# Ceres Solver - A fast non-linear least squares minimizer

# Copyright 2016 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.

#

# Authors: alexs.mac@gmail.com (Alex Stewart)

#

# Conditionally add a value to the output list based on whether the specified

# value is found in the input list.

function(update_output_if_found INPUT_LIST_VAR OUTPUT_LIST_VAR ITEM_TO_FIND VAR_TO_COPY_IF_FOUND VAR_TO_COPY_IF_NOT_FOUND)

  list(FIND ${INPUT_LIST_VAR} "${ITEM_TO_FIND}" HAVE_ITEM)

  # list(FIND ..) returns -1 if the element was not in the list, but CMake

  # interprets if (VAR) to be true if VAR is any non-zero number, even

  # negative ones, hence we have to explicitly check for >= 0.

  if (HAVE_ITEM GREATER -1)

    list(APPEND ${OUTPUT_LIST_VAR} "${VAR_TO_COPY_IF_FOUND}")

  else()

    list(APPEND ${OUTPUT_LIST_VAR} "${VAR_TO_COPY_IF_NOT_FOUND}")

  endif()

  set(${OUTPUT_LIST_VAR} ${${OUTPUT_LIST_VAR}} PARENT_SCOPE)

endfunction()

# Helpers for update_output_if_found() to improve legibility when dealing with

# USE_XXX & NO_XXX option types in ceres_compile_options_to_components().

macro(add_to_output_if_found INPUT_LIST_VAR OUTPUT_LIST_VAR ITEM_TO_FIND VAR_TO_COPY_IF_FOUND)

  update_output_if_found(${INPUT_LIST_VAR}

    ${OUTPUT_LIST_VAR}

    "${ITEM_TO_FIND}"

    "${VAR_TO_COPY_IF_FOUND}"

    "") # Copy nothing if not found.

endmacro()

macro(add_to_output_if_not_found INPUT_LIST_VAR OUTPUT_LIST_VAR ITEM_TO_FIND VAR_TO_COPY_IF_NOT_FOUND)

  update_output_if_found(${INPUT_LIST_VAR}

    ${OUTPUT_LIST_VAR}

    "${ITEM_TO_FIND}"

    "" # Copy nothing if found

    "${VAR_TO_COPY_IF_NOT_FOUND}")

endmacro()

# Convert the Ceres compile options specified by: CURRENT_CERES_COMPILE_OPTIONS

# into the correponding list of Ceres components (names), which may be used in:

# find_package(Ceres COMPONENTS <XXX>).

function(ceres_compile_options_to_components CURRENT_CERES_COMPILE_OPTIONS CERES_COMPONENTS_VAR)

  # To enable users to specify that they want *a* sparse linear algebra backend

  # without having to specify explicitly which one, for each sparse library we

  # add the 'meta-module': SparseLinearAlgebraLibrary in addition to their own

  # module name.

  add_to_output_if_found(CURRENT_CERES_COMPILE_OPTIONS ${CERES_COMPONENTS_VAR}

    CERES_USE_EIGEN_SPARSE "EigenSparse;SparseLinearAlgebraLibrary")

  add_to_output_if_not_found(CURRENT_CERES_COMPILE_OPTIONS ${CERES_COMPONENTS_VAR}

    CERES_NO_LAPACK "LAPACK")

  add_to_output_if_not_found(CURRENT_CERES_COMPILE_OPTIONS ${CERES_COMPONENTS_VAR}

    CERES_NO_SUITESPARSE "SuiteSparse;SparseLinearAlgebraLibrary")

  add_to_output_if_not_found(CURRENT_CERES_COMPILE_OPTIONS ${CERES_COMPONENTS_VAR}

    CERES_NO_CXSPARSE "CXSparse;SparseLinearAlgebraLibrary")

  add_to_output_if_not_found(CURRENT_CERES_COMPILE_OPTIONS ${CERES_COMPONENTS_VAR}

    CERES_RESTRICT_SCHUR_SPECIALIZATION "SchurSpecializations")

  add_to_output_if_found(CURRENT_CERES_COMPILE_OPTIONS ${CERES_COMPONENTS_VAR}

    CERES_USE_CXX11 "C++11")

  add_to_output_if_found(CURRENT_CERES_COMPILE_OPTIONS ${CERES_COMPONENTS_VAR}

    CERES_USE_OPENMP "OpenMP")

  # Remove duplicates of SparseLinearAlgebraLibrary if multiple sparse backends

  # are present.

  list(REMOVE_DUPLICATES ${CERES_COMPONENTS_VAR})

  set(${CERES_COMPONENTS_VAR} "${${CERES_COMPONENTS_VAR}}" PARENT_SCOPE)

endfunction()