/*
** flattexture.cpp
** Texture class for standard Doom flats
**
**---------------------------------------------------------------------------
** Copyright 2004-2006 Randy Heit
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
**
*/

#include "doomtype.h"
#include "files.h"
#include "w_wad.h"
#include "v_palette.h"
#include "textures/textures.h"

//==========================================================================
//
// A texture defined between F_START and F_END markers
//
//==========================================================================

class FFlatTexture : public FTexture
{
public:
	FFlatTexture (int lumpnum);
	~FFlatTexture ();

	const BYTE *GetColumn (unsigned int column, const Span **spans_out);
	const BYTE *GetPixels ();
	void Unload ();

protected:
	BYTE *Pixels;
	Span DummySpans[2];


	void MakeTexture ();

	friend class FTexture;
};



//==========================================================================
//
// Since there is no way to detect the validity of a flat
// they can't be used anywhere else but between F_START and F_END
//
//==========================================================================

FTexture *FlatTexture_TryCreate(FileReader & file, int lumpnum)
{
	return new FFlatTexture(lumpnum);
}

//==========================================================================
//
//
//
//==========================================================================

FFlatTexture::FFlatTexture (int lumpnum)
: FTexture(NULL, lumpnum), Pixels(0)
{
	int area;
	int bits;

	area = Wads.LumpLength (lumpnum);

	switch (area)
	{
	default:
	case 64*64:		bits = 6;	break;
	case 8*8:		bits = 3;	break;
	case 16*16:		bits = 4;	break;
	case 32*32:		bits = 5;	break;
	case 128*128:	bits = 7;	break;
	case 256*256:	bits = 8;	break;
	}

	bMasked = false;
	WidthBits = HeightBits = bits;
	Width = Height = 1 << bits;
	WidthMask = (1 << bits) - 1;
	DummySpans[0].TopOffset = 0;
	DummySpans[0].Length = Height;
	DummySpans[1].TopOffset = 0;
	DummySpans[1].Length = 0;
}

//==========================================================================
//
//
//
//==========================================================================

FFlatTexture::~FFlatTexture ()
{
	Unload ();
}

//==========================================================================
//
//
//
//==========================================================================

void FFlatTexture::Unload ()
{
	if (Pixels != NULL)
	{
		delete[] Pixels;
		Pixels = NULL;
	}
}

//==========================================================================
//
//
//
//==========================================================================

const BYTE *FFlatTexture::GetColumn (unsigned int column, const Span **spans_out)
{
	if (Pixels == NULL)
	{
		MakeTexture ();
	}
	if ((unsigned)column >= (unsigned)Width)
	{
		if (WidthMask + 1 == Width)
		{
			column &= WidthMask;
		}
		else
		{
			column %= Width;
		}
	}
	if (spans_out != NULL)
	{
		*spans_out = DummySpans;
	}
	return Pixels + column*Height;
}

//==========================================================================
//
//
//
//==========================================================================

const BYTE *FFlatTexture::GetPixels ()
{
	if (Pixels == NULL)
	{
		MakeTexture ();
	}
	return Pixels;
}

//==========================================================================
//
//
//
//==========================================================================

void FFlatTexture::MakeTexture ()
{
	FWadLump lump = Wads.OpenLumpNum (SourceLump);
	Pixels = new BYTE[Width*Height];
	long numread = lump.Read (Pixels, Width*Height);
	if (numread < Width*Height)
	{
		memset (Pixels + numread, 0xBB, Width*Height - numread);
	}
	FlipSquareBlockRemap (Pixels, Width, Height, GPalette.Remap);
}