;-----------------------------------------------------------------------------
;
; This file contains x86 assembly edge walkers.
;
; Copyright (C) Microsoft Corporation, 1997.
;
; WARNING WARNING WARNING
; This assembly file generated from mas file.
; EDIT THE MAS FILE.
; I warned you.
; WARNING WARNING WARNING
;
;-----------------------------------------------------------------------------

include(`m4hdr.mh')dnl
include(`attrsx86.mh')dnl
.386p
.MODEL FLAT

INCLUDE offs_acp.inc
INCLUDE profile.inc

ALLOC_SPANS EQU ?AllocSpans@PrimProcessor@@QAEJPAIPAPAUtagD3DI_RASTSPAN@@@Z
FREE_SPANS EQU ?FreeSpans@PrimProcessor@@QAEXI@Z

EXTERN ALLOC_SPANS:NEAR
EXTERN FREE_SPANS:NEAR
                
.CODE
dnl
dnl d_WalkTrapSpans
dnl
dnl Generates a complete monolithic trapezoid edge walker.
dnl
dnl $1 is one of Z_Diff, Z_Diff_Spec, Z_Diff_Tex1, Z_Diff_Spec_Tex1,
dnl              Z_Tex1_Tex2, Z_DIdx, Z_DIdx_Tex1, Z_Tex1.
dnl $2 is one of Float Fixed.
dnl
define(`d_WalkTrapSpans', `
ifelse($2, `Fixed',
`IFDEF STEP_FIXED
')dnl
@WalkTrap$2Spans_$1_NoClip@16 PROC SYSCALL PUBLIC USES ebx esi edi,
        pStpCtx:DWORD, bAdvanceLast:DWORD

        LOCAL uSpansAvail:DWORD, cPix:DWORD
        LOCAL pSpan:DWORD, pXOther:DWORD
        LOCAL pXLeft:DWORD, pXRight:DWORD
ifelse(eval((d_index(`$1', `Diff') >= 0 || d_index(`$1', `Spec') >= 0) &&
            d_index(`$2', `Float') == 0), `1',
`        LOCAL iVal:DWORD
')dnl	

        PROF_ENTRY
        
        ; Initialize values:
        ; ebx will always contain the SETUPCTX.
        ; edi will always contain the number of available spans.
        ;
        ; esi will always contain the number of spans to go processed
        ; with bAdvance spans so that bAdvanceLast doesnt need to
        ; be checked.  The span count is doubled and !bAdvanceLast
        ; is subtracted from it so esi = uSpans * 2 - !bAdvanceLast
        ; (bAdvanceLast is assumed to be one or zero).
        ; Both exit checks decrement esi so if bAdvanceLast is FALSE
        ; the first exit check will hit zero since one was subtracted.
        ; Otherwise the second one will hit zero.
        
        mov ebx, pStpCtx
        
        mov esi, ecx
        shl esi, 1
        mov eax, bAdvanceLast
        
        mov ecx, [ebx+SCTX_uFlags]
        
        xor edi, edi
        xor eax, 1
        sub esi, eax

        test ecx, TRIF_X_DEC
        
        mov pXOther, edx
        
        ; Clear PWL flags.
        mov [ebx+SCTX_uPwlFlags], edi
        
        jnz L_XDec

        ; X increments.
        lea eax, [ebx+SCTX_X20]

        jmp L_StoreEdges

L_XDec:
        mov eax, edx
        lea edx, [ebx+SCTX_X20]

L_StoreEdges:
        mov pXLeft, eax
        mov pXRight, edx
        jmp L_SpanLoopEdges
        
L_SpanLoop:
        mov eax, pXLeft
        mov edx, pXRight

L_SpanLoopEdges:
        ; If the right edge is less than or equal to the left edge
        ; there are no pixels to draw.
        mov eax, [eax+ICV_iV]
        mov edx, [edx+ICV_iV]
        sub edx, eax
        jle L_NoPixels

        ; Check for available spans.
        test edi, edi
	
        mov cPix, edx
        
        jz L_NoSpansAvail

        ; Increment span pointer.
        mov edx, pSpan
        add edx, SIZEOF_RASTSPAN
        mov pSpan, edx
        
        jmp L_ConsumeSpan

L_NoSpansAvail:
        ; Try to alloc the remaining number of spans.
        mov ecx, esi
        inc ecx

        lea eax, pSpan
        
        shr ecx, 1
        mov uSpansAvail, ecx
        push eax
        lea edx, uSpansAvail
        push edx
        mov ecx, [ebx+SCTX_PrimProcessor]
        call ALLOC_SPANS
        test eax, eax
        jnz L_Exit

        ; Reload count of available spans and load span pointer into edx.
        mov edi, uSpansAvail
        mov edx, pSpan

L_ConsumeSpan:
        ; Decrement count of available spans and increment
        ; RASTPRIM span count.
        
        mov ecx, [ebx+SCTX_pPrim]
        dec edi
        mov eax, [ecx+RASTPRIM_uSpans]
        ; Assumes uSpans will never overflow 16 bits.
        inc eax
        mov [ecx+RASTPRIM_uSpans], eax
        
        ; Set uPix for span.  Relies on being able to set 32 bits
        ; even though uPix is a UINT16.
        mov eax, cPix
        mov [edx+RASTSPAN_uPix], eax

        ; Set uX and uY for span.
        ; Relies on uX and uY both being UINT16 in that order and
        ; that both require no masking.
        mov eax, [ebx+SCTX_X20+ICV_iV]
        mov ecx, [ebx+SCTX_iY]
        shl ecx, 16
        or eax, ecx
        mov [edx+RASTSPAN_uX], eax

        lea ecx, [ebx+SCTX_Attr]
        
        ; Fill RASTSPAN attributes.  edx is already set to the span.
d_FillSpan$2AttrsBody(`$1')dnl
        
L_NoPixels:
        ; Decrement the span count and check for exit.
        dec esi
        jz L_Success

        ;
        ; Advance long edge and all attributes.
        ;

        ; Increment iY and add X20 fraction.
        mov eax, [ebx+SCTX_iY]
        mov ecx, [ebx+SCTX_X20+ICV_iFrac]
        
        inc eax
        
        add ecx, [ebx+SCTX_X20+ICV_iDFrac]
        
        mov [ebx+SCTX_iY], eax
        
        js L_X20Carry

        ; No-carry step.  Put DAttrNC in edx.
        mov [ebx+SCTX_X20+ICV_iFrac], ecx
        mov eax, [ebx+SCTX_X20+ICV_iV]
        lea edx, [ebx+SCTX_DAttrNC]
        mov ecx, [ebx+SCTX_X20+ICV_iNC]

        jmp L_AddAttrs

L_X20Carry:
        ; Carry step.  Put DAttrCY in edx.
        and ecx, 07fffffffh
        mov eax, [ebx+SCTX_X20+ICV_iV]
        lea edx, [ebx+SCTX_DAttrCY]
        mov [ebx+SCTX_X20+ICV_iFrac], ecx
        mov ecx, [ebx+SCTX_X20+ICV_iCY]

L_AddAttrs:
        ; Store results and add attributes.  pDelta is already in edx.
        add eax, ecx
        lea ecx, [ebx+SCTX_Attr]
        mov [ebx+SCTX_X20+ICV_iV], eax
d_Add$2AttrsBody(`$1')dnl

        ; Long edge updating is done so check for exit again.
        dec esi
        jz L_Success

        ; Update short edge.
        mov edx, pXOther
        mov eax, [edx+ICV_iFrac]
        mov ecx, [edx+ICV_iV]
        add eax, [edx+ICV_iDFrac]
        js L_XOtherCarry

        ; No-carry step.
        add ecx, [edx+ICV_iNC]
        mov [edx+ICV_iFrac], eax
        mov [edx+ICV_iV], ecx
        jmp L_SpanLoop

L_XOtherCarry:
        ; Carry step.
        and eax, 07fffffffh
        add ecx, [edx+ICV_iCY]
        mov [edx+ICV_iFrac], eax
        mov [edx+ICV_iV], ecx
        jmp L_SpanLoop

L_Success:
        ; Set D3D_OK
        xor eax, eax
        
L_Exit:
        test edi, edi
        
        ; Temporarily keep return code in esi.
        mov esi, eax
        
        jz L_NoUnusedSpans

        mov ecx, [ebx+SCTX_PrimProcessor]
        push edi
        call FREE_SPANS

L_NoUnusedSpans:
        mov eax, esi
        ret 8
@WalkTrap$2Spans_$1_NoClip@16 ENDP
ifelse($2, `Fixed',
`ENDIF
')dnl
')dnl
dnl
d_RepStr(`d_RepStr(`d_WalkTrapSpans(AA, BB)',
         `AA', `Z_Diff', `Z_Diff_Spec', `Z_Diff_Tex1', `Z_Diff_Spec_Tex1',
               `Z_Tex1_Tex2', `Z_DIdx', `Z_DIdx_Tex1', `Z_Tex1')',
         `BB', `Float', `Fixed')dnl
                
END