Allow to use fltk for zynaddsubfx UI

Makefile

@@ -860,9 +860,13 @@ else
 endif
 ifeq ($(HAVE_ZYN_DEPS),true)
 ifeq ($(HAVE_ZYN_UI_DEPS),true)
-	@echo "ZynAddSubFX:    $(ANS_YES)(with UI)"
+ifeq ($(HAVE_NTK),true)
+	@echo "ZynAddSubFX:    $(ANS_YES)(with NTK UI)"
 else
-	@echo "ZynAddSubFX:    $(ANS_YES)(without UI) $(mS)NTK missing$(mE)"
+	@echo "ZynAddSubFX:    $(ANS_YES)(with FLTK UI)"
+endif
+else
+	@echo "ZynAddSubFX:    $(ANS_YES)(without UI) $(mS)FLTK or NTK missing$(mE)"
 endif
 else
 	@echo "ZynAddSubFX:    $(ANS_NO) $(mS)fftw3, mxml or zlib missing$(mE)"

source/Makefile.mk

@@ -157,6 +157,7 @@ HAVE_GTK3       = $(shell pkg-config --exists gtk+-3.0 && echo true)
 ifeq ($(LINUX),true)
 HAVE_ALSA       = $(shell pkg-config --exists alsa && echo true)
 HAVE_DGL        = $(shell pkg-config --exists gl x11 && echo true)
+HAVE_NTK        = $(shell pkg-config --exists ntk ntk_images && echo true)
 HAVE_PULSEAUDIO = $(shell pkg-config --exists libpulse-simple && echo true)
 HAVE_X11        = $(shell pkg-config --exists x11 && echo true)
 endif
@@ -170,12 +171,20 @@ HAVE_FLUIDSYNTH   = $(shell pkg-config --exists fluidsynth && echo true)
 HAVE_LINUXSAMPLER = $(shell pkg-config --atleast-version=1.0.0.svn41 linuxsampler && echo true)
 HAVE_PROJECTM     = $(shell pkg-config --exists libprojectM && echo true)
 
-HAVE_ZYN_DEPS     = $(shell pkg-config --exists fftw3 mxml zlib && echo true)
-HAVE_ZYN_UI_DEPS  = $(shell pkg-config --exists ntk_images ntk && echo true)
+# --------------------------------------------------------------
+# Check for optional libs (special non-pkgconfig unix tests)
 
 ifeq ($(UNIX),true)
+
 # libmagic doesn't have a pkg-config file, so we need to call the compiler to test it
-HAVE_LIBMAGIC     = $(shell echo '\#include <magic.h>' | $(CC) $(CFLAGS) -x c -w -c - -o .libmagic-tmp 2>/dev/null && echo true)
+HAVE_LIBMAGIC = $(shell echo '\#include <magic.h>' | $(CC) $(CFLAGS) -x c -w -c - -o .libmagic-tmp 2>/dev/null && echo true)
+
+# fltk doesn't have a pkg-config file but has fltk-config instead.
+# Also, don't try looking for it if we already have NTK.
+ifneq ($(HAVE_NTK),true)
+HAVE_FLTK = $(shell which fltk-config 1>/dev/null 2>/dev/null && echo true)
+endif
+
 endif
 
 # --------------------------------------------------------------
@@ -377,6 +386,14 @@ endif
 # --------------------------------------------------------------
 # Set libs stuff (part 3)
 
+HAVE_ZYN_DEPS    = $(shell pkg-config --exists fftw3 mxml zlib && echo true)
+ifeq ($(HAVE_FLTK),true)
+HAVE_ZYN_UI_DEPS = true
+endif
+ifeq ($(HAVE_NTK),true)
+HAVE_ZYN_UI_DEPS = true
+endif
+
 ifeq ($(HAVE_DGL),true)
 NATIVE_PLUGINS_LIBS  += $(DGL_LIBS)
 ifeq ($(HAVE_PROJECTM),true)
@@ -395,7 +412,11 @@ BASE_FLAGS           += -DHAVE_ZYN_DEPS
 NATIVE_PLUGINS_LIBS  += $(shell pkg-config --libs fftw3 mxml zlib)
 ifeq ($(HAVE_ZYN_UI_DEPS),true)
 BASE_FLAGS           += -DHAVE_ZYN_UI_DEPS
+ifeq ($(HAVE_NTK),true)
 NATIVE_PLUGINS_LIBS  += $(shell pkg-config --libs ntk_images ntk)
+else
+NATIVE_PLUGINS_LIBS  += $(shell fltk-config --use-images --ldstaticflags)
+endif
 endif
 endif
 

source/native-plugins/Makefile

@@ -23,8 +23,15 @@ ifneq ($(MACOS),true)
 ZYN_CXX_FLAGS += -DHAVE_SCHEDULER
 endif
 ifeq ($(HAVE_ZYN_UI_DEPS),true)
+ifeq ($(HAVE_NTK),true)
+FLUID          = ntk-fluid
 ZYN_CXX_FLAGS += -DNTK_GUI
 ZYN_CXX_FLAGS += $(shell pkg-config --cflags ntk_images ntk)
+else
+FLUID          = fluid
+ZYN_CXX_FLAGS += -DFLTK_GUI
+ZYN_CXX_FLAGS += $(shell fltk-config --use-images --cxxflags)
+endif
 endif
 endif
 
@@ -162,11 +169,11 @@ $(MODULEDIR)/$(MODULENAME).a: $(OBJS)
 
 zynaddsubfx/UI/%.cpp: zynaddsubfx/UI/%.fl
 	@echo "Generating $@/h"
-	@ntk-fluid -c -o zynaddsubfx/UI/$*.cpp -h zynaddsubfx/UI/$*.h $<
+	@$(FLUID) -c -o zynaddsubfx/UI/$*.cpp -h zynaddsubfx/UI/$*.h $<
 
 zynaddsubfx/UI/%.h: zynaddsubfx/UI/%.fl
 	@echo "Generating $@/cpp"
-	@ntk-fluid -c -o zynaddsubfx/UI/$*.cpp -h zynaddsubfx/UI/$*.h $<
+	@$(FLUID) -c -o zynaddsubfx/UI/$*.cpp -h zynaddsubfx/UI/$*.h $<
 
 # ----------------------------------------------------------------------------------------------------------------------------
 

source/native-plugins/zynaddsubfx-synth.cpp

@@ -37,11 +37,12 @@
 #  undef override
 # endif
 
-# include "UI/common.H"
 # include "UI/MasterUI.h"
 # include <FL/Fl_Shared_Image.H>
 # include <FL/Fl_Tiled_Image.H>
-# include <FL/Fl_Theme.H>
+# ifdef NTK_GUI
+#  include <FL/Fl_Theme.H>
+# endif
 
 # ifdef override_hack
 #  define override
@@ -57,19 +58,23 @@
 using juce::FloatVectorOperations;
 
 #ifdef WANT_ZYNADDSUBFX_UI
-static Fl_Tiled_Image* gModuleBackdrop = nullptr;
 static CarlaString gPixmapPath;
 extern CarlaString gUiPixmapPath;
+# ifdef NTK_GUI
+static Fl_Tiled_Image* gModuleBackdrop = nullptr;
+# endif
 
 void set_module_parameters(Fl_Widget* o)
 {
-    CARLA_SAFE_ASSERT_RETURN(gModuleBackdrop != nullptr,);
-
     o->box(FL_DOWN_FRAME);
     o->align(o->align() | FL_ALIGN_IMAGE_BACKDROP);
     o->color(FL_BLACK);
     o->labeltype(FL_SHADOW_LABEL);
+
+# ifdef NTK_GUI
+    CARLA_SAFE_ASSERT_RETURN(gModuleBackdrop != nullptr,);
     o->image(gModuleBackdrop);
+# endif
 }
 #endif
 
@@ -446,6 +451,7 @@ protected:
                     initialized = true;
                     fl_register_images();
 
+# ifdef NTK_GUI
                     Fl_Dial::default_style(Fl_Dial::PIXMAP_DIAL);
 
                     if (Fl_Shared_Image* const img = Fl_Shared_Image::get(gPixmapPath + "knob.png"))
@@ -454,7 +460,7 @@ protected:
                     if (Fl_Shared_Image* const img = Fl_Shared_Image::get(gPixmapPath + "window_backdrop.png"))
                         Fl::scheme_bg(new Fl_Tiled_Image(img));
 
-                    if(Fl_Shared_Image* const img = Fl_Shared_Image::get(gPixmapPath + "module_backdrop.png"))
+                    if (Fl_Shared_Image* const img = Fl_Shared_Image::get(gPixmapPath + "module_backdrop.png"))
                         gModuleBackdrop = new Fl_Tiled_Image(img);
 
                     Fl::background(50, 50, 50);
@@ -462,6 +468,7 @@ protected:
                     Fl::foreground(255, 255, 255);
 
                     Fl_Theme::set("Cairo");
+# endif
                 }
 
                 if (fUi == nullptr)