(*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2009 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

 *)

unit uLandTexture;

interface

uses SDLh;

procedure UpdateLandTexture(X, Width, Y, Height: LongInt);

procedure DrawLand(dX, dY: LongInt);

procedure FreeLand;

implementation

uses uMisc, uLand, uStore, GL, uConsts;

const TEXSIZE = 256;

	LANDTEXARW = LAND_WIDTH div TEXSIZE;

	LANDTEXARH = LAND_HEIGHT div TEXSIZE;

var

	LandTextures: array[0..LANDTEXARW - 1, 0..LANDTEXARH - 1] of

			record

			shouldUpdate: boolean;

			tex: PTexture;

			end;

	tmpPixels: array [0..TEXSIZE - 1, 0..TEXSIZE - 1] of LongWord;

function Pixels(x, y: Longword): Pointer;

var ty: Longword;

begin

for ty:= 0 to TEXSIZE - 1 do

	Move(LandPixels[y * TEXSIZE + ty, x * TEXSIZE], tmpPixels[ty, 0], sizeof(Longword) * TEXSIZE);

Pixels:= @tmpPixels

end;

procedure UpdateLandTexture(X, Width, Y, Height: LongInt);

var tx, ty: Longword;

begin

if (Width <= 0) or (Height <= 0) then exit;

TryDo((X >= 0) and (X < LAND_WIDTH), 'UpdateLandTexture: wrong X parameter', true);

TryDo(X + Width <= LAND_WIDTH, 'UpdateLandTexture: wrong Width parameter', true);

TryDo((Y >= 0) and (Y < LAND_HEIGHT), 'UpdateLandTexture: wrong Y parameter', true);

TryDo(Y + Height <= LAND_HEIGHT, 'UpdateLandTexture: wrong Height parameter', true);

for ty:= Y div TEXSIZE to (Y + Height - 1) div TEXSIZE do

	for tx:= X div TEXSIZE to (X + Width - 1) div TEXSIZE do

		LandTextures[tx, ty].shouldUpdate:= true

end;

procedure RealLandTexUpdate;

var x, y: LongWord;

begin

if LandTextures[0, 0].tex = nil then

	for x:= 0 to LANDTEXARW -1 do

		for y:= 0 to LANDTEXARH - 1 do

			with LandTextures[x, y] do

				tex:= NewTexture(TEXSIZE, TEXSIZE, Pixels(x, y))

else

	for x:= 0 to LANDTEXARW -1 do

		for y:= 0 to LANDTEXARH - 1 do

			with LandTextures[x, y] do

				if shouldUpdate then

					begin

					shouldUpdate:= false;

					glBindTexture(GL_TEXTURE_2D, tex^.id);

					glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, TEXSIZE, TEXSIZE, GL_RGBA, GL_UNSIGNED_BYTE, Pixels(x, y));

					end

end;

procedure DrawLand(dX, dY: LongInt);

var x, y: LongInt;

begin

RealLandTexUpdate;

for x:= 0 to LANDTEXARW -1 do

	for y:= 0 to LANDTEXARH - 1 do

		with LandTextures[x, y] do

			DrawTexture(dX + x * TEXSIZE, dY + y * TEXSIZE, tex)

end;

procedure FreeLand;

var x, y: LongInt;

begin

for x:= 0 to LANDTEXARW -1 do

	for y:= 0 to LANDTEXARH - 1 do

		with LandTextures[x, y] do

			FreeTexture(tex)

end;

end.