unit uLandObjects;
interface
uses SDLh;
{$include options.inc}

procedure AddObjects(Surface: PSDL_Surface);
procedure BlitImageAndGenerateCollisionInfo(cpX, cpY: Longword; Image, Surface: PSDL_Surface);

implementation
uses uLand, uStore, uConsts, uMisc, uConsole, uRandom;
const MaxRects = 256;
      MAXOBJECTRECTS = 16;
type  PRectArray = ^TRectsArray;
      TRectsArray = array[0..MaxRects] of TSDL_rect;

type TThemeObject = record
                    Surf: PSDL_Surface;
                    inland: TSDL_Rect;
                    outland: array[1..MAXOBJECTRECTS] of TSDL_Rect;
                    rectcnt: Longword;
                    Width, Height: Longword;
                    end;

var Rects: PRectArray;
    RectCount: Longword;

procedure BlitImageAndGenerateCollisionInfo(cpX, cpY: Longword; Image, Surface: PSDL_Surface);
var i, p: LongWord;
    x, y: Longword;
    bpp: integer;
    r: TSDL_Rect;
begin
r.x:= cpX;
r.y:= cpY;
SDL_UpperBlit(Image, nil, Surface, @r);
WriteToConsole('Generating collision info... ');

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

bpp:= Image.format.BytesPerPixel;
WriteToConsole('('+inttostr(bpp)+') ');
p:= LongWord(Image.pixels);
case bpp of
     1: OutError('We don''t work with 8 bit surfaces', true);
     2: for y:= 0 to Pred(Image.h) do
            begin
            i:= Longword(@Land[cpY + y, cpX]);
            for x:= 0 to Pred(Image.w) do
                if PWord(p + x * 2)^ <> 0 then PLongWord(i + x * 4)^:= $FFFFFF;
            inc(p, Image.pitch);
            end;
     3: for y:= 0 to Pred(Image.h) do
            begin
            i:= Longword(@Land[cpY + y, cpX]);
            for x:= 0 to Pred(Image.w) do
                if  (PByte(p + x * 3 + 0)^ <> 0)
                 or (PByte(p + x * 3 + 1)^ <> 0)
                 or (PByte(p + x * 3 + 2)^ <> 0) then PLongWord(i + x * 4)^:= $FFFFFF;
            inc(p, Image.pitch);
            end;
     4: for y:= 0 to Pred(Image.h) do
            begin
            i:= Longword(@Land[cpY + y, cpX]);
            for x:= 0 to Pred(Image.w) do
                if PLongword(p + x * 4)^ <> 0 then PLongWord(i + x * 4)^:= $FFFFFF;
            inc(p, Image.pitch);
            end;
     end;
if SDL_MustLock(Image) then
   SDL_UnlockSurface(Image);
WriteLnToConsole(msgOK)
end;

procedure AddRect(x1, y1, w1, h1: integer);
begin
with Rects[RectCount] do
     begin
     x:= x1;
     y:= y1;
     w:= w1;
     h:= h1
     end;
inc(RectCount);
TryDo(RectCount < MaxRects, 'AddRect: overflow', true)
end;

procedure InitRects;
begin
RectCount:= 0;
New(Rects)
end;

procedure FreeRects;
begin
Dispose(rects)
end;

function CheckIntersect(x1, y1, w1, h1: integer): boolean;
var i: Longword;
begin
Result:= false;
i:= 0;
if RectCount > 0 then
   repeat
   with Rects[i] do
        Result:= (x < x1 + w1) and (x1 < x + w) and
                 (y < y1 + h1) and (y1 < y + h);
   inc(i)
   until (i = RectCount) or (Result)
end;

function AddGirder(gX: integer; Surface: PSDL_Surface): boolean;
var tmpsurf: PSDL_Surface;
    x1, x2, y, k, i: integer;
    r, rr: TSDL_Rect;

    function CountNonZeroz(x, y: integer): Longword;
    var i: integer;
    begin
    Result:= 0;
    for i:= y to y + 15 do
        if Land[i, x] <> 0 then inc(Result)
    end;

begin
y:= 150;
repeat
  inc(y, 24);
  x1:= gX;
  x2:= gX;
  while (x1 > 100) and (CountNonZeroz(x1, y) = 0) do dec(x1, 2);
  i:= x1 - 12;
  repeat
    k:= CountNonZeroz(x1, y);
    dec(x1, 2)
  until (x1 < 100) or (k = 0) or (k = 16) or (x1 < i);
  inc(x1, 2);
  if k = 16 then
     begin
     while (x2 < 1900) and (CountNonZeroz(x2, y) = 0) do inc(x2, 2);
     i:= x2 + 12;
     repeat
       k:= CountNonZeroz(x2, y);
       inc(x2, 2)
     until (x2 > 1900) or (k = 0) or (k = 16) or (x2 > i);
     if (x2 < 1900) and (k = 16) and (x2 - x1 > 250)
        and not CheckIntersect(x1 - 32, y - 64, x2 - x1 + 64, 144) then break;
     end;
x1:= 0;
until y > 900;
if x1 > 0 then
   begin
   Result:= true;
   tmpsurf:= LoadImage(Pathz[ptGraphics] + 'Girder.png', false);
   rr.x:= x1;
   rr.y:= y;
   while rr.x + 100 < x2 do
         begin
         SDL_UpperBlit(tmpsurf, nil, Surface, @rr);
         inc(rr.x, 100);
         end;
   r.x:= 0;
   r.y:= 0;
   r.w:= x2 - rr.x;
   r.h:= 16;
   SDL_UpperBlit(tmpsurf, @r, Surface, @rr);
   SDL_FreeSurface(tmpsurf);
   AddRect(x1 - 8, y - 32, x2 - x1 + 16, 80);
   for k:= y to y + 15 do
       for i:= x1 to x2 do Land[k, i]:= $FFFFFF
   end else Result:= false
end;

function CheckLand(rect: TSDL_Rect; dX, dY, Color: Longword): boolean;
var i: Longword;
begin
Result:= true;
inc(rect.x, dX);
inc(rect.y, dY);
i:= 0;
{$WARNINGS OFF}
while (i <= rect.w) and Result do
      begin
      Result:= (Land[rect.y, rect.x + i] = Color) and (Land[rect.y + rect.h, rect.x + i] = Color);
      inc(i)
      end;
i:= 0;
while (i <= rect.h) and Result do
      begin
      Result:= (Land[rect.y + i, rect.x] = Color) and (Land[rect.y + i, rect.x + rect.w] = Color);
      inc(i)
      end;
{$WARNINGS ON}
end;

function CheckCanPlace(x, y: Longword; var Obj: TThemeObject): boolean;
var i: Longword;
begin
with Obj do
     if CheckLand(inland, x, y, $FFFFFF) then
        begin
        Result:= true;
        i:= 1;
        while Result and (i <= rectcnt) do
              begin
              Result:= CheckLand(outland[i], x, y, 0);
              inc(i)
              end;
        if Result then
           Result:= not CheckIntersect(x, y, Width, Height)
        end else
        Result:= false
end;

function TryPut(var Obj: TThemeObject; Surface: PSDL_Surface): boolean;
const MaxPointsIndex = 2047;
var x, y: Longword;
    ar: array[0..MaxPointsIndex] of TPoint;
    cnt, i: Longword;
begin
cnt:= 0;
with Obj do
     begin
     x:= 0;
     repeat
         y:= 0;
         repeat
             if CheckCanPlace(x, y, Obj) then
                begin
                ar[cnt].x:= x;
                ar[cnt].y:= y;
                inc(cnt);
                if cnt > MaxPointsIndex then // buffer is full, do not check the rest land
                   begin
                   y:= 5000;
                   x:= 5000;
                   end
                end;
             inc(y, 3);
         until y > 1023 - Height;
         inc(x, getrandom(6) + 3)
     until x > 2047 - Width;
     Result:= cnt <> 0;
     if Result then
        begin
        i:= getrandom(cnt);
        BlitImageAndGenerateCollisionInfo(ar[i].x, ar[i].y, Obj.Surf, Surface);
        AddRect(ar[i].x, ar[i].y, Width, Height);
        end
     end
end;

procedure AddThemeObjects(Surface: PSDL_Surface; MaxCount: Longword);
const MAXTHEMEOBJECTS = 32;
var f: textfile;
    s: string;
    ThemeObjects: array[1..MAXTHEMEOBJECTS] of TThemeObject;
    i, ii, t, n: Longword;
    b: boolean;
begin
s:= Pathz[ptThemeCurrent] + cThemeCFGFilename;
WriteLnToConsole('Adding objects...');
AssignFile(f, s);
{$I-}
Reset(f);
Readln(f, s); // skip color
Readln(f, n);
for i:= 1 to n do
    begin
    Readln(f, s); // filename
    with ThemeObjects[i] do
         begin
         Surf:= LoadImage(Pathz[ptThemeCurrent] + s + '.png', false);
         Read(f, Width, Height);
         with inland do Read(f, x, y, w, h);
         Read(f, rectcnt);
         for ii:= 1 to rectcnt do
             with outland[ii] do Read(f, x, y, w, h);
         ReadLn(f)
         end;
    end;
Closefile(f);
{$I+}
TryDo(IOResult = 0, 'Bad data or cannot access file', true);

// loaded objects, try to put on land
if n = 0 then exit;
i:= 1;
repeat
    t:= getrandom(n) + 1;
    ii:= t;
    repeat
      inc(ii);
      if ii > n then ii:= 1;
      b:= TryPut(ThemeObjects[ii], Surface)
    until b or (ii = t);
inc(i)
until (i > MaxCount) or not b
end;

procedure AddObjects(Surface: PSDL_Surface);
begin
InitRects;
AddGirder(512, Surface);
AddGirder(1024, Surface);
AddGirder(1300, Surface);
AddGirder(1536, Surface);
AddThemeObjects(Surface, 8);
FreeRects
end;

end.