llimagedxt.h

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#ifndef LL_LLIMAGEDXT_H
#define LL_LLIMAGEDXT_H

#include "llimage.h"

// This class decodes and encodes LL DXT files (which may unclude uncompressed RGB or RGBA mipped data)

class LLImageDXT : public LLImageFormatted
{
public:
        enum EFileFormat
        { 
                FORMAT_UNKNOWN = 0,
                FORMAT_I8 = 1,
                FORMAT_A8,
                FORMAT_RGB8,
                FORMAT_RGBA8,
                FORMAT_DXT1,
                FORMAT_DXT2,
                FORMAT_DXT3,
                FORMAT_DXT4,
                FORMAT_DXT5,
                FORMAT_DXR1,
                FORMAT_DXR2,
                FORMAT_DXR3,
                FORMAT_DXR4,
                FORMAT_DXR5,
                FORMAT_NOFILE = 0xff,
        };
        
        struct dxtfile_header_old_t
        {
                S32 format;
                S32 maxlevel;
                S32 maxwidth;
                S32 maxheight;
        };

        struct dxtfile_header_t
        {
                S32 fourcc;
                // begin DDSURFACEDESC2 struct
                S32 header_size; // size of the header
                S32 flags; // flags - unused
                S32 maxheight;
                S32 maxwidth;
                S32 image_size; // size of the compressed image
                S32 depth;
                S32 num_mips;
                S32 reserved[11];
                struct pixel_format
                {
                        S32 struct_size; // size of this structure
                        S32 flags;
                        S32 fourcc;
                        S32 bit_count;
                        S32 r_mask;
                        S32 g_mask;
                        S32 b_mask;
                        S32 a_mask;
                } pixel_fmt;
                S32 caps[4];
                S32 reserved2;
        };

protected:
        /*virtual*/ ~LLImageDXT();
        
public:
        LLImageDXT();

        /*virtual*/ BOOL updateData();

        /*virtual*/ BOOL decode(LLImageRaw* raw_image, F32 time=0.0);
                                BOOL encode(const LLImageRaw* raw_image, F32 time, bool explicit_mips);
        /*virtual*/ BOOL encode(const LLImageRaw* raw_image, F32 time=0.0);

        /*virtual*/ S32 calcHeaderSize();
        /*virtual*/ S32 calcDataSize(S32 discard_level = 0);

        BOOL getMipData(LLPointer<LLImageRaw>& raw, S32 discard=-1);
        
        void setFormat();
        S32 getMipOffset(S32 discard);
        
        EFileFormat getFileFormat() { return mFileFormat; }
        bool isCompressed() { return (mFileFormat >= FORMAT_DXT1 && mFileFormat <= FORMAT_DXR5); }

        bool convertToDXR(); // convert from DXT to DXR
        
        static void checkMinWidthHeight(EFileFormat format, S32& width, S32& height);
        static S32 formatBits(EFileFormat format);
        static S32 formatBytes(EFileFormat format, S32 width, S32 height);
        static S32 formatOffset(EFileFormat format, S32 width, S32 height, S32 max_width, S32 max_height);
        static S32 formatComponents(EFileFormat format);
        
        static EFileFormat getFormat(S32 fourcc);
        static S32 getFourCC(EFileFormat format);

        static void calcDiscardWidthHeight(S32 discard_level, EFileFormat format, S32& width, S32& height);
        static S32 calcNumMips(S32 width, S32 height);

private:
        static void extractMip(const U8 *indata, U8* mipdata, int width, int height,
                                                   int mip_width, int mip_height, EFileFormat format);
        
private:
        EFileFormat mFileFormat;
        S32 mHeaderSize;
};

#endif

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