quake2/ref_soft/r_spr8.asm
2001-12-22 00:00:00 +00:00

884 lines
22 KiB
NASM

.386P
.model FLAT
;
; d_spr8.s
; x86 assembly-language horizontal 8-bpp transparent span-drawing code.
;
include qasm.inc
include d_if.inc
if id386
;----------------------------------------------------------------------
; 8-bpp horizontal span drawing code for polygons, with transparency.
;----------------------------------------------------------------------
_TEXT SEGMENT
; out-of-line, rarely-needed clamping code
LClampHigh0:
mov esi,ds:dword ptr[_bbextents]
jmp LClampReentry0
LClampHighOrLow0:
jg LClampHigh0
xor esi,esi
jmp LClampReentry0
LClampHigh1:
mov edx,ds:dword ptr[_bbextentt]
jmp LClampReentry1
LClampHighOrLow1:
jg LClampHigh1
xor edx,edx
jmp LClampReentry1
LClampLow2:
mov ebp,2048
jmp LClampReentry2
LClampHigh2:
mov ebp,ds:dword ptr[_bbextents]
jmp LClampReentry2
LClampLow3:
mov ecx,2048
jmp LClampReentry3
LClampHigh3:
mov ecx,ds:dword ptr[_bbextentt]
jmp LClampReentry3
LClampLow4:
mov eax,2048
jmp LClampReentry4
LClampHigh4:
mov eax,ds:dword ptr[_bbextents]
jmp LClampReentry4
LClampLow5:
mov ebx,2048
jmp LClampReentry5
LClampHigh5:
mov ebx,ds:dword ptr[_bbextentt]
jmp LClampReentry5
pspans equ 4+16
align 4
public _D_SpriteDrawSpansXXX
_D_SpriteDrawSpansXXX:
push ebp ; preserve caller's stack frame
push edi
push esi ; preserve register variables
push ebx
;
; set up scaled-by-8 steps, for 8-long segments; also set up cacheblock
; and span list pointers, and 1/z step in 0.32 fixed-point
;
; FIXME: any overlap from rearranging?
fld ds:dword ptr[_d_sdivzstepu]
fmul ds:dword ptr[fp_8]
mov edx,ds:dword ptr[_cacheblock]
fld ds:dword ptr[_d_tdivzstepu]
fmul ds:dword ptr[fp_8]
mov ebx,ds:dword ptr[pspans+esp] ; point to the first span descriptor
fld ds:dword ptr[_d_zistepu]
fmul ds:dword ptr[fp_8]
mov ds:dword ptr[pbase],edx ; pbase = cacheblock
fld ds:dword ptr[_d_zistepu]
fmul ds:dword ptr[fp_64kx64k]
fxch st(3)
fstp ds:dword ptr[sdivz8stepu]
fstp ds:dword ptr[zi8stepu]
fstp ds:dword ptr[tdivz8stepu]
fistp ds:dword ptr[izistep]
mov eax,ds:dword ptr[izistep]
ror eax,16 ; put upper 16 bits in low word
mov ecx,ds:dword ptr[sspan_t_count+ebx]
mov ds:dword ptr[izistep],eax
cmp ecx,0
jle LNextSpan
LSpanLoop:
;
; set up the initial s/z, t/z, and 1/z on the FP stack, and generate the
; initial s and t values
;
; FIXME: pipeline FILD?
fild ds:dword ptr[sspan_t_v+ebx]
fild ds:dword ptr[sspan_t_u+ebx]
fld st(1) ; dv | du | dv
fmul ds:dword ptr[_d_sdivzstepv] ; dv*d_sdivzstepv | du | dv
fld st(1) ; du | dv*d_sdivzstepv | du | dv
fmul ds:dword ptr[_d_sdivzstepu] ; du*d_sdivzstepu | dv*d_sdivzstepv | du | dv
fld st(2) ; du | du*d_sdivzstepu | dv*d_sdivzstepv | du | dv
fmul ds:dword ptr[_d_tdivzstepu] ; du*d_tdivzstepu | du*d_sdivzstepu |
; dv*d_sdivzstepv | du | dv
fxch st(1) ; du*d_sdivzstepu | du*d_tdivzstepu |
; dv*d_sdivzstepv | du | dv
faddp st(2),st(0) ; du*d_tdivzstepu |
; du*d_sdivzstepu + dv*d_sdivzstepv | du | dv
fxch st(1) ; du*d_sdivzstepu + dv*d_sdivzstepv |
; du*d_tdivzstepu | du | dv
fld st(3) ; dv | du*d_sdivzstepu + dv*d_sdivzstepv |
; du*d_tdivzstepu | du | dv
fmul ds:dword ptr[_d_tdivzstepv] ; dv*d_tdivzstepv |
; du*d_sdivzstepu + dv*d_sdivzstepv |
; du*d_tdivzstepu | du | dv
fxch st(1) ; du*d_sdivzstepu + dv*d_sdivzstepv |
; dv*d_tdivzstepv | du*d_tdivzstepu | du | dv
fadd ds:dword ptr[_d_sdivzorigin] ; sdivz = d_sdivzorigin + dv*d_sdivzstepv +
; du*d_sdivzstepu; stays in %st(2) at end
fxch st(4) ; dv | dv*d_tdivzstepv | du*d_tdivzstepu | du |
; s/z
fmul ds:dword ptr[_d_zistepv] ; dv*d_zistepv | dv*d_tdivzstepv |
; du*d_tdivzstepu | du | s/z
fxch st(1) ; dv*d_tdivzstepv | dv*d_zistepv |
; du*d_tdivzstepu | du | s/z
faddp st(2),st(0) ; dv*d_zistepv |
; dv*d_tdivzstepv + du*d_tdivzstepu | du | s/z
fxch st(2) ; du | dv*d_tdivzstepv + du*d_tdivzstepu |
; dv*d_zistepv | s/z
fmul ds:dword ptr[_d_zistepu] ; du*d_zistepu |
; dv*d_tdivzstepv + du*d_tdivzstepu |
; dv*d_zistepv | s/z
fxch st(1) ; dv*d_tdivzstepv + du*d_tdivzstepu |
; du*d_zistepu | dv*d_zistepv | s/z
fadd ds:dword ptr[_d_tdivzorigin] ; tdivz = d_tdivzorigin + dv*d_tdivzstepv +
; du*d_tdivzstepu; stays in %st(1) at end
fxch st(2) ; dv*d_zistepv | du*d_zistepu | t/z | s/z
faddp st(1),st(0) ; dv*d_zistepv + du*d_zistepu | t/z | s/z
fld ds:dword ptr[fp_64k] ; fp_64k | dv*d_zistepv + du*d_zistepu | t/z | s/z
fxch st(1) ; dv*d_zistepv + du*d_zistepu | fp_64k | t/z | s/z
fadd ds:dword ptr[_d_ziorigin] ; zi = d_ziorigin + dv*d_zistepv +
; du*d_zistepu; stays in %st(0) at end
; 1/z | fp_64k | t/z | s/z
fld st(0) ; FIXME: get rid of stall on FMUL?
fmul ds:dword ptr[fp_64kx64k]
fxch st(1)
;
; calculate and clamp s & t
;
fdiv st(2),st(0) ; 1/z | z*64k | t/z | s/z
fxch st(1)
fistp ds:dword ptr[izi] ; 0.32 fixed-point 1/z
mov ebp,ds:dword ptr[izi]
;
; set pz to point to the first z-buffer pixel in the span
;
ror ebp,16 ; put upper 16 bits in low word
mov eax,ds:dword ptr[sspan_t_v+ebx]
mov ds:dword ptr[izi],ebp
mov ebp,ds:dword ptr[sspan_t_u+ebx]
imul ds:dword ptr[_d_zrowbytes]
shl ebp,1 ; a word per pixel
add eax,ds:dword ptr[_d_pzbuffer]
add eax,ebp
mov ds:dword ptr[pz],eax
;
; point %edi to the first pixel in the span
;
mov ebp,ds:dword ptr[_d_viewbuffer]
mov eax,ds:dword ptr[sspan_t_v+ebx]
push ebx ; preserve spans pointer
mov edx,ds:dword ptr[_tadjust]
mov esi,ds:dword ptr[_sadjust]
mov edi,ds:dword ptr[_d_scantable+eax*4] ; v * screenwidth
add edi,ebp
mov ebp,ds:dword ptr[sspan_t_u+ebx]
add edi,ebp ; pdest = &pdestspan[scans->u];
;
; now start the FDIV for the end of the span
;
cmp ecx,8
ja LSetupNotLast1
dec ecx
jz LCleanup1 ; if only one pixel, no need to start an FDIV
mov ds:dword ptr[spancountminus1],ecx
; finish up the s and t calcs
fxch st(1) ; z*64k | 1/z | t/z | s/z
fld st(0) ; z*64k | z*64k | 1/z | t/z | s/z
fmul st(0),st(4) ; s | z*64k | 1/z | t/z | s/z
fxch st(1) ; z*64k | s | 1/z | t/z | s/z
fmul st(0),st(3) ; t | s | 1/z | t/z | s/z
fxch st(1) ; s | t | 1/z | t/z | s/z
fistp ds:dword ptr[s] ; 1/z | t | t/z | s/z
fistp ds:dword ptr[t] ; 1/z | t/z | s/z
fild ds:dword ptr[spancountminus1]
fld ds:dword ptr[_d_tdivzstepu] ; _d_tdivzstepu | spancountminus1
fld ds:dword ptr[_d_zistepu] ; _d_zistepu | _d_tdivzstepu | spancountminus1
fmul st(0),st(2) ; _d_zistepu*scm1 | _d_tdivzstepu | scm1
fxch st(1) ; _d_tdivzstepu | _d_zistepu*scm1 | scm1
fmul st(0),st(2) ; _d_tdivzstepu*scm1 | _d_zistepu*scm1 | scm1
fxch st(2) ; scm1 | _d_zistepu*scm1 | _d_tdivzstepu*scm1
fmul ds:dword ptr[_d_sdivzstepu] ; _d_sdivzstepu*scm1 | _d_zistepu*scm1 |
; _d_tdivzstepu*scm1
fxch st(1) ; _d_zistepu*scm1 | _d_sdivzstepu*scm1 |
; _d_tdivzstepu*scm1
faddp st(3),st(0) ; _d_sdivzstepu*scm1 | _d_tdivzstepu*scm1
fxch st(1) ; _d_tdivzstepu*scm1 | _d_sdivzstepu*scm1
faddp st(3),st(0) ; _d_sdivzstepu*scm1
faddp st(3),st(0)
fld ds:dword ptr[fp_64k]
fdiv st(0),st(1) ; this is what we've gone to all this trouble to
; overlap
jmp LFDIVInFlight1
LCleanup1:
; finish up the s and t calcs
fxch st(1) ; z*64k | 1/z | t/z | s/z
fld st(0) ; z*64k | z*64k | 1/z | t/z | s/z
fmul st(0),st(4) ; s | z*64k | 1/z | t/z | s/z
fxch st(1) ; z*64k | s | 1/z | t/z | s/z
fmul st(0),st(3) ; t | s | 1/z | t/z | s/z
fxch st(1) ; s | t | 1/z | t/z | s/z
fistp ds:dword ptr[s] ; 1/z | t | t/z | s/z
fistp ds:dword ptr[t] ; 1/z | t/z | s/z
jmp LFDIVInFlight1
align 4
LSetupNotLast1:
; finish up the s and t calcs
fxch st(1) ; z*64k | 1/z | t/z | s/z
fld st(0) ; z*64k | z*64k | 1/z | t/z | s/z
fmul st(0),st(4) ; s | z*64k | 1/z | t/z | s/z
fxch st(1) ; z*64k | s | 1/z | t/z | s/z
fmul st(0),st(3) ; t | s | 1/z | t/z | s/z
fxch st(1) ; s | t | 1/z | t/z | s/z
fistp ds:dword ptr[s] ; 1/z | t | t/z | s/z
fistp ds:dword ptr[t] ; 1/z | t/z | s/z
fadd ds:dword ptr[zi8stepu]
fxch st(2)
fadd ds:dword ptr[sdivz8stepu]
fxch st(2)
fld ds:dword ptr[tdivz8stepu]
faddp st(2),st(0)
fld ds:dword ptr[fp_64k]
fdiv st(0),st(1) ; z = 1/1/z
; this is what we've gone to all this trouble to
; overlap
LFDIVInFlight1:
add esi,ds:dword ptr[s]
add edx,ds:dword ptr[t]
mov ebx,ds:dword ptr[_bbextents]
mov ebp,ds:dword ptr[_bbextentt]
cmp esi,ebx
ja LClampHighOrLow0
LClampReentry0:
mov ds:dword ptr[s],esi
mov ebx,ds:dword ptr[pbase]
shl esi,16
cmp edx,ebp
mov ds:dword ptr[sfracf],esi
ja LClampHighOrLow1
LClampReentry1:
mov ds:dword ptr[t],edx
mov esi,ds:dword ptr[s] ; sfrac = scans->sfrac;
shl edx,16
mov eax,ds:dword ptr[t] ; tfrac = scans->tfrac;
sar esi,16
mov ds:dword ptr[tfracf],edx
;
; calculate the texture starting address
;
sar eax,16
add esi,ebx
imul eax,ds:dword ptr[_cachewidth] ; (tfrac >> 16) * cachewidth
add esi,eax ; psource = pbase + (sfrac >> 16) +
; ((tfrac >> 16) * cachewidth);
;
; determine whether last span or not
;
cmp ecx,8
jna LLastSegment
;
; not the last segment; do full 8-wide segment
;
LNotLastSegment:
;
; advance s/z, t/z, and 1/z, and calculate s & t at end of span and steps to
; get there
;
; pick up after the FDIV that was left in flight previously
fld st(0) ; duplicate it
fmul st(0),st(4) ; s = s/z * z
fxch st(1)
fmul st(0),st(3) ; t = t/z * z
fxch st(1)
fistp ds:dword ptr[snext]
fistp ds:dword ptr[tnext]
mov eax,ds:dword ptr[snext]
mov edx,ds:dword ptr[tnext]
sub ecx,8 ; count off this segments' pixels
mov ebp,ds:dword ptr[_sadjust]
push ecx ; remember count of remaining pixels
mov ecx,ds:dword ptr[_tadjust]
add ebp,eax
add ecx,edx
mov eax,ds:dword ptr[_bbextents]
mov edx,ds:dword ptr[_bbextentt]
cmp ebp,2048
jl LClampLow2
cmp ebp,eax
ja LClampHigh2
LClampReentry2:
cmp ecx,2048
jl LClampLow3
cmp ecx,edx
ja LClampHigh3
LClampReentry3:
mov ds:dword ptr[snext],ebp
mov ds:dword ptr[tnext],ecx
sub ebp,ds:dword ptr[s]
sub ecx,ds:dword ptr[t]
;
; set up advancetable
;
mov eax,ecx
mov edx,ebp
sar edx,19 ; sstep >>= 16;
mov ebx,ds:dword ptr[_cachewidth]
sar eax,19 ; tstep >>= 16;
jz LIsZero
imul eax,ebx ; (tstep >> 16) * cachewidth;
LIsZero:
add eax,edx ; add in sstep
; (tstep >> 16) * cachewidth + (sstep >> 16);
mov edx,ds:dword ptr[tfracf]
mov ds:dword ptr[advancetable+4],eax ; advance base in t
add eax,ebx ; ((tstep >> 16) + 1) * cachewidth +
; (sstep >> 16);
shl ebp,13 ; left-justify sstep fractional part
mov ds:dword ptr[sstep],ebp
mov ebx,ds:dword ptr[sfracf]
shl ecx,13 ; left-justify tstep fractional part
mov ds:dword ptr[advancetable],eax ; advance extra in t
mov ds:dword ptr[tstep],ecx
mov ecx,ds:dword ptr[pz]
mov ebp,ds:dword ptr[izi]
cmp bp,ds:word ptr[ecx]
jl Lp1
mov al,ds:byte ptr[esi] ; get first source texel
cmp al,offset TRANSPARENT_COLOR
jz Lp1
mov ds:word ptr[ecx],bp
mov ds:byte ptr[edi],al ; store first dest pixel
Lp1:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep] ; advance tfrac fractional part by tstep frac
sbb eax,eax ; turn tstep carry into -1 (0 if none)
add ebx,ds:dword ptr[sstep] ; advance sfrac fractional part by sstep frac
adc esi,ds:dword ptr[advancetable+4+eax*4] ; point to next source texel
cmp bp,ds:word ptr[2+ecx]
jl Lp2
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp2
mov ds:word ptr[2+ecx],bp
mov ds:byte ptr[1+edi],al
Lp2:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
cmp bp,ds:word ptr[4+ecx]
jl Lp3
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp3
mov ds:word ptr[4+ecx],bp
mov ds:byte ptr[2+edi],al
Lp3:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
cmp bp,ds:word ptr[6+ecx]
jl Lp4
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp4
mov ds:word ptr[6+ecx],bp
mov ds:byte ptr[3+edi],al
Lp4:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
cmp bp,ds:word ptr[8+ecx]
jl Lp5
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp5
mov ds:word ptr[8+ecx],bp
mov ds:byte ptr[4+edi],al
Lp5:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
;
; start FDIV for end of next segment in flight, so it can overlap
;
pop eax
cmp eax,8 ; more than one segment after this?
ja LSetupNotLast2 ; yes
dec eax
jz LFDIVInFlight2 ; if only one pixel, no need to start an FDIV
mov ds:dword ptr[spancountminus1],eax
fild ds:dword ptr[spancountminus1]
fld ds:dword ptr[_d_zistepu] ; _d_zistepu | spancountminus1
fmul st(0),st(1) ; _d_zistepu*scm1 | scm1
fld ds:dword ptr[_d_tdivzstepu] ; _d_tdivzstepu | _d_zistepu*scm1 | scm1
fmul st(0),st(2) ; _d_tdivzstepu*scm1 | _d_zistepu*scm1 | scm1
fxch st(1) ; _d_zistepu*scm1 | _d_tdivzstepu*scm1 | scm1
faddp st(3),st(0) ; _d_tdivzstepu*scm1 | scm1
fxch st(1) ; scm1 | _d_tdivzstepu*scm1
fmul ds:dword ptr[_d_sdivzstepu] ; _d_sdivzstepu*scm1 | _d_tdivzstepu*scm1
fxch st(1) ; _d_tdivzstepu*scm1 | _d_sdivzstepu*scm1
faddp st(3),st(0) ; _d_sdivzstepu*scm1
fld ds:dword ptr[fp_64k] ; 64k | _d_sdivzstepu*scm1
fxch st(1) ; _d_sdivzstepu*scm1 | 64k
faddp st(4),st(0) ; 64k
fdiv st(0),st(1) ; this is what we've gone to all this trouble to
; overlap
jmp LFDIVInFlight2
align 4
LSetupNotLast2:
fadd ds:dword ptr[zi8stepu]
fxch st(2)
fadd ds:dword ptr[sdivz8stepu]
fxch st(2)
fld ds:dword ptr[tdivz8stepu]
faddp st(2),st(0)
fld ds:dword ptr[fp_64k]
fdiv st(0),st(1) ; z = 1/1/z
; this is what we've gone to all this trouble to
; overlap
LFDIVInFlight2:
push eax
cmp bp,ds:word ptr[10+ecx]
jl Lp6
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp6
mov ds:word ptr[10+ecx],bp
mov ds:byte ptr[5+edi],al
Lp6:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
cmp bp,ds:word ptr[12+ecx]
jl Lp7
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp7
mov ds:word ptr[12+ecx],bp
mov ds:byte ptr[6+edi],al
Lp7:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
cmp bp,ds:word ptr[14+ecx]
jl Lp8
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp8
mov ds:word ptr[14+ecx],bp
mov ds:byte ptr[7+edi],al
Lp8:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
add edi,8
add ecx,16
mov ds:dword ptr[tfracf],edx
mov edx,ds:dword ptr[snext]
mov ds:dword ptr[sfracf],ebx
mov ebx,ds:dword ptr[tnext]
mov ds:dword ptr[s],edx
mov ds:dword ptr[t],ebx
mov ds:dword ptr[pz],ecx
mov ds:dword ptr[izi],ebp
pop ecx ; retrieve count
;
; determine whether last span or not
;
cmp ecx,8 ; are there multiple segments remaining?
ja LNotLastSegment ; yes
;
; last segment of scan
;
LLastSegment:
;
; advance s/z, t/z, and 1/z, and calculate s & t at end of span and steps to
; get there. The number of pixels left is variable, and we want to land on the
; last pixel, not step one past it, so we can't run into arithmetic problems
;
test ecx,ecx
jz LNoSteps ; just draw the last pixel and we're done
; pick up after the FDIV that was left in flight previously
fld st(0) ; duplicate it
fmul st(0),st(4) ; s = s/z * z
fxch st(1)
fmul st(0),st(3) ; t = t/z * z
fxch st(1)
fistp ds:dword ptr[snext]
fistp ds:dword ptr[tnext]
mov ebx,ds:dword ptr[_tadjust]
mov eax,ds:dword ptr[_sadjust]
add eax,ds:dword ptr[snext]
add ebx,ds:dword ptr[tnext]
mov ebp,ds:dword ptr[_bbextents]
mov edx,ds:dword ptr[_bbextentt]
cmp eax,2048
jl LClampLow4
cmp eax,ebp
ja LClampHigh4
LClampReentry4:
mov ds:dword ptr[snext],eax
cmp ebx,2048
jl LClampLow5
cmp ebx,edx
ja LClampHigh5
LClampReentry5:
cmp ecx,1 ; don't bother
je LOnlyOneStep ; if two pixels in segment, there's only one step,
; of the segment length
sub eax,ds:dword ptr[s]
sub ebx,ds:dword ptr[t]
add eax,eax ; convert to 15.17 format so multiply by 1.31
add ebx,ebx ; reciprocal yields 16.48
imul ds:dword ptr[reciprocal_table-8+ecx*4] ; sstep = (snext - s) / (spancount-1)
mov ebp,edx
mov eax,ebx
imul ds:dword ptr[reciprocal_table-8+ecx*4] ; tstep = (tnext - t) / (spancount-1)
LSetEntryvec:
;
; set up advancetable
;
mov ebx,ds:dword ptr[spr8entryvec_table+ecx*4]
mov eax,edx
push ebx ; entry point into code for RET later
mov ecx,ebp
sar ecx,16 ; sstep >>= 16;
mov ebx,ds:dword ptr[_cachewidth]
sar edx,16 ; tstep >>= 16;
jz LIsZeroLast
imul edx,ebx ; (tstep >> 16) * cachewidth;
LIsZeroLast:
add edx,ecx ; add in sstep
; (tstep >> 16) * cachewidth + (sstep >> 16);
mov ecx,ds:dword ptr[tfracf]
mov ds:dword ptr[advancetable+4],edx ; advance base in t
add edx,ebx ; ((tstep >> 16) + 1) * cachewidth +
; (sstep >> 16);
shl ebp,16 ; left-justify sstep fractional part
mov ebx,ds:dword ptr[sfracf]
shl eax,16 ; left-justify tstep fractional part
mov ds:dword ptr[advancetable],edx ; advance extra in t
mov ds:dword ptr[tstep],eax
mov ds:dword ptr[sstep],ebp
mov edx,ecx
mov ecx,ds:dword ptr[pz]
mov ebp,ds:dword ptr[izi]
ret ; jump to the number-of-pixels handler
;----------------------------------------
LNoSteps:
mov ecx,ds:dword ptr[pz]
sub edi,7 ; adjust for hardwired offset
sub ecx,14
jmp LEndSpan
LOnlyOneStep:
sub eax,ds:dword ptr[s]
sub ebx,ds:dword ptr[t]
mov ebp,eax
mov edx,ebx
jmp LSetEntryvec
;----------------------------------------
public Spr8Entry2_8
Spr8Entry2_8:
sub edi,6 ; adjust for hardwired offsets
sub ecx,12
mov al,ds:byte ptr[esi]
jmp LLEntry2_8
;----------------------------------------
public Spr8Entry3_8
Spr8Entry3_8:
sub edi,5 ; adjust for hardwired offsets
sub ecx,10
jmp LLEntry3_8
;----------------------------------------
public Spr8Entry4_8
Spr8Entry4_8:
sub edi,4 ; adjust for hardwired offsets
sub ecx,8
jmp LLEntry4_8
;----------------------------------------
public Spr8Entry5_8
Spr8Entry5_8:
sub edi,3 ; adjust for hardwired offsets
sub ecx,6
jmp LLEntry5_8
;----------------------------------------
public Spr8Entry6_8
Spr8Entry6_8:
sub edi,2 ; adjust for hardwired offsets
sub ecx,4
jmp LLEntry6_8
;----------------------------------------
public Spr8Entry7_8
Spr8Entry7_8:
dec edi ; adjust for hardwired offsets
sub ecx,2
jmp LLEntry7_8
;----------------------------------------
public Spr8Entry8_8
Spr8Entry8_8:
cmp bp,ds:word ptr[ecx]
jl Lp9
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp9
mov ds:word ptr[ecx],bp
mov ds:byte ptr[edi],al
Lp9:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
LLEntry7_8:
cmp bp,ds:word ptr[2+ecx]
jl Lp10
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp10
mov ds:word ptr[2+ecx],bp
mov ds:byte ptr[1+edi],al
Lp10:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
LLEntry6_8:
cmp bp,ds:word ptr[4+ecx]
jl Lp11
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp11
mov ds:word ptr[4+ecx],bp
mov ds:byte ptr[2+edi],al
Lp11:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
LLEntry5_8:
cmp bp,ds:word ptr[6+ecx]
jl Lp12
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp12
mov ds:word ptr[6+ecx],bp
mov ds:byte ptr[3+edi],al
Lp12:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
LLEntry4_8:
cmp bp,ds:word ptr[8+ecx]
jl Lp13
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp13
mov ds:word ptr[8+ecx],bp
mov ds:byte ptr[4+edi],al
Lp13:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
LLEntry3_8:
cmp bp,ds:word ptr[10+ecx]
jl Lp14
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp14
mov ds:word ptr[10+ecx],bp
mov ds:byte ptr[5+edi],al
Lp14:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
LLEntry2_8:
cmp bp,ds:word ptr[12+ecx]
jl Lp15
mov al,ds:byte ptr[esi]
cmp al,offset TRANSPARENT_COLOR
jz Lp15
mov ds:word ptr[12+ecx],bp
mov ds:byte ptr[6+edi],al
Lp15:
add ebp,ds:dword ptr[izistep]
adc ebp,0
add edx,ds:dword ptr[tstep]
sbb eax,eax
add ebx,ds:dword ptr[sstep]
adc esi,ds:dword ptr[advancetable+4+eax*4]
LEndSpan:
cmp bp,ds:word ptr[14+ecx]
jl Lp16
mov al,ds:byte ptr[esi] ; load first texel in segment
cmp al,offset TRANSPARENT_COLOR
jz Lp16
mov ds:word ptr[14+ecx],bp
mov ds:byte ptr[7+edi],al
Lp16:
;
; clear s/z, t/z, 1/z from FP stack
;
fstp st(0)
fstp st(0)
fstp st(0)
pop ebx ; restore spans pointer
LNextSpan:
add ebx,offset sspan_t_size ; point to next span
mov ecx,ds:dword ptr[sspan_t_count+ebx]
cmp ecx,0 ; any more spans?
jg LSpanLoop ; yes
jz LNextSpan ; yes, but this one's empty
pop ebx ; restore register variables
pop esi
pop edi
pop ebp ; restore the caller's stack frame
ret
_TEXT ENDS
endif ; id386
END