unit uLandGenTemplateBased;

interface

uses uLandTemplates;

procedure GenTemplated(var Template: TEdgeTemplate);

implementation

uses uVariables, uConsts, uFloat, uLandOutline, uLandUtils, uRandom, SDLh, math;

procedure SetPoints(var Template: TEdgeTemplate; var pa: TPixAr; fps: PPointArray);

var i: LongInt;

begin

    with Template do

        begin

        pa.Count:= BasePointsCount;

        for i:= 0 to pred(pa.Count) do

            begin

            pa.ar[i].x:= BasePoints^[i].x + LongInt(GetRandom(BasePoints^[i].w));

            if pa.ar[i].x <> NTPX then

                pa.ar[i].x:= pa.ar[i].x + ((LAND_WIDTH - Template.TemplateWidth) div 2);

            pa.ar[i].y:= BasePoints^[i].y + LongInt(GetRandom(BasePoints^[i].h)) + LAND_HEIGHT - LongInt(Template.TemplateHeight)

            end;

        if canMirror then

            if getrandom(2) = 0 then

                begin

                for i:= 0 to pred(BasePointsCount) do

                if pa.ar[i].x <> NTPX then

                    pa.ar[i].x:= LAND_WIDTH - 1 - pa.ar[i].x;

                for i:= 0 to pred(FillPointsCount) do

                    fps^[i].x:= LAND_WIDTH - 1 - fps^[i].x;

                end;

(*  Experiment in making this option more useful

     if ((not isNegative) and (cTemplateFilter = 4)) or

        (canFlip and (getrandom(2) = 0)) then

           begin

           for i:= 0 to pred(BasePointsCount) do

               begin

               pa.ar[i].y:= LAND_HEIGHT - 1 - pa.ar[i].y + (LAND_HEIGHT - TemplateHeight) * 2;

               if pa.ar[i].y > LAND_HEIGHT - 1 then

                   pa.ar[i].y:= LAND_HEIGHT - 1;

               end;

           for i:= 0 to pred(FillPointsCount) do

               begin

               FillPoints^[i].y:= LAND_HEIGHT - 1 - FillPoints^[i].y + (LAND_HEIGHT - TemplateHeight) * 2;

               if FillPoints^[i].y > LAND_HEIGHT - 1 then

                   FillPoints^[i].y:= LAND_HEIGHT - 1;

               end;

           end;

     end

*)

// template recycling.  Pull these off the floor a bit

    if (not isNegative) and (cTemplateFilter = 4) then

        begin

        for i:= 0 to pred(BasePointsCount) do

            begin

            dec(pa.ar[i].y, 100);

            if pa.ar[i].y < 0 then

                pa.ar[i].y:= 0;

            end;

        for i:= 0 to pred(FillPointsCount) do

            begin

            dec(fps^[i].y, 100);

            if fps^[i].y < 0 then

                fps^[i].y:= 0;

            end;

        end;

    if (canFlip and (getrandom(2) = 0)) then

        begin

        for i:= 0 to pred(BasePointsCount) do

            pa.ar[i].y:= LAND_HEIGHT - 1 - pa.ar[i].y;

        for i:= 0 to pred(FillPointsCount) do

            fps^[i].y:= LAND_HEIGHT - 1 - fps^[i].y;

        end;

    end

end;

procedure Distort1(var Template: TEdgeTemplate; var pa: TPixAr);

var i: Longword;

begin

    for i:= 1 to Template.BezierizeCount do

        begin

        BezierizeEdge(pa, _0_5);

        RandomizePoints(pa);

        RandomizePoints(pa)

        end;

    for i:= 1 to Template.RandPassesCount do

        RandomizePoints(pa);

    BezierizeEdge(pa, _0_1);

end;

procedure FindPoint(si, fillPointsCount: LongInt; var newPoint: TPoint; var pa: TPixAr);

    minDistance = 32; // adjust/parametrize this for different details size

var p1, p2, p4, fp, mp: TPoint;

    i, t1, t2, a, b, p, q, iy, ix, aqpb: LongInt;

    dab, d, distL, distR: LongInt;

begin

    // [p1, p2] is the segment we're trying to divide

    p1:= pa.ar[si];

    p2:= pa.ar[si + 1];

    if p2.x = NTPX then

    // it is segment from last to first point, so need to find first point

    begin

        i:= si - 2;

        while (i >= 0) and (pa.ar[i].x <> NTPX) do

            dec(i);

        p2:= pa.ar[i + 1]

    end;

    // perpendicular vector

    a:= p2.y - p1.y;

    b:= p1.x - p2.x;

    dab:= DistanceI(a, b).Round;

    // its middle point

    mp.x:= (p1.x + p2.x) div 2;

    mp.y:= (p1.y + p2.y) div 2;

    // don't process too short segments or those which are too close to map borders

    if (p1.x = NTPX)

            or (dab < minDistance * 3) 

            or (mp.y > LAND_HEIGHT - mapBorderMargin)

    then

    begin

        newPoint:= p1;

        exit;

    end;

    // find distances to map borders

    if a <> 0 then

    begin

        // left border

        t1:= a * (mp.x - mapBorderMargin) + b * (mp.y - iy);

        if t1 > 0 then distL:= d else distR:= d;

        // right border

        if t1 > 0 then distR:= d else distL:= d;

    end;

    if b <> 0 then

    begin

        // top border

        t2:= b * (mp.y - mapBorderMargin) + a * (mp.x - ix);

        if t2 > 0 then distL:= min(d, distL) else distR:= min(d, distR);

        // bottom border

        ix:= (LAND_HEIGHT - mapBorderMargin - mp.y) * a div b + mp.x;

        d:= DistanceI(mp.y - LAND_HEIGHT + mapBorderMargin, mp.x - ix).Round;

        if t2 > 0 then distR:= min(d, distR) else distL:= min(d, distL);

    end;

    // now go through all other segments

    fp:= pa.ar[0];

    for i:= 0 to pa.Count - 2 do

        if pa.ar[i].x = NTPX then

            fp:= pa.ar[i + 1]

        else if (i <> si) then

        begin

        p4:= pa.ar[i + 1];

        if p4.x = NTPX then

            p4:= fp;

            // check if it intersects

            t1:= (mp.x - pa.ar[i].x) * b - a * (mp.y - pa.ar[i].y);

            t2:= (mp.x - p4.x) * b - a * (mp.y - p4.y);

            if (t1 > 0) <> (t2 > 0) then // yes it does, hard arith follows

            begin

                p:= p4.x - pa.ar[i].x;

                q:= p4.y - pa.ar[i].y;

                aqpb:= a * q - p * b;

                if (aqpb <> 0) then

                begin

                    // (ix; iy) is intersection point

                    iy:= (((pa.ar[i].x - mp.x) * b + mp.y * a) * q - pa.ar[i].y * p * b) div aqpb;

                    if abs(b) > abs(q) then

                        ix:= (iy - mp.y) * a div b + mp.x

                    else

                        ix:= (iy - pa.ar[i].y) * p div q + pa.ar[i].x;

                    d:= DistanceI(mp.y - iy, mp.x - ix).Round;

                    t1:= b * (mp.y - iy) + a * (mp.x - ix);

                    if t1 > 0 then distL:= min(d, distL) else distR:= min(d, distR);

                end;

            end;

        end;

    // go through all points, including fill points

    for i:= 0 to pa.Count + fillPointsCount - 1 do

        // if this point isn't on current segment

        if (si <> i) and (i <> si + 1) and (pa.ar[i].x <> NTPX) then

        begin

            // also check intersection with rays through pa.ar[i] if this point is good

            t1:= (p1.x - pa.ar[i].x) * b - a * (p1.y - pa.ar[i].y);

            t2:= (p2.x - pa.ar[i].x) * b - a * (p2.y - pa.ar[i].y);

            if (t1 > 0) <> (t2 > 0) then

            begin

                // ray from p1

                p:= pa.ar[i].x - p1.x;

                q:= pa.ar[i].y - p1.y;

                aqpb:= a * q - p * b;

                if (aqpb <> 0) then

                begin

                    // (ix; iy) is intersection point

                    iy:= (((p1.x - mp.x) * b + mp.y * a) * q - p1.y * p * b) div aqpb;

                    if abs(b) > abs(q) then

                        ix:= (iy - mp.y) * a div b + mp.x

                    else

                        ix:= (iy - p1.y) * p div q + p1.x;

                    d:= DistanceI(mp.y - iy, mp.x - ix).Round;

                    t1:= b * (mp.y - iy) + a * (mp.x - ix);

                    if t1 > 0 then distL:= min(d, distL) else distR:= min(d, distR);

                end;

                // and ray from p2

                p:= pa.ar[i].x - p2.x;

                q:= pa.ar[i].y - p2.y;

                aqpb:= a * q - p * b;

                if (aqpb <> 0) then

                begin

                    // (ix; iy) is intersection point

                    iy:= (((p2.x - mp.x) * b + mp.y * a) * q - p2.y * p * b) div aqpb;

                    if abs(b) > abs(q) then

                        ix:= (iy - mp.y) * a div b + mp.x

                    else

                        ix:= (iy - p2.y) * p div q + p2.x;

                    d:= DistanceI(mp.y - iy, mp.x - ix).Round;

                    t2:= b * (mp.y - iy) + a * (mp.x - ix);

                    if t2 > 0 then distL:= min(d, distL) else distR:= min(d, distR);

                end;

            end;

        end;

    // don't move new point for more than length of initial segment

    // adjust/parametrize for more flat surfaces (try values 3/4, 1/2 of dab, or even 1/4)

    d:= dab;

    if distL > d then distL:= d;

    if distR > d then distR:= d;

    if distR + distL < minDistance * 2 + 10 then

    begin

        // limits are too narrow, leave point alone

        newPoint:= p1

    end

    else

    begin

        // select distance within [-distL; distR]

        d:= -distL + minDistance + GetRandom(distR + distL - minDistance * 2);

        //d:= distR - minDistance;

        //d:= - distL + minDistance;

        // calculate new point

        newPoint.x:= mp.x + a * d div dab;

        newPoint.y:= mp.y + b * d div dab;

    end;

end;

procedure DivideEdges(fillPointsCount: LongInt; var pa: TPixAr);

var i, t: LongInt;

    newPoint: TPoint;

begin

    i:= 0;

    while i < pa.Count - 1 do

    begin

        FindPoint(i, fillPointsCount, newPoint, pa);

        if (newPoint.x <> pa.ar[i].x) or (newPoint.y <> pa.ar[i].y) then

        begin

            // point found, free a slot for it in array, don't forget to move appended fill points

            for t:= pa.Count + fillPointsCount downto i + 2 do

                pa.ar[t]:= pa.ar[t - 1];

            inc(pa.Count);

            pa.ar[i + 1]:= newPoint;

            inc(i)

        end;

        inc(i)

    end;

end;

procedure Distort2(var Template: TEdgeTemplate; fps: PPointArray; var pa: TPixAr);

var i: Longword;

begin

    // append fill points to ensure distortion won't move them to other side of segment

    for i:= 0 to pred(Template.FillPointsCount) do

        begin

            pa.ar[pa.Count + i].x:= fps^[i].x;

            pa.ar[pa.Count + i].y:= fps^[i].y;

        end;

    // divide while it divides

    repeat

        i:= pa.Count;

        DivideEdges(Template.FillPointsCount, pa)

    until i = pa.Count;

    // make it smooth

    BezierizeEdge(pa, _0_2);

end;

procedure GenTemplated(var Template: TEdgeTemplate);

var pa: TPixAr;

    i: Longword;

    y, x: Longword;

    fps: TPointArray;

begin

    fps:=Template.FillPoints^;

    ResizeLand(Template.TemplateWidth, Template.TemplateHeight);

    for y:= 0 to LAND_HEIGHT - 1 do

        for x:= 0 to LAND_WIDTH - 1 do

            Land[y, x]:= lfBasic;

    {$HINTS OFF}

    SetPoints(Template, pa, @fps);

    {$HINTS ON}

    Distort2(Template, @fps, pa);

    DrawEdge(pa, 0);

    with Template do

        for i:= 0 to pred(FillPointsCount) do

            with fps[i] do

                FillLand(x, y, 0, 0);

    DrawEdge(pa, lfBasic);

    // HACK: force to only cavern even if a cavern map is invertable if cTemplateFilter = 4 ?

    if (cTemplateFilter = 4)

    or (Template.canInvert and (getrandom(2) = 0))

    or (not Template.canInvert and Template.isNegative) then

        begin

        hasBorder:= true;

        for y:= 0 to LAND_HEIGHT - 1 do

            for x:= 0 to LAND_WIDTH - 1 do

                if (y < topY) or (x < leftX) or (x > rightX) then

                    Land[y, x]:= 0

                else

                    begin

                    if Land[y, x] = 0 then

                        Land[y, x]:= lfBasic

                    else if Land[y, x] = lfBasic then

                        Land[y, x]:= 0;

                    end;

        end;

end;

end.