brender-v1.1.2/ZB/T_PIZA.ASM

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2022-05-04 20:14:23 -05:00
;; Copyright (c) 1991,1993-1995 Argonaut Technologies Limited. All rights reserved.
;;
;; $Id: t_piza.asm 1.1 1995/08/31 16:52:47 sam Exp $
;; $Locker: $
;;
;; Trapezoid rendering for arbitary width texture mapping
;; Transparent Version.
;; See t_piza2.asm for non-transparent version
;;
.386p
.model c,flat
include zb.inc
WRAP equ 1
WRAPROW equ 1
TRANSP equ 1
.data
noffset dd ?
.code
; Macro to increment those parts of the per scan line
; increment that depend on whether there has been a carry
; from the fractional part of the current screen x coordinate
scan_inc macro carry,LIGHT,BPP
local lab2
if LIGHT
mov ebx,zb.pi.current
endif ; LIGHT
if LIGHT
mov ecx,zb.pi.d_&carry&
endif ; LIGHT
mov esi,zb.pz.current
mov edi,zb.pz.d_&carry&
add esi,edi
mov zb.pz.current,esi
add ebx,ecx
mov zb.pi.current,ebx
mov ebx,zb.awsl.u_current
mov ecx,zb.awsl.du_&carry&
mov ebp,zb.awsl.source_current
mov edi,zb.awsl.dsource_&carry&
add ebx,ecx ; zb.awsl.u_current += zb.awsl.dsource_&carry&
sbb ecx,ecx ; Save -carry
add ebp,edi ; zb.awsl.source_current += zb.awsl.dsource_&carry&
mov zb.awsl.u_current,ebx
if WRAP
mov ebx,dword ptr zb.awsl.u_int_current
add ebx,zb.awsl.du_int_&carry&
sub ebx,ecx ; zb.awsl.u_int_current += carry;
mov dword ptr zb.awsl.u_int_current,ebx
endif ; WRAP
ifidni <BPP>,<2>
shl ecx,1
elseifidni <BPP>,<3>
lea ecx,[ecx+ecx*2]
elseifidni <BPP>,<4>
shl ecx,2
endif ; <BPP>
sub ebp,ecx ; zb.awsl.source_current += carry*BPP
mov ebx,zb.awsl.v_current
mov ecx,zb.awsl.dv_&carry&
add ebx,ecx
mov zb.awsl.v_current,ebx
jnc lab2
mov edi,zb.awsl.texture_stride
add ebp,edi
lab2:
mov zb.awsl.source_current,ebp
endm
TriangleRenderZ2 macro fn,LIGHT,BPP,BUMP
fn proc uses eax ebx ecx edx esi edi ebp
outer:
mov eax,zb.awsl.edge
mov ebx,[eax].scan_edge.count
test ebx,ebx
jz exit
dec ebx ; zb.awsl.edge->count--
mov [eax].scan_edge.count,ebx
if BUMP
mov ecx,zb.bump_buffer
sub ecx,zb.texture_buffer
mov noffset,ecx
endif
mov edi,zb.awsl.start
mov ebx,zb.awsl._end
cmp edi,ebx
mov eax,zb.awsl.u_current
mov ebx,zb.awsl.v_current
mov al,byte ptr zb.awsl.u_int_current
mov ecx,zb.pz.current
mov zb.pz.currentpix,ecx
if LIGHT
mov ecx,zb.pi.current
mov zb.pi.currentpix,ecx
endif ; LIGHT
mov ah,byte ptr zb.awsl.u_int_current+1
mov esi,zb.awsl.source_current
mov ebp,zb.awsl.zstart
jge scan_back
; Forward scan
loopf:
mov ecx,zb.awsl._end
cmp edi,ecx
jge next
if TRANSP
ifidni <BPP>,<1>
mov dl,[esi]
test dl,dl
jz failf ; Skip if transparent
elseifidni <BPP>,<2>
mov dl,[esi]
mov dh,1[esi]
or dl,dh
jz failf
elseifidni <BPP>,<3>
mov dl,[esi]
mov dh,1[esi]
or dl,dh
mov dh,2[esi]
or dl,dh
jz failf
endif ; <BPP>
endif ; TRANSP
; 16 bit z test
mov bl,byte ptr zb.pz.currentpix+2
mov dl,[ebp]
mov bh,byte ptr zb.pz.currentpix+3
mov dh,1[ebp]
cmp dl,bl
sbb dh,bh
jb failf ; Skip if pixel failed z test
if LIGHT
xor ecx,ecx
mov [ebp],bl ; Store low byte of z
mov ch,byte ptr zb.pi.currentpix+2 ; Get lighting index
mov edx,zb.shade_table
mov cl,[esi] ; Get texel
mov 1[ebp],bh ; Store high byte of z
add edx,ecx
mov ecx,zb.pz.currentpix
add ebp,2 ; zptr += 2
mov bl,[edx] ; Light texel
mov edx,zb.pz.grad_x ; z += dz
mov [edi],bl ; Store texel
add ecx,edx
ifidni <BPP>,<1>
inc edi ; ptr++
else ; <BPP>
add edi,BPP
endif ; <BPP>
mov edx,zb.pi.currentpix
mov zb.pz.currentpix,ecx
mov ecx,zb.pi.grad_x ; i += di
add edx,ecx
mov zb.pi.currentpix,edx
jmp contf
failf:
add ebp,2 ; zptr += 2
ifidni <BPP>,<1>
inc edi ; ptr++
else ; <BPP>
add edi,BPP
endif ; <BPP>
mov ecx,zb.pz.currentpix
mov edx,zb.pz.grad_x ; z += dz
add ecx,edx
mov edx,zb.pi.currentpix
mov zb.pz.currentpix,ecx
mov ecx,zb.pi.grad_x ; i += di
add edx,ecx
mov zb.pi.currentpix,edx
elseif BUMP
; Bump mapping
mov [ebp],bl ; Store low byte of z
xor ecx,ecx
mov cl,[esi] ; Get texel
mov edx,noffset
mov dl,[esi+edx] ; Get normal
and edx,0ffh
add edx,zb.lighting_table ; Calculate light level from normal
mov ch,[edx]
mov edx,zb.shade_table
mov cl,[edx+ecx] ; Light texel
mov 1[ebp],bh ; Store high byte of z
mov [edi],cl
mov ecx,zb.pz.currentpix
add ebp,2 ; zptr += 2
mov edx,zb.pz.grad_x
add ecx,edx ; z += dz
ifidni <BPP>,<1>
inc edi ; ptr++
else ; <BPP>
add edi,BPP
endif ; <BPP>
mov zb.pz.currentpix,ecx
jmp contf
failf:
add ebp,2 ; zptr += 2
ifidni <BPP>,<1>
inc edi ; ptr++
else ; <BPP>
add edi,BPP
endif ; <BPP>
mov ecx,zb.pz.currentpix
mov edx,zb.pz.grad_x ; z += dz
add ecx,edx
mov zb.pz.currentpix,ecx
else ; LIGHT
; No lighting
mov [ebp],bl ; Store low byte of z
ifidni <BPP>,<1>
mov cl,[esi] ; Get texel
mov 1[ebp],bh ; Store high byte of z
mov [edi],cl
elseifidni <BPP>,<2>
mov cl,[esi]
mov 1[ebp],bh ; Store high byte of z
mov ch,1[esi]
mov [edi],cl
mov 1[edi],ch
elseifidni <BPP>,<3>
mov cl,[esi] ; Get texel
mov 1[ebp],bh ; Store high byte of z
mov [edi],cl
mov ch,1[esi]
mov 1[edi],ch ; Store green
mov cl,2[esi]
mov 2[edi],cl ; Store red
elseifidni <BPP>,<4>
mov ecx,[esi]
mov 1[ebp],bh
mov [edi],ecx
endif ; <BPP>
mov ecx,zb.pz.currentpix
add ebp,2 ; zptr += 2
mov edx,zb.pz.grad_x
add ecx,edx ; z += dz
ifidni <BPP>,<1>
inc edi ; ptr++
else ; <BPP>
add edi,BPP
endif ; <BPP>
mov zb.pz.currentpix,ecx
jmp contf
failf:
add ebp,2 ; zptr += 2
ifidni <BPP>,<1>
inc edi ; ptr++
else ; <BPP>
add edi,BPP
endif ; <BPP>
mov ecx,zb.pz.currentpix
mov edx,zb.pz.grad_x ; z += dz
add ecx,edx
mov zb.pz.currentpix,ecx
endif ; LIGHT
contf:
; Redo this with high and low halfwords of du swapped
mov ecx,zb.awsl.du
add eax,ecx ; u += du
mov ecx,zb.awsl.dsource
sbb edx,edx ; edx = -carry
add esi,ecx
mov ecx,zb.awsl.du_int
sub eax,edx ; zb.awsl.du += carry
ifidni <BPP>,<2>
shl edx,1
elseifidni <BPP>,<3>
lea edx,[edx+2*edx]
elseifidni <BPP>,<4>
shl edx,2
endif ; <BPP>
sub esi,edx ; esi += carry
add eax,ecx ; u_int += du_int
mov ecx,zb.awsl.dv
mov edx,zb.awsl.texture_stride;
add ebx,ecx
jnc nostridef
add esi,edx
nostridef:
test ah,ah
jl nowidthf
mov ecx,zb.awsl.texture_width
add eax,ecx
ifidni <BPP>,<1>
add esi,ecx
elseifidni <BPP>,<2>
lea esi,[esi+2*ecx]
elseifidni <BPP>,<3>
lea ecx,[ecx+2*ecx]
add esi,ecx
elseifidni <BPP>,<4>
lea esi,[esi+4*ecx]
endif ; <BPP>
nowidthf:
mov ecx,zb.awsl.texture_start
cmp esi,ecx ; Have we underrun?
jge nosizef
mov ecx,zb.awsl.texture_size
add esi,ecx
nosizef:
jmp loopf
scan_back:
; Backwards scan
loopb:
mov ecx,zb.awsl._end
cmp edi,ecx
jle next
mov ecx,zb.pz.currentpix
mov edx,zb.pz.grad_x ; z += dz
sub ecx,edx
if LIGHT
mov edx,zb.pi.currentpix
endif
mov zb.pz.currentpix,ecx
if LIGHT
mov ecx,zb.pi.grad_x ; i += di
sub edx,ecx
mov zb.pi.currentpix,edx
endif
; Redo this with high and low halfwords of du swapped
mov ecx,zb.awsl.du
add eax,ecx ; u += du
mov ecx,zb.awsl.dsource
sbb edx,edx ; edx = -carry
add esi,ecx
mov ecx,zb.awsl.du_int
sub eax,edx
add eax,ecx ; u_int += du_int
ifidni <BPP>,<1>
sub esi,edx
elseifidni <BPP>,<2>
shl edx,1
sub esi,edx
elseifidni <BPP>,<3>
lea edx,[edx+edx*2]
sub esi,edx
elseifidni <BPP>,<4>
shl edx,2
sub esi,edx
endif
mov ecx,zb.awsl.dv
add ebx,ecx
jnc nostrideb
mov ecx,zb.awsl.texture_stride
add esi,ecx
nostrideb:
test ah,ah
jl nowidthb
mov ecx,zb.awsl.texture_width
add eax,ecx
ifidni <BPP>,<1>
add esi,ecx
elseifidni <BPP>,<2>
lea esi,[esi+2*ecx]
elseifidni <BPP>,<3>
lea ecx,[ecx+2*ecx]
add esi,ecx
elseifidni <BPP>,<4>
lea esi,[esi+4*ecx]
endif ; <BPP>
nowidthb:
mov ecx,zb.awsl.texture_start
cmp esi,ecx
jge nosizeb
mov ecx,zb.awsl.texture_size
add esi,ecx
nosizeb:
sub ebp,2 ; zptr += 2
ifidni <BPP>,<1>
dec edi ; ptr += 1
else ; <BPP>
sub edi,BPP
endif ; <BPP>
if TRANSP
ifidni <BPP>,<1>
mov bl,[esi]
test bl,bl
jz loopb ; Skip if transparent
elseifidni <BPP>,<2>
mov bl,[esi]
mov bh,1[esi]
or bl,bh
jz failb
elseifidni <BPP>,<3>
mov bl,[esi]
mov bh,1[esi]
or bl,bh
mov bh,2[esi]
or bl,bh
jz failb
endif ; <BPP>
endif ; <TRANSP>
mov dl,byte ptr zb.pz.currentpix+2
mov bl,[ebp]
mov dh,byte ptr zb.pz.currentpix+3
mov bh,1[ebp]
sub bl,dl
sbb bh,dh
jb loopb ; Skip if pixel failed z test
mov [ebp],dl ; Store low byte of z
if LIGHT
xor ecx,ecx
endif ; <LIGHT>
mov 1[ebp],dh ; Store high byte of z
if LIGHT
mov ch,byte ptr zb.pi.currentpix+2
mov edx,zb.shade_table
endif ; <LIGHT>
ifidni <BPP>,<1>
mov cl,[esi] ; Get texel
if LIGHT
mov cl,[ecx+edx] ; Light texel
endif
if BUMP
and ecx,0ffh
mov edx,noffset
mov dl,[esi+edx]
and edx,0ffh
add edx,zb.lighting_table ; Calculate light level from normal
mov ch,[edx]
mov edx,zb.shade_table
mov cl,[edx+ecx] ; Light texel
endif
mov [edi],cl
elseifidni <BPP>,<2>
mov cl,[esi]
mov [edi],cl ; Store texel
mov cl,1[esi]
mov 1[edi],cl ; Store texel
elseifidni <BPP>,<3>
mov ecx,[esi]
mov [edi],cl ; Store texel
mov 1[edi],ch ; Store texel
ror ecx,16
mov 2[edi],cl ; Store texel
elseifidni <BPP>,<4>
mov ecx,[esi]
mov [edi],ecx ; Store texel
endif ; <BPP>
failb:
jmp loopb
next:
; Per scan line updates
assume eax:ptr scan_edge
mov eax,zb.awsl.edge
mov ebx,[eax].f
mov ecx,[eax].d_f
add ebx,ecx ; edge->f += edge->d_f
mov [eax].f,ebx
mov ecx,[eax].d_i
mov ebx,zb.awsl._end
ifidni <BPP>,<1>
adc ebx,ecx ; zb.awsl._end += edge->d_i+carry
elseifidni <BPP>,<2>
adc ecx,0
shl ecx,1
add ebx,ecx
elseifidni <BPP>,<3>
adc ecx,0
lea ecx,[ecx+2*ecx]
add ebx,ecx ; zb.awsl._end += 3*(edge->d_i+carry)
elseifidni <BPP>,<3>
adc ecx,0
shl ecx,2
add ebx,ecx
endif ; <BPP>
mov zb.awsl._end,ebx
mov ebx,zb.main.f
mov ecx,zb.main.d_f
add ebx,ecx
mov zb.main.f,ebx
mov ebx,zb.awsl.start
mov ecx,zb.main.d_i
mov esi,zb.awsl.zstart
jnc noscarry
; if (carry) ...
adc ecx,0
lea esi,[esi+2*ecx]
ifidni <BPP>,<1>
add ebx,ecx
elseifidni <BPP>,<2>
lea ebx,[ebx+2*ecx]
elseifidni <BPP>,<3>
lea ecx,[ecx+2*ecx]
add ebx,ecx
elseifidni <BPP>,<4>
lea ebx,[ebx+4*ecx]
endif
mov zb.awsl.start,ebx
mov zb.awsl.zstart,esi
scan_inc carry,LIGHT,BPP
jmp cont
; ... else ...
noscarry:
lea esi,[esi+2*ecx]
ifidni <BPP>,<1>
add ebx,ecx
elseifidni <BPP>,<2>
lea ebx,[ebx+2*ecx]
elseifidni <BPP>,<3>
lea ecx,[ecx+2*ecx]
add ebx,ecx
elseifidni <BPP>,<4>
lea ebx,[ebx+4*ecx]
endif
mov zb.awsl.start,ebx
mov zb.awsl.zstart,esi
scan_inc nocarry,LIGHT,BPP
; ... endif
cont:
mov ebx,dword ptr zb.awsl.u_int_current
test bh,bh ; Test sign of low halfword
jl lab1
mov ecx,zb.awsl.texture_width
add ebx,ecx
mov dword ptr zb.awsl.u_int_current,ebx
mov ebx,zb.awsl.source_current
ifidni <BPP>,<1>
add ebx,ecx
elseifidni <BPP>,<2>
lea ebx,[ebx+2*ecx]
elseifidni <BPP>,<3>
lea ecx,[ecx+2*ecx]
add ebx,ecx
elseifidni <BPP>,<4>
lea ebx,[ebx+4*ecx]
endif
mov zb.awsl.source_current,ebx
lab1:
mov ebx,zb.awsl.source_current
mov ecx,zb.awsl.texture_start
cmp ebx,ecx
jge outer
mov ecx,zb.awsl.texture_size
add ebx,ecx
mov zb.awsl.source_current,ebx
jmp outer
exit:
ret
fn endp
endm
;TriangleRenderZ2 TrapezoidRenderPIZ2TA,0,1,0
;TriangleRenderZ2 TrapezoidRenderPIZ2TAN,0,1,1
TriangleRenderZ2 TrapezoidRenderPIZ2TIA,1,1,0 ; Hawkeye
;TriangleRenderZ2 TrapezoidRenderPIZ2TA15,0,2,0
;TriangleRenderZ2 TrapezoidRenderPIZ2TA24,0,3,0
end