hedgewars/uLandGraphics.pas
author nemo
Thu, 01 Jul 2010 23:41:10 -0400
changeset 3608 c509bbc779e7
parent 3603 b6b1989744ef
child 3689 e2be39ee19f0
permissions -rw-r--r--
Revert prior attempted optimisation. Gridding the land pays in some situations, but not all. Restricting to an upper bound might help, but overall, seems too fuzzy to be worth it. On one side is increased cost of Add/Delete + extra test on collision check, on the other is skipping the list iteration. Perhaps for large lists.

(*
 * Hedgewars, a free turn based strategy game
 * Copyright (c) 2005-2010 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
 *)

{$INCLUDE "options.inc"}

unit uLandGraphics;
interface
uses uFloat, uConsts;

type PRangeArray = ^TRangeArray;
     TRangeArray = array[0..31] of record
                                   Left, Right: LongInt;
                                   end;

function  SweepDirty: boolean;
function  Despeckle(X, Y: LongInt): boolean;
function  CheckLandValue(X, Y: LongInt; LandFlag: Word): boolean;
procedure DrawExplosion(X, Y, Radius: LongInt);
procedure DrawHLinesExplosions(ar: PRangeArray; Radius: LongInt; y, dY: LongInt; Count: Byte);
procedure DrawTunnel(X, Y, dX, dY: hwFloat; ticks, HalfWidth: LongInt);
procedure FillRoundInLand(X, Y, Radius: LongInt; Value: Longword);
procedure ChangeRoundInLand(X, Y, Radius: LongInt; doSet: boolean);

function TryPlaceOnLand(cpX, cpY: LongInt; Obj: TSprite; Frame: LongInt; doPlace: boolean): boolean;

implementation
uses SDLh, uMisc, uLand, uLandTexture;

procedure FillCircleLines(x, y, dx, dy: LongInt; Value: Longword);
var i: LongInt;
begin
if ((y + dy) and LAND_HEIGHT_MASK) = 0 then
    for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
        if (Land[y + dy, i] and lfIndestructible) = 0 then
            Land[y + dy, i]:= Value;
if ((y - dy) and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
        if (Land[y - dy, i] and lfIndestructible) = 0 then
            Land[y - dy, i]:= Value;
if ((y + dx) and LAND_HEIGHT_MASK) = 0 then
    for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
        if (Land[y + dx, i] and lfIndestructible) = 0 then
            Land[y + dx, i]:= Value;
if ((y - dx) and LAND_HEIGHT_MASK) = 0 then
    for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
        if (Land[y - dx, i] and lfIndestructible) = 0 then
            Land[y - dx, i]:= Value;
end;

procedure ChangeCircleLines(x, y, dx, dy: LongInt; doSet: boolean);
var i: LongInt;
begin
if not doSet then
   begin
   if ((y + dy) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
          if (Land[y + dy, i] > 0) and (Land[y + dy, i] < 256) then dec(Land[y + dy, i]); // check > 0 because explosion can erase collision data
   if ((y - dy) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
          if (Land[y - dy, i] > 0) and (Land[y - dy, i] < 256) then dec(Land[y - dy, i]);
   if ((y + dx) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
          if (Land[y + dx, i] > 0) and (Land[y + dx, i] < 256) then dec(Land[y + dx, i]);
   if ((y - dx) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
          if (Land[y - dx, i] > 0) and (Land[y - dx, i] < 256) then dec(Land[y - dx, i]);
   end else
   begin
   if ((y + dy) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
          if (Land[y + dy, i] < 256) then
              inc(Land[y + dy, i]);
   if ((y - dy) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
          if (Land[y - dy, i] < 256) then
              inc(Land[y - dy, i]);
   if ((y + dx) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
          if (Land[y + dx, i] < 256) then
              inc(Land[y + dx, i]);
   if ((y - dx) and LAND_HEIGHT_MASK) = 0 then
      for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
          if (Land[y - dx, i] < 256) then
              inc(Land[y - dx, i]);
   end
end;

procedure FillRoundInLand(X, Y, Radius: LongInt; Value: Longword);
var dx, dy, d: LongInt;
begin
  dx:= 0;
  dy:= Radius;
  d:= 3 - 2 * Radius;
  while (dx < dy) do
     begin
     FillCircleLines(x, y, dx, dy, Value);
     if (d < 0)
     then d:= d + 4 * dx + 6
     else begin
          d:= d + 4 * (dx - dy) + 10;
          dec(dy)
          end;
     inc(dx)
     end;
  if (dx = dy) then FillCircleLines(x, y, dx, dy, Value);
end;

procedure ChangeRoundInLand(X, Y, Radius: LongInt; doSet: boolean);
var dx, dy, d: LongInt;
begin
  dx:= 0;
  dy:= Radius;
  d:= 3 - 2 * Radius;
  while (dx < dy) do
     begin
     ChangeCircleLines(x, y, dx, dy, doSet);
     if (d < 0)
     then d:= d + 4 * dx + 6
     else begin
          d:= d + 4 * (dx - dy) + 10;
          dec(dy)
          end;
     inc(dx)
     end;
  if (dx = dy) then ChangeCircleLines(x, y, dx, dy, doSet)
end;

procedure FillLandCircleLines0(x, y, dx, dy: LongInt);
var i, t: LongInt;
begin
t:= y + dy;
if (t and LAND_HEIGHT_MASK) = 0 then
    for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
        if (not isMap and ((Land[t, i] and lfIndestructible) = 0)) or ((Land[t, i] and lfBasic) <> 0) then
            if (cReducedQuality and rqBlurryLand) = 0 then
                LandPixels[t, i]:= 0
            else
                LandPixels[t div 2, i div 2]:= 0;

t:= y - dy;
if (t and LAND_HEIGHT_MASK) = 0 then
    for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
        if (not isMap and ((Land[t, i] and lfIndestructible) = 0)) or ((Land[t, i] and lfBasic) <> 0) then
            if (cReducedQuality and rqBlurryLand) = 0 then
                LandPixels[t, i]:= 0
            else
                LandPixels[t div 2, i div 2]:= 0;

t:= y + dx;
if (t and LAND_HEIGHT_MASK) = 0 then
    for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
        if (not isMap and ((Land[t, i] and lfIndestructible) = 0)) or ((Land[t, i] and lfBasic) <> 0) then
            if (cReducedQuality and rqBlurryLand) = 0 then
                LandPixels[t, i]:= 0
            else
                LandPixels[t div 2, i div 2]:= 0;

t:= y - dx;
if (t and LAND_HEIGHT_MASK) = 0 then
    for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
        if (not isMap and ((Land[t, i] and lfIndestructible) = 0)) or ((Land[t, i] and lfBasic) <> 0) then
            if (cReducedQuality and rqBlurryLand) = 0 then
                LandPixels[t, i]:= 0
            else
                LandPixels[t div 2, i div 2]:= 0;

end;

procedure FillLandCircleLinesBG(x, y, dx, dy: LongInt);
var i, t: LongInt;
begin
t:= y + dy;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) then
           if (cReducedQuality and rqBlurryLand) = 0 then
               LandPixels[t, i]:= LandBackPixel(i, t)
           else
               LandPixels[t div 2, i div 2]:= LandBackPixel(i, t)
       else
           if ((Land[t, i] and lfObject) <> 0) then
               if (cReducedQuality and rqBlurryLand) = 0 then
                   LandPixels[t, i]:= 0
               else
                   LandPixels[t div 2, i div 2]:= 0;

t:= y - dy;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) then
           if (cReducedQuality and rqBlurryLand) = 0 then
               LandPixels[t, i]:= LandBackPixel(i, t)
           else
               LandPixels[t div 2, i div 2]:= LandBackPixel(i, t)
       else
           if ((Land[t, i] and lfObject) <> 0) then
               if (cReducedQuality and rqBlurryLand) = 0 then
                   LandPixels[t, i]:= 0
               else
                   LandPixels[t div 2, i div 2]:= 0;

t:= y + dx;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) then
           if (cReducedQuality and rqBlurryLand) = 0 then
           LandPixels[t, i]:= LandBackPixel(i, t)
            else 
           LandPixels[t div 2, i div 2]:= LandBackPixel(i, t)
       else
            if ((Land[t, i] and lfObject) <> 0) then
            if (cReducedQuality and rqBlurryLand) = 0 then
          LandPixels[t, i]:= 0
            else
           LandPixels[t div 2, i div 2]:= 0;

t:= y - dx;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) then
            if (cReducedQuality and rqBlurryLand) = 0 then
          LandPixels[t, i]:= LandBackPixel(i, t)
        else 
         LandPixels[t div 2, i div 2]:= LandBackPixel(i, t)

       else
          if ((Land[t, i] and lfObject) <> 0) then
              if (cReducedQuality and rqBlurryLand) = 0 then
                LandPixels[t, i]:= 0
              else
                LandPixels[t div 2, i div 2]:= 0;

end;

procedure FillLandCircleLinesEBC(x, y, dx, dy: LongInt);
var i, t: LongInt;
begin
t:= y + dy;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) or ((Land[t, i] and lfObject) <> 0) then
          begin
           if (cReducedQuality and rqBlurryLand) = 0 then
            LandPixels[t, i]:= cExplosionBorderColor
          else
            LandPixels[t div 2, i div 2]:= cExplosionBorderColor;

          Land[t, i]:= Land[t, i] or lfDamaged;
          //Despeckle(i, t);
          LandDirty[t div 32, i div 32]:= 1;
          end;

t:= y - dy;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dx, 0) to min(x + dx, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) or ((Land[t, i] and lfObject) <> 0) then
          begin
           if (cReducedQuality and rqBlurryLand) = 0 then
              LandPixels[t, i]:= cExplosionBorderColor 
            else
              LandPixels[t div 2, i div 2]:= cExplosionBorderColor;
          Land[t, i]:= Land[t, i] or lfDamaged;
          //Despeckle(i, t);
          LandDirty[t div 32, i div 32]:= 1;
          end;

t:= y + dx;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) or ((Land[t, i] and lfObject) <> 0) then
           begin
           if (cReducedQuality and rqBlurryLand) = 0 then
           LandPixels[t, i]:= cExplosionBorderColor
            else
           LandPixels[t div 2, i div 2]:= cExplosionBorderColor;

           Land[t, i]:= Land[t, i] or lfDamaged;
           //Despeckle(i, t);
           LandDirty[t div 32, i div 32]:= 1;
           end;

t:= y - dx;
if (t and LAND_HEIGHT_MASK) = 0 then
   for i:= max(x - dy, 0) to min(x + dy, LAND_WIDTH - 1) do
       if ((Land[t, i] and lfBasic) <> 0) or ((Land[t, i] and lfObject) <> 0) then
          begin
           if (cReducedQuality and rqBlurryLand) = 0 then
          LandPixels[t, i]:= cExplosionBorderColor 
            else
          LandPixels[t div 2, i div 2]:= cExplosionBorderColor;

          Land[t, i]:= Land[t, i] or lfDamaged;
          //Despeckle(i, y - dy);
          LandDirty[t div 32, i div 32]:= 1;
          end;
end;

procedure DrawExplosion(X, Y, Radius: LongInt);
var dx, dy, ty, tx, d: LongInt;
begin

// draw background land texture
    begin
    dx:= 0;
    dy:= Radius;
    d:= 3 - 2 * Radius;

    while (dx < dy) do
        begin
        FillLandCircleLinesBG(x, y, dx, dy);
        if (d < 0)
        then d:= d + 4 * dx + 6
        else begin
            d:= d + 4 * (dx - dy) + 10;
            dec(dy)
            end;
        inc(dx)
        end;
    if (dx = dy) then FillLandCircleLinesBG(x, y, dx, dy);
    end;

// draw a hole in land
if Radius > 20 then
    begin
    dx:= 0;
    dy:= Radius - 15;
    d:= 3 - 2 * dy;

    while (dx < dy) do
        begin
        FillLandCircleLines0(x, y, dx, dy);
        if (d < 0)
        then d:= d + 4 * dx + 6
        else begin
            d:= d + 4 * (dx - dy) + 10;
            dec(dy)
            end;
        inc(dx)
        end;
    if (dx = dy) then FillLandCircleLines0(x, y, dx, dy);
    end;

  // FillRoundInLand after erasing land pixels to allow Land 0 check for mask.png to function
    FillRoundInLand(X, Y, Radius, 0);

// draw explosion border
    begin
    inc(Radius, 4);
    dx:= 0;
    dy:= Radius;
    d:= 3 - 2 * Radius;
    while (dx < dy) do
        begin
        FillLandCircleLinesEBC(x, y, dx, dy);
        if (d < 0)
        then d:= d + 4 * dx + 6
        else begin
            d:= d + 4 * (dx - dy) + 10;
            dec(dy)
            end;
        inc(dx)
        end;
    if (dx = dy) then FillLandCircleLinesEBC(x, y, dx, dy);
    end;

tx:= max(X - Radius - 1, 0);
dx:= min(X + Radius + 1, LAND_WIDTH) - tx;
ty:= max(Y - Radius - 1, 0);
dy:= min(Y + Radius + 1, LAND_HEIGHT) - ty;
UpdateLandTexture(tx, dx, ty, dy)
end;

procedure DrawHLinesExplosions(ar: PRangeArray; Radius: LongInt; y, dY: LongInt; Count: Byte);
var tx, ty, i: LongInt;
begin
for i:= 0 to Pred(Count) do
    begin
    for ty:= max(y - Radius, 0) to min(y + Radius, LAND_HEIGHT) do
        for tx:= max(0, ar^[i].Left - Radius) to min(LAND_WIDTH, ar^[i].Right + Radius) do
            if (Land[ty, tx] and lfBasic) <> 0 then
                if (cReducedQuality and rqBlurryLand) = 0 then
                    LandPixels[ty, tx]:= LandBackPixel(tx, ty)
                else
                    LandPixels[ty div 2, tx div 2]:= LandBackPixel(tx, ty)
            else 
                if (Land[ty, tx] and lfObject) <> 0 then
                    if (cReducedQuality and rqBlurryLand) = 0 then
                        LandPixels[ty, tx]:= 0
                    else
                        LandPixels[ty div 2, tx div 2]:= 0;
    inc(y, dY)
    end;

inc(Radius, 4);
dec(y, Count * dY);

for i:= 0 to Pred(Count) do
    begin
    for ty:= max(y - Radius, 0) to min(y + Radius, LAND_HEIGHT) do
        for tx:= max(0, ar^[i].Left - Radius) to min(LAND_WIDTH, ar^[i].Right + Radius) do
            if ((Land[ty, tx] and lfBasic) <> 0) or ((Land[ty, tx] and lfObject) <> 0) then
                begin
                    if (cReducedQuality and rqBlurryLand) = 0 then
                        LandPixels[ty, tx]:= cExplosionBorderColor
                    else
                        LandPixels[ty div 2, tx div 2]:= cExplosionBorderColor;

                Land[ty, tx]:= Land[ty, tx] or lfDamaged;
                LandDirty[ty div 32, tx div 32]:= 1;
                end;
    inc(y, dY)
    end;


UpdateLandTexture(0, LAND_WIDTH, 0, LAND_HEIGHT)
end;

//
//  - (dX, dY) - direction, vector of length = 0.5
//
procedure DrawTunnel(X, Y, dX, dY: hwFloat; ticks, HalfWidth: LongInt);
var nx, ny, dX8, dY8: hwFloat;
    i, t, tx, ty, stX, stY, ddy, ddx: Longint;
begin  // (-dY, dX) is (dX, dY) rotated by PI/2
stY:= hwRound(Y);
stX:= hwRound(X);

nx:= X + dY * (HalfWidth + 8);
ny:= Y - dX * (HalfWidth + 8);

dX8:= dX * 8;
dY8:= dY * 8;
for i:= 0 to 7 do
    begin
    X:= nx - dX8;
    Y:= ny - dY8;
    for t:= -8 to ticks + 8 do
    begin
    X:= X + dX;
    Y:= Y + dY;
    tx:= hwRound(X);
    ty:= hwRound(Y);
    if ((ty and LAND_HEIGHT_MASK) = 0) and
       ((tx and LAND_WIDTH_MASK) = 0) and
       (((Land[ty, tx] and lfBasic) <> 0) or 
       ((Land[ty, tx] and lfObject) <> 0)) then
        begin
        Land[ty, tx]:= Land[ty, tx] or lfDamaged;
            if (cReducedQuality and rqBlurryLand) = 0 then
            LandPixels[ty, tx]:= cExplosionBorderColor
            else
            LandPixels[ty div 2, tx div 2]:= cExplosionBorderColor
        end
    end;
    nx:= nx - dY;
    ny:= ny + dX;
    end;

for i:= -HalfWidth to HalfWidth do
    begin
    X:= nx - dX8;
    Y:= ny - dY8;
    for t:= 0 to 7 do
    begin
    X:= X + dX;
    Y:= Y + dY;
    tx:= hwRound(X);
    ty:= hwRound(Y);
    if ((ty and LAND_HEIGHT_MASK) = 0) and
       ((tx and LAND_WIDTH_MASK) = 0) and
       (((Land[ty, tx] and lfBasic) <> 0) or 
       ((Land[ty, tx] and lfObject) <> 0)) then
        begin
        Land[ty, tx]:= Land[ty, tx] or lfDamaged;
            if (cReducedQuality and rqBlurryLand) = 0 then
        LandPixels[ty, tx]:= cExplosionBorderColor
            else
        LandPixels[ty div 2, tx div 2]:= cExplosionBorderColor

        end
    end;
    X:= nx;
    Y:= ny;
    for t:= 0 to ticks do
        begin
        X:= X + dX;
        Y:= Y + dY;
        tx:= hwRound(X);
        ty:= hwRound(Y);
        if ((ty and LAND_HEIGHT_MASK) = 0) and ((tx and LAND_WIDTH_MASK) = 0) and ((Land[ty, tx] and lfIndestructible) = 0) then
            begin
            if (Land[ty, tx] and lfBasic) <> 0 then
                if (cReducedQuality and rqBlurryLand) = 0 then
                    LandPixels[ty, tx]:= LandBackPixel(tx, ty)
                else
                    LandPixels[ty div 2, tx div 2]:= LandBackPixel(tx, ty)
            else 
              if (Land[ty, tx] and lfObject) <> 0 then
                if (cReducedQuality and rqBlurryLand) = 0 then
                LandPixels[ty, tx]:= 0
                else
                LandPixels[ty div 2, tx div 2]:= 0;

            Land[ty, tx]:= 0;
            end
        end;
    for t:= 0 to 7 do
    begin
    X:= X + dX;
    Y:= Y + dY;
    tx:= hwRound(X);
    ty:= hwRound(Y);
    if ((ty and LAND_HEIGHT_MASK) = 0) and
       ((tx and LAND_WIDTH_MASK) = 0) and
       (((Land[ty, tx] and lfBasic) <> 0) or 
       ((Land[ty, tx] and lfObject) <> 0)) then
        begin
        Land[ty, tx]:= Land[ty, tx] or lfDamaged;
        if (cReducedQuality and rqBlurryLand) = 0 then
        LandPixels[ty, tx]:= cExplosionBorderColor
        else
        LandPixels[ty div 2, tx div 2]:= cExplosionBorderColor

        end
    end;
    nx:= nx - dY;
    ny:= ny + dX;
    end;

for i:= 0 to 7 do
    begin
    X:= nx - dX8;
    Y:= ny - dY8;
    for t:= -8 to ticks + 8 do
    begin
    X:= X + dX;
    Y:= Y + dY;
    tx:= hwRound(X);
    ty:= hwRound(Y);
    if ((ty and LAND_HEIGHT_MASK) = 0) and
       ((tx and LAND_WIDTH_MASK) = 0) and
       (((Land[ty, tx] and lfBasic) <> 0) or 
       ((Land[ty, tx] and lfObject) <> 0)) then
        begin
        Land[ty, tx]:= Land[ty, tx] or lfDamaged;
        if (cReducedQuality and rqBlurryLand) = 0 then
        LandPixels[ty, tx]:= cExplosionBorderColor
        else
        LandPixels[ty div 2, tx div 2]:= cExplosionBorderColor
        end
    end;
    nx:= nx - dY;
    ny:= ny + dX;
    end;

tx:= max(stX - HalfWidth * 2 - 4 - abs(hwRound(dX * ticks)), 0);
ty:= max(stY - HalfWidth * 2 - 4 - abs(hwRound(dY * ticks)), 0);
ddx:= min(stX + HalfWidth * 2 + 4 + abs(hwRound(dX * ticks)), LAND_WIDTH) - tx;
ddy:= min(stY + HalfWidth * 2 + 4 + abs(hwRound(dY * ticks)), LAND_HEIGHT) - ty;

UpdateLandTexture(tx, ddx, ty, ddy)
end;

function TryPlaceOnLand(cpX, cpY: LongInt; Obj: TSprite; Frame: LongInt; doPlace: boolean): boolean;
var X, Y, bpp, h, w, row, col, numFramesFirstCol: LongInt;
    p: PByteArray;
    Image: PSDL_Surface;
begin
numFramesFirstCol:= SpritesData[Obj].imageHeight div SpritesData[Obj].Height;

TryDo(SpritesData[Obj].Surface <> nil, 'Assert SpritesData[Obj].Surface failed', true);
Image:= SpritesData[Obj].Surface;
w:= SpritesData[Obj].Width;
h:= SpritesData[Obj].Height;
row:= Frame mod numFramesFirstCol;
col:= Frame div numFramesFirstCol;

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

bpp:= Image^.format^.BytesPerPixel;
TryDo(bpp = 4, 'It should be 32 bpp sprite', true);
// Check that sprite fits free space
p:= @(PByteArray(Image^.pixels)^[ Image^.pitch * row * h + col * w * 4 ]);
case bpp of
     4: for y:= 0 to Pred(h) do
            begin
            for x:= 0 to Pred(w) do
                if PLongword(@(p^[x * 4]))^ <> 0 then
                   if ((cpY + y) < Longint(topY)) or
                      ((cpY + y) > LAND_HEIGHT) or
                      ((cpX + x) < Longint(leftX)) or
                      ((cpX + x) > Longint(rightX)) or
                      (Land[cpY + y, cpX + x] <> 0) then
                      begin
                      if SDL_MustLock(Image) then
                         SDL_UnlockSurface(Image);
                      exit(false)
                      end;
            p:= @(p^[Image^.pitch]);
            end;
     end;

TryPlaceOnLand:= true;
if not doPlace then
   begin
   if SDL_MustLock(Image) then
      SDL_UnlockSurface(Image);
   exit
   end;

// Checked, now place
p:= @(PByteArray(Image^.pixels)^[ Image^.pitch * row * h + col * w * 4 ]);
case bpp of
     4: for y:= 0 to Pred(h) do
            begin
            for x:= 0 to Pred(w) do
                if PLongword(@(p^[x * 4]))^ <> 0 then
                   begin
                   Land[cpY + y, cpX + x]:= lfObject;
                   if (cReducedQuality and rqBlurryLand) = 0 then
                       LandPixels[cpY + y, cpX + x]:= PLongword(@(p^[x * 4]))^
                   else
                       LandPixels[(cpY + y) div 2, (cpX + x) div 2]:= PLongword(@(p^[x * 4]))^
                   end;
            p:= @(p^[Image^.pitch]);
            end;
     end;
if SDL_MustLock(Image) then
   SDL_UnlockSurface(Image);

x:= max(cpX, leftX);
w:= min(cpX + Image^.w, LAND_WIDTH) - x;
y:= max(cpY, topY);
h:= min(cpY + Image^.h, LAND_HEIGHT) - y;
UpdateLandTexture(x, w, y, h)
end;

// was experimenting with applying as damage occurred.
function Despeckle(X, Y: LongInt): boolean;
var nx, ny, i, j, c: LongInt;
begin
if ((Land[Y, X] and lfDamaged) <> 0) and ((Land[Y, X] and lfIndestructible) = 0) then // check neighbours
    begin
    c:= 0;
    for i:= -1 to 1 do
        for j:= -1 to 1 do
            if (i <> 0) or (j <> 0) then
                begin
                ny:= Y + i;
                nx:= X + j;
                if ((ny and LAND_HEIGHT_MASK) = 0) and ((nx and LAND_WIDTH_MASK) = 0) then
                    if Land[ny, nx] > 255 then
                        inc(c);
                end;

    if c < 4 then // 0-3 neighbours
        begin
        if (cReducedQuality and rqBlurryLand) = 0 then
            if (Land[Y, X] and lfBasic) <> 0 then 
                LandPixels[Y, X]:= LandBackPixel(X, Y) 
            else
                LandPixels[Y, X]:= 0
        else
            if (Land[Y, X] and lfBasic) <> 0 then 
                LandPixels[Y div 2, X div 2]:= LandBackPixel(X, Y) 
            else
                LandPixels[Y div 2, X div 2]:= 0;

        Land[Y, X]:= 0;
        exit(true);
        end;
    end;
Despeckle:= false
end;

function SweepDirty: boolean;
var x, y, xx, yy, ty, tx: LongInt;
    bRes, updateBlock, resweep, recheck: boolean;
begin
bRes:= false;
reCheck:= true;

while recheck do
    begin
    recheck:= false;
    for y:= 0 to LAND_HEIGHT div 32 - 1 do
        begin
        for x:= 0 to LAND_WIDTH div 32 - 1 do
            begin
            if LandDirty[y, x] <> 0 then
                begin
                updateBlock:= false;
                resweep:= true;
                ty:= y * 32;
                tx:= x * 32;
                while(resweep) do
                    begin
                    resweep:= false;
                    for yy:= ty to ty + 31 do
                        for xx:= tx to tx + 31 do
                            if Despeckle(xx, yy) then
                                begin
                                bRes:= true;
                                updateBlock:= true;
                                resweep:= true;
                                if (yy = ty) and (y > 0) then
                                    begin
                                    LandDirty[y-1, x]:= 1;
                                    recheck:= true;
                                    end
                                else if (yy = ty+31) and (y < LAND_HEIGHT div 32 - 1) then
                                    begin
                                    LandDirty[y+1, x]:= 1;
                                    recheck:= true;
                                    end;
                                if (xx = tx) and (x > 0) then
                                    begin
                                    LandDirty[y, x-1]:= 1;
                                    recheck:= true;
                                    end
                                else if (xx = tx+31) and (x < LAND_WIDTH div 32 - 1) then
                                    begin
                                    LandDirty[y, x+1]:= 1;
                                    recheck:= true;
                                    end
                                end;
                    end;
                if updateBlock then UpdateLandTexture(tx, 32, ty, 32);
                LandDirty[y, x]:= 0;
                end;
            end;
        end;
     end;

SweepDirty:= bRes;
end;

// Return true if outside of land or not the value tested, used right now for some X/Y movement that does not use normal hedgehog movement in GSHandlers.inc
function CheckLandValue(X, Y: LongInt; LandFlag: Word): boolean;
begin
     CheckLandValue:= ((X and LAND_WIDTH_MASK <> 0) or (Y and LAND_HEIGHT_MASK <> 0)) or ((Land[Y, X] and LandFlag) = 0)
end;
end.