get adpcm tools working on mac and somewhat unify the codebase

dsptools/libdsptool/CMakeLists.txt

@@ -3,14 +3,16 @@ project(DspTool LANGUAGES C)
 
 option(BUILD_SHARED_LIBS "Build as a Shared Object or DLL" OFF)
 
-set(HEADERS ../common.h dsptool.h)
+set(HEADERS dsptool.h ${COMMON}/util.h)
 set(SOURCES math.c decode.c encode.c)
 
 add_library(DspTool ${HEADERS} ${SOURCES})
 add_library(DspTool::DspTool ALIAS DspTool)
 
-target_include_directories(DspTool PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 set_property(TARGET DspTool PROPERTY C_STANDARD 99)
+target_include_directories(DspTool
+	PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}
+	PRIVATE ${COMMON})
 if (BUILD_SHARED_LIBS)
 	target_compile_definitions(DspTool PRIVATE BUILD_SHARED)
 endif()

dsptools/libdsptool/decode.c

@@ -1,7 +1,7 @@
 /* (c) 2017 Alex Barney (MIT) */
 
 #include <stdint.h>
-#include "../common.h"
+#include "util.h"
 #include "dsptool.h"
 
 static inline uint8_t GetHighNibble(uint8_t value)

dsptools/libdsptool/encode.c

@@ -6,7 +6,7 @@
 #include <math.h>
 #include <float.h>
 #include <string.h>
-#include "../common.h"
+#include "util.h"
 #include "dsptool.h"
 
 /* Temporal Vector