(*

 * 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, uLandTemplates, uFloat, GL, uConsts;

procedure UpdateLandTexture(Y, Height: LongInt);

procedure DrawLand (X, Y: LongInt);

implementation

uses uMisc, uLand, uStore;

var LandTexture: PTexture = nil;

    updTopY: LongInt = LAND_HEIGHT;

    updBottomY: LongInt = 0;

procedure UpdateLandTexture(Y, Height: LongInt);

begin

if (Height <= 0) then exit;

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

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

if Y < updTopY then updTopY:= Y;

if Y + Height > updBottomY then updBottomY:= Y + Height

end;

procedure RealLandTexUpdate;

begin

if updBottomY = 0 then exit;

if LandTexture = nil then

	LandTexture:= NewTexture(LAND_WIDTH, LAND_HEIGHT, @LandPixels)

else

	begin

	glBindTexture(GL_TEXTURE_2D, LandTexture^.id);

	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, updTopY, LAND_WIDTH, updBottomY - updTopY, GL_RGBA, GL_UNSIGNED_BYTE, @LandPixels[updTopY, 0]);

	end;

updTopY:= LAND_HEIGHT + 1;

updBottomY:= 0

end;

procedure DrawLand(X, Y: LongInt);

begin

RealLandTexUpdate;

DrawTexture(X, Y, LandTexture)

end;

end.