DEADSOFTWARE

optimized horizontal and vertical traces
[d2df-sdl.git] / src / game / g_grid.pas
index 2afca2f3c16c0db534a6ec68cb4bb665c200e186..354c3c16cccd6d92bdadfef3c7e753dc5c280bc0 100644 (file)
@@ -87,6 +87,10 @@ type
     mProxyCount: Integer; // currently used
     mProxyMaxCount: Integer;
 
+  private
+    // optimized horizontal tracer
+    //function traceRayHOpt (out ex, ey: Integer; const ax0, ay0, ax1, ay1, x0, len, dx: Integer; cb: TGridRayQueryCB; tagmask: Integer): ITP;
+
   public
     dbgShowTraceLog: Boolean;
     {$IF DEFINED(D2F_DEBUG)}
@@ -1282,6 +1286,9 @@ var
   lq: LongWord;
   f, ptag, distSq: Integer;
   x0, y0, x1, y1: Integer;
+  // horizontal walker
+  wklen, wkstep: Integer;
+  hopt: Boolean;
 begin
   result := Default(ITP);
   lastObj := Default(ITP);
@@ -1491,10 +1498,6 @@ begin
   //if assigned(dbgRayTraceTileHitCB) then e_WriteLog('1:TRACING!', MSG_NOTIFY);
   {$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
@@ -1507,8 +1510,228 @@ begin
   end;
   lq := mLastQuery;
 
+  // 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;
+
+  {$IF DEFINED(D2F_DEBUG_RAYTRACE)}
+  if assigned(dbgRayTraceTileHitCB) then dbgRayTraceTileHitCB((xptr^ div tsize*tsize)+minx, (yptr^ div tsize*tsize)+miny);
+  {$ENDIF}
+
   ccidx := -1;
-  // draw it; can omit checks
+  //  can omit checks
   while (xd <> term) do
   begin
     // check cell(s)