directx ????????

cl781121

????????????? ??????????????????directx ???????????
?????backtofront???????????????????????????????????????????????????????????backtofront????????????????????????????????????????????????????????????????????????????
?????????????????????????????????????????????

??????????????? ????

snghun

????

????

1. 
   
2.       MOV   DX,03DAh
   
3. SYNC:IN    AL,DX
   
4.       TEST  AL,08h
   
5.       JZ    SYNC

复制代码

snghun

03DA ?????????????????

03DA ???? 0000N000 ??????????�????�????�????�?

?????????

1. 
   
2. 03DA r CGA status register EGA/VGA: input status 1 register
   
3.    bit 7-4     not used
   
4.    bit 3 = 1   in vertical retrace
   
5.    bit 2 = 1   light pen switch is off
   
6.    bit 1 = 1   positive edge from light pen has set trigger
   
7.    bit 0 = 0   do not use memory
   
8.          = 1   memory access without interfering with display

复制代码

bit 3 = 1 in vertical retrace
?????
?3 = 1 ??�?????�?

snghun

????????? DirectDraw ???????

1. 
   
2. //============================================================
   
3. // win_ddraw_wait_vsync
   
4. //============================================================
   
5. void win_ddraw_wait_vsync(void)
   
6. {
   
7.   HRESULT result;
   
8.   BOOL is_vblank;
   
9. 
   
10. // if we're not already in VBLANK, wait for it
    
11.   result = IDirectDraw::GetVerticalBlankStatus(ddraw, &is_vblank);
    
12.   if (result == DD_OK && !is_vblank)
    
13.   {
    
14.     result = IDirectDraw::WaitForVerticalBlank(ddraw, DDWAITVB_BLOCKBEGIN, 0);
    
15.   }
    
16. }
    
17. //============================================================

复制代码

clayman

........................................