build for Linux: disable JUCE web browser (no gtk.h), vst3-only, linux install

CMakeLists.txt

@@ -68,6 +68,19 @@ endif()
 
 add_subdirectory(${JUCE_ROOT} juce)
 
+# RMX-19 has no web view. juce_audio_processors depends on juce_gui_extra, whose
+# Linux source includes <gtk/gtk.h> and the WebKit headers unless the browser
+# component is switched off. Disabling it keeps the Linux build free of GTK and
+# WebKit (and of native file-chooser dialogs, which this plug-in never uses).
+add_compile_definitions(JUCE_WEB_BROWSER=0)
+
+# AU is only buildable on Apple; on Linux (and everywhere else) ship VST3.
+if(APPLE)
+  set(RMX19_FORMATS AU VST3)
+else()
+  set(RMX19_FORMATS VST3)
+endif()
+
 juce_add_plugin(RMX19
   PRODUCT_NAME            "RMX-19"
   PLUGIN_NAME             "RMX-19"
@@ -79,7 +92,7 @@ juce_add_plugin(RMX19
   DESCRIPTION             "19 inch rack digital sound module"
   PLUGIN_MANUFACTURER_CODE "Rmlb"
   PLUGIN_CODE             "Rmx1"
-  FORMATS                 AU VST3
+  FORMATS                 ${RMX19_FORMATS}
   IS_SYNTH                TRUE
   NEEDS_MIDI_INPUT        TRUE
   EDITOR_WANTS_KEYBOARD_FOCUS TRUE

Makefile

@@ -1,13 +1,14 @@
-# RMX-19 build & install Makefile (macOS arm64)
+# RMX-19 build & install Makefile (macOS arm64 and Linux)
 #
-#   make            configure + build VST3 and AU (Release, arm64)
-#   make install    build, codesign (ad-hoc), install into ~/Library/Audio/Plug-Ins,
-#                   strip the quarantine attribute from the installed bundles
+#   make            configure + build (VST3 everywhere; AU additionally on macOS)
+#   make install    build and install the VST3 (and AU on macOS). macOS bundles
+#                   are ad-hoc codesigned and de-quarantined; on Linux the plug-in
+#                   is copied to ~/.vst3
 #   make uninstall  remove installed bundles
 #   make clean      delete the CMake build tree
 #
-# Note: after install, restart (or cold-start) the audio host so macOS rescans
-# AudioComponents. A fresh AU/AUv3 may first appear after a host relaunch.
+# Note (macOS): after install, restart (or cold-start) the audio host so it
+# rescans AudioComponents. A fresh AU/AUv3 may first appear after a host relaunch.
 
 BUILD_DIR  ?= build
 CONFIG     ?= Release
@@ -24,10 +25,18 @@ JUCE_TAG   := 8.0.4
 VST3_SRC   := $(ARTEFACTS)/VST3/$(PLUGIN_BASE).vst3
 AU_SRC     := $(ARTEFACTS)/AU/$(PLUGIN_BASE).component
 
+UNAME_S    := $(shell uname -s)
+
+ifeq ($(UNAME_S),Darwin)
 VST3_DEST  := $(HOME)/Library/Audio/Plug-Ins/VST3/$(PLUGIN_BASE).vst3
 AU_DEST    := $(HOME)/Library/Audio/Plug-Ins/Components/$(PLUGIN_BASE).component
-
 USER_PLUGIN_DIRS := $(HOME)/Library/Audio/Plug-Ins/VST3 $(HOME)/Library/Audio/Plug-Ins/Components
+else
+# Linux/BSD: the VST3 SDK scans ~/.vst3 by default. No AU, no codesigning.
+VST3_DEST  := $(HOME)/.vst3/$(PLUGIN_BASE).vst3
+AU_DEST    :=
+USER_PLUGIN_DIRS := $(HOME)/.vst3
+endif
 
 .EXPORT_ALL_VARIABLES:
 CMAKE_BUILD_TYPE := $(CONFIG)
@@ -52,6 +61,7 @@ juce:
 configure: juce
 	$(CMAKE) -S . -B $(BUILD_DIR) -DCMAKE_BUILD_TYPE=$(CONFIG) -DJUCE_ROOT=$(JUCE_DIR)
 
+ifeq ($(UNAME_S),Darwin)
 install: build
 	@codesign --force --deep --sign - "$(VST3_SRC)" >/dev/null 2>&1 || true
 	@codesign --force --deep --sign - "$(AU_SRC)"   >/dev/null 2>&1 || true
@@ -68,10 +78,18 @@ install: build
 	@codesign -dv "$(VST3_DEST)" 2>&1 | head -1
 	@echo ""
 	@echo "Restart your DAW / AudioHost to make the AU rescan."
+else
+install: build
+	@mkdir -p $(USER_PLUGIN_DIRS)
+	@rm -rf "$(VST3_DEST)"
+	@cp -Rf "$(VST3_SRC)" "$(USER_PLUGIN_DIRS)/"
+	@echo "installed:"
+	@echo "  $(VST3_DEST)"
+endif
 
 uninstall:
 	@rm -rf "$(VST3_DEST)" "$(AU_DEST)"
-	@echo "removed RMX-19 from user Audio Plug-Ins."
+	@echo "removed RMX-19 from user plug-in folder(s)."
 
 clean:
 	@rm -rf $(BUILD_DIR)

README.md

@@ -206,24 +206,40 @@ the host map onto the factory bank.
 
 ### Prerequisites
 
-- macOS on Apple Silicon (arm64), macOS 12.0 or later
+macOS on Apple Silicon (arm64), macOS 12.0 or later:
+
 - CMake ≥ 3.22
 - A C++17 compiler (Apple Clang via Xcode / Command Line Tools)
 - `git` (to fetch the JUCE framework)
 
+Linux:
+
+- CMake ≥ 3.22, a C++17 compiler (GCC or Clang), `git`, `pkg-config`
+- Development packages used by JUCE (Debian/Ubuntu):
+  `libasound2-dev libx11-dev libxext-dev libxinerama-dev libxrandr-dev`
+  `libxcursor-dev libxcomposite-dev libfreetype6-dev libfontconfig1-dev
+  libcurl4-openssl-dev libgl1-mesa-dev`
+- No GTK/WebKit packages are needed: the plug-in does not use the web browser,
+  native file-chooser dialogs, or `<gtk/gtk.h>`.
+
 The build fetches **JUCE 8.0.4** automatically into `build/JUCE` on first
 configure - no manual JUCE setup is required.
 
 ### Commands
 
 ```sh
-make            # configure + build VST3 and AU (Release, arm64)
-make install    # build, ad-hoc codesign, and install into ~/Library/Audio/Plug-Ins
+make            # configure + build VST3 (and AU on macOS)
+make install    # build + install (~/Library/Audio/Plug-Ins on macOS, ~/.vst3 on Linux)
 make uninstall  # remove installed bundles
-make clean      # delete the build tree (and the fetched JUCE)
+make clean      # delete the CMake build tree
 make info       # print build paths
 ```
 
+On Linux the AU format is skipped automatically; only the VST3 is produced, and
+`make install` copies it to `~/.vst3` (JUCE's default Linux VST3 scan path).
+A plain `cmake -S . -B build -DJUCE_ROOT=<JUCE source> && cmake --build build`
+works on Linux as well.
+
 `make` (configure) is designed to be cheap when nothing changed and refreshes
 the git branch/hash and timestamp embedded in the LCD footer on every
 configure, so the About screen always reflects the current source state.