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Quellcode

minU:=poly.v[0].tu;
for x:=1 to poly.numVertex-1 do begin
  minU:=min(minU,poly.v[x].tu);
end;

minV:=poly.v[0].tv;
for x:=1 to poly.numVertex-1 do begin
  minV:=min(minV,poly.v[x].tv);
end;

Quellcode

u1:=floor(minU)-u;
v1:=floor(minV)-v;

tx:=round((u1*invW)*(texture.width-1)); 
ty:=round((v1*invW)*(texture.height-1));

Quellcode

procedure v3dRasterizeCorrect(poly:v3dPoly; texture:gfxImage; var vp:v3dViewPort);
procedure SetSide(b,e:v3dVertex; var side:v3dScreenSide); 
var 
    len:single; 
    startoffset,endoffset:single;
    offsetstep:single;
    y:longint;
    subpix:single;
    Z,Zstep:single;
    W,Wstep:single; 
    U,Ustep:single; 
    V,Vstep:single;  
begin

    len:=e.v.y - b.v.y;

    if len<=0 then begin
        side[ceil(b.v.y)].offset:=ceil(b.v.y*vp.screen.width + b.v.x);
        exit;
    end;

    startoffset:=b.v.y*vp.screen.width + b.v.x;
    endoffset:=e.v.y*vp.screen.width + e.v.x;

    offsetstep:= (endoffset - startoffset) / len;

    subpix:=ceil(b.v.y) - b.v.y;

    startoffset:=startoffset + offsetstep*subpix;

    


    Zstep:=(e.v.z - b.v.z) / len; 

    Ustep:=(e.tu - b.tu) / len; 
    Vstep:=(e.tv - b.tv) / len; 

    Wstep:=(e.v.w - b.v.w) / len;
 

    Z:=b.v.z + Zstep*subpix; 

    U:=b.tu + Ustep*subpix; 
    V:=b.tv + Vstep*subpix; 

    W:=b.v.w + Wstep*subpix;


    for y:=ceil(b.v.y) to ceil(e.v.y)-1 do begin

        side[y].offset:=ceil(startoffset);
        side[y].z:=Z;
        side[y].w:=W;
        side[y].u:=U; 
        side[y].v:=V; 

        side[y].subpix:=ceil(b.v.y) - b.v.y;


        startoffset:=startoffset+offsetstep;

        z:=z+Zstep;
        w:=w+Wstep;

        u:=u+Ustep;
        v:=v+Vstep; 

    end;


end; 


var
    x,y:longint;
    top,middle,bottom:longint;
    len:longint;
    offset:dword; 
    
    invW:single;
    Z,Zstep:single;
    W,Wstep:single;
    U,Ustep,V,Vstep:single;
    tX,ty:longint;

begin



    top:=0;
    bottom:=0;

    for x:=0 to poly.numVertex-1 do begin
        if poly.v[top].v.y > poly.v[x].v.y then top:=x;
        if poly.v[bottom].v.y < poly.v[x].v.y then bottom:=x;
    end;

    x:=top;
    y:=top;

    dec(y);
    if y<0 then y:=poly.numVertex-1;

    repeat

        SetSide(poly.v[x],poly.v[y],vp.rightside);


        x:=y;

        dec(y);
        if y<0 then y:=poly.numVertex-1;

    until x=bottom;


    x:=top;
    y:=top;

    inc(y);
    if y>= poly.numVertex then y:=0;

    repeat


        SetSide(poly.v[x],poly.v[y],vp.leftside);

        x:=y;

        inc(y);
        if y>= poly.numVertex then y:=0;


    until x=bottom;

{
    middle:=ceil((poly.v[top].v.y + poly.v[bottom].v.y) / 2);

    if vp.leftside[middle].offset > vp.rightside[middle].offset then begin
        vp.tempSide:=vp.leftside;
        vp.leftside:=vp.rightside;
        vp.rightside:=vp.tempSide;
    end;
}

    for y:=ceil(poly.v[top].v.y) to ceil(poly.v[bottom].v.y)-1 do begin
        

        len:=vp.rightSide[y].offset - vp.leftSide[y].offset;
        if len <= 0 then continue;

        Zstep:=(vp.rightSide[y].z-vp.leftSide[y].z) / len;
        Ustep:=(vp.rightSide[y].u-vp.leftSide[y].u) / len; 
        Vstep:=(vp.rightSide[y].v-vp.leftSide[y].v) / len; 
        Wstep:=(vp.rightSide[y].w-vp.leftSide[y].w) / len; 

        offset:=vp.leftSide[y].offset;

        z:=vp.leftSide[y].z + Zstep*vp.leftSide[y].subpix;
        u:=vp.leftSide[y].u + Ustep*vp.leftSide[y].subpix; 
        v:=vp.leftSide[y].v + Vstep*vp.leftSide[y].subpix; 
        w:=vp.leftSide[y].w + Wstep*vp.leftSide[y].subpix; 




        repeat 

            if (z+vp.clearReduction) > (vp.Zbuffer[offset]+vp.clearReduction) then begin 
                invW:=1 / w;


                        tx:=round((u*invW)*(texture.width-1));  
                        ty:=round((v*invW)*(texture.height-1));
                        


                    pdword(pointer2nativeUint(vp.screen.data) + offset shl 2)^:=getPixelclip(texture,tx,ty);


                    vp.Zbuffer[offset]:=z; 


            end; 

            inc(offset);
            z:=z + Zstep;
            w:=w + Wstep; 
            u:=u + Ustep; 
            v:=v + Vstep; 

            dec(len); 
        until len=0; 


    end;


end;