S4 Tier 0: the bank plays — VST3 marshals MIDI to the S3 core, reads the live bank + resolves WAV the M4 way, mono downmix, lock-free load handoff, LICE sample-pick

CMakeLists.txt

@@ -621,6 +621,18 @@ target_include_directories(editor_geometry PUBLIC src/vst)
 add_library(bridge_marshal STATIC src/vst/bridge_marshal.cpp)
 target_include_directories(bridge_marshal PUBLIC src/vst)
 
+# sample_map (Phase S4) — PURE mapping logic for the Tier-0 instrument: the live bank
+# blob -> selected sample (via the SHARED bank_book JSON parse, NOT a second parser),
+# interleaved->mono downmix (the Tier-0 channel policy), the Tier-0 chromatic keymap
+# build, and the selected-sample instance-state (de)serialization. Links the three pure
+# modules it composes — bank_book (shared JSON), wav_trim (shared WAV parse), and
+# sampler_core (the Keymap/SampleData it yields) — and NEITHER SDK. The VST3 shell
+# (reasampler_processor.cpp) does the bridge read + file I/O off the audio thread, then
+# calls these; the process callback stays allocation-free.
+add_library(sample_map STATIC src/vst/sample_map.cpp)
+target_include_directories(sample_map PUBLIC src/vst src)
+target_link_libraries(sample_map PUBLIC bank_book wav_trim sampler_core)
+
 add_executable(editor_geometry_tests tests/test_editor_geometry.cpp)
 target_link_libraries(editor_geometry_tests PRIVATE editor_geometry)
 add_test(NAME editor_geometry_tests COMMAND editor_geometry_tests)
@@ -629,6 +641,13 @@ add_executable(bridge_marshal_tests tests/test_bridge_marshal.cpp)
 target_link_libraries(bridge_marshal_tests PRIVATE bridge_marshal)
 add_test(NAME bridge_marshal_tests COMMAND bridge_marshal_tests)
 
+# sample_map: the S4 mapping heart. Links ONLY sample_map (+ its pure deps) — NEITHER
+# the VST3 SDK nor the REAPER SDK — the same structural plain-data-boundary proof the
+# sampler_core test enforces.
+add_executable(sample_map_tests tests/test_sample_map.cpp)
+target_link_libraries(sample_map_tests PRIVATE sample_map)
+add_test(NAME sample_map_tests COMMAND sample_map_tests)
+
 # ---------------------------------------------------------------------------
 # 4) The REAPER extension — a loadable module (dlopen'd by REAPER, not linked).
 # ---------------------------------------------------------------------------
@@ -788,7 +807,14 @@ if(WIN32)
         ${VST3_SDK}/public.sdk/source/main/moduleinit.cpp
         ${LICE_SRC}
     )
-    target_link_libraries(reasampler_vst PRIVATE vst3_sdk editor_geometry bridge_marshal)
+    # editor_geometry + bridge_marshal: the pure spike helpers. sample_map (S4): the pure
+    # bank->keymap mapping + state (de)ser the processor drives off the audio thread;
+    # linking it pulls its pure deps (bank_book, wav_trim, sampler_core, bank_model,
+    # peaks) transitively. capture_paths: the shared M4 path resolution (resolveBankFile /
+    # projectDirOfRpp) the bridge + processor use. Its PUBLIC include dirs (src, src/vst)
+    # give the shell TUs their headers (ext_keys.h, bank_book.h, sampler_core.h, ...).
+    target_link_libraries(reasampler_vst PRIVATE vst3_sdk editor_geometry bridge_marshal
+        sample_map capture_paths)
     # SDK_INC gives reaper_vst3_interfaces.h + reaper_plugin_functions.h for the bridge;
     # WDL_INC gives LICE for the editor. The VST3 SDK headers come from vst3_sdk PUBLIC.
     target_include_directories(reasampler_vst PRIVATE ${SDK_INC} ${WDL_INC})