From: Richard W.M. Jones Date: Fri, 25 Oct 2019 10:37:58 +0000 (+0100) Subject: Copy source and binaries from download into git. X-Git-Url: http://git.annexia.org/?a=commitdiff_plain;h=1d22e16f3ce315828ed66b13dd793463160d0c19;p=pyrit.git Copy source and binaries from download into git. --- 1d22e16f3ce315828ed66b13dd793463160d0c19 diff --git a/README b/README new file mode 100644 index 0000000..1a5d493 --- /dev/null +++ b/README @@ -0,0 +1 @@ +https://www.pouet.net/prod.php?which=78045 diff --git a/pyrit.asm b/pyrit.asm new file mode 100644 index 0000000..50c49b4 --- /dev/null +++ b/pyrit.asm @@ -0,0 +1,244 @@ +; Pyrit + +; a 256-byte intro by Rrrola + +; greets to everyone who's computer is too fast :) + +; This is loosely based on my intro 'Gem' (shown on Demobit), +; but the code is much better. + +; Vector3: X right, Y down, Z forward. +; On the FP stack it looks like {Y X Z} (Y is often used in comparisons). +; In memory it looks like {Z X Y}, which saves a displacement byte. +; (u'v) is the dot product: ux*vx + uy*vy + uz*vz. + +org 100h ; assume al=0 bx=0 sp=di=-2 si=0100h bp=09??h + +;Set video mode and earth+sky palette + dec di ; u16[100h] = -20401, u16[10Ch] = -30515 + mov al,13h + dec di ; initial pixel_adr@di = -4 + +P:shr cl,1 ; B@cl = 0..8..31,31..0 + + int 10h ; set video mode / color: bx=index dh=R ch=G cl=B + + movsx cx,bl ; 0..127,128..255 (palette index) + xor ch,cl ; 0..127,127..0 + mov cl,ch + mov ax,cx + mul ax ; R@dh = 0..16..63,63..16..0 + + shr cx,1 ; G@ch = 0..63,63..0 + + inc bl ; keep default color 0 + js Q ; R@dh = 0..63,63..16..0 + xchg cl,dh ; B@cl = 0..16..63,63..0 +Q:mov ax,1010h + jnz P ;bx=0 cx=0 + + +;Each frame: Generate normals to p0..p11=[bp+200h,300h,...]. +M:mov ax,0x4731 ; highest 9 bits: float32 exponent 1/256 (for T) + ; lower byte = 2*number of rotations+1 + ; lowest 4 bits must be 0x1 for 'test cl,al' + mov dx,0xA000-10-20-20-4 + mov es,dx ; dx:bx = YX:XX = 0x9fca:0 + pusha ; adr: -18 -16 -14 -12 -10 -8 -6 -4 -2 + ; stack: di si bp sp bx dx cx ax 0 + ; data: -4 100 9?? -2 0 9fca {T/256} + mov cx,12 +G:add bp,si ; i@cx = 12...1; bp points to p[12-i]; carry=0 + pusha + +;Generate 12 planes with unit normals. + +; fld1 ; platonic dodecahedron: exact is atan((1+sqrt5)/2)=1.017rad + fld dword[di-2] ;|t=T/256: morphing shape: cube, platonic12, rhombic12 + + fsincos + + fldz ;|a=0 b c (a*a+b*b+c*c = 1) +; fldlg2 ;irregular shape + +N:test cl,al ;=1 ;|a b c + jnz K + fchs +K:fstp st3 ;|b c +-a (scramble so that all 12 planes are generated) + loop N ;cl=0 ;|z x y + +;Do a bunch of slow rotations. z x y -> cx-sy cy+sx z + +R:fstp st3 ;|x y z +Z:fld st1 ;|y x y z ;|x sy x cy z + fld dword[di-2] ;|t=T/256 + fsincos ;|c=cos(t) s=sin(t) y x y z ;|c s x sy x cy z + fmulp st4 ;|s y x cy z ;|s x sy cx cy z + fmulp ;|sy x cy z ;|sx sy cx cy z + add al,0x7F ; loop 2x +BIG equ $-1 ;=28799 (anything higher and you'll get overflow glitches) + jo Z + faddp st3 ;|sy cx cy+sx z + fsubp ;|new.z=cx-sy .x=cy+sx .y=z + jc R ; loop 24x + +S:fstp dword[bp+si] ;[bp+100]=.z [bp+104]=.x [bp+108]=.y + sub si,di + jpo S + + popa + loop G +C:popa ;=16993, background color multiplier + +; the visible pixels are A0000..AF9FF, I want X=0 Y=0 in the center +;Each pixel: cx=T dx:bx=YX:XX(init=9fca:0) di=adr(init=-4) +X:inc dx ; part of "dx:bx += 0x0000CCCD" +X2: + stosb + + pusha ; adr: -18 -16 -14 -12 -10 -8 -6 -4 -2 + fninit ; stack: di si bp sp bx dx cx ax 0 + mov bx,es ; s16: pixadr 100 9?? -2 ..X..Y T result + mov di,-4 ;di = address of pushed ax + +;Compute ray direction. + fild word[byte BIG+si-100h] ; store 28799 as a double, read as two floats +C2 equ $-2 ;=20036, foreground color multiplier + fst qword[bx] ; t_front@float[bx] = 0, t_back@float[bx+4] = 6.879 + fild word[di+4-9] + fild word[di+4-8] ;|y=Y x=X z=BIG + +;Intersect the pyrite. + call GEM + popa ; color -> pushed ax +; mov al,dl ; show only palette + +;; Faster, but lower quality: draw each pixel twice. +; stosb +; add bx,0xCCCD; dx:bx = YXX += 0000CCCD +; adc dx,0 + + add bx,0xCCCD; dx:bx = YXX += 0000CCCD + jnc X2 + jnz X ; do 65536 pixels + + in al,60h + dec ax ; ah=0 (checkboard uses positive color indices) + loopnz M ; T-- +; ret ; fallthrough + +GEM: +;Hit the pyrite. + xchg ax,cx ; ax = T + +; Faster (+4 or +8 bytes): test the shape only in the center of the screen + add dh,dh + jo B + add dl,dl + jo B + +;Ray-plane intersection. +;Find the front plane with maximum t and back plane with minimum t. +; tf@[bx], tb@[bx+4] ray parameter t +; pf@[bx+si], pb@[bx+4+si] pointer to plane + mov cx,12 ; i@cx = 12...1 +I:add bp,si ; bp points to p[i] + fldlg2 ;|pd=0.301 y x z + fadd dword[bp+si] ;|N=pd-(ro'p[i]) y x z ; ro = 0 0 -1 + + push si ; Dot product: +D:fld dword[bp+si] ;|p[i].z ... + fmul st4 ;|rd.z*p[i].z ... + sub si,di ; 100 104 108 + jpo D ;|(rd*p[i]).y .x .z N rd.y .x .z + pop si + faddp + faddp ;|D=(rd'p[i]) N y x z + +;If we hit the plane from the front (D<0), update tf. Otherwise update tb. + push bx + fst dword[bp+di]; -> p[i].dot_rd (will be read later) + test [bp+di+2],sp ; sf=1 if we're in front of the plane + js FRONT + sub bx,di ; bx = address of tf?tb +FRONT: ; D<0: if tf*D < N { tf=N/D; pf=current; } maximalize tf + fld st0 ; D>=0: if tb*D < N { tb=N/D; pb=current; } minimalize tb + fmul dword[bx] ;|(tf?tb)*D D N y x z + +;;DosBOX-compatible FPU comparison, +5 bytes (+3 but we need ax) +; push ax +; fcomp st2 ;|D N y x z +; fnstsw ax +; sahf ; cf = (tf?tb)*D < N +; pop ax +; jc NEXT + + fcomip st2 + jc NEXT + +;another alternative, +6 bytes +; fsub st2 +; fstp dword[bp-8] +; test [bp-6],sp ; sf=1 if <0 +; js NEXT + + + fdivr st1 ;|t=N/D N y x z + fst dword[bx] ; -> tf?tb + mov [bx+si],bp ; pf?pb = current +NEXT: + fcompp + pop bx ;|y x z + + mov dx,[bx+6] + cmp dx,[bx+2] ; if tf>tb { no_hit: early exit } + jng B ;si=100 ;|y x z + + loop I + +;Reflect: reflect(i,n) = i - 2*n*(i'n) + mov bx,[bx+si] ; pf +Y:fld dword[bx+di] ;|(rd'pf) rd.y .x .z ; reads pf->dot_rd + fmul dword[bx+si] ;|(rd'pf)*pf.z rd.y .x .z + fadd st0 ;|2*(rd'pf)*pf.z rd.y .x .z + fsubr st3 ;|R.z=rd.z-2*(rd'pf)*pf.z rd.y .x .z + sub si,di ;100 104 108 + jpo Y ;si=10C ;|(R=i-2*n(i'n)).y R.x R.z rd.y .x .z + +;Environment map: chessboard below, sky gradient above. +B: +; Subtle highlight on the pyrite. + fld st0 + fimul word[byte C+si-100h] ; 16993 (background) or 20036 (pyrit) + fistp dword[di] ;|y x z + sar dword[di],22 ; if y>=-0.5 { chessboard } else { sky } + js E ; the sky is just y (= y^2 after gamma) + +; Everything the same brightness. (-6 bytes) +; fist word[di] ;|y x z +; sar word[di],8 ; if y>=-0.5 { chessboard } else { sky } +; js E ; the sky is just y (= y^2 after gamma) + +; Dark background version. +; fist word[di] ;|y x z +; shld cx,si,16-3 +; xor cl,9 ; hit?8:9 - make the background darker +; sar word[di],cl ; if y>=-0.5 { chessboard } else { sky } +; js E ; the sky is just y (= y^2 after gamma) + + fidivr word[si] ;|C/y x z (C = hit?-30515:-20401) + fmul st1,st0 + fmul st2 ;|u=z*C/y v=x*C/y z + + fistp dword[bp+di] + sub al,[bp+di+1] + fistp dword[bp+di] + xor al,[bp+di+1] ; xortex@ax = (T-u) XOR v + +; aam -32-24 ; more interesting floor texture + and al,9<<3 + add al,10<<3 ; tex = (xortex AND 0b1001) + 10 [10|11|18|19] + mul byte[di] + mov [di],ah ; pushed al = tex*y + +E:ret diff --git a/pyrit.com b/pyrit.com new file mode 100644 index 0000000..30e5210 Binary files /dev/null and b/pyrit.com differ diff --git a/pyrit.png b/pyrit.png new file mode 100644 index 0000000..c996d8c Binary files /dev/null and b/pyrit.png differ diff --git a/pyrit_dosbox_compatible.com b/pyrit_dosbox_compatible.com new file mode 100644 index 0000000..2a2e0a1 Binary files /dev/null and b/pyrit_dosbox_compatible.com differ diff --git a/pyrit_vsync.com b/pyrit_vsync.com new file mode 100644 index 0000000..363ac03 Binary files /dev/null and b/pyrit_vsync.com differ