?? r_drawa.asm
字號:
.386P
.model FLAT
;
; r_drawa.s
; x86 assembly-language edge clipping and emission code
;
include qasm.inc
include d_if.inc
if id386
; !!! if these are changed, they must be changed in r_draw.c too !!!
FULLY_CLIPPED_CACHED equ 080000000h
FRAMECOUNT_MASK equ 07FFFFFFFh
_DATA SEGMENT
Ld0 dd 0.0
Ld1 dd 0.0
Lstack dd 0
Lfp_near_clip dd NEAR_CLIP
Lceilv0 dd 0
Lv dd 0
Lu0 dd 0
Lv0 dd 0
Lzi0 dd 0
_DATA ENDS
_TEXT SEGMENT
;----------------------------------------------------------------------
; edge clipping code
;----------------------------------------------------------------------
pv0 equ 4+12
pv1 equ 8+12
clip equ 12+12
align 4
public _R_ClipEdge
_R_ClipEdge:
push esi ; preserve register variables
push edi
push ebx
mov ds:dword ptr[Lstack],esp ; for clearing the stack later
; float d0, d1, f;
; mvertex_t clipvert;
mov ebx,ds:dword ptr[clip+esp]
mov esi,ds:dword ptr[pv0+esp]
mov edx,ds:dword ptr[pv1+esp]
; if (clip)
; {
test ebx,ebx
jz Lemit
; do
; {
Lcliploop:
; d0 = DotProduct (pv0->position, clip->normal) - clip->dist;
; d1 = DotProduct (pv1->position, clip->normal) - clip->dist;
fld ds:dword ptr[mv_position+0+esi]
fmul ds:dword ptr[cp_normal+0+ebx]
fld ds:dword ptr[mv_position+4+esi]
fmul ds:dword ptr[cp_normal+4+ebx]
fld ds:dword ptr[mv_position+8+esi]
fmul ds:dword ptr[cp_normal+8+ebx]
fxch st(1)
faddp st(2),st(0) ; d0mul2 | d0add0
fld ds:dword ptr[mv_position+0+edx]
fmul ds:dword ptr[cp_normal+0+ebx]
fld ds:dword ptr[mv_position+4+edx]
fmul ds:dword ptr[cp_normal+4+ebx]
fld ds:dword ptr[mv_position+8+edx]
fmul ds:dword ptr[cp_normal+8+ebx]
fxch st(1)
faddp st(2),st(0) ; d1mul2 | d1add0 | d0mul2 | d0add0
fxch st(3) ; d0add0 | d1add0 | d0mul2 | d1mul2
faddp st(2),st(0) ; d1add0 | dot0 | d1mul2
faddp st(2),st(0) ; dot0 | dot1
fsub ds:dword ptr[cp_dist+ebx] ; d0 | dot1
fxch st(1) ; dot1 | d0
fsub ds:dword ptr[cp_dist+ebx] ; d1 | d0
fxch st(1)
fstp ds:dword ptr[Ld0]
fstp ds:dword ptr[Ld1]
; if (d0 >= 0)
; {
mov eax,ds:dword ptr[Ld0]
mov ecx,ds:dword ptr[Ld1]
or ecx,eax
js Lp2
; both points are unclipped
Lcontinue:
;
; R_ClipEdge (&clipvert, pv1, clip->next);
; return;
; }
; } while ((clip = clip->next) != NULL);
mov ebx,ds:dword ptr[cp_next+ebx]
test ebx,ebx
jnz Lcliploop
; }
;// add the edge
; R_EmitEdge (pv0, pv1);
Lemit:
;
; set integer rounding to ceil mode, set to single precision
;
; FIXME: do away with by manually extracting integers from floats?
; FIXME: set less often
fldcw ds:word ptr[_fpu_ceil_cw]
; edge_t *edge, *pcheck;
; int u_check;
; float u, u_step;
; vec3_t local, transformed;
; float *world;
; int v, v2, ceilv0;
; float scale, lzi0, u0, v0;
; int side;
; if (r_lastvertvalid)
; {
cmp ds:dword ptr[_r_lastvertvalid],0
jz LCalcFirst
; u0 = r_u1;
; v0 = r_v1;
; lzi0 = r_lzi1;
; ceilv0 = r_ceilv1;
mov eax,ds:dword ptr[_r_lzi1]
mov ecx,ds:dword ptr[_r_u1]
mov ds:dword ptr[Lzi0],eax
mov ds:dword ptr[Lu0],ecx
mov ecx,ds:dword ptr[_r_v1]
mov eax,ds:dword ptr[_r_ceilv1]
mov ds:dword ptr[Lv0],ecx
mov ds:dword ptr[Lceilv0],eax
jmp LCalcSecond
; }
LCalcFirst:
; else
; {
; world = &pv0->position[0];
call near ptr LTransformAndProject ; v0 | lzi0 | u0
fst ds:dword ptr[Lv0]
fxch st(2) ; u0 | lzi0 | v0
fstp ds:dword ptr[Lu0] ; lzi0 | v0
fstp ds:dword ptr[Lzi0] ; v0
; ceilv0 = (int)(v0 - 2000) + 2000; // ceil(v0);
fistp ds:dword ptr[Lceilv0]
; }
LCalcSecond:
; world = &pv1->position[0];
mov esi,edx
call near ptr LTransformAndProject ; v1 | lzi1 | u1
fld ds:dword ptr[Lu0] ; u0 | v1 | lzi1 | u1
fxch st(3) ; u1 | v1 | lzi1 | u0
fld ds:dword ptr[Lzi0] ; lzi0 | u1 | v1 | lzi1 | u0
fxch st(3) ; lzi1 | u1 | v1 | lzi0 | u0
fld ds:dword ptr[Lv0] ; v0 | lzi1 | u1 | v1 | lzi0 | u0
fxch st(3) ; v1 | lzi1 | u1 | v0 | lzi0 | u0
; r_ceilv1 = (int)(r_v1 - 2000) + 2000; // ceil(r_v1);
fist ds:dword ptr[_r_ceilv1]
fldcw ds:word ptr[_fpu_chop_cw] ; put back normal floating-point state
fst ds:dword ptr[_r_v1]
fxch st(4) ; lzi0 | lzi1 | u1 | v0 | v1 | u0
; if (r_lzi1 > lzi0)
; lzi0 = r_lzi1;
fcom st(1)
fnstsw ax
test ah,1
jz LP0
fstp st(0)
fld st(0)
LP0:
fxch st(1) ; lzi1 | lzi0 | u1 | v0 | v1 | u0
fstp ds:dword ptr[_r_lzi1] ; lzi0 | u1 | v0 | v1 | u0
fxch st(1)
fst ds:dword ptr[_r_u1]
fxch st(1)
; if (lzi0 > r_nearzi) // for mipmap finding
; r_nearzi = lzi0;
fcom ds:dword ptr[_r_nearzi]
fnstsw ax
test ah,045h
jnz LP1
fst ds:dword ptr[_r_nearzi]
LP1:
; // for right edges, all we want is the effect on 1/z
; if (r_nearzionly)
; return;
mov eax,ds:dword ptr[_r_nearzionly]
test eax,eax
jz LP2
LPop5AndDone:
mov eax,ds:dword ptr[_cacheoffset]
mov edx,ds:dword ptr[_r_framecount]
cmp eax,07FFFFFFFh
jz LDoPop
and edx,offset FRAMECOUNT_MASK
or edx,offset FULLY_CLIPPED_CACHED
mov ds:dword ptr[_cacheoffset],edx
LDoPop:
fstp st(0) ; u1 | v0 | v1 | u0
fstp st(0) ; v0 | v1 | u0
fstp st(0) ; v1 | u0
fstp st(0) ; u0
fstp st(0)
jmp Ldone
LP2:
; // create the edge
; if (ceilv0 == r_ceilv1)
; return; // horizontal edge
mov ebx,ds:dword ptr[Lceilv0]
mov edi,ds:dword ptr[_edge_p]
mov ecx,ds:dword ptr[_r_ceilv1]
mov edx,edi
mov esi,ds:dword ptr[_r_pedge]
add edx,offset et_size
cmp ebx,ecx
jz LPop5AndDone
mov eax,ds:dword ptr[_r_pedge]
mov ds:dword ptr[et_owner+edi],eax
; side = ceilv0 > r_ceilv1;
;
; edge->nearzi = lzi0;
fstp ds:dword ptr[et_nearzi+edi] ; u1 | v0 | v1 | u0
; if (side == 1)
; {
jc LSide0
LSide1:
; // leading edge (go from p2 to p1)
; u_step = ((u0 - r_u1) / (v0 - r_v1));
fsubp st(3),st(0) ; v0 | v1 | u0-u1
fsub st(0),st(1) ; v0-v1 | v1 | u0-u1
fdivp st(2),st(0) ; v1 | ustep
; r_emitted = 1;
mov ds:dword ptr[_r_emitted],1
; edge = edge_p++;
mov ds:dword ptr[_edge_p],edx
; pretouch next edge
mov eax,ds:dword ptr[edx]
; v2 = ceilv0 - 1;
; v = r_ceilv1;
mov eax,ecx
lea ecx,ds:dword ptr[-1+ebx]
mov ebx,eax
; edge->surfs[0] = 0;
; edge->surfs[1] = surface_p - surfaces;
mov eax,ds:dword ptr[_surface_p]
mov esi,ds:dword ptr[_surfaces]
sub edx,edx
sub eax,esi
shr eax,offset SURF_T_SHIFT
mov ds:dword ptr[et_surfs+edi],edx
mov ds:dword ptr[et_surfs+2+edi],eax
sub esi,esi
; u = r_u1 + ((float)v - r_v1) * u_step;
mov ds:dword ptr[Lv],ebx
fild ds:dword ptr[Lv] ; v | v1 | ustep
fsubrp st(1),st(0) ; v-v1 | ustep
fmul st(0),st(1) ; (v-v1)*ustep | ustep
fadd ds:dword ptr[_r_u1] ; u | ustep
jmp LSideDone
; }
LSide0:
; else
; {
; // trailing edge (go from p1 to p2)
; u_step = ((r_u1 - u0) / (r_v1 - v0));
fsub st(0),st(3) ; u1-u0 | v0 | v1 | u0
fxch st(2) ; v1 | v0 | u1-u0 | u0
fsub st(0),st(1) ; v1-v0 | v0 | u1-u0 | u0
fdivp st(2),st(0) ; v0 | ustep | u0
; r_emitted = 1;
mov ds:dword ptr[_r_emitted],1
; edge = edge_p++;
mov ds:dword ptr[_edge_p],edx
; pretouch next edge
mov eax,ds:dword ptr[edx]
; v = ceilv0;
; v2 = r_ceilv1 - 1;
dec ecx
; edge->surfs[0] = surface_p - surfaces;
; edge->surfs[1] = 0;
mov eax,ds:dword ptr[_surface_p]
mov esi,ds:dword ptr[_surfaces]
sub edx,edx
sub eax,esi
shr eax,offset SURF_T_SHIFT
mov ds:dword ptr[et_surfs+2+edi],edx
mov ds:dword ptr[et_surfs+edi],eax
mov esi,1
; u = u0 + ((float)v - v0) * u_step;
mov ds:dword ptr[Lv],ebx
fild ds:dword ptr[Lv] ; v | v0 | ustep | u0
fsubrp st(1),st(0) ; v-v0 | ustep | u0
fmul st(0),st(1) ; (v-v0)*ustep | ustep | u0
faddp st(2),st(0) ; ustep | u
fxch st(1) ; u | ustep
; }
LSideDone:
; edge->u_step = u_step*0x100000;
; edge->u = u*0x100000 + 0xFFFFF;
fmul ds:dword ptr[fp_1m] ; u*0x100000 | ustep
fxch st(1) ; ustep | u*0x100000
fmul ds:dword ptr[fp_1m] ; ustep*0x100000 | u*0x100000
fxch st(1) ; u*0x100000 | ustep*0x100000
fadd ds:dword ptr[fp_1m_minus_1] ; u*0x100000 + 0xFFFFF | ustep*0x100000
fxch st(1) ; ustep*0x100000 | u*0x100000 + 0xFFFFF
fistp ds:dword ptr[et_u_step+edi] ; u*0x100000 + 0xFFFFF
fistp ds:dword ptr[et_u+edi]
; // we need to do this to avoid stepping off the edges if a very nearly
; // horizontal edge is less than epsilon above a scan, and numeric error
; // causes it to incorrectly extend to the scan, and the extension of the
; // line goes off the edge of the screen
; // FIXME: is this actually needed?
; if (edge->u < r_refdef.vrect_x_adj_shift20)
; edge->u = r_refdef.vrect_x_adj_shift20;
; if (edge->u > r_refdef.vrectright_adj_shift20)
; edge->u = r_refdef.vrectright_adj_shift20;
mov eax,ds:dword ptr[et_u+edi]
mov edx,ds:dword ptr[_r_refdef+rd_vrect_x_adj_shift20]
cmp eax,edx
jl LP4
mov edx,ds:dword ptr[_r_refdef+rd_vrectright_adj_shift20]
cmp eax,edx
jng LP5
LP4:
mov ds:dword ptr[et_u+edi],edx
mov eax,edx
LP5:
; // sort the edge in normally
; u_check = edge->u;
;
; if (edge->surfs[0])
; u_check++; // sort trailers after leaders
add eax,esi
; if (!newedges[v] || newedges[v]->u >= u_check)
; {
mov esi,ds:dword ptr[_newedges+ebx*4]
test esi,esi
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