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-
- {$r-}
- program polygoned_and_shaded_cube;
- uses
- crt;
- const
- border=false;
- vidseg:word=$a000;
- divd=128;
- dist=150;
- point:array[0..7,0..2] of integer=(
- (-30,-30,-30),(-30,-30,30),(30,-30,30),(30,-30,-30),
- (-30, 30,-30),(-30, 30,30),(30, 30,30),(30, 30,-30));
- planes:array[0..5,0..3] of byte=(
- (0,4,5,1),(0,3,7,4),(0,1,2,3),(4,5,6,7),(7,6,2,3),(1,2,6,5));
- var
- stab:array[0..255] of integer;
- polyz:array[0..5] of integer;
- pind:array[0..5] of byte;
- virscr:pointer;
- virseg:word;
-
- { -------------------------------------------------------------------------- }
-
- procedure setborder(col:byte); assembler;
- asm
- xor ch,ch
- mov cl,border
- jcxz @out
- mov dx,3dah
- in al,dx
- mov dx,3c0h
- mov al,11h+32
- out dx,al
- mov al,col
- out dx,al
- @out:
- end;
-
- { -------------------------------------------------------------------------- }
-
- procedure retrace; assembler;
- asm
- mov dx,3dah
- @vert1:
- in al,dx
- test al,8
- jz @vert1
- @vert2:
- in al,dx
- test al,8
- jnz @vert2
- end;
-
- { -------------------------------------------------------------------------- }
-
- procedure setpal(c,r,g,b:byte); assembler;
- asm
- mov dx,3c8h
- mov al,[c]
- out dx,al
- inc dx
- mov al,[r]
- out dx,al
- mov al,[g]
- out dx,al
- mov al,[b]
- out dx,al
- end;
-
- { -------------------------------------------------------------------------- }
-
- procedure cls(lvseg:word); assembler;
- asm
- mov es,[lvseg]
- xor di,di
- xor ax,ax
- mov cx,320*200/2
- rep stosw
- end;
-
- procedure flip(src,dst:word); assembler;
- asm
- push ds
- mov ax,[dst]
- mov es,ax
- mov ax,[src]
- mov ds,ax
- xor si,si
- xor di,di
- mov cx,320*200/2
- rep movsw
- pop ds
- end;
-
- { -------------------------------------------------------------------------- }
-
- procedure horline(xb,xe,y:integer; c:byte; where:word); assembler;
- asm
- mov bx,[xb]
- cmp bx,0 { if zero don't draw }
- jz @out
- mov cx,[xe]
- jcxz @out
- cmp bx,cx { see if x-end is smaller than x-begin }
- jb @skip
- xchg bx,cx { yes: switch coords }
- @skip:
- dec bx { atatch planes }
- inc cx
- sub cx,bx { length of line in cx }
- mov es,[where] { segment to draw in }
- mov ax,[y] { heigth of line }
- shl ax,6
- mov di,ax
- shl ax,2
- add di,ax { y*320 in di (offset) }
- add di,bx { add x-begin }
- mov al,[c] { get color }
- shr cx,1 { div length by 2 }
- jnc @skip2 { carry set? }
- stosb { draw byte }
- @skip2:
- mov ah,al { copy color in hi-byte }
- rep stosw { draw (rest of) line }
- @out:
- end;
-
- procedure polygon(x1,y1,x2,y2,x3,y3,x4,y4:integer; c:byte);
- var
- xpos:array[0..199,0..1] of integer;
- mny,mxy,y:integer;
- i:word;
- s1,s2,s3,s4:shortint;
- begin
- mny:=y1;
- if y2<mny then mny:=y2;
- if y3<mny then mny:=y3;
- if y4<mny then mny:=y4;
- mxy:=y1;
- if y2>mxy then mxy:=y2;
- if y3>mxy then mxy:=y3;
- if y4>mxy then mxy:=y4;
- s1:=byte(y1<y2)*2-1;
- s2:=byte(y2<y3)*2-1;
- s3:=byte(y3<y4)*2-1;
- s4:=byte(y4<y1)*2-1;
- y:=y1;
- if y1<>y2 then repeat
- xpos[y,byte(y1<y2)]:=integer(x2-x1)*(y-y1) div (y2-y1)+x1;
- inc(y,s1);
- until y=y2+s1 else xpos[y,byte(y1<y2)]:=x1;
- y:=y2;
- if y2<>y3 then repeat
- xpos[y,byte(y2<y3)]:=integer(x3-x2)*(y-y2) div (y3-y2)+x2;
- inc(y,s2);
- until y=y3+s2 else xpos[y,byte(y2<y3)]:=x2;
- y:=y3;
- if y3<>y4 then repeat
- xpos[y,byte(y3<y4)]:=integer(x4-x3)*(y-y3) div (y4-y3)+x3;
- inc(y,s3);
- until y=y4+s3 else xpos[y,byte(y3<y4)]:=x3;
- y:=y4;
- if y4<>y1 then repeat
- xpos[y,byte(y4<y1)]:=integer(x1-x4)*(y-y4) div (y1-y4)+x4;
- inc(y,s4);
- until y=y1+s4 else xpos[y,byte(y1<y4)]:=x4;
- for y:=mny to mxy do
- horline(xpos[y,0],xpos[y,1],y,c,virseg);
- end;
-
- { -------------------------------------------------------------------------- }
-
- procedure quicksort(lo,hi:integer);
-
- procedure sort(l,r:integer);
- var i,j,x,y:integer;
- begin
- i:=l; j:=r; x:=polyz[(l+r) div 2];
- repeat
- while polyz[i]<x do inc(i);
- while x<polyz[j] do dec(j);
- if i<=j then begin
- y:=polyz[i]; polyz[i]:=polyz[j]; polyz[j]:=y;
- y:=pind[i]; pind[i]:=pind[j]; pind[j]:=y;
- inc(i); dec(j);
- end;
- until i>j;
- if l<j then sort(l,j);
- if i<r then sort(i,r);
- end;
-
- begin
- sort(lo,hi);
- end;
-
- { -------------------------------------------------------------------------- }
-
- function sinus(i:byte):integer; begin sinus:=stab[i]; end;
- function cosinus(i:byte):integer; begin cosinus:=stab[(i+192) mod 255]; end;
-
- { -------------------------------------------------------------------------- }
-
- procedure rotate_cube;
- const xst=1; yst=1; zst=-1;
- var xp,yp,zp:array[0..7] of integer; x,y,z,i,j,k:integer; n,Key,phix,phiy,phiz:byte;
- begin
- phix:=0; phiy:=0; phiz:=0;
- fillchar(xp,sizeof(xp),0);
- fillchar(yp,sizeof(yp),0);
- repeat
- {retrace;}
- setborder(5);
- for n:=3 to 5 do
- polygon(xp[planes[pind[n],0]],yp[planes[pind[n],0]],
- xp[planes[pind[n],1]],yp[planes[pind[n],1]],
- xp[planes[pind[n],2]],yp[planes[pind[n],2]],
- xp[planes[pind[n],3]],yp[planes[pind[n],3]],0);
- for n:=0 to 7 do begin
- i:=(cosinus(phiy)*point[n,0]-sinus(phiy)*point[n,2]) div divd;
- j:=(cosinus(phiz)*point[n,1]-sinus(phiz)*i) div divd;
- k:=(cosinus(phiy)*point[n,2]+sinus(phiy)*point[n,0]) div divd;
- x:=(cosinus(phiz)*i+sinus(phiz)*point[n,1]) div divd;
- y:=(cosinus(phix)*j+sinus(phix)*k) div divd;
- z:=(cosinus(phix)*k-sinus(phix)*j) div divd;
- xp[n]:=160+(-x*dist) div (z-dist);
- yp[n]:=100+(-y*dist) div (z-dist);
- zp[n]:=z;
- end;
- for n:=0 to 5 do begin
- polyz[n]:=(zp[planes[n,0]]+zp[planes[n,1]]+zp[planes[n,2]]+zp[planes[n,3]]) div 4;
- pind[n]:=n;
- end;
- quicksort(0,5);
- for n:=3 to 5 do
- polygon(xp[planes[pind[n],0]],yp[planes[pind[n],0]],
- xp[planes[pind[n],1]],yp[planes[pind[n],1]],
- xp[planes[pind[n],2]],yp[planes[pind[n],2]],
- xp[planes[pind[n],3]],yp[planes[pind[n],3]],polyz[n]+25);
- inc(phix,xst); inc(phiy,yst); inc(phiz,zst);
- setborder(3);
- flip(virseg,vidseg);
- setborder(0);
- until keypressed;
- end;
-
- { -------------------------------------------------------------------------- }
-
- var i:word;
- begin
- asm mov ax,13h; int 10h; end;
- getmem(virscr,64000);
- virseg:=seg(virscr^);
- cls(virseg);
- for i:=0 to 255 do stab[i]:=round(sin(i*pi/128)*divd);
- for i:=1 to 63 do setpal(i,i div 4,i div 2,i);
- rotate_cube;
- freemem(virscr,64000);
- textmode(lastmode);
- end.
-