unit uLandGraphics;

interface

type PRangeArray = ^TRangeArray;

     TRangeArray = array[0..31] of record

                                   Left, Right: integer;

                                   end;

procedure DrawExplosion(X, Y, Radius: integer);

procedure DrawHLinesExplosions(ar: PRangeArray; Radius: integer; y, dY: integer; Count: Byte);

procedure DrawTunnel(X, Y, dX, dY: Double; ticks, HalfWidth: integer);

procedure FillRoundInLand(X, Y, Radius: integer; Value: Longword);

implementation

procedure FillCircleLines(x, y, dx, dy: integer; Value: Longword);

var i: integer;

begin

if ((y + dy) and $FFFFFC00) = 0 then

   for i:= max(x - dx, 0) to min(x + dx, 2047) do Land[y + dy, i]:= Value;

if ((y - dy) and $FFFFFC00) = 0 then

   for i:= max(x - dx, 0) to min(x + dx, 2047) do Land[y - dy, i]:= Value;

if ((y + dx) and $FFFFFC00) = 0 then

   for i:= max(x - dy, 0) to min(x + dy, 2047) do Land[y + dx, i]:= Value;

if ((y - dx) and $FFFFFC00) = 0 then

   for i:= max(x - dy, 0) to min(x + dy, 2047) do Land[y - dx, i]:= Value;

end;

procedure FillRoundInLand(X, Y, Radius: integer; Value: Longword);

var dx, dy, d: integer;

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 ClearLandPixel(y, x: integer);

var p: PByteArray;

begin

p:= @PByteArray(LandSurface.pixels)^[LandSurface.pitch*y];

case LandSurface.format.BytesPerPixel of

     1: ;// not supported

     2: PWord(@p[x * 2])^:= 0;

     3: begin

        p[x * 3 + 0]:= 0;

        p[x * 3 + 1]:= 0;

        p[x * 3 + 2]:= 0;

        end;

     4: PLongword(@p[x * 4])^:= 0;

     end

end;

procedure SetLandPixel(y, x: integer);

var p: PByteArray;

begin

p:= @PByteArray(LandSurface.pixels)^[LandSurface.pitch*y];

case LandSurface.format.BytesPerPixel of

     1: ;// not supported

     2: PWord(@p[x * 2])^:= cExplosionBorderColor;

     3: begin

        p[x * 3 + 0]:= cExplosionBorderColor and $FF;

        p[x * 3 + 1]:= (cExplosionBorderColor shr 8) and $FF;

        p[x * 3 + 2]:= cExplosionBorderColor shr 16;

        end;

     4: PLongword(@p[x * 4])^:= cExplosionBorderColor;

     end

end;

procedure FillLandCircleLines0(x, y, dx, dy: integer);

var i: integer;

begin

if ((y + dy) and $FFFFFC00) = 0 then

   for i:= max(x - dx, 0) to min(x + dx, 2047) do ClearLandPixel(y + dy, i);

if ((y - dy) and $FFFFFC00) = 0 then

   for i:= max(x - dx, 0) to min(x + dx, 2047) do ClearLandPixel(y - dy, i);

if ((y + dx) and $FFFFFC00) = 0 then

   for i:= max(x - dy, 0) to min(x + dy, 2047) do ClearLandPixel(y + dx, i);

if ((y - dx) and $FFFFFC00) = 0 then

   for i:= max(x - dy, 0) to min(x + dy, 2047) do ClearLandPixel(y - dx, i);

end;

procedure FillLandCircleLinesEBC(x, y, dx, dy: integer);

var i: integer;

begin

if ((y + dy) and $FFFFFC00) = 0 then

   for i:= max(x - dx, 0) to min(x + dx, 2047) do

       if Land[y + dy, i] = COLOR_LAND then SetLandPixel(y + dy, i);

if ((y - dy) and $FFFFFC00) = 0 then

   for i:= max(x - dx, 0) to min(x + dx, 2047) do

       if Land[y - dy, i] = COLOR_LAND then SetLandPixel(y - dy, i);

if ((y + dx) and $FFFFFC00) = 0 then

   for i:= max(x - dy, 0) to min(x + dy, 2047) do

       if Land[y + dx, i] = COLOR_LAND then SetLandPixel(y + dx, i);

if ((y - dx) and $FFFFFC00) = 0 then

   for i:= max(x - dy, 0) to min(x + dy, 2047) do

       if Land[y - dx, i] = COLOR_LAND then SetLandPixel(y - dx, i);

end;

procedure DrawExplosion(X, Y, Radius: integer);

var dx, dy, d: integer;

begin

FillRoundInLand(X, Y, Radius, 0);

if SDL_MustLock(LandSurface) then

   SDLTry(SDL_LockSurface(LandSurface) >= 0, true);

  dx:= 0;

  dy:= Radius;

  d:= 3 - 2 * Radius;

  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);

  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);  

if SDL_MustLock(LandSurface) then

   SDL_UnlockSurface(LandSurface);

end;

procedure DrawHLinesExplosions(ar: PRangeArray; Radius: integer; y, dY: integer; Count: Byte);

var tx, ty, i: LongInt;

begin

if SDL_MustLock(LandSurface) then

   SDL_LockSurface(LandSurface);

for i:= 0 to Pred(Count) do

    begin

    for ty:= max(y - Radius, 0) to min(y + Radius, 1023) do

        for tx:= max(0, ar[i].Left - Radius) to min(2047, ar[i].Right + Radius) do

            ClearLandPixel(ty, tx);

    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, 1023) do

        for tx:= max(0, ar[i].Left - Radius) to min(2047, ar[i].Right + Radius) do

            if Land[ty, tx] = $FFFFFF then

                  SetLandPixel(ty, tx);

    inc(y, dY)

    end;

if SDL_MustLock(LandSurface) then

   SDL_UnlockSurface(LandSurface);

end;

//

//  - (dX, dY) - direction, vector of length = 0.5

//

procedure DrawTunnel(X, Y, dX, dY: Double; ticks, HalfWidth: integer);

var nx, ny: Double;

    i, t, tx, ty: Longint;

begin  // (-dY, dX) is (dX, dY) rotated by PI/2

if SDL_MustLock(LandSurface) then

   SDL_LockSurface(LandSurface);

nx:= X + dY * (HalfWidth + 8);

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

for i:= 0 to 7 do

    begin

    X:= nx - 8 * dX;

    Y:= ny - 8 * dY;

    for t:= -8 to ticks + 8 do

        {$include tunsetborder.inc}

    nx:= nx - dY;

    ny:= ny + dX;

    end;

for i:= -HalfWidth to HalfWidth do

    begin

    X:= nx - dX * 8;

    Y:= ny - dY * 8;

    for t:= 0 to 7 do

        {$include tunsetborder.inc}

    X:= nx;

    Y:= ny;

    for t:= 0 to ticks do

        begin

        X:= X + dX;

        Y:= Y + dY;

        tx:= round(X);

        ty:= round(Y);

        if ((ty and $FFFFFC00) = 0) and ((tx and $FFFFF800) = 0) then

           begin

           Land[ty, tx]:= 0;

           ClearLandPixel(ty, tx);

           end

        end;

    for t:= 0 to 7 do

        {$include tunsetborder.inc}

    nx:= nx - dY;

    ny:= ny + dX;

    end;

for i:= 0 to 7 do

    begin

    X:= nx - 8 * dX;

    Y:= ny - 8 * dY;

    for t:= -8 to ticks + 8 do

        {$include tunsetborder.inc}

    nx:= nx - dY;

    ny:= ny + dX;

    end;

if SDL_MustLock(LandSurface) then

   SDL_UnlockSurface(LandSurface)

end;

end.