/*
**	Command & Conquer Renegade(tm)
**	Copyright 2025 Electronic Arts Inc.
**
**	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, either version 3 of the License, or
**	(at your option) any later version.
**
**	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, see <http://www.gnu.org/licenses/>.
*/

#ifndef DDSFILE_H
#define DDSFILE_H

#if defined(_MSC_VER)
#pragma once
#endif

#include "always.h"
#include "ww3dformat.h"
#include "wwstring.h"

struct IDirect3DSurface8;

// ----------------------------------------------------------------------------
//
// This structure represents the old DX7 color key structure. It is needed
// LegacyDDSURFACEDESC which is needed when loading DDS files. DO NOT MODIFY!
//
// ----------------------------------------------------------------------------

struct LegacyDDCOLORKEY
{ 
	unsigned ColorSpaceLowValue; 
	unsigned ColorSpaceHighValue; 
}; 

// ----------------------------------------------------------------------------
//
// This structure represents the old DX7 CAPS2 structure. It is needed
// LegacyDDSURFACEDESC which is needed when loading DDS files. DO NOT MODIFY!
//
// ----------------------------------------------------------------------------

struct LegacyDDSCAPS2
{
	unsigned Caps;
	unsigned Caps2;
	unsigned Caps3;
	unsigned Caps4; 
};

// ----------------------------------------------------------------------------
//
// This structure represents the old DX7 pixel format structure. It is needed
// LegacyDDSURFACEDESC which is needed when loading DDS files. DO NOT MODIFY!
//
// ----------------------------------------------------------------------------

struct LegacyDDPIXELFORMAT
{
	unsigned Size; 
	unsigned Flags; 
	unsigned FourCC; 
	union 
	{ 
		unsigned RGBBitCount; 
		unsigned YUVBitCount; 
		unsigned ZBufferBitDepth; 
		unsigned AlphaBitDepth; 
		unsigned LuminanceBitCount;
		unsigned BumpBitCount;
	};
	union 
	{ 
		unsigned RBitMask; 
		unsigned YBitMask; 
		unsigned StencilBitDepth;
		unsigned LuminanceBitMask;
		unsigned BumpDuBitMask;
	};
	union 
	{ 
		unsigned GBitMask; 
		unsigned UBitMask; 
		unsigned ZBitMask;
		unsigned BumpDvBitMask;
	};
	union 
	{ 
		unsigned BBitMask; 
		unsigned VBitMask; 
		unsigned StencilBitMask;
		unsigned BumpLuminanceBitMask;
	};
	union 
	{ 
		unsigned RGBAlphaBitMask; 
		unsigned YUVAlphaBitMask; 
		unsigned LuminanceAlphaBitMask;
		unsigned RGBZBitMask; 
		unsigned YUVZBitMask; 
	};
};

// ----------------------------------------------------------------------------
//
// This structure represents the old DX7 surface description structure.
// It is needed when loading DDS files. DO NOT MODIFY!
//
// ----------------------------------------------------------------------------

struct LegacyDDSURFACEDESC2 {
	unsigned Size;
	unsigned Flags;
	unsigned Height;
	unsigned Width;
	union
	{
		unsigned Pitch;
		unsigned LinearSize;
	};
	unsigned BackBufferCount;
	union
	{
		unsigned MipMapCount;
		unsigned RefreshRate;
	};
	unsigned AlphaBitDepth;
	unsigned Reserved;
	void* Surface;
	union
	{
		LegacyDDCOLORKEY CKDestOverlay;
		unsigned EmptyFaceColor;
	};
	LegacyDDCOLORKEY CKDestBlt;
	LegacyDDCOLORKEY CKSrcOverlay;
	LegacyDDCOLORKEY CKSrcBlt;
	LegacyDDPIXELFORMAT PixelFormat;
	LegacyDDSCAPS2 Caps;
	unsigned TextureStage;
};

// ----------------------------------------------------------------------------
//
// Utility class for loading DDS files. Simply create an instance of the class
// locally, call Load() and use the copy functions to retrieve the surface.
// The class handles conversion of the surface to equal compressed formats
// and all non-compressed formats. the compressed DXTn formats can't be cross-
// converted except for DXT1 which can be converted to DXT2 (this feature is
// needed as the NVidia cards have problems with DXT1).
//
// ----------------------------------------------------------------------------

class DDSFileClass
{
	unsigned Width;
	unsigned Height;
	unsigned FullWidth;
	unsigned FullHeight;
	unsigned MipLevels;
	unsigned long DateTime;
	unsigned ReductionFactor;
	unsigned char* DDSMemory;
	WW3DFormat Format;
	unsigned* LevelSizes;
	unsigned* LevelOffsets;
	LegacyDDSURFACEDESC2 SurfaceDesc;
	char Name[256];

	static unsigned Calculate_DXTC_Surface_Size(unsigned width, unsigned height, WW3DFormat format);

public:
	// You can pass the name in .tga or .dds format, the class will automatically try and load .dds file.
	// Note that creating the object will only give you image info - call Load() to load the surfaces.
	DDSFileClass(const char* name,unsigned reduction_factor);
	~DDSFileClass();

	unsigned Get_Width(unsigned level) const;
	unsigned Get_Height(unsigned level) const;
	unsigned Get_Full_Width() const { return FullWidth; }		// Get the width of level 0 of non-reduced texture
	unsigned Get_Full_Height() const { return FullHeight; }		// Get the height of level 0 of non-reduced texture
	unsigned long Get_Date_Time() const { return DateTime; }

	unsigned Get_Mip_Level_Count() const { return MipLevels; }
	const unsigned char* Get_Memory_Pointer(unsigned level) const;
	unsigned Get_Level_Size(unsigned level) const;
	WW3DFormat Get_Format() const { return Format; }

	// Copy pixels to the destination surface.
	void Copy_Level_To_Surface(unsigned level,IDirect3DSurface8* d3d_surface);
	void Copy_Level_To_Surface(
		unsigned level,
		WW3DFormat dest_format, 
		unsigned dest_width, 
		unsigned dest_height, 
		unsigned char* dest_surface, 
		unsigned dest_pitch);

	// Get pixel in A8R8G8B8 format. This isn't the fastest possible way of reading data from DDS.
	unsigned Get_Pixel(unsigned level,unsigned x,unsigned y) const;

// Uncompress one 4x4 block from the compressed image.
// Returns: true if block contained alpha, false is not
// Note: Destination can't be DXT or paletted surface!
	bool Get_4x4_Block(
		unsigned char* dest_ptr,			// Destination surface pointer
		unsigned dest_pitch,					// Destination surface pitch, in bytes
		WW3DFormat dest_format,				// Destination surface format, A8R8G8B8 is fastest
		unsigned level,						// DDS mipmap level to copy from
		unsigned source_x,					// DDS x offset to copy from, must be aligned by 4!
		unsigned source_y) const;			// DDS y offset to copy from, must be aligned by 4!

	bool Load();
	bool Is_Available() const { return !!LevelSizes; }
};

// ----------------------------------------------------------------------------

#endif