/*
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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 2
 * 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, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Morten Mikkelsen.
 *
 * ***** END GPL LICENSE BLOCK *****
 * filter.c
 *
 * $Id$
 */

/** \file blender/imbuf/intern/filter.c
 *  \ingroup imbuf
 */


#include "MEM_guardedalloc.h"

#include "BLI_utildefines.h"



#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"
#include "IMB_filter.h"

#include "imbuf.h"

/************************************************************************/
/*				FILTERS					*/
/************************************************************************/

static void filtrow(unsigned char *point, int x)
{
	unsigned int c1,c2,c3,error;

	if (x>1){
		c1 = c2 = *point;
		error = 2;
		for(x--;x>0;x--){
			c3 = point[4];
			c1 += (c2<<1) + c3 + error;
			error = c1 & 3;
			*point = c1 >> 2;
			point += 4;
			c1=c2;
			c2=c3;
		}
		*point = (c1 + (c2<<1) + c2 + error) >> 2;
	}
}

static void filtrowf(float *point, int x)
{
	float c1,c2,c3;
	
	if (x>1){
		c1 = c2 = *point;
		for(x--;x>0;x--){
			c3 = point[4];
			c1 += (c2 * 2) + c3;
			*point = 0.25f*c1;
			point += 4;
			c1=c2;
			c2=c3;
		}
		*point = 0.25f*(c1 + (c2 * 2) + c2);
	}
}



static void filtcolum(unsigned char *point, int y, int skip)
{
	unsigned int c1,c2,c3,error;
	unsigned char *point2;

	if (y>1){
		c1 = c2 = *point;
		point2 = point;
		error = 2;
		for(y--;y>0;y--){
			point2 += skip;
			c3 = *point2;
			c1 += (c2<<1) + c3 +error;
			error = c1 & 3;
			*point = c1 >> 2;
			point=point2;
			c1=c2;
			c2=c3;
		}
		*point = (c1 + (c2<<1) + c2 + error) >> 2;
	}
}

static void filtcolumf(float *point, int y, int skip)
{
	float c1,c2,c3, *point2;
	
	if (y>1){
		c1 = c2 = *point;
		point2 = point;
		for(y--;y>0;y--){
			point2 += skip;
			c3 = *point2;
			c1 += (c2 * 2) + c3;
			*point = 0.25f*c1;
			point=point2;
			c1=c2;
			c2=c3;
		}
		*point = 0.25f*(c1 + (c2 * 2) + c2);
	}
}

void IMB_filtery(struct ImBuf *ibuf)
{
	unsigned char *point;
	float *pointf;
	int x, y, skip;

	point = (unsigned char *)ibuf->rect;
	pointf = ibuf->rect_float;

	x = ibuf->x;
	y = ibuf->y;
	skip = x<<2;

	for (;x>0;x--){
		if (point) {
			if (ibuf->depth > 24) filtcolum(point,y,skip);
			point++;
			filtcolum(point,y,skip);
			point++;
			filtcolum(point,y,skip);
			point++;
			filtcolum(point,y,skip);
			point++;
		}
		if (pointf) {
			if (ibuf->depth > 24) filtcolumf(pointf,y,skip);
			pointf++;
			filtcolumf(pointf,y,skip);
			pointf++;
			filtcolumf(pointf,y,skip);
			pointf++;
			filtcolumf(pointf,y,skip);
			pointf++;
		}
	}
}


void imb_filterx(struct ImBuf *ibuf)
{
	unsigned char *point;
	float *pointf;
	int x, y, skip;

	point = (unsigned char *)ibuf->rect;
	pointf = ibuf->rect_float;

	x = ibuf->x;
	y = ibuf->y;
	skip = (x<<2) - 3;

	for (;y>0;y--){
		if (point) {
			if (ibuf->depth > 24) filtrow(point,x);
			point++;
			filtrow(point,x);
			point++;
			filtrow(point,x);
			point++;
			filtrow(point,x);
			point+=skip;
		}
		if (pointf) {
			if (ibuf->depth > 24) filtrowf(pointf,x);
			pointf++;
			filtrowf(pointf,x);
			pointf++;
			filtrowf(pointf,x);
			pointf++;
			filtrowf(pointf,x);
			pointf+=skip;
		}
	}
}

void IMB_filterN(ImBuf *out, ImBuf *in)
{
	register char *row1, *row2, *row3;
	register char *cp, *r11, *r13, *r21, *r23, *r31, *r33;
	int rowlen, x, y;
	
	rowlen= in->x;
	
	for(y=0; y<in->y; y++) {
		/* setup rows */
		row2= (char*)(in->rect + y*rowlen);
		row1= (y == 0)? row2: row2 - 4*rowlen;
		row3= (y == in->y-1)? row2: row2 + 4*rowlen;
		
		cp= (char *)(out->rect + y*rowlen);
		
		for(x=0; x<rowlen; x++) {
			if(x == 0) {
				r11 = row1;
				r21 = row1;
				r31 = row1;
			}
			else {
				r11 = row1-4;
				r21 = row1-4;
				r31 = row1-4;
			}

			if(x == rowlen-1) {
				r13 = row1;
				r23 = row1;
				r33 = row1;
			}
			else {
				r13 = row1+4;
				r23 = row1+4;
				r33 = row1+4;
			}

			cp[0]= (r11[0] + 2*row1[0] + r13[0] + 2*r21[0] + 4*row2[0] + 2*r23[0] + r31[0] + 2*row3[0] + r33[0])>>4;
			cp[1]= (r11[1] + 2*row1[1] + r13[1] + 2*r21[1] + 4*row2[1] + 2*r23[1] + r31[1] + 2*row3[1] + r33[1])>>4;
			cp[2]= (r11[2] + 2*row1[2] + r13[2] + 2*r21[2] + 4*row2[2] + 2*r23[2] + r31[2] + 2*row3[2] + r33[2])>>4;
			cp[3]= (r11[3] + 2*row1[3] + r13[3] + 2*r21[3] + 4*row2[3] + 2*r23[3] + r31[3] + 2*row3[3] + r33[3])>>4;
			cp+=4; row1+=4; row2+=4; row3+=4;
		}
	}
}

void IMB_filter(struct ImBuf *ibuf)
{
	IMB_filtery(ibuf);
	imb_filterx(ibuf);
}

void IMB_mask_filter_extend(char *mask, int width, int height)
{
	char *row1, *row2, *row3;
	int rowlen, x, y;
	char *temprect;

	rowlen= width;

	/* make a copy, to prevent flooding */
	temprect= MEM_dupallocN(mask);

	for(y=1; y<=height; y++) {
		/* setup rows */
		row1= (char *)(temprect + (y-2)*rowlen);
		row2= row1 + rowlen;
		row3= row2 + rowlen;
		if(y==1)
			row1= row2;
		else if(y==height)
			row3= row2;

		for(x=0; x<rowlen; x++) {
			if (mask[((y-1)*rowlen)+x]==0) {
				if (*row1 || *row2 || *row3 || *(row1+1) || *(row3+1) ) {
					mask[((y-1)*rowlen)+x] = FILTER_MASK_MARGIN;
				} else if((x!=rowlen-1) && (*(row1+2) || *(row2+2) || *(row3+2)) ) {
					mask[((y-1)*rowlen)+x] = FILTER_MASK_MARGIN;
				}
			}

			if(x!=0) {
				row1++; row2++; row3++;
			}
		}
	}

	MEM_freeN(temprect);
}

void IMB_mask_clear(ImBuf *ibuf, char *mask, int val)
{
	int x,y;
	if (ibuf->rect_float) {
		for(x=0; x<ibuf->x; x++) {
			for(y=0; y<ibuf->y; y++) {
				if (mask[ibuf->x*y + x] == val) {
					float *col= ibuf->rect_float + 4*(ibuf->x*y + x);
					col[0] = col[1] = col[2] = col[3] = 0.0f;
				}
			}
		}
	} else {
		/* char buffer */
		for(x=0; x<ibuf->x; x++) {
			for(y=0; y<ibuf->y; y++) {
				if (mask[ibuf->x*y + x] == val) {
					char *col= (char *)(ibuf->rect + ibuf->x*y + x);
					col[0] = col[1] = col[2] = col[3] = 0;
				}
			}
		}
	}
}

static int filter_make_index(const int x, const int y, const int w, const int h)
{
	if(x<0 || x>=w || y<0 || y>=h) return -1;	/* return bad index */
	else return y*w+x;
}

static int check_pixel_assigned(const void *buffer, const char *mask, const int index, const int depth, const int is_float)
{
	int res = 0;

	if(index>=0) {
		const int alpha_index = depth*index+(depth-1);

		if(mask!=NULL) {
			res = mask[index]!=0 ? 1 : 0;
		}
		else if( (is_float && ((const float *) buffer)[alpha_index]!=0.0f) ||
				(!is_float && ((const unsigned char *) buffer)[alpha_index]!=0) ) {
			res=1;
		}
	}

	return res;
}

/* if alpha is zero, it checks surrounding pixels and averages color. sets new alphas to 1.0
 * 
 * When a mask is given, only effect pixels with a mask value of 1, defined as BAKE_MASK_MARGIN in rendercore.c
 * */
void IMB_filter_extend(struct ImBuf *ibuf, char *mask, int filter)
{
	const int width= ibuf->x;
	const int height= ibuf->y;
	const int depth= 4;		/* always 4 channels */
	const int chsize= ibuf->rect_float ? sizeof(float) : sizeof(unsigned char);
	const int bsize= width*height*depth*chsize;
	const int is_float= ibuf->rect_float!=NULL;
	void *dstbuf= (void *) MEM_dupallocN(ibuf->rect_float ? (void *) ibuf->rect_float : (void *) ibuf->rect);
	char *dstmask= mask==NULL ? NULL : (char *) MEM_dupallocN(mask);
	void *srcbuf= ibuf->rect_float ? (void *) ibuf->rect_float : (void *) ibuf->rect;
	char *srcmask= mask;
	int cannot_early_out= 1, r, n, k, i, j, c;
	float weight[25];

	/* build a weights buffer */
	n= 1;
	/*k= 0;
	for(i = -n; i <= n; i++)
		for(j = -n; j <= n; j++)
			weight[k++] = sqrt((float) i * i + j * j);
			*/
	weight[0]=1; weight[1]=2; weight[2]=1;
	weight[3]=2; weight[4]=0; weight[5]=2;
	weight[6]=1; weight[7]=2; weight[8]=1;

	/* run passes */
	for(r = 0; cannot_early_out == 1 && r < filter; r++) {
		int x, y;
		cannot_early_out = 0;

		for(y= 0; y<height; y++) {
			for(x= 0; x<width; x++) {
				const int index= filter_make_index(x, y, width, height);

				/* only update unassigned pixels */
				if(!check_pixel_assigned(srcbuf, srcmask, index, depth, is_float)) {
					float tmp[4];
					float wsum=0;
					float acc[4]={0,0,0,0};
					k = 0;

					if (check_pixel_assigned(srcbuf, srcmask, filter_make_index(x-1, y, width, height), depth, is_float) ||
						check_pixel_assigned(srcbuf, srcmask, filter_make_index(x+1, y, width, height), depth, is_float) ||
						check_pixel_assigned(srcbuf, srcmask, filter_make_index(x, y-1, width, height), depth, is_float) ||
						check_pixel_assigned(srcbuf, srcmask, filter_make_index(x, y+1, width, height), depth, is_float)) {
						for(i= -n; i<=n; i++) {
							for(j=-n; j<=n; j++) {
								if(i != 0 || j != 0) {
									const int tmpindex= filter_make_index(x+i, y+j, width, height);

									if(check_pixel_assigned(srcbuf, srcmask, tmpindex, depth, is_float))	{ 
										if(is_float) {
											for(c=0; c<depth; c++)
												tmp[c] = ((const float *) srcbuf)[depth*tmpindex+c];
										}
										else {
											for(c=0; c<depth; c++)
												tmp[c] = (float) ((const unsigned char *) srcbuf)[depth*tmpindex+c];
										}

										wsum+= weight[k];

										for(c=0; c<depth; c++)
											acc[c]+= weight[k] * tmp[c];
									}
								}
								k++;
							}
						}

						if(wsum!=0) {
							for(c=0; c<depth; c++)
								acc[c]/= wsum;

							if(is_float) {
								for(c=0; c<depth; c++)
									((float *) dstbuf)[depth*index+c] = acc[c];
							}
							else {
								for(c=0; c<depth; c++) {
									((unsigned char *) dstbuf)[depth*index+c]= acc[c] > 255 ? 255 : (acc[c] < 0 ? 0 : ((unsigned char) (acc[c]+0.5f)));
								}
							}

							if(dstmask!=NULL) dstmask[index]=FILTER_MASK_MARGIN;	/* assigned */
							cannot_early_out = 1;
						}
					}
				}
			}
		}

		/* keep the original buffer up to date. */
		memcpy(srcbuf, dstbuf, bsize);
		if(dstmask!=NULL) memcpy(srcmask, dstmask, width*height);
	}

	/* free memory */
	MEM_freeN(dstbuf);
	if(dstmask!=NULL) MEM_freeN(dstmask);
}

/* threadsafe version, only recreates existing maps */
void IMB_remakemipmap(ImBuf *ibuf, int use_filter)
{
	ImBuf *hbuf = ibuf;
	int curmap = 0;
	
	ibuf->miptot= 1;
	
	while(curmap < IB_MIPMAP_LEVELS) {
		
		if(ibuf->mipmap[curmap]) {
			
			if(use_filter) {
				ImBuf *nbuf= IMB_allocImBuf(hbuf->x, hbuf->y, 32, IB_rect);
				IMB_filterN(nbuf, hbuf);
				imb_onehalf_no_alloc(ibuf->mipmap[curmap], nbuf);
				IMB_freeImBuf(nbuf);
			}
			else
				imb_onehalf_no_alloc(ibuf->mipmap[curmap], hbuf);
		}
		
		ibuf->miptot= curmap+2;
		hbuf= ibuf->mipmap[curmap];
		if(hbuf)
			hbuf->miplevel= curmap+1;
		
		if(!hbuf || (hbuf->x <= 2 && hbuf->y <= 2))
			break;
		
		curmap++;
	}
}

/* frees too (if there) and recreates new data */
void IMB_makemipmap(ImBuf *ibuf, int use_filter)
{
	ImBuf *hbuf = ibuf;
	int curmap = 0;

	imb_freemipmapImBuf(ibuf);
	
	ibuf->miptot= 1;

	while(curmap < IB_MIPMAP_LEVELS) {
		if(use_filter) {
			ImBuf *nbuf= IMB_allocImBuf(hbuf->x, hbuf->y, 32, IB_rect);
			IMB_filterN(nbuf, hbuf);
			ibuf->mipmap[curmap] = IMB_onehalf(nbuf);
			IMB_freeImBuf(nbuf);
		}
		else
			ibuf->mipmap[curmap] = IMB_onehalf(hbuf);

		ibuf->miptot= curmap+2;
		hbuf= ibuf->mipmap[curmap];
		hbuf->miplevel= curmap+1;

		if(!hbuf || (hbuf->x <= 2 && hbuf->y <= 2))
			break;

		curmap++;
	}
}

ImBuf *IMB_getmipmap(ImBuf *ibuf, int level)
{
	CLAMP(level, 0, ibuf->miptot-1);
	return (level == 0)? ibuf: ibuf->mipmap[level-1];
}

void IMB_premultiply_rect(unsigned int *rect, int depth, int w, int h)
{
	char *cp;
	int x, y, val;

	if(depth == 24) {	/* put alpha at 255 */
		cp= (char *)(rect);

		for(y=0; y<h; y++)
			for(x=0; x<w; x++, cp+=4)
				cp[3]= 255;
	}
	else {
		cp= (char *)(rect);

		for(y=0; y<h; y++) {
			for(x=0; x<w; x++, cp+=4) {
				val= cp[3];
				cp[0]= (cp[0]*val)>>8;
				cp[1]= (cp[1]*val)>>8;
				cp[2]= (cp[2]*val)>>8;
			}
		}
	}
}

void IMB_premultiply_rect_float(float *rect_float, int depth, int w, int h)
{
	float val, *cp;
	int x, y;

	if(depth==24) {	/* put alpha at 1.0 */
		cp= rect_float;

		for(y=0; y<h; y++)
			for(x=0; x<w; x++, cp+=4)
				cp[3]= 1.0;
	}
	else {
		cp= rect_float;
		for(y=0; y<h; y++) {
			for(x=0; x<w; x++, cp+=4) {
				val= cp[3];
				cp[0]= cp[0]*val;
				cp[1]= cp[1]*val;
				cp[2]= cp[2]*val;
			}
		}
	}

}

void IMB_premultiply_alpha(ImBuf *ibuf)
{
	if(ibuf==NULL)
		return;

	if(ibuf->rect)
		IMB_premultiply_rect(ibuf->rect, ibuf->depth, ibuf->x, ibuf->y);

	if(ibuf->rect_float)
		IMB_premultiply_rect_float(ibuf->rect_float, ibuf->depth, ibuf->x, ibuf->y);
}