameter values into the provided AttributeTransformData instance.
void AttributeQuantizationTransform::CopyToAttributeTransformData(
AttributeTransformData *out_data) const {
out_data->set_transform_type(ATTRIBUTE_QUANTIZATION_TRANSFORM);
out_data->AppendParameterValue(quantization_bits_);
for (int i = 0; i < min_values_.size(); ++i) {
out_data->AppendParameterValue(min_values_[i]);
}
out_data->AppendParameterValue(range_);
}
void AttributeQuantizationTransform::SetParameters(int quantization_bits,
const float *min_values,
int num_components,
float range) {
quantization_bits_ = quantization_bits;
min_values_.assign(min_values, min_values + num_components);
range_ = range;
}
bool AttributeQuantizationTransform::ComputeParameters(
const PointAttribute &attribute, const int quantization_bits) {
if (quantization_bits_ != -1) {
return false; // already initialized.
}
quantization_bits_ = quantization_bits;
const int num_components = attribute.num_components();
range_ = 0.f;
min_values_ = std::vector<float>(num_components, 0.f);
const std::unique_ptr<float[]> max_values(new float[num_components]);
const std::unique_ptr<float[]> att_val(new float[num_components]);
// Compute minimum values and max value difference.
attribute.GetValue(AttributeValueIndex(0), att_val.get());
attribute.GetValue(AttributeValueIndex(0), min_values_.data());
attribute.GetValue(AttributeValueIndex(0), max_values.get());
for (AttributeValueIndex i(1); i < static_cast<uint32_t>(attribute.size());
++i) {
attribute.GetValue(i, att_val.get());
for (int c = 0; c < num_components; ++c) {
if (min_values_[c] > att_val[c]) {
min_values_[c] = att_val[c];
}
if (max_values[c] < att_val[c]) {
max_values[c] = att_val[c];
}
}
}
for (int c = 0; c < num_components; ++c) {
if (std::isnan(min_values_[c]) || std::isinf(min_values_[c]) ||
std::isnan(max_values[c]) || std::isinf(max_values[c])) {
return false;
}
const float dif = max_values[c] - min_values_[c];
if (dif > range_) {
range_ = dif;
}
}
// In case all values are the same, initialize the range to unit length. This
// will ensure that all values are quantized properly to the same value.
if (range_ == 0.f) {
range_ = 1.f;
}
return true;
}
bool AttributeQuantizationTransform::EncodeParameters(
EncoderBuffer *encoder_buffer) const {
if (is_initialized()) {
encoder_buffer->Encode(min_values_.data(),
sizeof(float) * min_values_.size());
encoder_buffer->Encode(range_);
encoder_buffer->Encode(static_cast<uint8_t>(quantization_bits_));
return true;
}
return false;
}
std::unique_ptr<PointAttribute>
AttributeQuantizationTransform::GeneratePortableAttribute(
const PointAttribute &attribute, int num_points) const {
DRACO_DCHECK(is_initialized());
// Allocate portable attribute.
const int num_entries = num_points;
const int num_components = attribute.num_components();
std::unique_ptr<PointAttribute> portable_attribute =
InitPortableAttribute(num_entries, num_components, 0, attribute, true);
// Quantize all values using the order given by point_ids.
int32_t *const portable_attribute_data = reinterpret_cast<int32_t *>(
portable_attribute->GetAddress(AttributeValueIndex(0)));
const uint32_t max_quantized_value = (1 << (quantization_bits_)) - 1;
Quantizer quantizer;
quantizer.Init(range(), max_quantized_value);
int32_t dst_index = 0;
const std::unique_ptr<float[]> att_val(new float[num_components]);
for (PointIndex i(0); i < num_points; ++i) {
const AttributeValueIndex att_val_id = attribute.mapped_index(i);
attribute.GetValue(att_val_id, att_val.get());
for (int c = 0; c < num_components; ++c) {
const float value = (att_val[c] - min_values()[c]);
const int32_t q_val = quantizer.QuantizeFloat(value);
portable_attribute_data[dst_index++] = q_val;
}
}
return portable_attribute;
}
std::unique_ptr<PointAttribute>
AttributeQuantizationTransform::GeneratePortableAttribute(
const PointAttribute &attribute, const std::vector<PointIndex> &point_ids,
int num_points) const {
DRACO_DCHECK(is_initialized());
// Allocate portable attribute.
const int num_entries = static_cast<int>(point_ids.size());
const int num_components = attribute.num_components();
std::unique_ptr<PointAttribute> portable_attribute = InitPortableAttribute(
num_entries, num_components, num_points, attribute, true);
// Quantize all values using the order given by point_ids.
int32_t *const portable_attribute_data = reinterpret_cast<int32_t *>(
portable_attribute->GetAddress(AttributeValueIndex(0)));
const uint32_t max_quantized_value = (1 << (quantization_bits_)) - 1;
Quantizer quantizer;
quantizer.Init(range(), max_quantized_value);
int32_t dst_index = 0;
const std::unique_ptr<float[]> att_val(new float[num_components]);
for (uint32_t i = 0; i < point_ids.size(); ++i) {
const AttributeValueIndex att_val_id = attribute.mapped_index(point_ids[i]);
attribute.GetValue(att_val_id, att_val.get());
for (int c = 0; c < num_components; ++c) {
const float value = (att_val[c] - min_values()[c]);
const int32_t q_val = quantizer.QuantizeFloat(value);
portable_attribute_data[dst_index++] = q_val;
}
}
return portable_attribute;
}
} // namespace draco
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