(*
 * Hedgewars, a free turn based strategy game
 * Copyright (c) 2005-2008 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
 *)

unit uLand;
interface
uses SDLh, uLandTemplates, uFloat,
{$IFDEF GLES11}
	gles11,
{$ELSE}
	GL,
{$ENDIF}
	uConsts;
{$include options.inc}
type TLandArray = packed array[0 .. LAND_HEIGHT - 1, 0 .. LAND_WIDTH - 1] of LongWord;
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; // I'm putting this here for now.  I'd like it to be toggleable by user (so user can set a border on a non-cave map) - will turn off air attacks
     hasGirders: boolean;  // I think should be on template by template basis. some caverns might have open water and large spaces.  Some islands do not need? It might be better to tweak the girder code based upon space above.  dunno.
     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.  Maybe not a good idea, but, for now?  Could also be used to prevent placing a girder outside play area on maps with hasBorder = true

// in your coding style, it appears to be "isXXXX" for a verb, and "FooBar" for everything else - should be PlayHeight ?

procedure GenMap;
function  GenPreview: TPreview;
procedure CheckLandDigest(s: shortstring);

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

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

procedure LogLandDigest;
var ctx: TSHA1Context;
    dig: TSHA1Digest;
    s: shortstring;
begin
SHA1Init(ctx);
SHA1UpdateLongwords(ctx, @Land, sizeof(Land) div 4);
dig:= SHA1Final(ctx);
s:='M{'+inttostr(dig[0])+':'
       +inttostr(dig[1])+':'
       +inttostr(dig[2])+':'
       +inttostr(dig[3])+':'
       +inttostr(dig[4])+'}';
CheckLandDigest(s);
SendIPCRaw(@s[0], Length(s) + 1)
end;

procedure CheckLandDigest(s: shortstring);
const digest: shortstring = '';
begin
{$IFDEF DEBUGFILE}
AddFileLog('CheckLandDigest: ' + s);
{$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);
Vector(opa.ar[pi], opa.ar[i], opa.ar[ni], NVx, NVy);
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;
       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);
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;

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);

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;
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 - 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
radz[0]:= 0;
for i:= 0 to Pred(pa.Count) do
  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;

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]:= COLOR_LAND;

SetPoints(Template, pa);
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, COLOR_LAND);

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]:= COLOR_LAND
               else if Land[y, x] = COLOR_LAND 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 LandPixels[y, x]:= p^[x] or $FF000000;

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

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

procedure GenLandSurface;
var tmpsurf: PSDL_Surface;
begin
WriteLnToConsole('Generating land...');

GenBlank(EdgeTemplates[SelectTemplate]);

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
// 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 (($FF000000 and p^[x]) = 0) then  // Tiy was having trouble generating transparent black
                Land[cpY + y, cpX + x]:= 0
            else if p^[x] = $FF0000FF then
                Land[cpY + y, cpX + x]:= COLOR_INDESTRUCTIBLE
            else if p^[x] = $FFFFFFFF then
                Land[cpY + y, cpX + x]:= COLOR_LAND;

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

    if SDL_MustLock(tmpsurf) then
       SDL_UnlockSurface(tmpsurf);
    SDL_FreeSurface(tmpsurf);
    end;
end;

procedure LoadMap;
var tmpsurf: PSDL_Surface;
	s: string;
	f: textfile;
begin
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);
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;
hasGirders:= true;
LoadThemeConfig;

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]:= COLOR_INDESTRUCTIBLE;
	// 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]:= COLOR_INDESTRUCTIBLE;
			Land[y, rightX - w]:= COLOR_INDESTRUCTIBLE;
			if (y + w) mod 32 < 16 then
				c:= $FF000000
			else
				c:= $FF00FFFF;
			LandPixels[y, leftX + w]:= c;
			LandPixels[y, rightX - w]:= c;
			end;

		for x:= leftX to rightX do
			begin
			Land[topY + w, x]:= COLOR_INDESTRUCTIBLE;
			if (x + w) mod 32 < 16 then
				c:= $FF000000
			else
				c:= $FF00FFFF;
			LandPixels[topY + w, x]:= c;
			end;
		end;
	end;

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

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...');
GenBlank(EdgeTemplates[SelectTemplate]);

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;

initialization

end.