+#define ALPHA_FROM_TRANSPARENCY(x) ((100 - x) * SDL_ALPHA_OPAQUE / 100)
+#define ALPHA_FADING_STEPSIZE(x) ((x) / 25)
+
+// values for special settings for mobile devices
+#if defined(PLATFORM_ANDROID)
+#define USE_TOUCH_INPUT_OVERLAY
+#define USE_COMPLETE_DISPLAY
+#define HAS_SCREEN_KEYBOARD
+#define SCREEN_KEYBOARD_POS(h) ((h) / 2)
+#endif
+
+// values for drag-and-drop support (some parts not added before SDL 2.0.5)
+#if !SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_DROPTEXT (SDL_DROPFILE + 1)
+#define SDL_DROPBEGIN (SDL_DROPFILE + 2)
+#define SDL_DROPCOMPLETE (SDL_DROPFILE + 3)
+#endif
+
+// default input keys
+#define DEFAULT_KEY_LEFT KSYM_Left
+#define DEFAULT_KEY_RIGHT KSYM_Right
+#define DEFAULT_KEY_UP KSYM_Up
+#define DEFAULT_KEY_DOWN KSYM_Down
+#if defined(PLATFORM_MACOSX)
+#define DEFAULT_KEY_SNAP KSYM_Control_L
+#define DEFAULT_KEY_DROP KSYM_KP_Enter
+#else
+#define DEFAULT_KEY_SNAP KSYM_Control_L
+#define DEFAULT_KEY_DROP KSYM_Control_R
+#endif
+#define DEFAULT_KEY_OKAY KSYM_Return
+#define DEFAULT_KEY_CANCEL KSYM_Escape
+
+// default shortcut keys
+#define DEFAULT_KEY_SAVE_GAME KSYM_F1
+#define DEFAULT_KEY_LOAD_GAME KSYM_F2
+#define DEFAULT_KEY_TOGGLE_PAUSE KSYM_space
+#define DEFAULT_KEY_FOCUS_PLAYER_1 KSYM_F5
+#define DEFAULT_KEY_FOCUS_PLAYER_2 KSYM_F6
+#define DEFAULT_KEY_FOCUS_PLAYER_3 KSYM_F7
+#define DEFAULT_KEY_FOCUS_PLAYER_4 KSYM_F8
+#define DEFAULT_KEY_FOCUS_PLAYER_ALL KSYM_F9
+#define DEFAULT_KEY_TAPE_EJECT KSYM_UNDEFINED
+#define DEFAULT_KEY_TAPE_EXTRA KSYM_UNDEFINED
+#define DEFAULT_KEY_TAPE_STOP KSYM_UNDEFINED
+#define DEFAULT_KEY_TAPE_PAUSE KSYM_UNDEFINED
+#define DEFAULT_KEY_TAPE_RECORD KSYM_UNDEFINED
+#define DEFAULT_KEY_TAPE_PLAY KSYM_UNDEFINED
+#define DEFAULT_KEY_SOUND_SIMPLE KSYM_UNDEFINED
+#define DEFAULT_KEY_SOUND_LOOPS KSYM_UNDEFINED
+#define DEFAULT_KEY_SOUND_MUSIC KSYM_UNDEFINED
+#define DEFAULT_KEY_SNAP_LEFT KSYM_UNDEFINED
+#define DEFAULT_KEY_SNAP_RIGHT KSYM_UNDEFINED
+#define DEFAULT_KEY_SNAP_UP KSYM_UNDEFINED
+#define DEFAULT_KEY_SNAP_DOWN KSYM_UNDEFINED
+
+// default debug setup keys and values
+#define DEFAULT_FRAME_DELAY_0 20 // 100 % speed
+#define DEFAULT_FRAME_DELAY_1 500 // 4 % speed
+#define DEFAULT_FRAME_DELAY_2 250 // 8 % speed
+#define DEFAULT_FRAME_DELAY_3 125 // 16 % speed
+#define DEFAULT_FRAME_DELAY_4 60 // 33 % speed
+#define DEFAULT_FRAME_DELAY_5 40 // 50 % speed
+#define DEFAULT_FRAME_DELAY_6 30 // 66 % speed
+#define DEFAULT_FRAME_DELAY_7 10 // 200 % speed
+#define DEFAULT_FRAME_DELAY_8 5 // 400 % speed
+#define DEFAULT_FRAME_DELAY_9 0 // maximum speed
+
+#define DEFAULT_KEY_FRAME_DELAY_0 KSYM_0
+#define DEFAULT_KEY_FRAME_DELAY_1 KSYM_1
+#define DEFAULT_KEY_FRAME_DELAY_2 KSYM_2
+#define DEFAULT_KEY_FRAME_DELAY_3 KSYM_3
+#define DEFAULT_KEY_FRAME_DELAY_4 KSYM_4
+#define DEFAULT_KEY_FRAME_DELAY_5 KSYM_5
+#define DEFAULT_KEY_FRAME_DELAY_6 KSYM_6
+#define DEFAULT_KEY_FRAME_DELAY_7 KSYM_7
+#define DEFAULT_KEY_FRAME_DELAY_8 KSYM_8
+#define DEFAULT_KEY_FRAME_DELAY_9 KSYM_9
+
+#define NUM_DEBUG_FRAME_DELAY_KEYS 10
+
+#define DEFAULT_FRAME_DELAY_USE_MOD_KEY FALSE
+#define DEFAULT_FRAME_DELAY_GAME_ONLY TRUE
+
+// values for key_status
+#define KEY_NOT_PRESSED FALSE
+#define KEY_RELEASED FALSE
+#define KEY_PRESSED TRUE
+
+// values for button status
+#define MB_NOT_PRESSED FALSE
+#define MB_NOT_RELEASED TRUE
+#define MB_RELEASED FALSE
+#define MB_PRESSED TRUE
+#define MB_MENU_CHOICE FALSE
+#define MB_MENU_MARK TRUE
+#define MB_MENU_INITIALIZE (-1)
+#define MB_MENU_LEAVE (-2)
+#define MB_LEFTBUTTON 1
+#define MB_MIDDLEBUTTON 2
+#define MB_RIGHTBUTTON 3
+#define MB_WHEEL_UP 4
+#define MB_WHEEL_DOWN 5
+#define MB_WHEEL_LEFT 6
+#define MB_WHEEL_RIGHT 7
+#define IS_WHEEL_BUTTON_VERTICAL(b) ((b) == MB_WHEEL_UP || \
+ (b) == MB_WHEEL_DOWN)
+#define IS_WHEEL_BUTTON_HORIZONTAL(b) ((b) == MB_WHEEL_LEFT || \
+ (b) == MB_WHEEL_RIGHT)
+#define IS_WHEEL_BUTTON(b) (IS_WHEEL_BUTTON_VERTICAL(b) || \
+ IS_WHEEL_BUTTON_HORIZONTAL(b))
+#define DEFAULT_WHEEL_STEPS 3
+
+#define BUTTON_STEPSIZE(b) ((b) == MB_LEFTBUTTON ? 1 : \
+ (b) == MB_MIDDLEBUTTON ? 5 : \
+ (b) == MB_RIGHTBUTTON ? 10 : 1)
+
+// values for move directions
+#define MV_BIT_LEFT 0
+#define MV_BIT_RIGHT 1
+#define MV_BIT_UP 2
+#define MV_BIT_DOWN 3
+
+#define NUM_DIRECTIONS 4
+
+// diagonal movement directions are used in a different contect than buttons
+#define MV_BIT_UPLEFT 4
+#define MV_BIT_UPRIGHT 5
+#define MV_BIT_DOWNLEFT 6
+#define MV_BIT_DOWNRIGHT 7
+
+#define NUM_DIRECTIONS_FULL 8
+
+// values for special "button" bitmasks
+#define BUTTON_1 4
+#define BUTTON_2 5
+
+#define NUM_PLAYER_ACTIONS 6
+
+// values for special "focus player" bitmasks
+#define BIT_SET_FOCUS 6
+
+// values for drawing stages for global animations
+#define DRAW_GLOBAL_ANIM_STAGE_1 1
+#define DRAW_GLOBAL_ANIM_STAGE_2 2
+
+// values for drawing target (various functions)
+#define DRAW_TO_BACKBUFFER 0
+#define DRAW_TO_FIELDBUFFER 1
+#define DRAW_TO_SCREEN 2
+#define DRAW_TO_FADE_SOURCE 3
+#define DRAW_TO_FADE_TARGET 4
+
+// values for move directions and special "button" key bitmasks
+#define MV_NONE 0
+#define MV_LEFT (1 << MV_BIT_LEFT)
+#define MV_RIGHT (1 << MV_BIT_RIGHT)
+#define MV_UP (1 << MV_BIT_UP)
+#define MV_DOWN (1 << MV_BIT_DOWN)
+
+#define MV_UPLEFT (MV_UP | MV_LEFT)
+#define MV_UPRIGHT (MV_UP | MV_RIGHT)
+#define MV_DOWNLEFT (MV_DOWN | MV_LEFT)
+#define MV_DOWNRIGHT (MV_DOWN | MV_RIGHT)
+
+#define MV_HORIZONTAL (MV_LEFT | MV_RIGHT)
+#define MV_VERTICAL (MV_UP | MV_DOWN)
+#define MV_ALL_DIRECTIONS (MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN)
+#define MV_ANY_DIRECTION (MV_ALL_DIRECTIONS)
+#define MV_NO_DIRECTION (MV_NONE)
+
+#define KEY_BUTTON_1 (1 << BUTTON_1)
+#define KEY_BUTTON_2 (1 << BUTTON_2)
+#define KEY_BUTTON_SNAP KEY_BUTTON_1
+#define KEY_BUTTON_DROP KEY_BUTTON_2