Squashed 'third_party/ceres/' content from commit e51e9b4

Change-Id: I763587619d57e594d3fa158dc3a7fe0b89a1743b
git-subtree-dir: third_party/ceres
git-subtree-split: e51e9b46f6ca88ab8b2266d0e362771db6d98067
diff --git a/internal/ceres/line_search_preprocessor.cc b/internal/ceres/line_search_preprocessor.cc
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+++ b/internal/ceres/line_search_preprocessor.cc
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+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2015 Google Inc. All rights reserved.
+// http://ceres-solver.org/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+//   this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors may be
+//   used to endorse or promote products derived from this software without
+//   specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: sameeragarwal@google.com (Sameer Agarwal)
+
+#include "ceres/line_search_preprocessor.h"
+
+#include <numeric>
+#include <string>
+#include "ceres/casts.h"
+#include "ceres/context_impl.h"
+#include "ceres/evaluator.h"
+#include "ceres/minimizer.h"
+#include "ceres/problem_impl.h"
+#include "ceres/program.h"
+#include "ceres/wall_time.h"
+
+namespace ceres {
+namespace internal {
+namespace {
+
+bool IsProgramValid(const Program& program, std::string* error) {
+  if (program.IsBoundsConstrained()) {
+    *error = "LINE_SEARCH Minimizer does not support bounds.";
+    return false;
+  }
+  return program.ParameterBlocksAreFinite(error);
+}
+
+bool SetupEvaluator(PreprocessedProblem* pp) {
+  pp->evaluator_options = Evaluator::Options();
+  // This ensures that we get a Block Jacobian Evaluator without any
+  // requirement on orderings.
+  pp->evaluator_options.linear_solver_type = CGNR;
+  pp->evaluator_options.num_eliminate_blocks = 0;
+  pp->evaluator_options.num_threads = pp->options.num_threads;
+  pp->evaluator_options.context = pp->problem->context();
+  pp->evaluator_options.evaluation_callback = pp->options.evaluation_callback;
+  pp->evaluator.reset(Evaluator::Create(pp->evaluator_options,
+                                        pp->reduced_program.get(),
+                                        &pp->error));
+  return (pp->evaluator.get() != NULL);
+}
+
+}  // namespace
+
+LineSearchPreprocessor::~LineSearchPreprocessor() {
+}
+
+bool LineSearchPreprocessor::Preprocess(const Solver::Options& options,
+                                        ProblemImpl* problem,
+                                        PreprocessedProblem* pp) {
+  CHECK(pp != nullptr);
+  pp->options = options;
+  ChangeNumThreadsIfNeeded(&pp->options);
+
+  pp->problem = problem;
+  Program* program = problem->mutable_program();
+  if (!IsProgramValid(*program, &pp->error)) {
+    return false;
+  }
+
+  pp->reduced_program.reset(
+      program->CreateReducedProgram(&pp->removed_parameter_blocks,
+                                    &pp->fixed_cost,
+                                    &pp->error));
+
+  if (pp->reduced_program.get() == NULL) {
+    return false;
+  }
+
+  if (pp->reduced_program->NumParameterBlocks() == 0) {
+    return true;
+  }
+
+  if (!SetupEvaluator(pp)) {
+    return false;
+  }
+
+  SetupCommonMinimizerOptions(pp);
+  return true;
+}
+
+}  // namespace internal
+}  // namespace ceres