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      1 // Ceres Solver - A fast non-linear least squares minimizer
      2 // Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
      3 // http://code.google.com/p/ceres-solver/
      4 //
      5 // Redistribution and use in source and binary forms, with or without
      6 // modification, are permitted provided that the following conditions are met:
      7 //
      8 // * Redistributions of source code must retain the above copyright notice,
      9 //   this list of conditions and the following disclaimer.
     10 // * Redistributions in binary form must reproduce the above copyright notice,
     11 //   this list of conditions and the following disclaimer in the documentation
     12 //   and/or other materials provided with the distribution.
     13 // * Neither the name of Google Inc. nor the names of its contributors may be
     14 //   used to endorse or promote products derived from this software without
     15 //   specific prior written permission.
     16 //
     17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
     18 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     19 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     20 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
     21 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27 // POSSIBILITY OF SUCH DAMAGE.
     28 //
     29 // Author: keir (at) google.com (Keir Mierle)
     30 
     31 #include "ceres/scratch_evaluate_preparer.h"
     32 
     33 #include "ceres/parameter_block.h"
     34 #include "ceres/program.h"
     35 #include "ceres/residual_block.h"
     36 
     37 namespace ceres {
     38 namespace internal {
     39 
     40 ScratchEvaluatePreparer* ScratchEvaluatePreparer::Create(
     41     const Program &program,
     42     int num_threads) {
     43   ScratchEvaluatePreparer* preparers = new ScratchEvaluatePreparer[num_threads];
     44   int max_derivatives_per_residual_block =
     45       program.MaxDerivativesPerResidualBlock();
     46   for (int i = 0; i < num_threads; i++) {
     47     preparers[i].Init(max_derivatives_per_residual_block);
     48   }
     49   return preparers;
     50 }
     51 
     52 void ScratchEvaluatePreparer::Init(int max_derivatives_per_residual_block) {
     53   jacobian_scratch_.reset(
     54       new double[max_derivatives_per_residual_block]);
     55 }
     56 
     57 // Point the jacobian blocks into the scratch area of this evaluate preparer.
     58 void ScratchEvaluatePreparer::Prepare(const ResidualBlock* residual_block,
     59                                       int /* residual_block_index */,
     60                                       SparseMatrix* /* jacobian */,
     61                                       double** jacobians) {
     62   double* jacobian_block_cursor = jacobian_scratch_.get();
     63   int num_residuals = residual_block->NumResiduals();
     64   int num_parameter_blocks = residual_block->NumParameterBlocks();
     65   for (int j = 0; j < num_parameter_blocks; ++j) {
     66     const ParameterBlock* parameter_block =
     67         residual_block->parameter_blocks()[j];
     68     if (parameter_block->IsConstant()) {
     69       jacobians[j] = NULL;
     70     } else {
     71       jacobians[j] = jacobian_block_cursor;
     72       jacobian_block_cursor += num_residuals * parameter_block->LocalSize();
     73     }
     74   }
     75 }
     76 
     77 }  // namespace internal
     78 }  // namespace ceres
     79