X-Git-Url: http://deadsoftware.ru/gitweb?a=blobdiff_plain;f=src%2Fgame%2Fg_grid.pas;h=8ff01a629340b582ad58c0cb40046f8b80c251a3;hb=dc9a52bb70e79e18ad014ce777029bb8ee1d85c4;hp=900a3661d90c49ccec2363d6e9e6814b71164b75;hpb=db59ff57bab603a3b811cb725b37ec43e5838125;p=d2df-sdl.git

diff --git a/src/game/g_grid.pas b/src/game/g_grid.pas
index 900a366..8ff01a6 100644
--- a/src/game/g_grid.pas
+++ b/src/game/g_grid.pas
@@ -13,145 +13,112 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *)
-{$MODE DELPHI}
-{$modeswitch nestedprocvars}
+// universal spatial grid
+{$INCLUDE ../shared/a_modes.inc}
+{$DEFINE grid_use_buckets}
 unit g_grid;
 
 interface
 
-uses e_log;
-
-const
-  GridDefaultTileSize = 32;
 
 type
-  GridQueryCB = function (obj: TObject; tag: Integer): Boolean is nested; // return `true` to stop
+  TBodyProxyId = Integer;
 
-type
-  TBodyGrid = class;
+  generic TBodyGridBase<ITP> = class(TObject)
+  public
+    type TGridQueryCB = function (obj: ITP; tag: Integer): Boolean is nested; // return `true` to stop
 
-  TBodyProxy = class(TObject)
   private
-    mX, mY, mWidth, mHeight: Integer; // aabb
-    mQueryMark: DWord; // was this object visited at this query?
-    mObj: TObject;
-    mGrid: TBodyGrid;
-    mTag: Integer;
-    prevLink: TBodyProxy; // only for used
-    nextLink: TBodyProxy; // either used or free
+    const
+      GridDefaultTileSize = 32;
+      GridCellBucketSize = 8; // WARNING! can't be less than 2!
 
   private
-    procedure setup (aX, aY, aWidth, aHeight: Integer; aObj: TObject; aTag: Integer);
-
-  public
-    constructor Create (aGrid: TBodyGrid; aX, aY, aWidth, aHeight: Integer; aObj: TObject; aTag: Integer);
-    destructor Destroy (); override;
+    type
+      PBodyProxyRec = ^TBodyProxyRec;
+      TBodyProxyRec = record
+      private
+        mX, mY, mWidth, mHeight: Integer; // aabb
+        mQueryMark: DWord; // was this object visited at this query?
+        mObj: ITP;
+        mTag: Integer;
+        nextLink: TBodyProxyId; // next free or nothing
+
+      private
+        procedure setup (aX, aY, aWidth, aHeight: Integer; aObj: ITP; aTag: Integer);
+      end;
 
-    property x: Integer read mX;
-    property y: Integer read mY;
-    property width: Integer read mWidth;
-    property height: Integer read mHeight;
-    property obj: TObject read mObj;
-    property tag: Integer read mTag;
-    property grid: TBodyGrid read mGrid;
-  end;
+      PGridCell = ^TGridCell;
+      TGridCell = record
+        {$IFDEF grid_use_buckets}
+        bodies: array [0..GridCellBucketSize-1] of Integer; // -1: end of list
+        {$ELSE}
+        body: Integer;
+        {$ENDIF}
+        next: Integer; // in this cell; index in mCells
+      end;
 
-  PGridCell = ^TGridCell;
-  TGridCell = record
-    body: TBodyProxy;
-    next: Integer; // in this cell; index in mCells
-  end;
+      TGridInternalCB = function (grida: Integer): Boolean of object; // return `true` to stop
 
-  TBodyGrid = class(TObject)
   private
     mTileSize: Integer;
+    mMinX, mMinY: Integer; // so grids can start at any origin
     mWidth, mHeight: Integer; // in tiles
     mGrid: array of Integer; // mWidth*mHeight, index in mCells
     mCells: array of TGridCell; // cell pool
     mFreeCell: Integer; // first free cell index or -1
-    mLastQuery: Integer;
+    mLastQuery: DWord;
     mUsedCells: Integer;
-    mProxyFree: TBodyProxy; // free
-    mProxyList: TBodyProxy; // used
-    mProxyCount: Integer; // total allocated
+    mProxies: array of TBodyProxyRec;
+    mProxyFree: TBodyProxyId; // free
+    mProxyCount: Integer; // currently used
+    mProxyMaxCount: Integer;
+
+    mUData: TBodyProxyId; // for inserter/remover
+    mTagMask: Integer; // for iterator
+    mItCB: TGridQueryCB; // for iterator
 
   private
     function allocCell: Integer;
     procedure freeCell (idx: Integer); // `next` is simply overwritten
 
-    function allocProxy (aX, aY, aWidth, aHeight: Integer; aObj: TObject; aTag: Integer): TBodyProxy;
-    procedure freeProxy (body: TBodyProxy);
-
-    procedure insert (body: TBodyProxy);
-    procedure remove (body: TBodyProxy);
-
-  public
-    constructor Create (aPixWidth, aPixHeight: Integer; aTileSize: Integer=GridDefaultTileSize);
-    destructor Destroy (); override;
+    function allocProxy (aX, aY, aWidth, aHeight: Integer; aObj: ITP; aTag: Integer): TBodyProxyId;
+    procedure freeProxy (body: TBodyProxyId);
 
-    function insertBody (aObj: TObject; ax, ay, aWidth, aHeight: Integer; aTag: Integer=0): TBodyProxy;
-    procedure removeBody (aObj: TBodyProxy); // WARNING! this will NOT destroy proxy!
+    procedure insert (body: TBodyProxyId);
+    procedure remove (body: TBodyProxyId);
 
-    procedure moveBody (body: TBodyProxy; dx, dy: Integer);
-    procedure resizeBody (body: TBodyProxy; sx, sy: Integer);
-    procedure moveResizeBody (body: TBodyProxy; dx, dy, sx, sy: Integer);
+    function forGridRect (x, y, w, h: Integer; cb: TGridInternalCB): Boolean;
 
-    function forEachInAABB (x, y, w, h: Integer; cb: GridQueryCB): Boolean;
-
-    function getProxyForBody (aObj: TObject; x, y, w, h: Integer): TBodyProxy;
-
-    procedure dumpStats ();
-  end;
-
-
-type
-  TBinaryHeapLessFn = function (a, b: TObject): Boolean;
-
-  TBinaryHeapObj = class(TObject)
-  private
-    elem: array of TObject;
-    elemUsed: Integer;
-    lessfn: TBinaryHeapLessFn;
-
-  private
-    procedure heapify (root: Integer);
+    function inserter (grida: Integer): Boolean;
+    function remover (grida: Integer): Boolean;
+    function iterator (grida: Integer): Boolean;
 
   public
-    constructor Create (alessfn: TBinaryHeapLessFn);
+    constructor Create (aMinPixX, aMinPixY, aPixWidth, aPixHeight: Integer; aTileSize: Integer=GridDefaultTileSize);
     destructor Destroy (); override;
 
-    procedure clear ();
+    function insertBody (aObj: ITP; ax, ay, aWidth, aHeight: Integer; aTag: Integer=0): TBodyProxyId;
+    procedure removeBody (aObj: TBodyProxyId); // WARNING! this WILL destroy proxy!
 
-    procedure insert (val: TObject);
+    procedure moveBody (body: TBodyProxyId; dx, dy: Integer);
+    procedure resizeBody (body: TBodyProxyId; sx, sy: Integer);
+    procedure moveResizeBody (body: TBodyProxyId; dx, dy, sx, sy: Integer);
 
-    function front (): TObject;
-    procedure popFront ();
+    function forEachInAABB (x, y, w, h: Integer; cb: TGridQueryCB; tagmask: Integer=-1): Boolean;
 
-    property count: Integer read elemUsed;
+    procedure dumpStats ();
   end;
 
 
 implementation
 
 uses
-  SysUtils;
+  SysUtils, e_log;
 
 
 // ////////////////////////////////////////////////////////////////////////// //
-constructor TBodyProxy.Create (aGrid: TBodyGrid; aX, aY, aWidth, aHeight: Integer; aObj: TObject; aTag: Integer);
-begin
-  mGrid := aGrid;
-  setup(aX, aY, aWidth, aHeight, aObj, aTag);
-end;
-
-
-destructor TBodyProxy.Destroy ();
-begin
-  inherited;
-end;
-
-
-procedure TBodyProxy.setup (aX, aY, aWidth, aHeight: Integer; aObj: TObject; aTag: Integer);
+procedure TBodyGridBase.TBodyProxyRec.setup (aX, aY, aWidth, aHeight: Integer; aObj: ITP; aTag: Integer);
 begin
   mX := aX;
   mY := aY;
@@ -160,13 +127,12 @@ begin
   mQueryMark := 0;
   mObj := aObj;
   mTag := aTag;
-  prevLink := nil;
-  nextLink := nil;
+  nextLink := -1;
 end;
 
 
 // ////////////////////////////////////////////////////////////////////////// //
-constructor TBodyGrid.Create (aPixWidth, aPixHeight: Integer; aTileSize: Integer=GridDefaultTileSize);
+constructor TBodyGridBase.Create (aMinPixX, aMinPixY, aPixWidth, aPixHeight: Integer; aTileSize: Integer=GridDefaultTileSize);
 var
   idx: Integer;
 begin
@@ -175,55 +141,52 @@ begin
   if aPixWidth < aTileSize then aPixWidth := aTileSize;
   if aPixHeight < aTileSize then aPixHeight := aTileSize;
   mTileSize := aTileSize;
+  mMinX := aMinPixX;
+  mMinY := aMinPixY;
   mWidth := (aPixWidth+aTileSize-1) div aTileSize;
   mHeight := (aPixHeight+aTileSize-1) div aTileSize;
   SetLength(mGrid, mWidth*mHeight);
   SetLength(mCells, mWidth*mHeight);
+  SetLength(mProxies, 8192);
   mFreeCell := 0;
   // init free list
   for idx := 0 to High(mCells) do
   begin
-    mCells[idx].body := nil;
+    {$IFDEF grid_use_buckets}
+    mCells[idx].bodies[0] := -1;
+    {$ELSE}
+    mCells[idx].body := -1;
+    {$ENDIF}
     mCells[idx].next := idx+1;
   end;
   mCells[High(mCells)].next := -1; // last cell
   // init grid
   for idx := 0 to High(mGrid) do mGrid[idx] := -1;
+  // init proxies
+  for idx := 0 to High(mProxies) do mProxies[idx].nextLink := idx+1;
+  mProxies[High(mProxies)].nextLink := -1;
   mLastQuery := 0;
   mUsedCells := 0;
-  mProxyFree := nil;
-  mProxyList := nil;
+  mProxyFree := 0;
   mProxyCount := 0;
+  mProxyMaxCount := 0;
+  mUData := 0;
+  mTagMask := -1;
+  mItCB := nil;
   e_WriteLog(Format('created grid with size: %dx%d (tile size: %d); pix: %dx%d', [mWidth, mHeight, mTileSize, mWidth*mTileSize, mHeight*mTileSize]), MSG_NOTIFY);
 end;
 
 
-destructor TBodyGrid.Destroy ();
-var
-  px: TBodyProxy;
+destructor TBodyGridBase.Destroy ();
 begin
-  // free all owned proxies
-  while mProxyFree <> nil do
-  begin
-    px := mProxyFree;
-    mProxyFree := px.nextLink;
-    px.Free();
-  end;
-
-  while mProxyList <> nil do
-  begin
-    px := mProxyList;
-    mProxyList := px.nextLink;
-    px.Free();
-  end;
-
   mCells := nil;
   mGrid := nil;
+  mProxies := nil;
   inherited;
 end;
 
 
-procedure TBodyGrid.dumpStats ();
+procedure TBodyGridBase.dumpStats ();
 var
   idx, mcb, cidx, cnt: Integer;
 begin
@@ -239,11 +202,11 @@ begin
     end;
     if (mcb < cnt) then mcb := cnt;
   end;
-  e_WriteLog(Format('grid size: %dx%d (tile size: %d); pix: %dx%d; used cells: %d; max bodies in cell: %d; proxies allocated: %d', [mWidth, mHeight, mTileSize, mWidth*mTileSize, mHeight*mTileSize, mUsedCells, mcb, mProxyCount]), MSG_NOTIFY);
+  e_WriteLog(Format('grid size: %dx%d (tile size: %d); pix: %dx%d; used cells: %d; max bodies in cell: %d; max proxies allocated: %d; proxies used: %d', [mWidth, mHeight, mTileSize, mWidth*mTileSize, mHeight*mTileSize, mUsedCells, mcb, mProxyMaxCount, mProxyCount]), MSG_NOTIFY);
 end;
 
 
-function TBodyGrid.allocCell: Integer;
+function TBodyGridBase.allocCell: Integer;
 var
   idx: Integer;
 begin
@@ -254,7 +217,11 @@ begin
     SetLength(mCells, mFreeCell+32768); // arbitrary number
     for idx := mFreeCell to High(mCells) do
     begin
-      mCells[idx].body := nil;
+      {$IFDEF grid_use_buckets}
+      mCells[idx].bodies[0] := -1;
+      {$ELSE}
+      mCells[idx].body := -1;
+      {$ENDIF}
       mCells[idx].next := idx+1;
     end;
     mCells[High(mCells)].next := -1; // last cell
@@ -267,12 +234,12 @@ begin
 end;
 
 
-procedure TBodyGrid.freeCell (idx: Integer);
+procedure TBodyGridBase.freeCell (idx: Integer);
 begin
   if (idx >= 0) and (idx < High(mCells)) then
   begin
-    if mCells[idx].body = nil then exit; // the thing that should not be
-    mCells[idx].body := nil;
+    //if mCells[idx].body = -1 then exit; // the thing that should not be
+    //mCells[idx].body := -1;
     mCells[idx].next := mFreeCell;
     mFreeCell := idx;
     Dec(mUsedCells);
@@ -280,322 +247,310 @@ begin
 end;
 
 
-function TBodyGrid.allocProxy (aX, aY, aWidth, aHeight: Integer; aObj: TObject; aTag: Integer): TBodyProxy;
+function TBodyGridBase.allocProxy (aX, aY, aWidth, aHeight: Integer; aObj: ITP; aTag: Integer): TBodyProxyId;
+var
+  olen, idx: Integer;
+  px: PBodyProxyRec;
 begin
-  if (mProxyFree = nil) then
+  if (mProxyFree = -1) then
   begin
-    // no free proxies, create new
-    result := TBodyProxy.Create(self, aX, aY, aWidth, aHeight, aObj, aTag);
-    Inc(mProxyCount);
-  end
-  else
-  begin
-    // get one from list
-    result := mProxyFree;
-    mProxyFree := result.nextLink;
-    result.setup(aX, aY, aWidth, aHeight, aObj, aTag);
+    // no free proxies, resize list
+    olen := Length(mProxies);
+    SetLength(mProxies, olen+8192); // arbitrary number
+    for idx := olen to High(mProxies) do mProxies[idx].nextLink := idx+1;
+    mProxies[High(mProxies)].nextLink := -1;
+    mProxyFree := olen;
   end;
+  // get one from list
+  result := mProxyFree;
+  px := @mProxies[result];
+  mProxyFree := px.nextLink;
+  px.setup(aX, aY, aWidth, aHeight, aObj, aTag);
   // add to used list
-  result.nextLink := mProxyList;
-  if (mProxyList <> nil) then mProxyList.prevLink := result;
-  mProxyList := result;
+  px.nextLink := -1;
+  // statistics
+  Inc(mProxyCount);
+  if (mProxyMaxCount < mProxyCount) then mProxyMaxCount := mProxyCount;
 end;
 
-procedure TBodyGrid.freeProxy (body: TBodyProxy);
+procedure TBodyGridBase.freeProxy (body: TBodyProxyId);
 begin
-  if body = nil then exit; // just in case
-  // remove from used list
-  if (body.prevLink = nil) then
-  begin
-    // this must be head
-    if (body <> mProxyList) then raise Exception.Create('wutafuuuuu in grid?');
-    mProxyList := body.nextLink;
-  end
-  else
-  begin
-    body.prevLink.nextLink := body.nextLink;
-  end;
-  if (body.nextLink <> nil) then body.nextLink.prevLink := body.prevLink;
+  if (body < 0) or (body > High(mProxies)) then exit; // just in case
+  if (mProxyCount = 0) then raise Exception.Create('wutafuuuuu in grid (no allocated proxies, what i should free now?)');
   // add to free list
-  //body.mObj := nil; //WARNING! DON'T DO THIS! `removeBody()` depends on valid mObj
-  body.prevLink := nil;
-  body.nextLink := mProxyFree;
+  mProxies[body].mObj := nil;
+  mProxies[body].nextLink := mProxyFree;
   mProxyFree := body;
+  Dec(mProxyCount);
+end;
+
+
+function TBodyGridBase.forGridRect (x, y, w, h: Integer; cb: TGridInternalCB): Boolean;
+var
+  gx, gy: Integer;
+begin
+  result := false;
+  if (w < 1) or (h < 1) or not assigned(cb) then exit;
+  // fix coords
+  Dec(x, mMinX);
+  Dec(y, mMinY);
+  // go on
+  if (x+w <= 0) or (y+h <= 0) then exit;
+  if (x >= mWidth*mTileSize) or (y >= mHeight*mTileSize) then exit;
+  for gy := y div mTileSize to (y+h-1) div mTileSize do
+  begin
+    if (gy < 0) then continue;
+    if (gy >= mHeight) then break;
+    for gx := x div mTileSize to (x+w-1) div mTileSize do
+    begin
+      if (gx < 0) then continue;
+      if (gx >= mWidth) then break;
+      if (cb(gy*mWidth+gx)) then begin result := true; exit; end;
+    end;
+  end;
 end;
 
 
-procedure TBodyGrid.insert (body: TBodyProxy);
+function TBodyGridBase.inserter (grida: Integer): Boolean;
 var
-  dx, dy, gx, gy, cidx: Integer;
+  cidx: Integer;
+  pc: PInteger;
+  {$IFDEF grid_use_buckets}
+  pi: PGridCell;
+  f: Integer;
+  {$ENDIF}
 begin
-  if body = nil then exit;
-  if (body.mWidth < 1) or (body.mHeight < 1) then exit;
-  // out of grid?
-  if (body.mX+body.mWidth <= 0) or (body.mY+body.mHeight <= 0) then exit;
-  if (body.mX >= mWidth*mTileSize) or (body.mY >= mHeight*mTileSize) then exit;
-  //e_WriteLog(Format('grid: inserting body: (%d,%d)-(%dx%d)', [body.mX, body.mY, body.mWidth, body.mHeight]), MSG_NOTIFY);
-  gy := body.mY div mTileSize;
-  dy := 0;
-  while (dy < body.mHeight) do
+  result := false; // never stop
+  // add body to the given grid cell
+  pc := @mGrid[grida];
+  {$IFDEF grid_use_buckets}
+  if (pc^ <> -1) then
   begin
-    if (gy >= 0) and (gy < mHeight) then
+    pi := @mCells[pc^];
+    f := 0;
+    for f := 0 to High(TGridCell.bodies) do
     begin
-      dx := 0;
-      gx := body.mX div mTileSize;
-      while (dx < body.mWidth) do
+      if (pi.bodies[f] = -1) then
       begin
-        if (gx >= 0) and (gx < mWidth) then
-        begin
-          //e_WriteLog(Format('  00: allocating cell for grid coords (%d,%d), body coords:(%d,%d)', [gx, gy, dx, dy]), MSG_NOTIFY);
-          cidx := allocCell();
-          //e_WriteLog(Format('  01: allocated cell for grid coords (%d,%d), body coords:(%d,%d): #%d', [gx, gy, dx, dy, cidx]), MSG_NOTIFY);
-          mCells[cidx].body := body;
-          mCells[cidx].next := mGrid[gy*mWidth+gx];
-          mGrid[gy*mWidth+gx] := cidx;
-          //e_WriteLog(Format('  02: put cell for grid coords (%d,%d), body coords:(%d,%d): #%d', [gx, gy, dx, dy, cidx]), MSG_NOTIFY);
-        end;
-        Inc(dx, mTileSize);
-        Inc(gx);
+        // can add here
+        pi.bodies[f] := mUData;
+        if (f+1 < Length(TGridCell.bodies)) then pi.bodies[f+1] := -1;
+        exit;
       end;
     end;
-    Inc(dy, mTileSize);
-    Inc(gy);
   end;
+  // either no room, or no cell at all
+  cidx := allocCell();
+  mCells[cidx].bodies[0] := mUData;
+  mCells[cidx].bodies[1] := -1;
+  mCells[cidx].next := pc^;
+  pc^ := cidx;
+  {$ELSE}
+  cidx := allocCell();
+  //e_WriteLog(Format('  01: allocated cell for grid coords (%d,%d), body coords:(%d,%d): #%d', [gx, gy, dx, dy, cidx]), MSG_NOTIFY);
+  mCells[cidx].body := mUData;
+  mCells[cidx].next := pc^;
+  pc^ := cidx;
+  {$ENDIF}
 end;
 
 
-// absolutely not tested
-procedure TBodyGrid.remove (body: TBodyProxy);
+procedure TBodyGridBase.insert (body: TBodyProxyId);
 var
-  dx, dy, gx, gy, idx, pidx, tmp: Integer;
+  px: PBodyProxyRec;
+  oudata: Integer;
 begin
-  if body = nil then exit;
-  if (body.mWidth < 1) or (body.mHeight < 1) then exit;
-  // out of grid?
-  if (body.mX+body.mWidth <= 0) or (body.mY+body.mHeight <= 0) then exit;
-  if (body.mX >= mWidth*mTileSize) or (body.mY >= mHeight*mTileSize) then exit;
-  gy := body.mY div mTileSize;
-  dy := 0;
+  if (body < 0) or (body > High(mProxies)) then exit; // just in case
+  px := @mProxies[body];
+  oudata := mUData;
+  mUData := body;
+  forGridRect(px.mX, px.mY, px.mWidth, px.mHeight, inserter);
+  mUData := oudata;
+end;
+
+
+function TBodyGridBase.remover (grida: Integer): Boolean;
+var
+  pidx, idx, tmp, f: Integer;
+  pc: PGridCell;
+begin
+  result := false; // never stop
+  // find and remove cell
   pidx := -1;
-  while (dy < body.mHeight) do
+  idx := mGrid[grida];
+  while (idx >= 0) do
   begin
-    if (gy >= 0) and (gy < mHeight) then
+    tmp := mCells[idx].next;
+    {$IFDEF grid_use_buckets}
+    pc := @mCells[idx];
+    f := 0;
+    while (f < High(TGridCell.bodies)) do
     begin
-      dx := 0;
-      gx := body.mX div mTileSize;
-      while (dx < body.mWidth) do
+      if (pc.bodies[f] = mUData) then
       begin
-        if (gx >= 0) and (gx < mWidth) then
+        // i found her!
+        if (f = 0) and (pc.bodies[1] = -1) then
+        begin
+          // this cell contains no elements, remove it
+          tmp := mCells[idx].next;
+          if (pidx = -1) then mGrid[grida] := tmp else mCells[pidx].next := tmp;
+          freeCell(idx);
+        end
+        else
         begin
-          // find and remove cell
-          pidx := -1;
-          idx := mGrid[gy*mWidth+gx];
-          while idx >= 0 do
+          // remove element from bucket
+          Inc(f);
+          while (f < High(TGridCell.bodies)) do
           begin
-            tmp := mCells[idx].next;
-            if mCells[idx].body = body then
-            begin
-              if pidx = -1 then mGrid[gy*mWidth+gx] := tmp else mCells[pidx].next := tmp;
-              freeCell(idx);
-            end
-            else
-            begin
-              pidx := idx;
-            end;
-            idx := tmp;
+            pc.bodies[f-1] := pc.bodies[f];
+            if (pc.bodies[f] = -1) then break;
+            Inc(f);
           end;
+          pc.bodies[High(TGridCell.bodies)] := -1; // just in case
         end;
-        Inc(dx, mTileSize);
-        Inc(gx);
+        exit; // assume that we cannot have one object added to bucket twice
       end;
+      Inc(f);
+    end;
+    {$ELSE}
+    if (mCells[idx].body = mUData) then
+    begin
+      if (pidx = -1) then mGrid[grida] := tmp else mCells[pidx].next := tmp;
+      freeCell(idx);
+      exit; // assume that we cannot have one object added to bucket twice
     end;
-    Inc(dy, mTileSize);
-    Inc(gy);
+    {$ENDIF}
+    pidx := idx;
+    idx := tmp;
   end;
 end;
 
 
-function TBodyGrid.insertBody (aObj: TObject; aX, aY, aWidth, aHeight: Integer; aTag: Integer=0): TBodyProxy;
+// absolutely not tested
+procedure TBodyGridBase.remove (body: TBodyProxyId);
+var
+  px: PBodyProxyRec;
+  oudata: Integer;
+begin
+  if (body < 0) or (body > High(mProxies)) then exit; // just in case
+  px := @mProxies[body];
+  oudata := mUData;
+  mUData := body;
+  forGridRect(px.mX, px.mY, px.mWidth, px.mHeight, remover);
+  mUData := oudata;
+end;
+
+
+function TBodyGridBase.insertBody (aObj: ITP; aX, aY, aWidth, aHeight: Integer; aTag: Integer=0): TBodyProxyId;
 begin
   result := allocProxy(aX, aY, aWidth, aHeight, aObj, aTag);
   insert(result);
 end;
 
 
-// WARNING! this will NOT destroy proxy!
-procedure TBodyGrid.removeBody (aObj: TBodyProxy);
+procedure TBodyGridBase.removeBody (aObj: TBodyProxyId);
 begin
-  if aObj = nil then exit;
-  if (aObj.mGrid <> self) then raise Exception.Create('trying to remove alien proxy from grid');
-  removeBody(aObj);
-  //HACK!
+  if (aObj < 0) or (aObj > High(mProxies)) then exit; // just in case
+  remove(aObj);
   freeProxy(aObj);
-  if (mProxyFree <> aObj) then raise Exception.Create('grid deletion invariant fucked');
-  mProxyFree := aObj.nextLink;
-  aObj.nextLink := nil;
 end;
 
 
-procedure TBodyGrid.moveResizeBody (body: TBodyProxy; dx, dy, sx, sy: Integer);
+procedure TBodyGridBase.moveResizeBody (body: TBodyProxyId; dx, dy, sx, sy: Integer);
+var
+  px: PBodyProxyRec;
 begin
-  if (body = nil) or ((dx = 0) and (dy = 0) and (sx = 0) and (sy = 0)) then exit;
+  if (body < 0) or (body > High(mProxies)) then exit; // just in case
+  if ((dx = 0) and (dy = 0) and (sx = 0) and (sy = 0)) then exit;
   remove(body);
-  Inc(body.mX, dx);
-  Inc(body.mY, dy);
-  Inc(body.mWidth, sx);
-  Inc(body.mHeight, sy);
+  px := @mProxies[body];
+  Inc(px.mX, dx);
+  Inc(px.mY, dy);
+  Inc(px.mWidth, sx);
+  Inc(px.mHeight, sy);
   insert(body);
 end;
 
-procedure TBodyGrid.moveBody (body: TBodyProxy; dx, dy: Integer);
+procedure TBodyGridBase.moveBody (body: TBodyProxyId; dx, dy: Integer);
 begin
   moveResizeBody(body, dx, dy, 0, 0);
 end;
 
-procedure TBodyGrid.resizeBody (body: TBodyProxy; sx, sy: Integer);
+procedure TBodyGridBase.resizeBody (body: TBodyProxyId; sx, sy: Integer);
 begin
   moveResizeBody(body, 0, 0, sx, sy);
 end;
 
 
-function TBodyGrid.forEachInAABB (x, y, w, h: Integer; cb: GridQueryCB): Boolean;
+function TBodyGridBase.iterator (grida: Integer): Boolean;
 var
-  gx, gy, idx: Integer;
-  minx, miny, maxx, maxy: Integer;
+  idx: Integer;
+  px: PBodyProxyRec;
+  {$IFDEF grid_use_buckets}
+  pi: PGridCell;
+  f: Integer;
+  {$ENDIF}
 begin
   result := false;
-  if not assigned(cb) then exit;
-  if (w < 1) or (h < 1) then exit;
-  minx := x;
-  miny := y;
-  maxx := x+w-1;
-  maxy := y+h-1;
-  if (minx > maxx) or (miny > maxy) then exit;
-  if (maxx < 0) or (maxy < 0) then exit;
-  if (minx >= mWidth*mTileSize) or (miny >= mHeight*mTileSize) then exit;
-  // increase query counter
-  Inc(mLastQuery);
-  if (mLastQuery = 0) then
+  idx := mGrid[grida];
+  while (idx >= 0) do
   begin
-    // just in case of overflow
-    mLastQuery := 1;
-    for idx := 0 to High(mCells) do if (mCells[idx].body <> nil) then mCells[idx].body.mQueryMark := 0;
-  end;
-  //e_WriteLog(Format('grid: query #%d: (%d,%d)-(%dx%d)', [mLastQuery, minx, miny, maxx, maxy]), MSG_NOTIFY);
-  // process grid
-  for gy := miny div mTileSize to maxy div mTileSize do
-  begin
-    if (gy < 0) then continue;
-    if (gy >= mHeight) then break;
-    for gx := minx div mTileSize to maxx div mTileSize do
+    {$IFDEF grid_use_buckets}
+    pi := @mCells[idx];
+    for f := 0 to High(TGridCell.bodies) do
     begin
-      if (gx < 0) then continue;
-      if (gx >= mWidth) then break;
-      idx := mGrid[gy*mWidth+gx];
-      while idx >= 0 do
+      if (pi.bodies[f] = -1) then break;
+      px := @mProxies[pi.bodies[f]];
+      if (px.mQueryMark <> mLastQuery) and ((mTagMask = -1) or ((px.mTag and mTagMask) <> 0)) then
       begin
-        if (mCells[idx].body <> nil) and (mCells[idx].body.mQueryMark <> mLastQuery) then
-        begin
-          //e_WriteLog(Format('  query #%d body hit: (%d,%d)-(%dx%d) tag:%d', [mLastQuery, mCells[idx].body.mX, mCells[idx].body.mY, mCells[idx].body.mWidth, mCells[idx].body.mHeight, mCells[idx].body.mTag]), MSG_NOTIFY);
-          mCells[idx].body.mQueryMark := mLastQuery;
-          if (cb(mCells[idx].body.mObj, mCells[idx].body.mTag)) then begin result := true; exit; end;
-        end;
-        idx := mCells[idx].next;
+        //e_WriteLog(Format('  query #%d body hit: (%d,%d)-(%dx%d) tag:%d', [mLastQuery, mCells[idx].body.mX, mCells[idx].body.mY, mCells[idx].body.mWidth, mCells[idx].body.mHeight, mCells[idx].body.mTag]), MSG_NOTIFY);
+        px.mQueryMark := mLastQuery;
+        if (mItCB(px.mObj, px.mTag)) then begin result := true; exit; end;
       end;
     end;
+    idx := pi.next;
+    {$ELSE}
+    if (mCells[idx].body <> -1) then
+    begin
+      px := @mProxies[mCells[idx].body];
+      if (px.mQueryMark <> mLastQuery) and ((mTagMask = -1) or ((px.mTag and mTagMask) <> 0)) then
+      begin
+        //e_WriteLog(Format('  query #%d body hit: (%d,%d)-(%dx%d) tag:%d', [mLastQuery, mCells[idx].body.mX, mCells[idx].body.mY, mCells[idx].body.mWidth, mCells[idx].body.mHeight, mCells[idx].body.mTag]), MSG_NOTIFY);
+        px.mQueryMark := mLastQuery;
+        if (mItCB(px.mObj, px.mTag)) then begin result := true; exit; end;
+      end;
+    end;
+    idx := mCells[idx].next;
+    {$ENDIF}
   end;
 end;
 
-
-function TBodyGrid.getProxyForBody (aObj: TObject; x, y, w, h: Integer): TBodyProxy;
-
-  function qq (obj: TObject; tag: Integer): Boolean;
-  begin
-    result := (obj = aObj);
-  end;
-
-begin
-  result := nil;
-  forEachInAABB(x, y, w, h, qq);
-end;
-
-
-// ////////////////////////////////////////////////////////////////////////// //
-constructor TBinaryHeapObj.Create (alessfn: TBinaryHeapLessFn);
-begin
-  if not assigned(alessfn) then raise Exception.Create('wutafuck?!');
-  lessfn := alessfn;
-  SetLength(elem, 8192); // 'cause why not?
-  elemUsed := 0;
-end;
-
-
-destructor TBinaryHeapObj.Destroy ();
-begin
-  inherited;
-end;
-
-
-procedure TBinaryHeapObj.clear ();
-begin
-  elemUsed := 0;
-end;
-
-
-procedure TBinaryHeapObj.heapify (root: Integer);
+function TBodyGridBase.forEachInAABB (x, y, w, h: Integer; cb: TGridQueryCB; tagmask: Integer=-1): Boolean;
 var
-  smallest, right: Integer;
-  tmp: TObject;
+  idx: Integer;
+  otagmask: Integer;
+  ocb: TGridQueryCB;
 begin
-  while true do
-  begin
-    smallest := 2*root+1; // left child
-    if (smallest >= elemUsed) then break; // anyway
-    right := smallest+1; // right child
-    if not lessfn(elem[smallest], elem[root]) then smallest := root;
-    if (right < elemUsed) and (lessfn(elem[right], elem[smallest])) then smallest := right;
-    if (smallest = root) then break;
-    // swap
-    tmp := elem[root];
-    elem[root] := elem[smallest];
-    elem[smallest] := tmp;
-    root := smallest;
-  end;
-end;
-
+  result := false;
+  if not assigned(cb) then exit;
 
-procedure TBinaryHeapObj.insert (val: TObject);
-var
-  i, par: Integer;
-begin
-  if (val = nil) then exit;
-  i := elemUsed;
-  if (i = Length(elem)) then SetLength(elem, Length(elem)+16384); // arbitrary number
-  Inc(elemUsed);
-  while (i <> 0) do
+  // increase query counter
+  Inc(mLastQuery);
+  if (mLastQuery = 0) then
   begin
-    par := (i-1) div 2; // parent
-    if not lessfn(val, elem[par]) then break;
-    elem[i] := elem[par];
-    i := par;
+    // just in case of overflow
+    mLastQuery := 1;
+    for idx := 0 to High(mProxies) do mProxies[idx].mQueryMark := 0;
   end;
-  elem[i] := val;
-end;
-
-function TBinaryHeapObj.front (): TObject;
-begin
-  if elemUsed > 0 then result := elem[0] else result := nil;
-end;
-
+  //e_WriteLog(Format('grid: query #%d: (%d,%d)-(%dx%d)', [mLastQuery, minx, miny, maxx, maxy]), MSG_NOTIFY);
 
-procedure TBinaryHeapObj.popFront ();
-begin
-  if (elemUsed > 0) then
-  begin
-    Dec(elemUsed);
-    elem[0] := elem[elemUsed];
-    heapify(0);
-  end;
+  otagmask := mTagMask;
+  mTagMask := tagmask;
+  ocb := mItCB;
+  mItCB := cb;
+  result := forGridRect(x, y, w, h, iterator);
+  mTagMask := otagmask;
+  mItCB := ocb;
 end;