MAX_SPHERES = 5
MAX_LIGHTS = 3
;ray
main_loop:
xor eax,eax ; y
.next_line:
xor ebx,ebx ; x
@@:
push eax
push ebx
call find_intersection
pop ebx
pop eax
add ebx,1
cmp ebx,XRES
jnz @b
add eax,1
cmp eax,YRES
jnz .next_line
ret
init_calc: ; do some intial calculations
ret
find_intersection: ;with for now single sphere
; eax - y
; ebx - x
push ebp
mov ebp,esp
sub esp,128
and ebp,0xfffffff0
.dz equ dword[ebp-8]
.dy equ dword[ebp-12]
.dx equ [ebp-16]
.a equ dword[ebp-20]
.b equ dword[ebp-24]
.c equ dword[ebp-28]
.delta equ dword[ebp-32]
.iy equ dword[ebp-36]
.ix equ [ebp-40]
.t1 equ [ebp-44]
.t2 equ [ebp-48]
.n equ [ebp-64]
.sph_xyz equ [ebp-80]
.one_write equ byte [ebp-81] ;tells if sth written in 'nearest' data
.sph_counter equ dword [ebp-85]
mov .iy,eax
mov .ix,ebx
mov .one_write,0
xorps xmm0,xmm0
cvtpi2ps xmm0,.ix
mov ecx,XRES
cvtsi2ss xmm2,ecx
shufps xmm2,xmm2,0
divps xmm0,xmm2
subps xmm0,[camera]
movaps .dx,xmm0
movaps xmm1,xmm0
mulps xmm1,xmm0
haddps xmm1,xmm1
haddps xmm1,xmm1
movss .a,xmm1
mov .sph_counter,0
.next_sph:
xorps xmm5,xmm5
movaps xmm5,[camera]
mov edx,.sph_counter
shl edx,4
add edx,sphere
subps xmm5,[edx] ;[sphere] ;;[edx]
mulps xmm5,[float2]
movaps xmm0,.dx
mulps xmm5,xmm0
haddps xmm5,xmm5
haddps xmm5,xmm5
movss .b,xmm5
movaps xmm4,[edx] ;[sphere] ; [edx]
mulps xmm4,xmm4
; haddps xmm4,xmm4
; haddps xmm4,xmm4
movaps xmm5,[camera]
mulps xmm5,xmm5
addps xmm4,xmm5
haddps xmm4,xmm4
haddps xmm4,xmm4
; addss xmm4,xmm5
movaps xmm5,[edx] ;;[sphere] ;; [edx]
mulps xmm5,[camera]
haddps xmm5,xmm5
haddps xmm5,xmm5
mulss xmm5,[float2]
subss xmm4,xmm5
mov ebx,.sph_counter
shl ebx,2
add ebx,sph_radius
movss xmm5,[ebx] ;[R] ; [ebx]
mulss xmm5,xmm5
subss xmm4,xmm5
movss .c,xmm4
movss xmm5,.b
mulss xmm5,xmm5
mulss xmm4,.a
mulss xmm4,[float4]
subss xmm5,xmm4
movss .delta,xmm5
xorps xmm6,xmm6
cmpnltss xmm5,xmm6
movd ecx,xmm5 ; ecx = -1 greater than 0.0
cmp ecx,0
jnz @f
jmp .next_s ; no intersection
; add .sph_counter,1
; cmp .sph_counter,MAX_SPHERES
; jnz .next_sph
; jmp .put_pixel
@@:
movss xmm5,.delta
sqrtss xmm5,xmm5
movss xmm4,xmm5
subss xmm6,.b
movss xmm7,xmm6
subss xmm6,xmm5
divss xmm6,[float2]
divss xmm6,.a
movss .t1,xmm6
addss xmm4,xmm7
divss xmm4,[float2]
divss xmm4,.a
movss .t2,xmm4
movss xmm5,xmm4
cmpnltss xmm4,.t1
movd ecx,xmm4
or ecx,ecx
jne @f
movss xmm5,.t2
@@:
cmp .one_write,0 ; test if sth in 'nearest' data is written
jz @f
movss xmm4,xmm5
cmpnltss xmm4,[smalest_t]
movd ecx,xmm4
or ecx,ecx
jz .next_s
@@:
movss [smalest_t],xmm5
; push .a
; pop [smalest_a]
; push .b
; pop [smalest_b]
; push .c
; pop [smalest_c]
; push .delta
; pop [smalest_delta]
movaps xmm0,[edx]
movaps [nearest_sphere],xmm0
push dword[ebx]
pop dword[nearest_radius]
mov .one_write,1
.next_s:
add .sph_counter,1
cmp .sph_counter,MAX_SPHERES
jnz .next_sph
.put_pixel:
cmp .one_write,0
je .end
movss xmm5,[smalest_t]
shufps xmm5,xmm5,0 ; calc and put pixel
movaps xmm6,.dx
mulps xmm6,xmm5
movaps xmm4,[camera]
addps xmm4,xmm6 ; xmm4 - x,y,z on the sphere
movaps xmm7,xmm4
subps xmm4,[nearest_sphere]
; movaps xmm6,xmm7
; addps xmm6,[nearest_sphere]
; movaps .sph_xyz,xmm6
movss xmm0,[nearest_radius]
shufps xmm0,xmm0,0
divps xmm4,xmm0 ; xmm4 - normal to surface vector
movaps xmm1,xmm4 ; copy of normal in xmm1
xor eax,eax
xorps xmm3,xmm3
movss xmm2,[light_factor]
shufps xmm2,xmm2,0
.next_light:
; push eax
mov ebx,eax
shl ebx,4
;add eax,light
movaps xmm5,[light+ebx];[light] ;; [eax]
subps xmm5,xmm7 ; calc light unit vector
movaps xmm6,xmm5
mulps xmm5,xmm5
haddps xmm5,xmm5
haddps xmm5,xmm5
sqrtss xmm5,xmm5
divps xmm6,xmm5 ; xmm6 - normalized light vector
; dot_product
movaps xmm4,xmm1 ; xmm4 - normal to surface
mulps xmm4,xmm6
haddps xmm4,xmm4
haddps xmm4,xmm4
shufps xmm4,xmm4,0
; movaps xmm5,xmm4
; mulps xmm5,xmm5
; mulps xmm5,xmm5
; mulps xmm5,[color]
mulps xmm4,[lights_color+ebx] ; xmm4 - computed col. light vector dep.
; addps xmm4,xmm5
mulps xmm4,xmm2
addps xmm3,xmm4
; pop eax
add eax,1
cmp eax,MAX_LIGHTS
jnz .next_light
if 0
; mix with texture
movaps xmm0,.sph_xyz
movss xmm1,[nearest_radius]
shufps xmm1,xmm1,0
divps xmm0,xmm1
mulps xmm0,[correct_tex] ; f64
; addps xmm0,[correct_tex]
cvtss2si eax,xmm0
psrldq xmm0,4
cvtss2si ebx,xmm0
imul ebx,[tex_x]
add ebx,eax
lea ebx,[ebx*3]
add ebx,bitmap
;mov eax,[ebx]
movd xmm1,[ebx]
xorps xmm7,xmm7
punpcklbw xmm1,xmm7
punpcklwd xmm1,xmm7
cvtdq2ps xmm1,xmm1
mulps xmm3,xmm1
divps xmm3,[float255]
; divps xmm1,[float2]
; divps xmm3,[float2]
; addps xmm3,xmm1
end if
minps xmm3,[float255]
cvtps2dq xmm3,xmm3
packssdw xmm3,xmm3
packuswb xmm3,xmm3
mov edi,screen
mov ecx,XRES
imul ecx,.iy
add ecx,.ix
lea ecx,[ecx*3]
add edi,ecx
movd [edi],xmm3
.end:
add esp,128
pop ebp
ret