Use cubic spline for initial guess

[bruingineer]

use wpi spline generator to create the initial guess translation. heading is interpolated separately between each waypoint and initial guess point.

[spacey-sooty]

I dont think this should manually copy in Eigen or wpimath....

[calcmogul]

Instead, after fetching Sleipnir, it could set the following then fetch allwpilib via FetchContent:

set(USE_SYSTEM_EIGEN ON)
set(USE_SYSTEM_FMTLIB ON)
set(WITH_JAVA OFF)
set(WITH_CSCORE OFF)
set(WITH_NTCORE OFF)
set(WITH_WPIMATH ON)
set(WITH_WPILIB OFF)
set(WITH_TESTS OFF)
set(WITH_GUI OFF)
set(WITH_SIMULATION_MODULES OFF)

[calcmogul]

I tried the thing I suggested, and WPILib's CMake setup is kinda broken. Here's the changes I had to make to WPILib:

diff --git a/wpimath/CMakeLists.txt b/wpimath/CMakeLists.txt
index a22ffc0b8..c7a99729c 100644
--- a/wpimath/CMakeLists.txt
+++ b/wpimath/CMakeLists.txt
@@ -200,6 +200,7 @@ target_include_directories(
 )
 
 install(TARGETS wpimath EXPORT wpimath)
+export(TARGETS wpimath FILE wpimath.cmake NAMESPACE wpimath::)
 
 configure_file(wpimath-config.cmake.in ${WPILIB_BINARY_DIR}/wpimath-config.cmake)
 install(FILES ${WPILIB_BINARY_DIR}/wpimath-config.cmake DESTINATION share/wpimath)
diff --git a/wpiutil/CMakeLists.txt b/wpiutil/CMakeLists.txt
index 4caa3521b..e01203f6c 100644
--- a/wpiutil/CMakeLists.txt
+++ b/wpiutil/CMakeLists.txt
@@ -258,6 +258,7 @@ target_include_directories(
 )
 
 install(TARGETS wpiutil EXPORT wpiutil)
+export(TARGETS wpiutil FILE wpiutil.cmake NAMESPACE wpiutil::)
 
 configure_file(wpiutil-config.cmake.in ${WPILIB_BINARY_DIR}/wpiutil-config.cmake)
 install(FILES ${WPILIB_BINARY_DIR}/wpiutil-config.cmake DESTINATION share/wpiutil)

Here's the TrajoptLib CMake changes:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 02e4ad4..f952f55 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,6 +15,9 @@ set(CMAKE_MODULE_PATH
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
 )
 
+# Allow overriding options in parent projects
+cmake_policy(SET CMP0077 NEW)
+
 project(TrajoptLib LANGUAGES CXX)
 
 # Use, i.e. don't skip the full RPATH for the build tree
@@ -146,6 +149,25 @@ elseif(${OPTIMIZER_BACKEND} STREQUAL "sleipnir")
     target_link_libraries(TrajoptLib PRIVATE Sleipnir)
 endif()
 
+# wpimath dependency
+set(WITH_CSCORE OFF CACHE INTERNAL "With CSCore")
+set(WITH_GUI OFF CACHE INTERNAL "With GUI")
+set(WITH_JAVA OFF CACHE INTERNAL "With Java")
+set(WITH_NTCORE OFF CACHE INTERNAL "With NTCore")
+set(WITH_SIMULATION_MODULES OFF CACHE INTERNAL "With Simulation Modules")
+set(WITH_TESTS OFF CACHE INTERNAL "With Tests")
+set(WITH_WPIMATH ON CACHE INTERNAL "With WPIMath")
+set(WITH_WPILIB OFF CACHE INTERNAL "With WPILib")
+fetchcontent_declare(
+    wpilib
+    #GIT_REPOSITORY https://github.com/wpilibsuite/allwpilib.git
+    #GIT_TAG v2024.3.2
+    GIT_REPOSITORY file:///home/tav/frc/wpilib/allwpilib
+    GIT_TAG 9ffce38bf71b1a96c009fc7e46c79b3beb6468a9
+)
+fetchcontent_makeavailable(wpilib)
+target_link_libraries(TrajoptLib PRIVATE Eigen3::Eigen wpimath)
+
 target_include_directories(
     TrajoptLib
     PUBLIC

I changed the fetchcontent target to a file:// repo and local commit hash for testing. I'll make a PR to your PR.

[calcmogul]

Here's the cleanup PR: bruingineer#1

[calcmogul]

With regard to the merge conflicts, the linear initial guess generator moved to https://github.com/SleipnirGroup/TrajoptLib/blob/main/include/trajopt/util/GenerateLinearInitialGuess.hpp, so this PR can mirror that structure.

[calcmogul]

TrajoptLib has moved to a subfolder within SleipnirGroup/Choreo. The changes here should be merged into SleipnirGroup/Choreo#478.