SDL中按键对应的值

　　想用SDL的按键检测，网上找了半天都没找到SDL中按键的值的定义，索性自己去看头文件，在SDL_keysym.h中。

　　其实很多键的值和它们的ASCII码是相同的。

　　其他更多的用法，可以参考这篇博客：http://blog.chinaunix.net/uid-28482676-id-3444915.html/

typedef enum {
        /** @name ASCII mapped keysyms
         *  The keyboard syms have been cleverly chosen to map to ASCII
         */
        /*@{*/
    SDLK_UNKNOWN        = ,
    SDLK_FIRST        = ,
    SDLK_BACKSPACE        = ,
    SDLK_TAB        = ,
    SDLK_CLEAR        = ,
    SDLK_RETURN        = ,
    SDLK_PAUSE        = ,
    SDLK_ESCAPE        = ,
    SDLK_SPACE        = ,
    SDLK_EXCLAIM        = ,
    SDLK_QUOTEDBL        = ,
    SDLK_HASH        = ,
    SDLK_DOLLAR        = ,
    SDLK_AMPERSAND        = ,
    SDLK_QUOTE        = ,
    SDLK_LEFTPAREN        = ,
    SDLK_RIGHTPAREN        = ,
    SDLK_ASTERISK        = ,
    SDLK_PLUS        = ,
    SDLK_COMMA        = ,
    SDLK_MINUS        = ,
    SDLK_PERIOD        = ,
    SDLK_SLASH        = ,
    SDLK_0            = ,
    SDLK_1            = ,
    SDLK_2            = ,
    SDLK_3            = ,
    SDLK_4            = ,
    SDLK_5            = ,
    SDLK_6            = ,
    SDLK_7            = ,
    SDLK_8            = ,
    SDLK_9            = ,
    SDLK_COLON        = ,
    SDLK_SEMICOLON        = ,
    SDLK_LESS        = ,
    SDLK_EQUALS        = ,
    SDLK_GREATER        = ,
    SDLK_QUESTION        = ,
    SDLK_AT            = ,
    /*
       Skip uppercase letters
     */
    SDLK_LEFTBRACKET    = ,
    SDLK_BACKSLASH        = ,
    SDLK_RIGHTBRACKET    = ,
    SDLK_CARET        = ,
    SDLK_UNDERSCORE        = ,
    SDLK_BACKQUOTE        = ,
    SDLK_a            = ,
    SDLK_b            = ,
    SDLK_c            = ,
    SDLK_d            = ,
    SDLK_e            = ,
    SDLK_f            = ,
    SDLK_g            = ,
    SDLK_h            = ,
    SDLK_i            = ,
    SDLK_j            = ,
    SDLK_k            = ,
    SDLK_l            = ,
    SDLK_m            = ,
    SDLK_n            = ,
    SDLK_o            = ,
    SDLK_p            = ,
    SDLK_q            = ,
    SDLK_r            = ,
    SDLK_s            = ,
    SDLK_t            = ,
    SDLK_u            = ,
    SDLK_v            = ,
    SDLK_w            = ,
    SDLK_x            = ,
    SDLK_y            = ,
    SDLK_z            = ,
    SDLK_DELETE        = ,
    /* End of ASCII mapped keysyms */
        /*@}*/

    /** @name International keyboard syms */
        /*@{*/
    SDLK_WORLD_0        = ,        /* 0xA0 */
    SDLK_WORLD_1        = ,
    SDLK_WORLD_2        = ,
    SDLK_WORLD_3        = ,
    SDLK_WORLD_4        = ,
    SDLK_WORLD_5        = ,
    SDLK_WORLD_6        = ,
    SDLK_WORLD_7        = ,
    SDLK_WORLD_8        = ,
    SDLK_WORLD_9        = ,
    SDLK_WORLD_10        = ,
    SDLK_WORLD_11        = ,
    SDLK_WORLD_12        = ,
    SDLK_WORLD_13        = ,
    SDLK_WORLD_14        = ,
    SDLK_WORLD_15        = ,
    SDLK_WORLD_16        = ,
    SDLK_WORLD_17        = ,
    SDLK_WORLD_18        = ,
    SDLK_WORLD_19        = ,
    SDLK_WORLD_20        = ,
    SDLK_WORLD_21        = ,
    SDLK_WORLD_22        = ,
    SDLK_WORLD_23        = ,
    SDLK_WORLD_24        = ,
    SDLK_WORLD_25        = ,
    SDLK_WORLD_26        = ,
    SDLK_WORLD_27        = ,
    SDLK_WORLD_28        = ,
    SDLK_WORLD_29        = ,
    SDLK_WORLD_30        = ,
    SDLK_WORLD_31        = ,
    SDLK_WORLD_32        = ,
    SDLK_WORLD_33        = ,
    SDLK_WORLD_34        = ,
    SDLK_WORLD_35        = ,
    SDLK_WORLD_36        = ,
    SDLK_WORLD_37        = ,
    SDLK_WORLD_38        = ,
    SDLK_WORLD_39        = ,
    SDLK_WORLD_40        = ,
    SDLK_WORLD_41        = ,
    SDLK_WORLD_42        = ,
    SDLK_WORLD_43        = ,
    SDLK_WORLD_44        = ,
    SDLK_WORLD_45        = ,
    SDLK_WORLD_46        = ,
    SDLK_WORLD_47        = ,
    SDLK_WORLD_48        = ,
    SDLK_WORLD_49        = ,
    SDLK_WORLD_50        = ,
    SDLK_WORLD_51        = ,
    SDLK_WORLD_52        = ,
    SDLK_WORLD_53        = ,
    SDLK_WORLD_54        = ,
    SDLK_WORLD_55        = ,
    SDLK_WORLD_56        = ,
    SDLK_WORLD_57        = ,
    SDLK_WORLD_58        = ,
    SDLK_WORLD_59        = ,
    SDLK_WORLD_60        = ,
    SDLK_WORLD_61        = ,
    SDLK_WORLD_62        = ,
    SDLK_WORLD_63        = ,
    SDLK_WORLD_64        = ,
    SDLK_WORLD_65        = ,
    SDLK_WORLD_66        = ,
    SDLK_WORLD_67        = ,
    SDLK_WORLD_68        = ,
    SDLK_WORLD_69        = ,
    SDLK_WORLD_70        = ,
    SDLK_WORLD_71        = ,
    SDLK_WORLD_72        = ,
    SDLK_WORLD_73        = ,
    SDLK_WORLD_74        = ,
    SDLK_WORLD_75        = ,
    SDLK_WORLD_76        = ,
    SDLK_WORLD_77        = ,
    SDLK_WORLD_78        = ,
    SDLK_WORLD_79        = ,
    SDLK_WORLD_80        = ,
    SDLK_WORLD_81        = ,
    SDLK_WORLD_82        = ,
    SDLK_WORLD_83        = ,
    SDLK_WORLD_84        = ,
    SDLK_WORLD_85        = ,
    SDLK_WORLD_86        = ,
    SDLK_WORLD_87        = ,
    SDLK_WORLD_88        = ,
    SDLK_WORLD_89        = ,
    SDLK_WORLD_90        = ,
    SDLK_WORLD_91        = ,
    SDLK_WORLD_92        = ,
    SDLK_WORLD_93        = ,
    SDLK_WORLD_94        = ,
    SDLK_WORLD_95        = ,        /* 0xFF */
        /*@}*/

    /** @name Numeric keypad */
        /*@{*/
    SDLK_KP0        = ,
    SDLK_KP1        = ,
    SDLK_KP2        = ,
    SDLK_KP3        = ,
    SDLK_KP4        = ,
    SDLK_KP5        = ,
    SDLK_KP6        = ,
    SDLK_KP7        = ,
    SDLK_KP8        = ,
    SDLK_KP9        = ,
    SDLK_KP_PERIOD        = ,
    SDLK_KP_DIVIDE        = ,
    SDLK_KP_MULTIPLY    = ,
    SDLK_KP_MINUS        = ,
    SDLK_KP_PLUS        = ,
    SDLK_KP_ENTER        = ,
    SDLK_KP_EQUALS        = ,
        /*@}*/

    /** @name Arrows + Home/End pad */
        /*@{*/
    SDLK_UP            = ,
    SDLK_DOWN        = ,
    SDLK_RIGHT        = ,
    SDLK_LEFT        = ,
    SDLK_INSERT        = ,
    SDLK_HOME        = ,
    SDLK_END        = ,
    SDLK_PAGEUP        = ,
    SDLK_PAGEDOWN        = ,
        /*@}*/

    /** @name Function keys */
        /*@{*/
    SDLK_F1            = ,
    SDLK_F2            = ,
    SDLK_F3            = ,
    SDLK_F4            = ,
    SDLK_F5            = ,
    SDLK_F6            = ,
    SDLK_F7            = ,
    SDLK_F8            = ,
    SDLK_F9            = ,
    SDLK_F10        = ,
    SDLK_F11        = ,
    SDLK_F12        = ,
    SDLK_F13        = ,
    SDLK_F14        = ,
    SDLK_F15        = ,
        /*@}*/

    /** @name Key state modifier keys */
        /*@{*/
    SDLK_NUMLOCK        = ,
    SDLK_CAPSLOCK        = ,
    SDLK_SCROLLOCK        = ,
    SDLK_RSHIFT        = ,
    SDLK_LSHIFT        = ,
    SDLK_RCTRL        = ,
    SDLK_LCTRL        = ,
    SDLK_RALT        = ,
    SDLK_LALT        = ,
    SDLK_RMETA        = ,
    SDLK_LMETA        = ,
    SDLK_LSUPER        = ,        /**< Left "Windows" key */
    SDLK_RSUPER        = ,        /**< Right "Windows" key */
    SDLK_MODE        = ,        /**< "Alt Gr" key */
    SDLK_COMPOSE        = ,        /**< Multi-key compose key */
        /*@}*/

    /** @name Miscellaneous function keys */
        /*@{*/
    SDLK_HELP        = ,
    SDLK_PRINT        = ,
    SDLK_SYSREQ        = ,
    SDLK_BREAK        = ,
    SDLK_MENU        = ,
    SDLK_POWER        = ,        /**< Power Macintosh power key */
    SDLK_EURO        = ,        /**< Some european keyboards */
    SDLK_UNDO        = ,        /**< Atari keyboard has Undo */
        /*@}*/

    /* Add any other keys here */

    SDLK_LAST
} SDLKey;