懷舊之使用匯編啓動hge

雖然其實只是抄了一遍而已，不過之後我會考慮使用純彙編啓動一次看看

	hge = hgeCreate(HGE_VERSION);

	hge->System_SetState(HGE_FRAMEFUNC, FrameFunc);
	hge->System_SetState(HGE_WINDOWED, true);

	if(hge->System_Initiate())
	{
		hge->System_Start();
		hge->System_Shutdown();
	}
	
	hge->Release();

首先是C++的代碼。以上代碼就足以運行一個簡單的hge了，當然庫和頭文件自己導進去，全局的hge指針也需要聲明下。

__asm
	{
		push        180h
		call        hgeCreate

		mov         ecx,dword ptr [eax]
		mov         edx,dword ptr [ecx+24h] 
		push        offset FrameFunc
		push        8    
		push        eax  
		mov         dword ptr [hge],eax 
		call        edx 

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx+20h] 
		push        1    
		push        1    
		push        eax  
		call        edx  

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx+4] 
		push        eax  
		call        edx  

		test        al,al 
		je          ENDMARK

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx+0Ch] 
		push        eax  
		call        edx 

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx+8] 
		push        eax  
		call        edx 

ENDMARK:
		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx] 
		push        eax  
		call        edx  
	}

用內聯彙編的話就是這個感覺。可以看到虛函數其實就是每次偏移然後call，hge指針包含了虛函數表的起始地址，每次根據偏移調用不同的函數，然後還要傳入this指針，這一步跟C如出一轍，但是簡化了調用過程。hge是stdcall，所以堆棧也不用自己手動恢復了。

ecx,dword ptr [eax]

其實我並不理解這句的用意。看起來是將hge的地址給eax，而又將eax的地址給力ecx，其實是完全沒有理解dword ptr的含義，繼續慢慢看書吧

果然內聯什麼的還是有點太弱了的感覺，直接使用win32彙編吧，原本編譯出來7k的程序，一下子變成了2.5k

.386 
.model flat,stdcall 
option casemap:none 

hgeCreate proto :DWORD

include \masm32\include\windows.inc 
include \masm32\include\kernel32.inc 
includelib \masm32\lib\kernel32.lib 

includelib hge.lib 
includelib hgehelp.lib

.data
hge DWORD ?

.code
start:
		push        180h
		call        hgeCreate
		mov         ecx,dword ptr [eax]
		mov         edx,dword ptr [ecx+24h] 
		push        offset FrameFunc
		push        8    
		push        eax  
		mov         dword ptr [hge],eax 
		call        edx 

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax]
		mov         edx,dword ptr [ecx+20h] 
		push        1    
		push        1    
		push        eax  
		call        edx  

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx+4] 
		push        eax  
		call        edx  

		test        al,al 
		je          ENDMARK

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx+0Ch] 
		push        eax  
		call        edx 

		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx+8] 
		push        eax  
		call        edx 

ENDMARK:
		mov         eax,dword ptr [hge] 
		mov         ecx,dword ptr [eax] 
		mov         edx,dword ptr [ecx] 
		push        eax  
		call        edx  
invoke ExitProcess,0

FrameFunc proc
	xor         al,al 
	ret
FrameFunc endp

end start