Update makefiles

Author: jpcima

common.mk

@@ -4,6 +4,10 @@ ifndef SFIZZ_DIR
 $(error sfizz: The source directory must be set before including)
 endif
 
+### Options
+
+SFIZZ_USE_SNDFILE ?= 1
+
 ###
 
 SFIZZ_MACHINE := $(shell $(CC) -dumpmachine)
@@ -125,13 +129,15 @@ SFIZZ_PKG_CONFIG ?= pkg-config
 
 # Sndfile dependency
 
+ifeq ($(SFIZZ_USE_SNDFILE),1)
 SFIZZ_SNDFILE_C_FLAGS ?= $(shell $(SFIZZ_PKG_CONFIG) --cflags sndfile)
 SFIZZ_SNDFILE_CXX_FLAGS ?= $(SFIZZ_SNDFILE_C_FLAGS)
 SFIZZ_SNDFILE_LINK_FLAGS ?= $(shell $(SFIZZ_PKG_CONFIG) --libs sndfile)
 
-SFIZZ_C_FLAGS += $(SFIZZ_SNDFILE_C_FLAGS)
-SFIZZ_CXX_FLAGS += $(SFIZZ_SNDFILE_CXX_FLAGS)
+SFIZZ_C_FLAGS += $(SFIZZ_SNDFILE_C_FLAGS) -DST_AUDIO_FILE_USE_SNDFILE=1
+SFIZZ_CXX_FLAGS += $(SFIZZ_SNDFILE_CXX_FLAGS) -DST_AUDIO_FILE_USE_SNDFILE=1
 SFIZZ_LINK_FLAGS += $(SFIZZ_SNDFILE_LINK_FLAGS)
+endif
 
 ### Abseil dependency
 

rack.mk

@@ -29,6 +29,7 @@
 #
 #        SFIZZ_RACK_PLUGIN_DIR = <the root directory of the Rack plugin>
 #        SFIZZ_PKG_CONFIG = <a custom pkg-config command>
+#        SFIZZ_USE_SNDFILE = <0 disabled, 1 enabled (default)>
 #        SFIZZ_SNDFILE_C_FLAGS = <compiler flags of sndfile for C>
 #        SFIZZ_SNDFILE_CXX_FLAGS = <compiler flags of sndfile for C++>
 #        SFIZZ_SNDFILE_LINK_FLAGS = <linker flags of sndfile>