[ext] Add Eigen submodule and integration

Co-authored-by: Niklas Hauser <[email protected]>

Author: hshose

.gitmodules

@@ -52,3 +52,6 @@
 [submodule "ext/segger/rtt"]
 	path = ext/segger/rtt
 	url = https://github.com/modm-ext/segger-rtt.git
+[submodule "ext/libeigen/eigen"]
+	path = ext/libeigen/eigen
+	url = https://github.com/modm-ext/eigen-partial.git

ext/libeigen/Version.in

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2025, Henrik Hose
+ * Copyright (c) 2025, Niklas Hauser
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#if __has_include(<eigen_conf_local.h>)
+#  include <eigen_conf_local.h>
+#endif
+
+#define EIGEN_DONT_VECTORIZE
+#define EIGEN_DISABLE_UNALIGNED_ARRAY_ASSERT
+
+%% if eigen_no_malloc
+#define EIGEN_NO_MALLOC
+%% endif
+
+#include <modm/architecture/interface/assert.h>
+
+#define eigen_assert(cond) \
+    modm_assert(cond, "eigen", __FILE__ ":" MODM_STRINGIFY(__LINE__) " -> \"" #cond "\"")
+
+#include "Version_orig"

ext/libeigen/eigen

@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2025, Henrik Hose
+# Copyright (c) 2025, Niklas Hauser
+#
+# This file is part of the modm project.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+# -----------------------------------------------------------------------------
+
+def init(module):
+    module.name = ":eigen"
+    module.description = """
+# Eigen Linear Algebra Library
+
+
+"""
+
+
+def prepare(module, options):
+    module.depends(":architecture:assert")
+    return True
+
+
+def build(env):
+    env.outbasepath = "modm/ext/eigen"
+    env.collect(":build:path.include", "modm/ext/eigen")
+
+    env.substitutions = {"eigen_no_malloc": not env.has_module(":platform:heap")}
+    env.copy("eigen/Eigen", "Eigen", ignore=env.ignore_files("Version"))
+    env.copy("eigen/Eigen/Version", "Eigen/Version_orig")
+    env.template("Version.in", "Eigen/Version")
+
+    if env.has_module(":io"):
+        env.outbasepath = "modm/src/modm/io"
+        env.copy("iostream_eigen.hpp")

ext/libeigen/eigen.lb

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025, Henrik Hose
+ * Copyright (c) 2025, Niklas Hauser
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#pragma once
+#include <Eigen/Dense>
+
+namespace modm
+{
+
+template<typename Derived>
+modm::IOStream& operator<<(modm::IOStream& s, const Eigen::MatrixBase<Derived>& m)
+{
+    for (Eigen::Index r = 0; r < m.rows(); ++r) {
+        for (Eigen::Index c = 0; c < m.cols(); ++c) {
+            s << m(r, c);
+            if (c + 1 < m.cols()) s << ", ";
+        }
+        if (r + 1 < m.rows()) s << "\n";
+    }
+    return s;
+}
+
+} // namespace modm

ext/libeigen/iostream_eigen.hpp

@@ -372,5 +372,8 @@ white(IOStream& ios);
 }	// namespace modm
 
 #include "iostream_chrono.hpp"
+%% if with_eigen
+#include "iostream_eigen.hpp"
+%% endif
 
 #endif // MODM_IOSTREAM_HPP

src/modm/io/iostream.hpp.in

@@ -49,6 +49,7 @@ def build(env):
         "with_fiber": env.has_module(":processing:fiber"),
         "family": target.family,
         "core": core,
+        "with_eigen": env.has_module(":eigen"),
     }
     env.outbasepath = "modm/src/modm/io"
     env.copy("iodevice.hpp")