Initial Vec2 impl ready for algo

src/custom_types.cpp

@@ -0,0 +1,35 @@
+// Copyright (C) 2026 Hector van der Aa <hector@h3cx.dev>
+// Copyright (C) 2026 Association Exergie <association.exergie@gmail.com>
+// SPDX-License-Identifier: GPL-3.0-or-later
+#include "custom_types.h"
+#include "math.h"
+
+Vec2 eqRectProjection(const LatLng target, const LatLng ref) {
+  const float R = 6371000.0;
+  float lat0_r = ref.lat_ * M_PI / 180;
+  float lng0_r = ref.lng_ * M_PI / 180;
+  float lat1_r = target.lat_ * M_PI / 180;
+  float lng1_r = target.lng_ * M_PI / 180;
+  float lat_avg = (lat0_r + lat1_r) * 0.5f;
+  float lat0_cos = cos(lat_avg);
+
+
+  Vec2 res;
+
+  res.x_ = (lng1_r - lng0_r) * lat0_cos * R;
+  res.y_ = (lat1_r - lat0_r) * R;
+  return res;
+}
+
+Vec2 abMidpoint(const Vec2 A, const Vec2 B) {
+  Vec2 res;
+  res.x_ = (A.x_ + B.x_) * 0.5f;
+  res.y_ = (A.y_ + B.y_) * 0.5f;
+  return res;
+}
+
+float abSqDist(const Vec2 A, const Vec2 B) {
+  float deltaX = B.x_ - A.x_;
+  float deltaY = B.y_ - A.y_;
+  return deltaX * deltaX + deltaY * deltaY;
+}