Replace the C++ implementation with the Rust port

The Rust port (formerly gipfel-rs) is now the official successor to the
FLTK/GSL C++ code base. This squashes the port into a single commit and
removes the C++ sources (they remain in the git history below).

Layout:
  crates/gipfel-core  headless core: hills, panorama geometry, projections
                      (maxima-generated derivatives), pure-Rust LM fit,
                      gipfel: JPEG comment + EXIF I/O, profiles, stitching
  crates/gipfel-cli   command-line tools (export, info, stitch, profiles)
  crates/gipfel-app   Cosmic DE (libcosmic) GUI, binary name `gipfel`
  codegen/            maxima scripts + regen.sh for the projection code
  tests/              golden files + C++ reference harnesses (historical)

The original README is kept for now; it will be updated to describe the
Rust build. gipfel.dat, AUTHORS, ChangeLog and NEWS are unchanged.

1 files changed, 16 insertions, 0 deletions

diff --git a/codegen/regen.sh b/codegen/regen.sh
new file mode 100755
index 0000000..dbf9f6b
--- /dev/null
+++ b/codegen/regen.sh
@@ -0,0 +1,16 @@
+#!/bin/sh
+# Regenerate the symbolic projection functions with maxima.
+# Run from anywhere; requires maxima (and rustfmt if available).
+set -e
+cd "$(dirname "$0")"
+OUT=../crates/gipfel-core/src/projection/generated
+
+for p in rectilinear cylindrical; do
+	maxima -b lsq_${p}.mac | python3 fixup.py > ${OUT}/${p}_funcs.rs
+done
+
+if command -v rustfmt >/dev/null; then
+	rustfmt ${OUT}/rectilinear_funcs.rs ${OUT}/cylindrical_funcs.rs 2>/dev/null || true
+fi
+echo "generated:"
+wc -l ${OUT}/*_funcs.rs