masm 像素碰撞检测

256 * 240 的 directx surface

_spriteDrawAndTest proc C _pBuffer, _pSprite, _xPos, _yPos, _pStruct, _AColor 
					;   esp + 4 +32   esp + 8 + 32 esp + 12 + 32
		option prologue:none, epilogue:none
		;.FPO    ( 0, 6, 0, 0, 0, 0 ) 
	
			pBuffer  equ [esp+36]
			pSprite  equ [esp+40]
			xPos     equ [esp+44]
			yPos     equ [esp+48]
			pStruct  equ [esp+52]
			AColor   equ [esp+56]
			
			movd xmm7, esp
			pushad  			 ; - N save old frame 

			mov ebx, yPos		 ; - U ebx <- yPos
			mov edi, pBuffer	 ; - V edi <- pBuffer
			
			shl ebx, 10		     ; - U * pitch 1024	
			mov eax, xPos		 ; - V eax <- xPos 
			
			mov esi, pSprite     ; - U esi <- source pointer
			lea edi, [edi+eax*4] ; - V add 
			
			mov ecx, pStruct  	 ; - U struct ;
			add edi, ebx 		 ; - V save old frame 
	
			mov ebp, [ecx+4]     ; - U rect.top
			mov eax, [ecx]       ; - V rect.left 
			
			mov ebx, AColor      ; - U BG color 
			mov edx, ebp         ; - V save old frame 
			
			mov esp, [ecx+16]    ; - U pitch 
			lea esi, [esi+eax*4] ; - V add esi ++ =;das
			
			imul edx, esp 		 ; - N 
	
			lea esi, [esi+edx*4] ; - U esi comp
			
			sub eax, [ecx+8]     ; over x 
			sub ebp, [ecx+12]    ; over y 

			;  esi <- tex    pointer 
			;  edi <- des    pointer 
			;  eax <- rv x           
			;  ebp <- rv y           
			;  ebx <- color          
			;  esp <- rv pitch       
			
			align 16
			
			sub edi, 4 			   ; - U ready to copy ... - 4 			   
			mov ecx, eax		   ; - V save old frame ... 
			
			sub esp, 1024		   ; - U rv pitch 
			align 16			   ; - V align is may be a jmp opd ... :)
			
	mn_main_loop:
	
			mov edx, [edi+esi]     ; - U load source pixel
			add edi, 4			   ; - V add inc to addring des pixel ...
							   
			cmp edx, ebx       	   ; - U is BG color ? 
			jne next_test          ; - V Y ? into mnc_nesc : next_test
			
		mnc_nesc: 				   ; BG color 
		
			inc eax                ; - U x pos addring over ? 
			jne mn_main_loop 	   ; - V Y ? into starting next line 

			add esi, esp  	       ; - U add pitch 
			mov eax, ecx  		   ; - V recover x cnt

			inc ebp			       ; - U y pos addring over ?
			jne mn_main_loop	   ; - V Y ? continue : child proc ret ... 
			
			movd esp, xmm7
			popad 
			xor eax, eax           ; no clash appear
			ret 
			
			align 16
			
next_test:; not BG color .. 	
		
			mov ecx, [edi]     ; - U load des buffer pixel 
			mov [edi], edx     ; - V write buffer ... 
			
			cmp ecx, ebx 	   ; - U test clash
			je  mnc_nesc       ; - V N clash appear ? continue mnc_nesc ... 
			
			inc eax            ; - U else into no test clash's main_loop (clash has happend ...) 
			jne xmn_main_loop  ; - V 
			
			add esi, esp  	   ; - U  
			mov eax, ecx 
			
			inc ebp			   ; - U
			je emd_end
			
			align 16
			
		xmn_main_loop:
		
			mov edx, [esi+edi]     ; - U load source pixel
			add edi, 4		   	   ; - V spare 
							   
			cmp edx, ebx       	   ; - U is BG color ? 
			jne no_BG      		   ; - V 
			
			inc eax 
			jne xmn_main_loop 
			
			add esi, esp  	   ; - U
			mov eax, ecx 
			
			inc ebp
			jne xmn_main_loop
			
			xor eax, eax 
			jmp emd_end
			
			align 16 
	no_BG:
	
			mov [edi], edx
			lea ecx, [ecx]
			
			inc eax
			jne xmn_main_loop 
			
			add esi, esp  	   ; - U
			mov eax, ecx 
			
			inc ebp			   ; - V 			
			jne xmn_main_loop
			
     emd_end:
	 
			movd esp, xmm7
			popad 
			mov eax, 1         ; appear clash ...
			ret 
			
_spriteDrawAndTest endp