消息處理:

我把Quake的消息分為兩類,一種是常用輸入設備產生的消息,譬如KeyBoard,Mouse,JoyStick等.

另一種就是網絡或本地傳輸數據包時引發的消息.

引擎中Com_EventLoop()函數負責將抓獲到的消息根據事件的類型分發給對應的處理函數,

Com_GetEvent()可以從com_eventQueue和eventqueue數組隊列中獲取到所有的未處理消息,

typedef enum sysEventType_s {

SE_NONE, // evTime is still valid

SE_KEY, // evValue is a key code, evValue2 is the down flag

SE_CHAR, // evValue is an ascii char

SE_MOUSE, // evValue and evValue2 are reletive signed x / y moves

SE_JOYSTICK_AXIS, // evValue is an axis number and evValue2 is the current state (-127 to 127)

SE_CONSOLE, // evPtr is a char*

SE_PACKET // evPtr is a netadr_t followed by data bytes to evPtrLength

} sysEventType_t;

typedef struct {

int evTime;

sysEventType_t evType;

int evValue, evValue2;

int evPtrLength; // bytes of data pointed to by evPtr, for journaling

void *evPtr; // this must be manually freed if not NULL

} sysEvent_t;

static sysEvent_t com_eventQueue[COM_MAX_EVENTS];

static sysEvent_t eventqueue[SYS_MAX_EVENTS];

從以上的聲明部分我們可以看到com_eventQueue和eventqueue其實就是一個sysEvent_t結構的數組.

這裡你可能要會問了,com_eventQueue裡面的數據又是從何而來的呢?當Com_GetEvent()函數發現com_eventQueue裡面沒有數據的時候,例如程序剛啟動時,它會調用Com_GetRealEvent()來蒐集未處理的消息.然後再從eventqueue中讀出事件.