hedgewars/uLand.pas
author nemo
Thu, 01 Jul 2010 23:41:10 -0400
changeset 3608 c509bbc779e7
parent 3607 2ad7885615c1
child 3612 b50215a8a43d
permissions -rw-r--r--
Revert prior attempted optimisation. Gridding the land pays in some situations, but not all. Restricting to an upper bound might help, but overall, seems too fuzzy to be worth it. On one side is increased cost of Add/Delete + extra test on collision check, on the other is skipping the list iteration. Perhaps for large lists.

(*
 * Hedgewars, a free turn based strategy game
 * Copyright (c) 2005-2010 Andrey Korotaev <unC0Rr@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 *)

{$INCLUDE "options.inc"}

unit uLand;
interface
uses SDLh, uLandTemplates, uFloat, uConsts, GLunit;

type
{$IFDEF DOWNSCALE}
    TLandArray = packed array[0 .. LAND_HEIGHT div 2 - 1, 0 .. LAND_WIDTH div 2 - 1] of LongWord;
{$ELSE}
    TLandArray = packed array[0 .. LAND_HEIGHT - 1, 0 .. LAND_WIDTH - 1] of LongWord;
{$ENDIF}
 
    TCollisionArray = packed array[0 .. LAND_HEIGHT - 1, 0 .. LAND_WIDTH - 1] of Word;
    TPreview  = packed array[0..127, 0..31] of byte;
    TDirtyTag = packed array[0 .. LAND_HEIGHT div 32 - 1, 0 .. LAND_WIDTH div 32 - 1] of byte;

var Land: TCollisionArray;
    LandPixels: TLandArray;
    LandDirty: TDirtyTag;
    hasBorder: boolean; 
    hasGirders: boolean;  
    isMap: boolean;  
    playHeight, playWidth, leftX, rightX, topY, MaxHedgehogs: Longword;  // idea is that a template can specify height/width.  Or, a map, a height/width by the dimensions of the image.  If the map has pixels near top of image, it triggers border.
    LandBackSurface: PSDL_Surface;
    digest: shortstring;

type direction = record x, y: LongInt; end;
const DIR_N: direction = (x: 0; y: -1);
    DIR_E: direction = (x: 1; y: 0);
    DIR_S: direction = (x: 0; y: 1);
    DIR_W: direction = (x: -1; y: 0);

procedure initModule;
procedure freeModule;
procedure GenMap;
function  GenPreview: TPreview;
procedure CheckLandDigest(s: shortstring);
function  LandBackPixel(x, y: LongInt): LongWord;

implementation
uses uConsole, uStore, uMisc, uRandom, uTeams, uLandObjects, Adler32, uIO, uLandTexture;

operator=(const a, b: direction) c: Boolean;
begin
    c := (a.x = b.x) and (a.y = b.y);
end;

type TPixAr = record
              Count: Longword;
              ar: array[0..Pred(cMaxEdgePoints)] of TPoint;
              end;

procedure LogLandDigest;
var s: shortstring;
    adler: LongInt;
begin
adler:= 1;
Adler32Update(adler, @Land, sizeof(Land));
s:= 'M'+inttostr(adler);

CheckLandDigest(s);
SendIPCRaw(@s[0], Length(s) + 1)
end;

procedure CheckLandDigest(s: shortstring);
begin
{$IFDEF DEBUGFILE}
    AddFileLog('CheckLandDigest: ' + s + ' digest : ' + digest);
{$ENDIF}
    if digest = '' then
        digest:= s
    else
        TryDo(s = digest, 'Different maps generated, sorry', true);
end;

procedure DrawLine(X1, Y1, X2, Y2: LongInt; Color: Longword);
var
  eX, eY, dX, dY: LongInt;
  i, sX, sY, x, y, d: LongInt;
begin
eX:= 0;
eY:= 0;
dX:= X2 - X1;
dY:= Y2 - Y1;

if (dX > 0) then sX:= 1
else
  if (dX < 0) then
     begin
     sX:= -1;
     dX:= -dX
     end else sX:= dX;

if (dY > 0) then sY:= 1
  else
  if (dY < 0) then
     begin
     sY:= -1;
     dY:= -dY
     end else sY:= dY;

if (dX > dY) then d:= dX
             else d:= dY;

x:= X1;
y:= Y1;

for i:= 0 to d do
    begin
    inc(eX, dX);
    inc(eY, dY);
    if (eX > d) then
       begin
       dec(eX, d);
       inc(x, sX);
       end;
    if (eY > d) then
       begin
       dec(eY, d);
       inc(y, sY);
       end;

    if ((x and LAND_WIDTH_MASK) = 0) and ((y and LAND_HEIGHT_MASK) = 0) then
       Land[y, x]:= Color;
    end
end;

procedure DrawEdge(var pa: TPixAr; Color: Longword);
var i: LongInt;
begin
i:= 0;
with pa do
while i < LongInt(Count) - 1 do
    if (ar[i + 1].X = NTPX) then inc(i, 2)
       else begin
       DrawLine(ar[i].x, ar[i].y, ar[i + 1].x, ar[i + 1].y, Color);
       inc(i)
       end
end;

procedure Vector(p1, p2, p3: TPoint; var Vx, Vy: hwFloat);
var d1, d2, d: hwFloat;
begin
Vx:= int2hwFloat(p1.X - p3.X);
Vy:= int2hwFloat(p1.Y - p3.Y);
d:= DistanceI(p2.X - p1.X, p2.Y - p1.Y);
d1:= DistanceI(p2.X - p3.X, p2.Y - p3.Y);
d2:= Distance(Vx, Vy);
if d1 < d then d:= d1;
if d2 < d then d:= d2;
d:= d * _1div3;
if d2.QWordValue = 0 then
   begin
   Vx:= _0;
   Vy:= _0
   end else
   begin
   d2:= _1 / d2;
   Vx:= Vx * d2;
   Vy:= Vy * d2;

   Vx:= Vx * d;
   Vy:= Vy * d
   end
end;

procedure AddLoopPoints(var pa, opa: TPixAr; StartI, EndI: LongInt; Delta: hwFloat);
var i, pi, ni: LongInt;
    NVx, NVy, PVx, PVy: hwFloat;
    x1, x2, y1, y2: LongInt;
    tsq, tcb, t, r1, r2, r3, cx1, cx2, cy1, cy2: hwFloat;
    X, Y: LongInt;
begin
pi:= EndI;
i:= StartI;
ni:= Succ(StartI);
{$HINTS OFF}
Vector(opa.ar[pi], opa.ar[i], opa.ar[ni], NVx, NVy);
{$HINTS ON}
repeat
    inc(pi);
    if pi > EndI then pi:= StartI;
    inc(i);
    if i > EndI then i:= StartI;
    inc(ni);
    if ni > EndI then ni:= StartI;
    PVx:= NVx;
    PVy:= NVy;
    Vector(opa.ar[pi], opa.ar[i], opa.ar[ni], NVx, NVy);

    x1:= opa.ar[pi].x;
    y1:= opa.ar[pi].y;
    x2:= opa.ar[i].x;
    y2:= opa.ar[i].y;
    cx1:= int2hwFloat(x1) - PVx;
    cy1:= int2hwFloat(y1) - PVy;
    cx2:= int2hwFloat(x2) + NVx;
    cy2:= int2hwFloat(y2) + NVy;
    t:= _0;
    while t.Round = 0 do
          begin
          tsq:= t * t;
          tcb:= tsq * t;
          r1:= (_1 - t*3 + tsq*3 - tcb);
          r2:= (     t*3 - tsq*6 + tcb*3);
          r3:= (           tsq*3 - tcb*3);
          X:= hwRound(r1 * x1 + r2 * cx1 + r3 * cx2 + tcb * x2);
          Y:= hwRound(r1 * y1 + r2 * cy1 + r3 * cy2 + tcb * y2);
          t:= t + Delta;
          pa.ar[pa.Count].x:= X;
          pa.ar[pa.Count].y:= Y;
          inc(pa.Count);
          TryDo(pa.Count <= cMaxEdgePoints, 'Edge points overflow', true)
          end;
until i = StartI;
pa.ar[pa.Count].x:= opa.ar[StartI].X;
pa.ar[pa.Count].y:= opa.ar[StartI].Y;
inc(pa.Count)
end;

procedure BezierizeEdge(var pa: TPixAr; Delta: hwFloat);
var i, StartLoop: LongInt;
    opa: TPixAr;
begin
opa:= pa;
pa.Count:= 0;
i:= 0;
StartLoop:= 0;
while i < LongInt(opa.Count) do
    if (opa.ar[i + 1].X = NTPX) then
       begin
       AddLoopPoints(pa, opa, StartLoop, i, Delta);
       inc(i, 2);
       StartLoop:= i;
       pa.ar[pa.Count].X:= NTPX;
       pa.ar[pa.Count].Y:= 0;
       inc(pa.Count);
       end else inc(i)
end;

procedure FillLand(x, y: LongInt);
var Stack: record
           Count: Longword;
           points: array[0..8192] of record
                                     xl, xr, y, dir: LongInt;
                                     end
           end;

    procedure Push(_xl, _xr, _y, _dir: LongInt);
    begin
    TryDo(Stack.Count <= 8192, 'FillLand: stack overflow', true);
    _y:= _y + _dir;
    if (_y < 0) or (_y >= LAND_HEIGHT) then exit;
    with Stack.points[Stack.Count] do
         begin
         xl:= _xl;
         xr:= _xr;
         y:= _y;
         dir:= _dir
         end;
    inc(Stack.Count)
    end;

    procedure Pop(var _xl, _xr, _y, _dir: LongInt);
    begin
    dec(Stack.Count);
    with Stack.points[Stack.Count] do
         begin
         _xl:= xl;
         _xr:= xr;
         _y:= y;
         _dir:= dir
         end
    end;

var xl, xr, dir: LongInt;
begin
Stack.Count:= 0;
xl:= x - 1;
xr:= x;
Push(xl, xr, y, -1);
Push(xl, xr, y,  1);
dir:= 0;
while Stack.Count > 0 do
      begin
      Pop(xl, xr, y, dir);
      while (xl > 0) and (Land[y, xl] <> 0) do dec(xl);
      while (xr < LAND_WIDTH - 1) and (Land[y, xr] <> 0) do inc(xr);
      while (xl < xr) do
            begin
            while (xl <= xr) and (Land[y, xl] = 0) do inc(xl);
            x:= xl;
            while (xl <= xr) and (Land[y, xl] <> 0) do
                  begin
                  Land[y, xl]:= 0;
                  inc(xl)
                  end;
            if x < xl then
               begin
               Push(x, Pred(xl), y, dir);
               Push(x, Pred(xl), y,-dir);
               end;
            end;
      end;
end;

function LandBackPixel(x, y: LongInt): LongWord;
var p: PLongWordArray;
begin
    if LandBackSurface = nil then LandBackPixel:= 0
    else
    begin
        p:= LandBackSurface^.pixels;
        LandBackPixel:= p^[LandBackSurface^.w * (y mod LandBackSurface^.h) + (x mod LandBackSurface^.w)];// or $FF000000;
    end
end;

procedure ColorizeLand(Surface: PSDL_Surface);
var tmpsurf: PSDL_Surface;
    r, rr: TSDL_Rect;
    x, yd, yu: LongInt;
begin
    tmpsurf:= LoadImage(Pathz[ptCurrTheme] + '/LandTex', ifCritical or ifIgnoreCaps);
    r.y:= 0;
    while r.y < LAND_HEIGHT do
    begin
        r.x:= 0;
        while r.x < LAND_WIDTH do
        begin
            SDL_UpperBlit(tmpsurf, nil, Surface, @r);
            inc(r.x, tmpsurf^.w)
        end;
        inc(r.y, tmpsurf^.h)
    end;
    SDL_FreeSurface(tmpsurf);

    // freed in freeModule() below
    LandBackSurface:= LoadImage(Pathz[ptCurrTheme] + '/LandBackTex', ifIgnoreCaps or ifTransparent);

    tmpsurf:= LoadImage(Pathz[ptCurrTheme] + '/Border', ifCritical or ifIgnoreCaps or ifTransparent);
    for x:= 0 to LAND_WIDTH - 1 do
    begin
        yd:= LAND_HEIGHT - 1;
        repeat
            while (yd > 0) and (Land[yd, x] =  0) do dec(yd);

            if (yd < 0) then yd:= 0;

            while (yd < LAND_HEIGHT) and (Land[yd, x] <> 0) do inc(yd);
            dec(yd);
            yu:= yd;

            while (yu > 0  ) and (Land[yu, x] <> 0) do dec(yu);
            while (yu < yd ) and (Land[yu, x] =  0) do inc(yu);

            if (yd < LAND_HEIGHT - 1) and ((yd - yu) >= 16) then
            begin
                rr.x:= x;
                rr.y:= yd - 15;
                r.x:= x mod tmpsurf^.w;
                r.y:= 16;
                r.w:= 1;
                r.h:= 16;
                SDL_UpperBlit(tmpsurf, @r, Surface, @rr);
            end;
            if (yu > 0) then
            begin
                rr.x:= x;
                rr.y:= yu;
                r.x:= x mod tmpsurf^.w;
                r.y:= 0;
                r.w:= 1;
                r.h:= min(16, yd - yu + 1);
                SDL_UpperBlit(tmpsurf, @r, Surface, @rr);
            end;
            yd:= yu - 1;
        until yd < 0;
    end;
    SDL_FreeSurface(tmpsurf);
end;

procedure SetPoints(var Template: TEdgeTemplate; var pa: TPixAr);
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
               FillPoints^[i].x:= LAND_WIDTH - 1 - FillPoints^[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(FillPoints^[i].y, 100);
               if FillPoints^[i].y < 0 then
                   FillPoints^[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
               FillPoints^[i].y:= LAND_HEIGHT - 1 - FillPoints^[i].y;
           end;
     end
end;

function CheckIntersect(V1, V2, V3, V4: TPoint): boolean;
var c1, c2, dm: LongInt;
begin
dm:= (V4.y - V3.y) * (V2.x - V1.x) - (V4.x - V3.x) * (V2.y - V1.y);
c1:= (V4.x - V3.x) * (V1.y - V3.y) - (V4.y - V3.y) * (V1.x - V3.x);
if dm = 0 then exit(false);

c2:= (V2.x - V3.x) * (V1.y - V3.y) - (V2.y - V3.y) * (V1.x - V3.x);
if dm > 0 then
   begin
   if (c1 < 0) or (c1 > dm) then exit(false);
   if (c2 < 0) or (c2 > dm) then exit(false)
   end else
   begin
   if (c1 > 0) or (c1 < dm) then exit(false);
   if (c2 > 0) or (c2 < dm) then exit(false)
   end;

//AddFileLog('1  (' + inttostr(V1.x) + ',' + inttostr(V1.y) + ')x(' + inttostr(V2.x) + ',' + inttostr(V2.y) + ')');
//AddFileLog('2  (' + inttostr(V3.x) + ',' + inttostr(V3.y) + ')x(' + inttostr(V4.x) + ',' + inttostr(V4.y) + ')');
CheckIntersect:= true
end;

function CheckSelfIntersect(var pa: TPixAr; ind: Longword): boolean;
var i: Longword;
begin
if (ind <= 0) or (ind >= Pred(pa.Count)) then exit(false);
for i:= 1 to pa.Count - 3 do
    if (i <= ind - 1) or (i >= ind + 2) then
      begin
      if (i <> ind - 1) and
         CheckIntersect(pa.ar[ind], pa.ar[ind - 1], pa.ar[i], pa.ar[i - 1]) then exit(true);
      if (i <> ind + 2) and
         CheckIntersect(pa.ar[ind], pa.ar[ind + 1], pa.ar[i], pa.ar[i - 1]) then exit(true);
      end;
CheckSelfIntersect:= false
end;

procedure RandomizePoints(var pa: TPixAr);
const cEdge = 55;
      cMinDist = 8;
var radz: array[0..Pred(cMaxEdgePoints)] of LongInt;
    i, k, dist, px, py: LongInt;
begin
for i:= 0 to Pred(pa.Count) do
  begin
  radz[i]:= 0;
  with pa.ar[i] do
    if x <> NTPX then
      begin
      radz[i]:= Min(Max(x - cEdge, 0), Max(LAND_WIDTH - cEdge - x, 0));
      radz[i]:= Min(radz[i], Min(Max(y - cEdge, 0), Max(LAND_HEIGHT - cEdge - y, 0)));
      if radz[i] > 0 then
        for k:= 0 to Pred(i) do
          begin
          dist:= Max(abs(x - pa.ar[k].x), abs(y - pa.ar[k].y));
          radz[k]:= Max(0, Min((dist - cMinDist) div 2, radz[k]));
          radz[i]:= Max(0, Min(dist - radz[k] - cMinDist, radz[i]))
        end
      end;
  end;

for i:= 0 to Pred(pa.Count) do
  with pa.ar[i] do
    if ((x and LAND_WIDTH_MASK) = 0) and ((y and LAND_HEIGHT_MASK) = 0) then
      begin
      px:= x;
      py:= y;
      x:= x + LongInt(GetRandom(7) - 3) * (radz[i] * 5 div 7) div 3;
      y:= y + LongInt(GetRandom(7) - 3) * (radz[i] * 5 div 7) div 3;
      if CheckSelfIntersect(pa, i) then
         begin
         x:= px;
         y:= py
         end;
      end
end;


procedure GenBlank(var Template: TEdgeTemplate);
var pa: TPixAr;
    i: Longword;
    y, x: Longword;
begin
for y:= 0 to LAND_HEIGHT - 1 do
    for x:= 0 to LAND_WIDTH - 1 do
        Land[y, x]:= lfBasic;

{$HINTS OFF}
SetPoints(Template, pa);
{$HINTS ON}
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);

DrawEdge(pa, 0);

with Template do
     for i:= 0 to pred(FillPointsCount) do
         with FillPoints^[i] do
              FillLand(x, y);

DrawEdge(pa, lfBasic);

MaxHedgehogs:= Template.MaxHedgehogs;
hasGirders:= Template.hasGirders;
playHeight:= Template.TemplateHeight;
playWidth:= Template.TemplateWidth;
leftX:= ((LAND_WIDTH - playWidth) div 2);
rightX:= (playWidth + ((LAND_WIDTH - playWidth) div 2)) - 1;
topY:= LAND_HEIGHT - playHeight;

// 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;

function SelectTemplate: LongInt;
begin
case cTemplateFilter of
     0: begin
     SelectTemplate:= getrandom(Succ(High(EdgeTemplates)));
     end;
     1: begin
     SelectTemplate:= SmallTemplates[getrandom(Succ(High(SmallTemplates)))];
     end;
     2: begin
     SelectTemplate:= MediumTemplates[getrandom(Succ(High(MediumTemplates)))];
     end;
     3: begin
     SelectTemplate:= LargeTemplates[getrandom(Succ(High(LargeTemplates)))];
     end;
     4: begin
     SelectTemplate:= CavernTemplates[getrandom(Succ(High(CavernTemplates)))];
     end;
     5: begin
     SelectTemplate:= WackyTemplates[getrandom(Succ(High(WackyTemplates)))];
     end;
end;
WriteLnToConsole('Selected template #'+inttostr(SelectTemplate)+' using filter #'+inttostr(cTemplateFilter));
end;

procedure LandSurface2LandPixels(Surface: PSDL_Surface);
var x, y: LongInt;
    p: PLongwordArray;
begin
TryDo(Surface <> nil, 'Assert (LandSurface <> nil) failed', true);

if SDL_MustLock(Surface) then
    SDLTry(SDL_LockSurface(Surface) >= 0, true);

p:= Surface^.pixels;
for y:= 0 to LAND_HEIGHT - 1 do
    begin
    for x:= 0 to LAND_WIDTH - 1 do
    if Land[y, x] <> 0 then
        if (cReducedQuality and rqBlurryLand) = 0 then
             LandPixels[y, x]:= p^[x] or AMask
        else
             LandPixels[y div 2, x div 2]:= p^[x] or AMask;

    p:= @(p^[Surface^.pitch div 4]);
    end;

if SDL_MustLock(Surface) then
    SDL_UnlockSurface(Surface);
end;

procedure GenMaze;
const small_cell_size = 128;
    medium_cell_size = 192;
    large_cell_size = 256;
    braidness = 10;

var x, y: LongInt;
    cellsize: LongInt; //selected by the user in the gui
    seen_cells_x, seen_cells_y: LongInt; //number of cells that can be visited by the generator, that is every second cell in x and y direction. the cells between there are walls that will be removed when we move from one cell to another
    num_edges_x, num_edges_y: LongInt; //number of resulting edges that need to be vertexificated
    num_cells_x, num_cells_y: LongInt; //actual number of cells, depending on cell size
    seen_list: array of array of LongInt;
    xwalls: array of array of Boolean;
    ywalls: array of array of Boolean;
    x_edge_list: array of array of Boolean;
    y_edge_list: array of array of Boolean;
    maze: array of array of Boolean;
    pa: TPixAr;
    num_vertices: LongInt;
    off_y: LongInt;
    num_steps: LongInt;
    current_step: LongInt;
    step_done: array of Boolean;
    done: Boolean;
    last_cell: array of record x, y: LongInt; end;
    came_from: array of array of record x, y: LongInt; end;
    came_from_pos: array of LongInt;
    maze_inverted: Boolean;

function when_seen(x: LongInt; y: LongInt): LongInt;
begin
if (x < 0) or (x >= seen_cells_x) or (y < 0) or (y >= seen_cells_y) then
    when_seen := current_step
else
    when_seen := seen_list[x, y];
end;

function is_x_edge(x, y: LongInt): Boolean;
begin
if (x < 0) or (x > num_edges_x) or (y < 0) or (y > num_cells_y) then
    is_x_edge := false
else
    is_x_edge := x_edge_list[x, y];
end;

function is_y_edge(x, y: LongInt): Boolean;
begin
if (x < 0) or (x > num_cells_x) or (y < 0) or (y > num_edges_y) then
    is_y_edge := false
else
    is_y_edge := y_edge_list[x, y];
end;

procedure see_cell;
var dir: direction;
    tries: LongInt;
    x, y: LongInt;
    found_cell: Boolean;
    next_dir_clockwise: Boolean;

begin
x := last_cell[current_step].x;
y := last_cell[current_step].y;
seen_list[x, y] := current_step;
case GetRandom(4) of
    0: dir := DIR_N;
    1: dir := DIR_E;
    2: dir := DIR_S;
    3: dir := DIR_W;
end;
tries := 0;
found_cell := false;
if getrandom(2) = 1 then next_dir_clockwise := true
else next_dir_clockwise := false;

while (tries < 5) and not found_cell do
begin
    if when_seen(x + dir.x, y + dir.y) = current_step then //we are seeing ourselves, try another direction
    begin
        //we have already seen the target cell, decide if we should remove the wall anyway
        //(or put a wall there if maze_inverted, but we are not doing that right now)
        if not maze_inverted and (GetRandom(braidness) = 0) then
        //or just warn that inverted+braid+indestructible terrain != good idea
        begin
            case dir.x of
                -1: if x > 0 then ywalls[x-1, y] := false;
                1: if x < seen_cells_x - 1 then ywalls[x, y] := false;
            end;
            case dir.y of
                -1: if y > 0 then xwalls[x, y-1] := false;
                1: if y < seen_cells_y - 1 then xwalls[x, y] := false;
            end;
        end;
        if next_dir_clockwise then
        begin
            if dir = DIR_N then
                dir := DIR_E
            else if dir = DIR_E then
                dir := DIR_S
            else if dir = DIR_S then
                dir := DIR_W
            else
                dir := DIR_N;
        end
        else
        begin
            if dir = DIR_N then
                dir := DIR_W
            else if dir = DIR_E then
                dir := DIR_N
            else if dir = DIR_S then
                dir := DIR_E
            else
                dir := DIR_S;
        end
    end
    else if when_seen(x + dir.x, y + dir.y) = -1 then //cell was not seen yet, go there
    begin
        case dir.y of
            -1: xwalls[x, y-1] := false;
            1: xwalls[x, y] := false;
        end;
        case dir.x of
            -1: ywalls[x-1, y] := false;
            1: ywalls[x, y] := false;
        end;
        last_cell[current_step].x := x+dir.x;
        last_cell[current_step].y := y+dir.y;
        came_from_pos[current_step] := came_from_pos[current_step] + 1;
        came_from[current_step, came_from_pos[current_step]].x := x;
        came_from[current_step, came_from_pos[current_step]].y := y;
        found_cell := true;
    end
    else //we are seeing someone else, quit
    begin
        step_done[current_step] := true;
        found_cell := true;
    end;

    tries := tries + 1;
end;
if not found_cell then
begin
    last_cell[current_step].x := came_from[current_step, came_from_pos[current_step]].x;
    last_cell[current_step].y := came_from[current_step, came_from_pos[current_step]].y;
    came_from_pos[current_step] := came_from_pos[current_step] - 1;
    if came_from_pos[current_step] >= 0 then see_cell
    else step_done[current_step] := true;
end;
end;

procedure add_vertex(x, y: LongInt);
var tmp_x, tmp_y: LongInt;
begin
if x = NTPX then
begin
    if pa.ar[num_vertices - 6].x = NTPX then
    begin
        num_vertices := num_vertices - 6;
    end
    else
    begin
        pa.ar[num_vertices].x := NTPX;
        pa.ar[num_vertices].y := 0;
    end
end
else
begin
    if maze_inverted or (x mod 2 = 0) then tmp_x := cellsize
    else tmp_x := cellsize * 2 div 3;
    if maze_inverted or (y mod 2 = 0) then tmp_y := cellsize
    else tmp_y := cellsize * 2 div 3;

    pa.ar[num_vertices].x := (x-1)*cellsize + tmp_x;
    pa.ar[num_vertices].y := (y-1)*cellsize + tmp_y + off_y;
end;
num_vertices := num_vertices + 1;
end;

procedure add_edge(x, y: LongInt; dir: direction);
var i: LongInt;
begin
if dir = DIR_N then
begin
    dir := DIR_W
end
else if dir = DIR_E then
begin
    dir := DIR_N
end
else if dir = DIR_S then
begin
    dir := DIR_E
end
else
begin
    dir := DIR_S;
end;

for i := 0 to 3 do
begin
        if dir = DIR_N then
            dir := DIR_E
        else if dir = DIR_E then
            dir := DIR_S
        else if dir = DIR_S then
            dir := DIR_W
        else
            dir := DIR_N;

    if (dir = DIR_N) and is_x_edge(x, y) then
        begin
            x_edge_list[x, y] := false;
            add_vertex(x+1, y);
            add_edge(x, y-1, DIR_N);
            break;
        end;

    if (dir = DIR_E) and is_y_edge(x+1, y) then
        begin
            y_edge_list[x+1, y] := false;
            add_vertex(x+2, y+1);
            add_edge(x+1, y, DIR_E);
            break;
        end;

    if (dir = DIR_S) and is_x_edge(x, y+1) then
        begin
            x_edge_list[x, y+1] := false;
            add_vertex(x+1, y+2);
            add_edge(x, y+1, DIR_S);
            break;
        end;

    if (dir = DIR_W) and is_y_edge(x, y) then
        begin
            y_edge_list[x, y] := false;
            add_vertex(x, y+1);
            add_edge(x-1, y, DIR_W);
            break;
        end;
end;

end;

begin
case cMazeSize of
    0: begin
        cellsize := small_cell_size;
        maze_inverted := false;
    end;
    1: begin
        cellsize := medium_cell_size;
        maze_inverted := false;
    end;
    2: begin
        cellsize := large_cell_size;
        maze_inverted := false;
    end;
    3: begin
        cellsize := small_cell_size;
        maze_inverted := true;
    end;
    4: begin
        cellsize := medium_cell_size;
        maze_inverted := true;
    end;
    5: begin
        cellsize := large_cell_size;
        maze_inverted := true;
    end;
end;

num_cells_x := LAND_WIDTH div cellsize;
if not odd(num_cells_x) then num_cells_x := num_cells_x - 1; //needs to be odd
num_cells_y := LAND_HEIGHT div cellsize;
if not odd(num_cells_y) then num_cells_y := num_cells_y - 1;
num_edges_x := num_cells_x - 1;
num_edges_y := num_cells_y - 1;
seen_cells_x := num_cells_x div 2;
seen_cells_y := num_cells_y div 2;

if maze_inverted then
    num_steps := 3 //TODO randomize, between 3 and 5?
else
    num_steps := 1;
SetLength(step_done, num_steps);
SetLength(last_cell, num_steps);
SetLength(came_from_pos, num_steps);
SetLength(came_from, num_steps, num_cells_x*num_cells_y);
done := false;
for current_step := 0 to num_steps - 1 do
    step_done[current_step] := false;
    came_from_pos[current_step] := 0;
current_step := 0;

SetLength(seen_list, seen_cells_x, seen_cells_y);
SetLength(xwalls, seen_cells_x, seen_cells_y - 1);
SetLength(ywalls, seen_cells_x - 1, seen_cells_y);
SetLength(x_edge_list, num_edges_x, num_cells_y);
SetLength(y_edge_list, num_cells_x, num_edges_y);
SetLength(maze, num_cells_x, num_cells_y);

num_vertices := 0;

playHeight := num_cells_y * cellsize;
playWidth := num_cells_x * cellsize;
off_y := LAND_HEIGHT - playHeight;

for x := 0 to playWidth do
    for y := 0 to off_y - 1 do
        Land[y, x] := 0;

for x := 0 to playWidth do
    for y := off_y to LAND_HEIGHT - 1 do
        Land[y, x] := lfBasic;

for y := 0 to num_cells_y - 1 do
    for x := 0 to num_cells_x - 1 do
        maze[x, y] := false;

for x := 0 to seen_cells_x - 1 do
    for y := 0 to seen_cells_y - 2 do
        xwalls[x, y] := true;

for x := 0 to seen_cells_x - 2 do
    for y := 0 to seen_cells_y - 1 do
        ywalls[x, y] := true;

for x := 0 to seen_cells_x - 1 do
    for y := 0 to seen_cells_y - 1 do
        seen_list[x, y] := -1;

for x := 0 to num_edges_x - 1 do
    for y := 0 to num_cells_y - 1 do
        x_edge_list[x, y] := false;

for x := 0 to num_cells_x - 1 do
    for y := 0 to num_edges_y - 1 do
        y_edge_list[x, y] := false;

for current_step := 0 to num_steps-1 do
begin
    x := GetRandom(seen_cells_x - 1) div LongWord(num_steps);
    last_cell[current_step].x := x + current_step * seen_cells_x div num_steps;
    last_cell[current_step].y := GetRandom(seen_cells_y);
end;

while not done do
begin
    done := true;
    for current_step := 0 to num_steps-1 do
    begin
        if not step_done[current_step] then
        begin
            see_cell;
            done := false;
        end;
    end;
end;

for x := 0 to seen_cells_x - 1 do
    for y := 0 to seen_cells_y - 1 do
        if seen_list[x, y] > -1 then
            maze[(x+1)*2-1, (y+1)*2-1] := true;

for x := 0 to seen_cells_x - 1 do
    for y := 0 to seen_cells_y - 2 do
        if not xwalls[x, y] then
            maze[x*2 + 1, y*2 + 2] := true;


for x := 0 to seen_cells_x - 2 do
     for y := 0 to seen_cells_y - 1 do
        if not ywalls[x, y] then
            maze[x*2 + 2, y*2 + 1] := true;

for x := 0 to num_edges_x - 1 do
    for y := 0 to num_cells_y - 1 do
        if maze[x, y] xor maze[x+1, y] then
            x_edge_list[x, y] := true
        else
            x_edge_list[x, y] := false;

for x := 0 to num_cells_x - 1 do
    for y := 0 to num_edges_y - 1 do
        if maze[x, y] xor maze[x, y+1] then
            y_edge_list[x, y] := true
        else
            y_edge_list[x, y] := false;

for x := 0 to num_edges_x - 1 do
    for y := 0 to num_cells_y - 1 do
        if x_edge_list[x, y] then
        begin
            x_edge_list[x, y] := false;
            add_vertex(x+1, y+1);
            add_vertex(x+1, y);
            add_edge(x, y-1, DIR_N);
            add_vertex(NTPX, 0);
        end;

pa.count := num_vertices;

RandomizePoints(pa);
BezierizeEdge(pa, _0_25);
RandomizePoints(pa);
BezierizeEdge(pa, _0_25);

DrawEdge(pa, 0);

if maze_inverted then
    FillLand(1, 1+off_y)
else
begin
    x := 0;
    while Land[cellsize div 2 + cellsize + off_y, x] = lfBasic do
        x := x + 1;
    while Land[cellsize div 2 + cellsize + off_y, x] = 0 do
        x := x + 1;
    FillLand(x+1, cellsize div 2 + cellsize + off_y);
end;

MaxHedgehogs:= 32;
if (GameFlags and gfDisableGirders) <> 0 then hasGirders:= false
else hasGirders := true;
leftX:= 0;
rightX:= playWidth;
topY:= off_y;
hasBorder := false;
end;

procedure GenLandSurface;
var tmpsurf: PSDL_Surface;
begin
    WriteLnToConsole('Generating land...');
    case cMapGen of
        0: GenBlank(EdgeTemplates[SelectTemplate]);
        1: GenMaze;
    end;
    AddProgress();

    tmpsurf:= SDL_CreateRGBSurface(SDL_SWSURFACE, LAND_WIDTH, LAND_HEIGHT, 32, RMask, GMask, BMask, 0);

    TryDo(tmpsurf <> nil, 'Error creating pre-land surface', true);
    ColorizeLand(tmpsurf);
    AddOnLandObjects(tmpsurf);

    LandSurface2LandPixels(tmpsurf);
    SDL_FreeSurface(tmpsurf);
    AddProgress();
end;

procedure MakeFortsMap;
var tmpsurf: PSDL_Surface;
begin
MaxHedgehogs:= 32;
// For now, defining a fort is playable area as 3072x1200 - there are no tall forts.  The extra height is to avoid triggering border with current code, also if user turns on a border, it will give a bit more maneuvering room.
playHeight:= 1200;
playWidth:= 2560;
leftX:= (LAND_WIDTH - playWidth) div 2;
rightX:= ((playWidth + (LAND_WIDTH - playWidth) div 2) - 1);
topY:= LAND_HEIGHT - playHeight;

WriteLnToConsole('Generating forts land...');

tmpsurf:= LoadImage(Pathz[ptForts] + '/' + ClansArray[0]^.Teams[0]^.FortName + 'L', ifAlpha or ifCritical or ifTransparent or ifIgnoreCaps);
BlitImageAndGenerateCollisionInfo(leftX+150, LAND_HEIGHT - tmpsurf^.h, tmpsurf^.w, tmpsurf);
SDL_FreeSurface(tmpsurf);

tmpsurf:= LoadImage(Pathz[ptForts] + '/' + ClansArray[1]^.Teams[0]^.FortName + 'R', ifAlpha or ifCritical or ifTransparent or ifIgnoreCaps);
BlitImageAndGenerateCollisionInfo(rightX - 150 - tmpsurf^.w, LAND_HEIGHT - tmpsurf^.h, tmpsurf^.w, tmpsurf);
SDL_FreeSurface(tmpsurf);
end;

// Hi unC0Rr.
// This is a function that Tiy assures me would not be good for gameplay.
// It allows the setting of arbitrary portions of landscape as indestructible, or regular, or even blank.
// He said I could add it here only when I swore it would not impact gameplay.  Which, as far as I can tell, is true.
// I would just like to play with it with my friends if you do not mind.
// Can allow for amusing maps.
procedure LoadMask;
var tmpsurf: PSDL_Surface;
    p: PLongwordArray;
    x, y, cpX, cpY: Longword;
begin
    tmpsurf:= LoadImage(Pathz[ptMapCurrent] + '/mask', ifAlpha or ifTransparent or ifIgnoreCaps);
    if (tmpsurf <> nil) and (tmpsurf^.w <= LAND_WIDTH) and (tmpsurf^.h <= LAND_HEIGHT) and (tmpsurf^.format^.BytesPerPixel = 4) then
    begin
        cpX:= (LAND_WIDTH - tmpsurf^.w) div 2;
        cpY:= LAND_HEIGHT - tmpsurf^.h;
        if SDL_MustLock(tmpsurf) then
            SDLTry(SDL_LockSurface(tmpsurf) >= 0, true);

            p:= tmpsurf^.pixels;
            for y:= 0 to Pred(tmpsurf^.h) do
            begin
                for x:= 0 to Pred(tmpsurf^.w) do
                begin
                    if ((AMask and p^[x]) = 0) then  // Tiy was having trouble generating transparent black
                        Land[cpY + y, cpX + x]:= 0
                    else if p^[x] = (AMask or RMask) then
                        Land[cpY + y, cpX + x]:= lfIndestructible
                    else if p^[x] = $FFFFFFFF then
                        Land[cpY + y, cpX + x]:= lfBasic;
                end;
                p:= @(p^[tmpsurf^.pitch div 4]);
            end;

        if SDL_MustLock(tmpsurf) then
            SDL_UnlockSurface(tmpsurf);
    end;
    if (tmpsurf <> nil) then 
        SDL_FreeSurface(tmpsurf);
    tmpsurf:= nil;
end;

procedure LoadMap;
var tmpsurf: PSDL_Surface;
    s: shortstring;
    f: textfile;
begin
isMap:= true;
WriteLnToConsole('Loading land from file...');
AddProgress;
tmpsurf:= LoadImage(Pathz[ptMapCurrent] + '/map', ifAlpha or ifCritical or ifTransparent or ifIgnoreCaps);
TryDo((tmpsurf^.w <= LAND_WIDTH) and (tmpsurf^.h <= LAND_HEIGHT), 'Map dimensions too big!', true);

// unC0Rr - should this be passed from the GUI? I am not sure which layer does what
s:= Pathz[ptMapCurrent] + '/map.cfg';
WriteLnToConsole('Fetching map HH limit');
Assign(f, s);
filemode:= 0; // readonly
Reset(f);
Readln(f);
if not eof(f) then Readln(f, MaxHedgehogs);

if (MaxHedgehogs = 0) then MaxHedgehogs:= 18;

playHeight:= tmpsurf^.h;
playWidth:= tmpsurf^.w;
leftX:= (LAND_WIDTH - playWidth) div 2;
rightX:= (playWidth + ((LAND_WIDTH - playWidth) div 2)) - 1;
topY:= LAND_HEIGHT - playHeight;

TryDo(tmpsurf^.format^.BytesPerPixel = 4, 'Map should be 32bit', true);

BlitImageAndGenerateCollisionInfo(
    (LAND_WIDTH - tmpsurf^.w) div 2,
    LAND_HEIGHT - tmpsurf^.h,
    tmpsurf^.w,
    tmpsurf);
SDL_FreeSurface(tmpsurf);

LoadMask;
end;

procedure GenMap;
var x, y, w, c: Longword;
begin
    hasBorder:= false;

    LoadThemeConfig;
    isMap:= false;
    
    if ((GameFlags and gfForts) <> 0) or (Pathz[ptMapCurrent] <> '') then
        FillChar(Land,SizeOf(TCollisionArray),0);
        
    if (GameFlags and gfForts) = 0 then
        if Pathz[ptMapCurrent] <> '' then
            LoadMap
        else
            GenLandSurface
    else
        MakeFortsMap;

    AddProgress;

{$IFDEF DEBUGFILE}LogLandDigest;{$ENDIF}

// check for land near top
c:= 0;
if (GameFlags and gfBorder) <> 0 then
    hasBorder:= true
else
    for y:= topY to topY + 5 do
        for x:= leftX to rightX do
            if Land[y, x] <> 0 then
                begin
                inc(c);
                if c > 200 then // avoid accidental triggering
                    begin
                    hasBorder:= true;
                    break;
                    end;
                end;

if hasBorder then
    begin
    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]:= lfIndestructible;
    // experiment hardcoding cave
    // also try basing cave dimensions on map/template dimensions, if they exist
    for w:= 0 to 5 do // width of 3 allowed hogs to be knocked through with grenade
        begin
        for y:= topY to LAND_HEIGHT - 1 do
            begin
                Land[y, leftX + w]:= lfIndestructible;
                Land[y, rightX - w]:= lfIndestructible;
                if (y + w) mod 32 < 16 then
                    c:= AMask
                else
                    c:= AMask or RMask or GMask; // FF00FFFF

                if (cReducedQuality and rqBlurryLand) = 0 then
                begin
                    LandPixels[y, leftX + w]:= c;
                    LandPixels[y, rightX - w]:= c;
                end
                else
                begin
                    LandPixels[y div 2, (leftX + w) div 2]:= c;
                    LandPixels[y div 2, (rightX - w) div 2]:= c;
                end;
            end;

        for x:= leftX to rightX do
            begin
                Land[topY + w, x]:= lfIndestructible;
                if (x + w) mod 32 < 16 then
                    c:= AMask
                else
                    c:= AMask or RMask or GMask; // FF00FFFF

                if (cReducedQuality and rqBlurryLand) = 0 then
                    LandPixels[topY + w, x]:= c
                else
                    LandPixels[(topY + w) div 2, x div 2]:= c;
            end;
        end;
    end;

if (GameFlags and gfDisableGirders) <> 0 then hasGirders:= false;

if ((GameFlags and gfForts) = 0)
    and ((GameFlags and gfDisableLandObjects) = 0)
    and (Pathz[ptMapCurrent] = '')
    then AddObjects;

FreeLandObjects;

UpdateLandTexture(0, LAND_WIDTH, 0, LAND_HEIGHT);
end;

function GenPreview: TPreview;
var x, y, xx, yy, t, bit: LongInt;
    Preview: TPreview;
begin
    WriteLnToConsole('Generating preview...');
    case cMapGen of
        0: GenBlank(EdgeTemplates[SelectTemplate]);
        1: GenMaze;
    end;

    for y:= 0 to 127 do
        for x:= 0 to 31 do
        begin
            Preview[y, x]:= 0;
            for bit:= 0 to 7 do
            begin
                t:= 0;
                for yy:= y * (LAND_HEIGHT div 128) to y * (LAND_HEIGHT div 128) + 7 do
                    for xx:= x * (LAND_WIDTH div 32) + bit * 8 to x * (LAND_WIDTH div 32) + bit * 8 + 7 do
                        if Land[yy, xx] <> 0 then inc(t);
                if t > 8 then
                    Preview[y, x]:= Preview[y, x] or ($80 shr bit);
            end;
        end;

    GenPreview:= Preview
end;

procedure initModule;
begin
    LandBackSurface:= nil;
    digest:= '';
    FillChar(LandPixels, sizeof(TLandArray), 0);
end;

procedure freeModule;
begin

end;

end.