patch_dct.h

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#ifndef LL_PATCH_DCT_H
#define LL_PATCH_DCT_H

class LLVector3;

// Code Values
const U8 ZERO_CODE      = 0x0;
const U8 ZERO_EOB = 0x2;
const U8 POSITIVE_VALUE = 0x6;
const U8 NEGATIVE_VALUE = 0x7;

const S8 NORMAL_PATCH_SIZE      = 16;
const S8 LARGE_PATCH_SIZE = 32;

const U8 END_OF_PATCHES = 97;

#define _PATCH_SIZE_16_AND_32_ONLY

// Top level header for group of headers
//typedef struct LL_Group_Header
//{
//      U16  stride;            // 2 = 2
//      U8  patch_size;         // 1 = 3
//      U8  layer_type;         // 1 = 4
//} LLGroupHeader;

class LLGroupHeader
{
public:
        U16     stride;                 // 2 = 2
        U8      patch_size;             // 1 = 3
        U8      layer_type;             // 1 = 4
};

// Individual patch header

//typedef struct LL_Patch_Header
//{
//      F32 dc_offset;          // 4 bytes
//      U16 range;                      // 2 = 7 ((S16) FP range (breaks if we need > 32K meters in 1 patch)
//      U8  quant_wbits;        // 1 = 8 (upper 4 bits is quant - 2, lower 4 bits is word bits - 2)
//      U16     patchids;               // 2 = 10 (actually only uses 10 bits, 5 for each)
//} LLPatchHeader;
class LLPatchHeader
{
public:
        F32     dc_offset;              // 4 bytes
        U16     range;                  // 2 = 7 ((S16) FP range (breaks if we need > 32K meters in 1 patch)
        U8      quant_wbits;    // 1 = 8 (upper 4 bits is quant - 2, lower 4 bits is word bits - 2)
        U16     patchids;               // 2 = 10 (actually only uses 10 bits, 5 for each)
};

// Compression routines
void init_patch_compressor(S32 patch_size, S32 patch_stride, S32 layer_type);
void prescan_patch(F32 *patch, LLPatchHeader *php, F32 &zmax, F32 &zmin);
void compress_patch(F32 *patch, S32 *cpatch, LLPatchHeader *php, S32 prequant);
void get_patch_group_header(LLGroupHeader *gopp);

// Decompression routines
void set_group_of_patch_header(LLGroupHeader *gopp);
void init_patch_decompressor(S32 size);
void decompress_patch(F32 *patch, S32 *cpatch, LLPatchHeader *ph);
void decompress_patchv(LLVector3 *v, S32 *cpatch, LLPatchHeader *ph);

#endif

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