/** 
 * @file patch_dct.cpp
 * @brief DCT patch.
 *
 * $LicenseInfo:firstyear=2000&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "llmath.h"
//#include "vmath.h"
#include "v3math.h"
#include "patch_dct.h"

typedef struct s_patch_compress_global_data
{
	S32 patch_size;
	S32 patch_stride;
	U32 charptr;
	S32 layer_type;
} PCGD;

PCGD	gPatchCompressGlobalData;

void reset_patch_compressor(void)
{
	PCGD *pcp = &gPatchCompressGlobalData;

	pcp->charptr = 0;
}

S32	gCurrentSize = 0;

F32 gPatchQuantizeTable[LARGE_PATCH_SIZE*LARGE_PATCH_SIZE];

void build_patch_quantize_table(S32 size)
{
	S32 i, j;
	for (j = 0; j < size; j++)
	{
		for (i = 0; i < size; i++)
		{
			gPatchQuantizeTable[j*size + i] = 1.f/(1.f + 2.f*(i+j));
		}
	}
}

F32	gPatchCosines[LARGE_PATCH_SIZE*LARGE_PATCH_SIZE];

void setup_patch_cosines(S32 size)
{
	S32 n, u;
	F32 oosob = F_PI*0.5f/size;

	for (u = 0; u < size; u++)
	{
		for (n = 0; n < size; n++)
		{
			gPatchCosines[u*size+n] = cosf((2.f*n+1.f)*u*oosob);
		}
	}
}

S32	gCopyMatrix[LARGE_PATCH_SIZE*LARGE_PATCH_SIZE];

void build_copy_matrix(S32 size)
{
	S32 i, j, count;
	BOOL	b_diag = FALSE;
	BOOL	b_right = TRUE;

	i = 0;
	j = 0;
	count = 0;

	while (  (i < size)
		   &&(j < size))
	{
		gCopyMatrix[j*size + i] = count;

		count++;

		if (!b_diag)
		{
			if (b_right)
			{
				if (i < size - 1)
					i++;
				else
					j++;
				b_right = FALSE;
				b_diag = TRUE;
			}
			else
			{
				if (j < size - 1)
					j++;
				else
					i++;
				b_right = TRUE;
				b_diag = TRUE;
			}
		}
		else
		{
			if (b_right)
			{
				i++;
				j--;
				if (  (i == size - 1)
					||(j == 0))
				{
					b_diag = FALSE;
				}
			}
			else
			{
				i--;
				j++;
				if (  (i == 0)
					||(j == size - 1))
				{
					b_diag = FALSE;
				}
			}
		}
	}
}


void init_patch_compressor(S32 patch_size, S32 patch_stride, S32 layer_type)
{
	PCGD *pcp = &gPatchCompressGlobalData;

	pcp->charptr = 0;

	pcp->patch_size = patch_size;
	pcp->patch_stride = patch_stride;
	pcp->layer_type = layer_type;

	if (patch_size != gCurrentSize)
	{
		gCurrentSize = patch_size;
		build_patch_quantize_table(patch_size);
		setup_patch_cosines(patch_size);
		build_copy_matrix(patch_size);
	}
}

void prescan_patch(F32 *patch, LLPatchHeader *php, F32 &zmax, F32 &zmin)
{
	S32		i, j;
	PCGD	*pcp = &gPatchCompressGlobalData;
	S32		stride = pcp->patch_stride;
	S32		size = pcp->patch_size;
	S32		jstride;

	zmax = -99999999.f;
	zmin = 99999999.f;

	for (j = 0; j < size; j++)
	{
		jstride = j*stride;
		for (i = 0; i < size; i++)
		{
			if (*(patch + jstride + i) > zmax)
			{
				zmax = *(patch + jstride + i);
			}
			if (*(patch + jstride + i) < zmin)
			{
				zmin = *(patch + jstride + i);
			}
		}
	}

	php->dc_offset = zmin;
	php->range = (U16) ((zmax - zmin) + 1.f);
}

void dct_line(F32 *linein, F32 *lineout, S32 line)
{
	S32 u;
	F32 total;
	F32 *pcp = gPatchCosines;
	S32	line_size = line*NORMAL_PATCH_SIZE;

#ifdef _PATCH_SIZE_16_AND_32_ONLY
	F32 *tlinein, *tpcp;

	tlinein = linein + line_size;

	total = *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein);

	*(lineout + line_size) = OO_SQRT2*total;

	for (u = 1; u < NORMAL_PATCH_SIZE; u++)
	{
		tlinein = linein + line_size;
		tpcp = pcp + (u<<4);

		total = *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein)*(*tpcp);

		*(lineout + line_size + u) = total;
	}
#else
	S32 n;
	S32	size = gPatchCompressGlobalData.patch_size;
	total = 0.f;
	for (n = 0; n < size; n++)
	{
		total += linein[line_size + n];
	}
	lineout[line_size] = OO_SQRT2*total;

	for (u = 1; u < size; u++)
	{
		total = 0.f;
		for (n = 0; n < size; n++)
		{
			total += linein[line_size + n]*pcp[u*size+n];
		}
		lineout[line_size + u] = total;
	}
#endif
}

void dct_line_large(F32 *linein, F32 *lineout, S32 line)
{
	S32 u;
	F32 total;
	F32 *pcp = gPatchCosines;
	S32	line_size = line*LARGE_PATCH_SIZE;

	F32 *tlinein, *tpcp;

	tlinein = linein + line_size;

	total = *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);

	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein++);
	total += *(tlinein);

	*(lineout + line_size) = OO_SQRT2*total;

	for (u = 1; u < LARGE_PATCH_SIZE; u++)
	{
		tlinein = linein + line_size;
		tpcp = pcp + (u<<5);

		total = *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));

		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein++)*(*(tpcp++));
		total += *(tlinein)*(*tpcp);

		*(lineout + line_size + u) = total;
	}
}

inline void dct_column(F32 *linein, S32 *lineout, S32 column)
{
	S32 u;
	F32 total;
	F32 oosob = 2.f/16.f;
	F32 *pcp = gPatchCosines;
	S32	*copy_matrix = gCopyMatrix;
	F32	*qt = gPatchQuantizeTable;

#ifdef _PATCH_SIZE_16_AND_32_ONLY
	F32 *tlinein, *tpcp;
	S32 sizeu;

	tlinein = linein + column;

	total = *(tlinein);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);

	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);

	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);

	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);
	total += *(tlinein += NORMAL_PATCH_SIZE);

	*(lineout + *(copy_matrix + column)) = (S32)(OO_SQRT2*total*oosob*(*(qt + column)));

	for (u = 1; u < NORMAL_PATCH_SIZE; u++)
	{
		tlinein = linein + column;
		tpcp = pcp + (u<<4);

		total = *(tlinein)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += NORMAL_PATCH_SIZE)*(*(tpcp));

		sizeu = NORMAL_PATCH_SIZE*u + column;

		*(lineout + *(copy_matrix + sizeu)) = (S32)(total*oosob*(*(qt+sizeu)));
	}
#else
	S32	size = gPatchCompressGlobalData.patch_size;
	F32 oosob = 2.f/size;
	S32 n;
	total = 0.f;
	for (n = 0; n < size; n++)
	{
		total += linein[size*n + column];
	}
	lineout[copy_matrix[column]] = OO_SQRT2*total*oosob*qt[column];

	for (u = 1; u < size; u++)
	{
		total = 0.f;
		for (n = 0; n < size; n++)
		{
			total += linein[size*n + column]*pcp[u*size+n];
		}
		lineout[copy_matrix[size*u + column]] = total*oosob*qt[size*u + column];
	}
#endif
}

inline void dct_column_large(F32 *linein, S32 *lineout, S32 column)
{
	S32 u;
	F32 total;
	F32 oosob = 2.f/32.f;
	F32 *pcp = gPatchCosines;
	S32	*copy_matrix = gCopyMatrix;
	F32	*qt = gPatchQuantizeTable;

	F32 *tlinein, *tpcp;
	S32 sizeu;

	tlinein = linein + column;

	total = *(tlinein);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);
	total += *(tlinein += LARGE_PATCH_SIZE);

	*(lineout + *(copy_matrix + column)) = (S32)(OO_SQRT2*total*oosob*(*(qt + column)));

	for (u = 1; u < LARGE_PATCH_SIZE; u++)
	{
		tlinein = linein + column;
		tpcp = pcp + (u<<5);

		total = *(tlinein)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));

		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp++));
		total += *(tlinein += LARGE_PATCH_SIZE)*(*(tpcp));

		sizeu = LARGE_PATCH_SIZE*u + column;

		*(lineout + *(copy_matrix + sizeu)) = (S32)(total*oosob*(*(qt+sizeu)));
	}
}

inline void dct_patch(F32 *block, S32 *cpatch)
{
	F32 temp[NORMAL_PATCH_SIZE*NORMAL_PATCH_SIZE];

#ifdef _PATCH_SIZE_16_AND_32_ONLY
	dct_line(block, temp, 0);
	dct_line(block, temp, 1);
	dct_line(block, temp, 2);
	dct_line(block, temp, 3);

	dct_line(block, temp, 4);
	dct_line(block, temp, 5);
	dct_line(block, temp, 6);
	dct_line(block, temp, 7);

	dct_line(block, temp, 8);
	dct_line(block, temp, 9);
	dct_line(block, temp, 10);
	dct_line(block, temp, 11);

	dct_line(block, temp, 12);
	dct_line(block, temp, 13);
	dct_line(block, temp, 14);
	dct_line(block, temp, 15);

	dct_column(temp, cpatch, 0);
	dct_column(temp, cpatch, 1);
	dct_column(temp, cpatch, 2);
	dct_column(temp, cpatch, 3);

	dct_column(temp, cpatch, 4);
	dct_column(temp, cpatch, 5);
	dct_column(temp, cpatch, 6);
	dct_column(temp, cpatch, 7);

	dct_column(temp, cpatch, 8);
	dct_column(temp, cpatch, 9);
	dct_column(temp, cpatch, 10);
	dct_column(temp, cpatch, 11);

	dct_column(temp, cpatch, 12);
	dct_column(temp, cpatch, 13);
	dct_column(temp, cpatch, 14);
	dct_column(temp, cpatch, 15);
#else
	S32 i;
	S32	size = gPatchCompressGlobalData.patch_size;
	for (i = 0; i < size; i++)
	{
		dct_line(block, temp, i);
	}
	for (i = 0; i < size; i++)
	{
		dct_column(temp, cpatch, i);
	}
#endif
}

inline void dct_patch_large(F32 *block, S32 *cpatch)
{
	F32 temp[LARGE_PATCH_SIZE*LARGE_PATCH_SIZE];

	dct_line_large(block, temp, 0);
	dct_line_large(block, temp, 1);
	dct_line_large(block, temp, 2);
	dct_line_large(block, temp, 3);

	dct_line_large(block, temp, 4);
	dct_line_large(block, temp, 5);
	dct_line_large(block, temp, 6);
	dct_line_large(block, temp, 7);

	dct_line_large(block, temp, 8);
	dct_line_large(block, temp, 9);
	dct_line_large(block, temp, 10);
	dct_line_large(block, temp, 11);

	dct_line_large(block, temp, 12);
	dct_line_large(block, temp, 13);
	dct_line_large(block, temp, 14);
	dct_line_large(block, temp, 15);

	dct_line_large(block, temp, 16);
	dct_line_large(block, temp, 17);
	dct_line_large(block, temp, 18);
	dct_line_large(block, temp, 19);

	dct_line_large(block, temp, 20);
	dct_line_large(block, temp, 21);
	dct_line_large(block, temp, 22);
	dct_line_large(block, temp, 23);

	dct_line_large(block, temp, 24);
	dct_line_large(block, temp, 25);
	dct_line_large(block, temp, 26);
	dct_line_large(block, temp, 27);

	dct_line_large(block, temp, 28);
	dct_line_large(block, temp, 29);
	dct_line_large(block, temp, 30);
	dct_line_large(block, temp, 31);

	dct_column_large(temp, cpatch, 0);
	dct_column_large(temp, cpatch, 1);
	dct_column_large(temp, cpatch, 2);
	dct_column_large(temp, cpatch, 3);

	dct_column_large(temp, cpatch, 4);
	dct_column_large(temp, cpatch, 5);
	dct_column_large(temp, cpatch, 6);
	dct_column_large(temp, cpatch, 7);

	dct_column_large(temp, cpatch, 8);
	dct_column_large(temp, cpatch, 9);
	dct_column_large(temp, cpatch, 10);
	dct_column_large(temp, cpatch, 11);

	dct_column_large(temp, cpatch, 12);
	dct_column_large(temp, cpatch, 13);
	dct_column_large(temp, cpatch, 14);
	dct_column_large(temp, cpatch, 15);

	dct_column_large(temp, cpatch, 16);
	dct_column_large(temp, cpatch, 17);
	dct_column_large(temp, cpatch, 18);
	dct_column_large(temp, cpatch, 19);

	dct_column_large(temp, cpatch, 20);
	dct_column_large(temp, cpatch, 21);
	dct_column_large(temp, cpatch, 22);
	dct_column_large(temp, cpatch, 23);

	dct_column_large(temp, cpatch, 24);
	dct_column_large(temp, cpatch, 25);
	dct_column_large(temp, cpatch, 26);
	dct_column_large(temp, cpatch, 27);

	dct_column_large(temp, cpatch, 28);
	dct_column_large(temp, cpatch, 29);
	dct_column_large(temp, cpatch, 30);
	dct_column_large(temp, cpatch, 31);
}

void compress_patch(F32 *patch, S32 *cpatch, LLPatchHeader *php, S32 prequant)
{
	S32		i, j;
	PCGD	*pcp = &gPatchCompressGlobalData;
	S32		stride = pcp->patch_stride;
	S32		size = pcp->patch_size;
	F32		block[LARGE_PATCH_SIZE*LARGE_PATCH_SIZE], *tblock;
	F32		*tpatch;

	S32		wordsize = prequant;
	F32		oozrange = 1.f/php->range;

	F32		dc = php->dc_offset;

	S32		range = (1<<prequant);
	F32		premult = oozrange*range;
//	F32		sub = (F32)(1<<(prequant - 1));
	F32		sub = (F32)(1<<(prequant - 1)) + dc*premult;

	php->quant_wbits = wordsize - 2;
	php->quant_wbits |= (prequant - 2)<<4;

	for (j = 0; j < size; j++)
	{
		tblock = block + j*size;
		tpatch = patch + j*stride;
		for (i = 0; i < size; i++)
		{
//			block[j*size + i] = (patch[j*stride + i] - dc)*premult - sub;
			*(tblock++) = *(tpatch++)*premult - sub;
		}
	}

	if (size == 16)
		dct_patch(block, cpatch);
	else
		dct_patch_large(block, cpatch);
}

void get_patch_group_header(LLGroupHeader *gopp)
{
	PCGD	*pcp = &gPatchCompressGlobalData;
	gopp->stride = pcp->patch_stride;
	gopp->patch_size = pcp->patch_size;
	gopp->layer_type = pcp->layer_type;
}
