X-Git-Url: http://deadsoftware.ru/gitweb?a=blobdiff_plain;f=src%2Fgame%2Fg_grid.pas;h=6017ad4b492dfbc436da477ccd41a685a3bca7b1;hb=b4a2614636a9cc12ce9766ec1e2bf04cd5bec0ea;hp=19c4d0d2ca8f31fc39170217693375c3d8cc5de2;hpb=a17222535319cb4089e3f9a92711731c015819b3;p=d2df-sdl.git diff --git a/src/game/g_grid.pas b/src/game/g_grid.pas index 19c4d0d..6017ad4 100644 --- a/src/game/g_grid.pas +++ b/src/game/g_grid.pas @@ -18,7 +18,9 @@ {$IF DEFINED(D2F_DEBUG)} {.$DEFINE D2F_DEBUG_RAYTRACE} {.$DEFINE D2F_DEBUG_XXQ} + {.$DEFINE D2F_DEBUG_MOVER} {$ENDIF} +{.$DEFINE GRID_USE_ORTHO_ACCEL} unit g_grid; interface @@ -128,6 +130,8 @@ type // `false` if `body` is surely invalid function getBodyXY (body: TBodyProxyId; out rx, ry: Integer): Boolean; inline; + function getBodyWH (body: TBodyProxyId; out rw, rh: Integer): Boolean; inline; + function getBodyDims (body: TBodyProxyId; out rx, ry, rw, rh: Integer): Boolean; inline; //WARNING: don't modify grid while any query is in progress (no checks are made!) // you can set enabled/disabled flag, tho (but iterator can still return objects disabled inside it) @@ -136,17 +140,21 @@ type //WARNING: don't modify grid while any query is in progress (no checks are made!) // you can set enabled/disabled flag, tho (but iterator can still return objects disabled inside it) - // no callback: return `true` on the first hit - function forEachAtPoint (x, y: Integer; cb: TGridQueryCB; tagmask: Integer=-1): ITP; + // no callback: return object on the first hit or nil + function forEachAtPoint (x, y: Integer; cb: TGridQueryCB; tagmask: Integer=-1; exittag: PInteger=nil): ITP; //WARNING: don't modify grid while any query is in progress (no checks are made!) // you can set enabled/disabled flag, tho (but iterator can still return objects disabled inside it) // cb with `(nil)` will be called before processing new tile - // no callback: return `true` on the nearest hit + // no callback: return object of the nearest hit or nil + // if `inverted` is true, trace will register bodies *exluding* tagmask //WARNING: don't change tags in callbacks here! function traceRay (const x0, y0, x1, y1: Integer; cb: TGridRayQueryCB; tagmask: Integer=-1): ITP; overload; function traceRay (out ex, ey: Integer; const ax0, ay0, ax1, ay1: Integer; cb: TGridRayQueryCB; tagmask: Integer=-1): ITP; + //function traceOrthoRayWhileIn (const x0, y0, x1, y1: Integer; tagmask: Integer=-1): ITP; overload; + //function traceOrthoRayWhileIn (out ex, ey: Integer; const ax0, ay0, ax1, ay1: Integer; tagmask: Integer=-1): ITP; + //WARNING: don't modify grid while any query is in progress (no checks are made!) // you can set enabled/disabled flag, tho (but iterator can still return objects disabled inside it) // trace line along the grid, calling `cb` for all objects in passed cells, in no particular order @@ -525,6 +533,41 @@ begin end; +function TBodyGridBase.getBodyWH (body: TBodyProxyId; out rw, rh: Integer): Boolean; inline; +begin + if (body >= 0) and (body < Length(mProxies)) then + begin + with mProxies[body] do begin rw := mWidth; rh := mHeight; end; + result := true; + end + else + begin + rw := 0; + rh := 0; + result := false; + end; +end; + + +function TBodyGridBase.getBodyDims (body: TBodyProxyId; out rx, ry, rw, rh: Integer): Boolean; inline; +begin + if (body >= 0) and (body < Length(mProxies)) then + begin + with mProxies[body] do begin rx := mX; ry := mY; rw := mWidth; rh := mHeight; end; + result := true; + end + else + begin + rx := 0; + ry := 0; + rw := 0; + rh := 0; + result := false; + end; +end; + + + // ////////////////////////////////////////////////////////////////////////// // function TBodyGridBase.getProxyEnabled (pid: TBodyProxyId): Boolean; inline; begin @@ -814,7 +857,15 @@ begin y0 := px.mY; w := px.mWidth; h := px.mHeight; + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format('proxy #%d: MOVERESIZE: xg=%d;yg=%d;w=%d;h=%d;nx=%d;ny=%d;nw=%d;nh=%d', [body, x0-mMinX, y0-mMinY, w, h, nx-mMinX, ny-mMinY, nw, nh]), MSG_NOTIFY); + {$ENDIF} if (nx = x0) and (ny = y0) and (nw = w) and (nh = h) then exit; + // map -> grid + Dec(x0, mMinX); + Dec(y0, mMinY); + Dec(nx, mMinX); + Dec(ny, mMinY); // did any corner crossed tile boundary? if (x0 div mTileSize <> nx div mTileSize) or (y0 div mTileSize <> ny div mTileSize) or @@ -822,16 +873,16 @@ begin ((y0+h) div mTileSize <> (ny+nh) div mTileSize) then begin removeInternal(body); - px.mX := nx; - px.mY := ny; + px.mX := nx+mMinX; + px.mY := ny+mMinY; px.mWidth := nw; px.mHeight := nh; insertInternal(body); end else begin - px.mX := nx; - px.mY := ny; + px.mX := nx+mMinX; + px.mY := ny+mMinY; px.mWidth := nw; px.mHeight := nh; end; @@ -856,9 +907,9 @@ begin if (nx = x0) and (ny = y0) then exit; // map -> grid Dec(x0, mMinX); - Dec(y0, mMinX); + Dec(y0, mMinY); Dec(nx, mMinX); - Dec(ny, mMinX); + Dec(ny, mMinY); // check for heavy work pw := px.mWidth; ph := px.mHeight; @@ -870,6 +921,9 @@ begin ogy1 := (y0+ph-1) div mTileSize; ngx1 := (nx+pw-1) div mTileSize; ngy1 := (ny+ph-1) div mTileSize; + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format('proxy #%d: checkmove: xg=%d;yg=%d;w=%d;h=%d;nx=%d;ny=%d og:(%d,%d)-(%d,%d); ng:(%d,%d)-(%d,%d)', [body, x0, y0, pw, ph, nx, ny, ogx0, ogy0, ogx1, ogy1, ngx0, ngy0, ngx1, ngy1]), MSG_NOTIFY); + {$ENDIF} if (ogx0 <> ngx0) or (ogy0 <> ngy0) or (ogx1 <> ngx1) or (ogy1 <> ngy1) then begin // crossed tile boundary, do heavy work @@ -877,7 +931,9 @@ begin gh := mHeight; // cycle with old rect, remove body where it is necessary // optimized for horizontal moves - //e_WriteLog(Format('og:(%d,%d)-(%d,%d); ng:(%d,%d)-(%d,%d)', [ogx0, ogy0, ogx1, ogy1, ngx0, ngy0, ngx1, ngy1]), MSG_NOTIFY); + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format('proxy #%d: xg=%d;yg=%d;w=%d;h=%d;nx=%d;ny=%d og:(%d,%d)-(%d,%d); ng:(%d,%d)-(%d,%d)', [body, x0, y0, pw, ph, nx, ny, ogx0, ogy0, ogx1, ogy1, ngx0, ngy0, ngx1, ngy1]), MSG_NOTIFY); + {$ENDIF} // remove stale marks if not ((ogy0 >= gh) or (ogy1 < 0)) and not ((ogx0 >= gw) or (ogx1 < 0)) then @@ -886,7 +942,9 @@ begin if (ogy0 < 0) then ogy0 := 0; if (ogx1 > gw-1) then ogx1 := gw-1; if (ogy1 > gh-1) then ogy1 := gh-1; - //e_WriteLog(Format(' norm og:(%d,%d)-(%d,%d)', [ogx0, ogy0, ogx1, ogy1]), MSG_NOTIFY); + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format(' norm og:(%d,%d)-(%d,%d)', [ogx0, ogy0, ogx1, ogy1]), MSG_NOTIFY); + {$ENDIF} for gx := ogx0 to ogx1 do begin if (gx < ngx0) or (gx > ngx1) then @@ -894,7 +952,9 @@ begin // this column is completely outside of new rect for gy := ogy0 to ogy1 do begin - //e_WriteLog(Format(' remove:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format(' remove0:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$ENDIF} remover(gy*gw+gx, body); end; end @@ -905,7 +965,9 @@ begin begin if (gy < ngy0) or (gy > ngy1) then begin - //e_WriteLog(Format(' remove:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format(' remove1:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$ENDIF} remover(gy*gw+gx, body); end; end; @@ -920,7 +982,9 @@ begin if (ngy0 < 0) then ngy0 := 0; if (ngx1 > gw-1) then ngx1 := gw-1; if (ngy1 > gh-1) then ngy1 := gh-1; - //e_WriteLog(Format(' norm ng:(%d,%d)-(%d,%d)', [ngx0, ngy0, ngx1, ngy1]), MSG_NOTIFY); + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format(' norm ng:(%d,%d)-(%d,%d)', [ngx0, ngy0, ngx1, ngy1]), MSG_NOTIFY); + {$ENDIF} for gx := ngx0 to ngx1 do begin if (gx < ogx0) or (gx > ogx1) then @@ -928,7 +992,9 @@ begin // this column is completely outside of old rect for gy := ngy0 to ngy1 do begin - //e_WriteLog(Format(' insert:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format(' insert0:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$ENDIF} inserter(gy*gw+gx, body); end; end @@ -939,7 +1005,9 @@ begin begin if (gy < ogy0) or (gy > ogy1) then begin - //e_WriteLog(Format(' insert:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format(' insert1:(%d,%d)', [gx, gy]), MSG_NOTIFY); + {$ENDIF} inserter(gy*gw+gx, body); end; end; @@ -947,6 +1015,12 @@ begin end; end; // done + end + else + begin + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format('proxy #%d: GRID OK: xg=%d;yg=%d;w=%d;h=%d;nx=%d;ny=%d og:(%d,%d)-(%d,%d); ng:(%d,%d)-(%d,%d)', [body, x0, y0, pw, ph, nx, ny, ogx0, ogy0, ogx1, ogy1, ngx0, ngy0, ngx1, ngy1]), MSG_NOTIFY); + {$ENDIF} end; // update coordinates px.mX := nx+mMinX; @@ -961,10 +1035,13 @@ begin if (body < 0) or (body > High(mProxies)) then exit; // just in case // check if tile coords was changed px := @mProxies[body]; - x0 := px.mX; - y0 := px.mY; + x0 := px.mX-mMinX; + y0 := px.mY-mMinY; w := px.mWidth; h := px.mHeight; + {$IF DEFINED(D2F_DEBUG_MOVER)} + e_WriteLog(Format('proxy #%d: RESIZE: xg=%d;yg=%d;w=%d;h=%d;nw=%d;nh=%d', [body, x0, y0, w, h, nw, nh]), MSG_NOTIFY); + {$ENDIF} if ((x0+w) div mTileSize <> (x0+nw) div mTileSize) or ((y0+h) div mTileSize <> (y0+nh) div mTileSize) then begin @@ -985,7 +1062,7 @@ end; // ////////////////////////////////////////////////////////////////////////// // // no callback: return `true` on the first hit -function TBodyGridBase.forEachAtPoint (x, y: Integer; cb: TGridQueryCB; tagmask: Integer=-1): ITP; +function TBodyGridBase.forEachAtPoint (x, y: Integer; cb: TGridQueryCB; tagmask: Integer=-1; exittag: PInteger=nil): ITP; var f: Integer; idx, curci: Integer; @@ -995,6 +1072,7 @@ var ptag: Integer; begin result := Default(ITP); + if (exittag <> nil) then exittag^ := 0; tagmask := tagmask and TagFullMask; if (tagmask = 0) then exit; @@ -1054,11 +1132,17 @@ begin begin if assigned(cb) then begin - if cb(px.mObj, ptag) then begin result := px.mObj; exit; end; + if cb(px.mObj, ptag) then + begin + result := px.mObj; + if (exittag <> nil) then exittag^ := ptag; + exit; + end; end else begin result := px.mObj; + if (exittag <> nil) then exittag^ := ptag; exit; end; end; @@ -1199,6 +1283,11 @@ var lq: LongWord; f, ptag, distSq: Integer; x0, y0, x1, y1: Integer; + // horizontal walker + {$IFDEF GRID_USE_ORTHO_ACCEL} + wklen, wkstep: Integer; + hopt: Boolean; + {$ENDIF} begin result := Default(ITP); lastObj := Default(ITP); @@ -1207,7 +1296,15 @@ begin ey := ay1; // why not? if (tagmask = 0) then exit; - if (ax0 = ax1) and (ay0 = ay1) then exit; // as the first point is ignored, just get outta here + if (ax0 = ax1) and (ay0 = ay1) then + begin + result := forEachAtPoint(ax0, ay0, nil, tagmask, @ptag); + if (result <> nil) then + begin + if assigned(cb) and not cb(result, ptag, ax0, ay0, ax0, ay0) then result := Default(ITP); + end; + exit; + end; lastDistSq := distanceSq(ax0, ay0, ax1, ay1)+1; @@ -1352,29 +1449,54 @@ begin dx2 -= dy2; // first move, to skip starting point - if (xd = term) then exit; + // DON'T DO THIS! loop will take care of that + if (xd = term) then + begin + result := forEachAtPoint(ax0, ay0, nil, tagmask, @ptag); + if (result <> nil) then + begin + if assigned(cb) then + begin + if cb(result, ptag, ax0, ay0, ax0, ay0) then + begin + ex := ax0; + ey := ay0; + end + else + begin + result := nil; + end; + end + else + begin + ex := ax0; + ey := ay0; + end; + end; + exit; + end; + prevx := xptr^+minx; prevy := yptr^+miny; + (* // move coords if (e >= 0) then begin yd += sty; e -= dx2; end else e += dy2; xd += stx; // done? if (xd = term) then exit; + *) {$IF DEFINED(D2F_DEBUG)} if (xptr^ < 0) or (yptr^ < 0) or (xptr^ >= gw*tsize) and (yptr^ >= gh*tsize) then raise Exception.Create('raycaster internal error (0)'); {$ENDIF} - lastGA := (yptr^ div tsize)*gw+(xptr^ div tsize); - ccidx := mGrid[lastGA]; + // DON'T DO THIS! loop will take care of that + //lastGA := (yptr^ div tsize)*gw+(xptr^ div tsize); + //ccidx := mGrid[lastGA]; {$IF DEFINED(D2F_DEBUG_RAYTRACE)} //if assigned(dbgRayTraceTileHitCB) then e_WriteLog('1:TRACING!', MSG_NOTIFY); {$ENDIF} - {$IF DEFINED(D2F_DEBUG_RAYTRACE)} - if assigned(dbgRayTraceTileHitCB) then dbgRayTraceTileHitCB((xptr^ div tsize*tsize)+minx, (yptr^ div tsize*tsize)+miny); - {$ENDIF} - //if (dbgShowTraceLog) then e_WriteLog(Format('raycast start: (%d,%d)-(%d,%d); xptr^=%d; yptr^=%d', [ax0, ay0, ax1, ay1, xptr^, yptr^]), MSG_NOTIFY); // increase query counter @@ -1387,8 +1509,230 @@ begin end; lq := mLastQuery; + {$IFDEF GRID_USE_ORTHO_ACCEL} + // if this is strict horizontal trace, use optimized codepath + if (ax0 = ax1) or (ay0 = ay1) then + begin + // horizontal trace: walk the whole tiles, calculating mindist once for each proxy in cell + // stx < 0: going left, otherwise `stx` is > 0, and we're going right + // vertical trace: walk the whole tiles, calculating mindist once for each proxy in cell + // stx < 0: going up, otherwise `stx` is > 0, and we're going down + hopt := (ay0 = ay1); // horizontal? + if (stx < 0) then wklen := -(term-xd) else wklen := term-xd; + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln('optimized htrace; wklen=%d', [wklen]); + {$ENDIF} + ga := (yptr^ div tsize)*gw+(xptr^ div tsize); + // one of those will never change + x := xptr^+minx; + y := yptr^+miny; + {$IF DEFINED(D2F_DEBUG)} + if hopt then + begin + if (y <> ay0) then raise Exception.Create('htrace fatal internal error'); + end + else + begin + if (x <> ax0) then raise Exception.Create('vtrace fatal internal error'); + end; + {$ENDIF} + while (wklen > 0) do + begin + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln(' htrace; ga=%d; x=%d, y=%d; y=%d; y=%d', [ga, xptr^+minx, yptr^+miny, y, ay0]); + {$ENDIF} + // new tile? + if (ga <> lastGA) then + begin + lastGA := ga; + ccidx := mGrid[lastGA]; + // convert coords to map (to avoid ajdusting coords inside the loop) + if hopt then x := xptr^+minx else y := yptr^+miny; + while (ccidx <> -1) do + begin + cc := @mCells[ccidx]; + for f := 0 to GridCellBucketSize-1 do + begin + if (cc.bodies[f] = -1) then break; + px := @mProxies[cc.bodies[f]]; + ptag := px.mTag; + if ((ptag and TagDisabled) = 0) and ((ptag and tagmask) <> 0) and (px.mQueryMark <> lq) and + // constant coord should be inside + ((hopt and (y >= px.mY) and (y < px.mY+px.mHeight)) or + ((not hopt) and (x >= px.mX) and (x < px.mX+px.mWidth))) then + begin + px.mQueryMark := lq; // mark as processed + // inside the proxy? + if (hopt and (x > px.mX) and (x < px.mX+px.mWidth-1)) or + ((not hopt) and (y > px.mY) and (y < px.mY+px.mHeight-1)) then + begin + if assigned(cb) then + begin + if cb(px.mObj, ptag, x, y, x, y) then + begin + result := lastObj; + ex := prevx; + ey := prevy; + exit; + end; + x := xptr^+minx; + end + else + begin + distSq := distanceSq(ax0, ay0, x, y); + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln(' EMBEDDED hhit(%d): a=(%d,%d), h=(%d,%d), distsq=%d; lastsq=%d', [cc.bodies[f], ax0, ay0, x, y, distSq, lastDistSq]); + {$ENDIF} + if (distSq < lastDistSq) then + begin + ex := x; + ey := y; + result := px.mObj; + exit; + end; + end; + continue; + end; + // remember this hitpoint if it is nearer than an old one + if hopt then + begin + prevy := y; + if (stx < 0) then + begin + // going left + if (x < px.mX) then continue; + prevx := px.mX+px.mWidth; + end + else + begin + // going right + if (x > px.mX{+px.mWidth}) then continue; + prevx := px.mX-1; + end; + end + else + begin + prevx := x; + if (stx < 0) then + begin + // going up + if (y < px.mY) then continue; + prevy := px.mY+px.mHeight; + end + else + begin + // going down + if (y > px.mY{+px.mHeight}) then continue; + prevy := px.mY-1; + end; + end; + if assigned(cb) then + begin + if (stx < 0) then + begin + if hopt then x := prevx-1 else y := prevy-1; + end + else + begin + if hopt then x := prevx+1 else y := prevy+1; + end; + if cb(px.mObj, ptag, x, y, prevx, prevy) then + begin + result := lastObj; + ex := prevx; + ey := prevy; + exit; + end; + x := xptr^+minx; + y := yptr^+miny; + end + else + begin + distSq := distanceSq(ax0, ay0, prevx, prevy); + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln(' hhit(%d): a=(%d,%d), h=(%d,%d), p=(%d,%d), distsq=%d; lastsq=%d', [cc.bodies[f], ax0, ay0, x, y, prevx, prevy, distSq, lastDistSq]); + {$ENDIF} + if (distSq < lastDistSq) then + begin + wasHit := true; + lastDistSq := distSq; + ex := prevx; + ey := prevy; + lastObj := px.mObj; + end; + end; + end; + end; + // next cell + ccidx := cc.next; + end; + if wasHit and not assigned(cb) then begin result := lastObj; exit; end; + end; + // skip to next tile + if hopt then + begin + if (stx > 0) then + begin + // to the right + wkstep := ((xptr^ or (mTileSize-1))+1)-xptr^; + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln(' right step: wklen=%d; wkstep=%d', [wklen, wkstep]); + {$ENDIF} + if (wkstep >= wklen) then break; + Inc(xptr^, wkstep); + Inc(ga); + end + else + begin + // to the left + wkstep := xptr^-((xptr^ and (not (mTileSize-1)))-1); + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln(' left step: wklen=%d; wkstep=%d', [wklen, wkstep]); + {$ENDIF} + if (wkstep >= wklen) then break; + Dec(xptr^, wkstep); + Dec(ga); + end; + end + else + begin + if (stx > 0) then + begin + // to the down + wkstep := ((yptr^ or (mTileSize-1))+1)-yptr^; + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln(' down step: wklen=%d; wkstep=%d', [wklen, wkstep]); + {$ENDIF} + if (wkstep >= wklen) then break; + Inc(yptr^, wkstep); + Inc(ga, mHeight); + end + else + begin + // to the up + wkstep := yptr^-((yptr^ and (not (mTileSize-1)))-1); + {$IF DEFINED(D2F_DEBUG)} + if dbgShowTraceLog then e_LogWritefln(' up step: wklen=%d; wkstep=%d', [wklen, wkstep]); + {$ENDIF} + if (wkstep >= wklen) then break; + Dec(yptr^, wkstep); + Dec(ga, mHeight); + end; + end; + Dec(wklen, wkstep); + end; + // we can travel less than one cell + if wasHit and not assigned(cb) then result := lastObj else begin ex := ax1; ey := ay1; end; + exit; + end; + {$ENDIF} + + {$IF DEFINED(D2F_DEBUG_RAYTRACE)} + if assigned(dbgRayTraceTileHitCB) then dbgRayTraceTileHitCB((xptr^ div tsize*tsize)+minx, (yptr^ div tsize*tsize)+miny); + {$ENDIF} + ccidx := -1; - // draw it; can omit checks + // can omit checks while (xd <> term) do begin // check cell(s) @@ -1397,6 +1741,9 @@ begin {$ENDIF} // new tile? ga := (yptr^ div tsize)*gw+(xptr^ div tsize); + {$IF DEFINED(D2F_DEBUG_RAYTRACE)} + if assigned(dbgRayTraceTileHitCB) then e_WriteLog(Format(' xd=%d; term=%d; gx=%d; gy=%d; ga=%d; lastga=%d', [xd, term, xptr^, yptr^, ga, lastGA]), MSG_NOTIFY); + {$ENDIF} if (ga <> lastGA) then begin // yes @@ -1517,6 +1864,16 @@ begin if (e >= 0) then begin yd += sty; e -= dx2; end else e += dy2; xd += stx; end; + // we can travel less than one cell + if wasHit and not assigned(cb) then + begin + result := lastObj; + end + else + begin + ex := ax1; // why not? + ey := ay1; // why not? + end; end;