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// Copyright 2016 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/compression/attributes/prediction_schemes/prediction_scheme_encoder_factory.h"
namespace draco {
PredictionSchemeMethod SelectPredictionMethod(
int att_id, const PointCloudEncoder *encoder) {
return SelectPredictionMethod(att_id, *encoder->options(), encoder);
}
PredictionSchemeMethod SelectPredictionMethod(
int att_id, const EncoderOptions &options,
const PointCloudEncoder *encoder) {
if (options.GetSpeed() >= 10) {
// Selected fastest, though still doing some compression.
return PREDICTION_DIFFERENCE;
}
if (encoder->GetGeometryType() == TRIANGULAR_MESH) {
// Use speed setting to select the best encoding method.
const PointAttribute *const att = encoder->point_cloud()->attribute(att_id);
if (att->attribute_type() == GeometryAttribute::TEX_COORD &&
att->num_components() == 2) {
if (options.GetSpeed() < 4) {
// Use texture coordinate prediction for speeds 0, 1, 2, 3.
return MESH_PREDICTION_TEX_COORDS_PORTABLE;
}
}
if (att->attribute_type() == GeometryAttribute::NORMAL) {
#ifdef DRACO_NORMAL_ENCODING_SUPPORTED
if (options.GetSpeed() < 4) {
// Use geometric normal prediction for speeds 0, 1, 2, 3.
// For this prediction, the position attribute needs to be either
// integer or quantized as well.
const int pos_att_id = encoder->point_cloud()->GetNamedAttributeId(
GeometryAttribute::POSITION);
const PointAttribute *const pos_att =
encoder->point_cloud()->GetNamedAttribute(
GeometryAttribute::POSITION);
if (pos_att && (IsDataTypeIntegral(pos_att->data_type()) ||
options.GetAttributeInt(pos_att_id, "quantization_bits",
-1) > 0)) {
return MESH_PREDICTION_GEOMETRIC_NORMAL;
}
}
#endif
return PREDICTION_DIFFERENCE; // default
}
// Handle other attribute types.
if (options.GetSpeed() >= 8) {
return PREDICTION_DIFFERENCE;
}
if (options.GetSpeed() >= 2 || encoder->point_cloud()->num_points() < 40) {
// Parallelogram prediction is used for speeds 2 - 7 or when the overhead
// of using constrained multi-parallelogram would be too high.
return MESH_PREDICTION_PARALLELOGRAM;
}
// Multi-parallelogram is used for speeds 0, 1.
return MESH_PREDICTION_CONSTRAINED_MULTI_PARALLELOGRAM;
}
// Default option is delta coding.
return PREDICTION_DIFFERENCE;
}
// Returns the preferred prediction scheme based on the encoder options.
PredictionSchemeMethod GetPredictionMethodFromOptions(
int att_id, const EncoderOptions &options) {
const int pred_type =
options.GetAttributeInt(att_id, "prediction_scheme", -1);
if (pred_type == -1) {
return PREDICTION_UNDEFINED;
}
if (pred_type < 0 || pred_type >= NUM_PREDICTION_SCHEMES) {
return PREDICTION_NONE;
}
return static_cast<PredictionSchemeMethod>(pred_type);
}
} // namespace draco
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