// Copyright NVIDIA Corporation 2007 -- Ignacio Castano <icastano@nvidia.com>
// 
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.

#pragma once
#ifndef NV_IMAGE_BLOCKDXT_H
#define NV_IMAGE_BLOCKDXT_H

#include "nvimage.h"

#include "nvmath/Color.h"

namespace nv
{
    struct ColorBlock;
    struct ColorSet;
    struct AlphaBlock4x4;
    class Stream;
    class Vector3;
    class Vector4;


    /// DXT1 block.
    struct BlockDXT1
    {
        Color16 col0;
        Color16 col1;
        union {
            uint8 row[4];
            uint indices;
        };

        bool isFourColorMode() const;

        uint evaluatePalette(Color32 color_array[4], bool d3d9) const;
        uint evaluatePaletteNV5x(Color32 color_array[4]) const;

        void evaluatePalette3(Color32 color_array[4], bool d3d9) const;
        void evaluatePalette4(Color32 color_array[4], bool d3d9) const;

        void decodeBlock(ColorBlock * block, bool d3d9 = false) const;
        void decodeBlockNV5x(ColorBlock * block) const;

        void setIndices(int * idx);

        void flip4();
        void flip2();
    };

    /// Return true if the block uses four color mode, false otherwise.
    inline bool BlockDXT1::isFourColorMode() const
    {
        return col0.u > col1.u;
    }


    /// DXT3 alpha block with explicit alpha.
    struct AlphaBlockDXT3
    {
        union {
            struct {
                uint alpha0 : 4;
                uint alpha1 : 4;
                uint alpha2 : 4;
                uint alpha3 : 4;
                uint alpha4 : 4;
                uint alpha5 : 4;
                uint alpha6 : 4;
                uint alpha7 : 4;
                uint alpha8 : 4;
                uint alpha9 : 4;
                uint alphaA : 4;
                uint alphaB : 4;
                uint alphaC : 4;
                uint alphaD : 4;
                uint alphaE : 4;
                uint alphaF : 4;
            };
            uint16 row[4];
        };

        void decodeBlock(ColorBlock * block, bool d3d9 = false) const;

        void flip4();
        void flip2();
    };


    /// DXT3 block.
    struct BlockDXT3
    {
        AlphaBlockDXT3 alpha;
        BlockDXT1 color;

        void decodeBlock(ColorBlock * block, bool d3d9 = false) const;
        void decodeBlockNV5x(ColorBlock * block) const;

        void flip4();
        void flip2();
    };


    /// DXT5 alpha block.
    struct AlphaBlockDXT5
    {
        union {
            struct {
                uint64 alpha0 : 8;	// 8
                uint64 alpha1 : 8;	// 16
                uint64 bits0 : 3;	// 3 - 19
                uint64 bits1 : 3; 	// 6 - 22
                uint64 bits2 : 3; 	// 9 - 25
                uint64 bits3 : 3;	// 12 - 28
                uint64 bits4 : 3;	// 15 - 31
                uint64 bits5 : 3;	// 18 - 34
                uint64 bits6 : 3;	// 21 - 37
                uint64 bits7 : 3;	// 24 - 40
                uint64 bits8 : 3;	// 27 - 43
                uint64 bits9 : 3; 	// 30 - 46
                uint64 bitsA : 3; 	// 33 - 49
                uint64 bitsB : 3;	// 36 - 52
                uint64 bitsC : 3;	// 39 - 55
                uint64 bitsD : 3;	// 42 - 58
                uint64 bitsE : 3;	// 45 - 61
                uint64 bitsF : 3;	// 48 - 64
            };
            uint64 u;
        };

        void evaluatePalette(uint8 alpha[8], bool d3d9) const;
        void evaluatePalette8(uint8 alpha[8], bool d3d9) const;
        void evaluatePalette6(uint8 alpha[8], bool d3d9) const;
        void indices(uint8 index_array[16]) const;

        uint index(uint index) const;
        void setIndex(uint index, uint value);

        void decodeBlock(ColorBlock * block, bool d3d9 = false) const;
        void decodeBlock(AlphaBlock4x4 * block, bool d3d9 = false) const;

        void flip4();
        void flip2();
    };


    /// DXT5 block.
    struct BlockDXT5
    {
        AlphaBlockDXT5 alpha;
        BlockDXT1 color;

        void decodeBlock(ColorBlock * block, bool d3d9 = false) const;
        void decodeBlockNV5x(ColorBlock * block) const;

        void flip4();
        void flip2();
    };

    /// ATI1 block.
    struct BlockATI1
    {
        AlphaBlockDXT5 alpha;

        void decodeBlock(ColorBlock * block, bool d3d9 = false) const;

        void flip4();
        void flip2();
    };

    /// ATI2 block.
    struct BlockATI2
    {
        AlphaBlockDXT5 x;
        AlphaBlockDXT5 y;

        void decodeBlock(ColorBlock * block, bool d3d9 = false) const;

        void flip4();
        void flip2();
    };

    /// CTX1 block.
    struct BlockCTX1
    {
        uint8 col0[2];
        uint8 col1[2];
        union {
            uint8 row[4];
            uint indices;
        };

        void evaluatePalette(Color32 color_array[4]) const;
        void setIndices(int * idx);

        void decodeBlock(ColorBlock * block) const;

        void flip4();
        void flip2();
    };

	/// BC6 block.
	struct BlockBC6
	{
		uint8 data[16];		// Not even going to try to write a union for this thing.
        void decodeBlock(Vector4 colors[16]) const;
	};

	/// BC7 block.
	struct BlockBC7
	{
		uint8 data[16];		// Not even going to try to write a union for this thing.
		void decodeBlock(ColorBlock * block) const;
	};



    // Serialization functions.
    Stream & operator<<(Stream & stream, BlockDXT1 & block);
    Stream & operator<<(Stream & stream, AlphaBlockDXT3 & block);
    Stream & operator<<(Stream & stream, BlockDXT3 & block);
    Stream & operator<<(Stream & stream, AlphaBlockDXT5 & block);
    Stream & operator<<(Stream & stream, BlockDXT5 & block);
    Stream & operator<<(Stream & stream, BlockATI1 & block);
    Stream & operator<<(Stream & stream, BlockATI2 & block);
    Stream & operator<<(Stream & stream, BlockCTX1 & block);
    Stream & operator<<(Stream & stream, BlockBC6 & block);
    Stream & operator<<(Stream & stream, BlockBC7 & block);

} // nv namespace

#endif // NV_IMAGE_BLOCKDXT_H