/**
 *
 * ***** 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): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 * allocimbuf.c
 *
 * $Id$
 */

#include "BLI_blenlib.h"
#include "MEM_guardedalloc.h"

#include "imbuf.h"
#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"

#include "IMB_allocimbuf.h"
#include "IMB_filter.h"

#include "BLO_sys_types.h" // for intptr_t support

/************************************************************************/
/*								SCALING									*/
/************************************************************************/


struct ImBuf *IMB_half_x(struct ImBuf *ibuf1)
{
	struct ImBuf *ibuf2;
	uchar *p1,*_p1,*dest;
	short a,r,g,b,x,y;
	float af,rf,gf,bf, *p1f, *_p1f, *destf;
	int do_rect, do_float;

	if (ibuf1==NULL) return (0);
	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);

	do_rect= (ibuf1->rect != NULL);
	do_float= (ibuf1->rect_float != NULL);
	
	if (ibuf1->x <= 1) return(IMB_dupImBuf(ibuf1));
	
	ibuf2 = IMB_allocImBuf((ibuf1->x)/2, ibuf1->y, ibuf1->depth, ibuf1->flags, 0);
	if (ibuf2==NULL) return (0);

	_p1 = (uchar *) ibuf1->rect;
	dest=(uchar *) ibuf2->rect;
         
	_p1f = ibuf1->rect_float;
	destf= ibuf2->rect_float;

	for(y=ibuf2->y;y>0;y--){
		p1 = _p1;
		p1f = _p1f;
		for(x = ibuf2->x ; x>0 ; x--){
			if (do_rect) {
				a = *(p1++) ;
				b = *(p1++) ;
				g = *(p1++) ;
				r = *(p1++);
				a += *(p1++) ;
				b += *(p1++) ;
				g += *(p1++) ;
				r += *(p1++);
				*(dest++) = a >> 1;
				*(dest++) = b >> 1;
				*(dest++) = g >> 1;
				*(dest++) = r >> 1;
			}
			if (do_float) {
				af = *(p1f++);
				bf = *(p1f++);
				gf = *(p1f++);
				rf = *(p1f++);
				af += *(p1f++);
				bf += *(p1f++);
				gf += *(p1f++);
				rf += *(p1f++);
				*(destf++) = 0.5f*af;
				*(destf++) = 0.5f*bf;
				*(destf++) = 0.5f*gf;
				*(destf++) = 0.5f*rf;
			}
		}
		if (do_rect) _p1 += (ibuf1->x << 2);
		if (do_float) _p1f += (ibuf1->x << 2);
	}
	return (ibuf2);
}


struct ImBuf *IMB_double_fast_x(struct ImBuf *ibuf1)
{
	struct ImBuf *ibuf2;
	int *p1,*dest, i, col, do_rect, do_float;
	float *p1f, *destf;

	if (ibuf1==NULL) return (0);
	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);

	do_rect= (ibuf1->rect != NULL);
	do_float= (ibuf1->rect_float != NULL);
	
	ibuf2 = IMB_allocImBuf(2 * ibuf1->x , ibuf1->y , ibuf1->depth, ibuf1->flags, 0);
	if (ibuf2==NULL) return (0);

	p1 = (int *) ibuf1->rect;
	dest=(int *) ibuf2->rect;
	p1f = (float *)ibuf1->rect_float;
	destf = (float *)ibuf2->rect_float;

	for(i = ibuf1->y * ibuf1->x ; i>0 ; i--) {
		if (do_rect) {
			col = *p1++;
			*dest++ = col;
			*dest++ = col;
		}
		if (do_float) {
			destf[0]= destf[4] =p1f[0];
			destf[1]= destf[5] =p1f[1];
			destf[2]= destf[6] =p1f[2];
			destf[3]= destf[7] =p1f[3];
			destf+= 8;
			p1f+= 4;
		}
	}

	return (ibuf2);
}

struct ImBuf *IMB_double_x(struct ImBuf *ibuf1)
{
	struct ImBuf *ibuf2;

	if (ibuf1==NULL) return (0);
	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);

	ibuf2 = IMB_double_fast_x(ibuf1);

	imb_filterx(ibuf2);
	return (ibuf2);
}


struct ImBuf *IMB_half_y(struct ImBuf *ibuf1)
{
	struct ImBuf *ibuf2;
	uchar *p1,*p2,*_p1,*dest;
	short a,r,g,b,x,y;
	int do_rect, do_float;
	float af,rf,gf,bf,*p1f,*p2f,*_p1f,*destf;

	p1= p2= NULL;
	p1f= p2f= NULL;
	if (ibuf1==NULL) return (0);
	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);
	if (ibuf1->y <= 1) return(IMB_dupImBuf(ibuf1));

	do_rect= (ibuf1->rect != NULL);
	do_float= (ibuf1->rect_float != NULL);

	ibuf2 = IMB_allocImBuf(ibuf1->x , (ibuf1->y) / 2 , ibuf1->depth, ibuf1->flags, 0);
	if (ibuf2==NULL) return (0);

	_p1 = (uchar *) ibuf1->rect;
	dest=(uchar *) ibuf2->rect;
	_p1f = (float *) ibuf1->rect_float;
	destf= (float *) ibuf2->rect_float;

	for(y=ibuf2->y ; y>0 ; y--){
		if (do_rect) {
			p1 = _p1;
			p2 = _p1 + (ibuf1->x << 2);
		}
		if (do_float) {
			p1f = _p1f;
			p2f = _p1f + (ibuf1->x << 2);
		}
		for(x = ibuf2->x ; x>0 ; x--){
			if (do_rect) {
				a = *(p1++) ;
				b = *(p1++) ;
				g = *(p1++) ;
				r = *(p1++);
				a += *(p2++) ;
				b += *(p2++) ;
				g += *(p2++) ;
				r += *(p2++);
				*(dest++) = a >> 1;
				*(dest++) = b >> 1;
				*(dest++) = g >> 1;
				*(dest++) = r >> 1;
			}
			if (do_float) {
				af = *(p1f++) ;
				bf = *(p1f++) ;
				gf = *(p1f++) ;
				rf = *(p1f++);
				af += *(p2f++) ;
				bf += *(p2f++) ;
				gf += *(p2f++) ;
				rf += *(p2f++);
				*(destf++) = 0.5f*af;
				*(destf++) = 0.5f*bf;
				*(destf++) = 0.5f*gf;
				*(destf++) = 0.5f*rf;
			}
		}
		if (do_rect) _p1 += (ibuf1->x << 3);
		if (do_float) _p1f += (ibuf1->x << 3);
	}
	return (ibuf2);
}


struct ImBuf *IMB_double_fast_y(struct ImBuf *ibuf1)
{
	struct ImBuf *ibuf2;
	int *p1, *dest1, *dest2;
	float *p1f, *dest1f, *dest2f;
	short x,y;
	int do_rect, do_float;

	if (ibuf1==NULL) return (0);
	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);

	do_rect= (ibuf1->rect != NULL);
	do_float= (ibuf1->rect_float != NULL);

	ibuf2 = IMB_allocImBuf(ibuf1->x , 2 * ibuf1->y , ibuf1->depth, ibuf1->flags, 0);
	if (ibuf2==NULL) return (0);

	p1 = (int *) ibuf1->rect;
	dest1= (int *) ibuf2->rect;
	p1f = (float *) ibuf1->rect_float;
	dest1f= (float *) ibuf2->rect_float;

	for(y = ibuf1->y ; y>0 ; y--){
		if (do_rect) {
			dest2 = dest1 + ibuf2->x;
			for(x = ibuf2->x ; x>0 ; x--) *dest1++ = *dest2++ = *p1++;
			dest1 = dest2;
		}
		 if (do_float) {
			dest2f = dest1f + (4*ibuf2->x);
			for(x = ibuf2->x*4 ; x>0 ; x--) *dest1f++ = *dest2f++ = *p1f++;
			dest1f = dest2f;
		}
	}

	return (ibuf2);
}

struct ImBuf *IMB_double_y(struct ImBuf *ibuf1)
{
	struct ImBuf *ibuf2;

	if (ibuf1==NULL) return (0);
	if (ibuf1->rect==NULL) return (0);

	ibuf2 = IMB_double_fast_y(ibuf1);
	
	IMB_filtery(ibuf2);
	return (ibuf2);
}


struct ImBuf *IMB_onehalf(struct ImBuf *ibuf1)
{
	struct ImBuf *ibuf2;
	uchar *p1, *p2 = NULL, *dest;
	float *p1f, *destf, *p2f = NULL;
	int x,y;
	int do_rect, do_float;

	if (ibuf1==NULL) return (0);
	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);

	do_rect= (ibuf1->rect != NULL);

	if (ibuf1->x <= 1) return(IMB_half_y(ibuf1));
	if (ibuf1->y <= 1) return(IMB_half_x(ibuf1));
	
	ibuf2=IMB_allocImBuf((ibuf1->x)/2, (ibuf1->y)/2, ibuf1->depth, ibuf1->flags, 0);
	if (ibuf2==NULL) return (0);

	p1f = ibuf1->rect_float;
	destf=ibuf2->rect_float;
	p1 = (uchar *) ibuf1->rect;
	dest=(uchar *) ibuf2->rect;

	do_float= (ibuf1->rect_float != NULL && ibuf2->rect_float != NULL);

	for(y=ibuf2->y;y>0;y--){
		if (do_rect) p2 = p1 + (ibuf1->x << 2);
		if (do_float) p2f = p1f + (ibuf1->x << 2);
		for(x=ibuf2->x;x>0;x--){
			if (do_rect) {
				dest[0] = (p1[0] + p2[0] + p1[4] + p2[4]) >> 2;
				dest[1] = (p1[1] + p2[1] + p1[5] + p2[5]) >> 2;
				dest[2] = (p1[2] + p2[2] + p1[6] + p2[6]) >> 2;
				dest[3] = (p1[3] + p2[3] + p1[7] + p2[7]) >> 2;
				p1 += 8; 
				p2 += 8; 
				dest += 4;
			}
			if (do_float){ 
				destf[0] = 0.25f*(p1f[0] + p2f[0] + p1f[4] + p2f[4]);
				destf[1] = 0.25f*(p1f[1] + p2f[1] + p1f[5] + p2f[5]);
				destf[2] = 0.25f*(p1f[2] + p2f[2] + p1f[6] + p2f[6]);
				destf[3] = 0.25f*(p1f[3] + p2f[3] + p1f[7] + p2f[7]);
				p1f += 8; 
				p2f += 8; 
				destf += 4;
			}
		}
		if (do_rect) p1=p2;
		if (do_float) p1f=p2f;
		if(ibuf1->x & 1) {
			if (do_rect) p1+=4;
			if (do_float) p1f+=4;
		}
	}
	return (ibuf2);
}


/* q_scale_linear_interpolation helper functions */

static void enlarge_picture_byte(
	unsigned char* src, unsigned char* dst, int src_width, 
	int src_height, int dst_width, int dst_height)
{
	double ratiox = (double) (dst_width - 1.0) 
		/ (double) (src_width - 1.001);
	double ratioy = (double) (dst_height - 1.0) 
		/ (double) (src_height - 1.001);
	uintptr_t x_src, dx_src, x_dst;
	uintptr_t y_src, dy_src, y_dst;

	dx_src = 65536.0 / ratiox;
	dy_src = 65536.0 / ratioy;

	y_src = 0;
	for (y_dst = 0; y_dst < dst_height; y_dst++) {
		unsigned char* line1 = src + (y_src >> 16) * 4 * src_width;
		unsigned char* line2 = line1 + 4 * src_width;
		uintptr_t weight1y = 65536 - (y_src & 0xffff);
		uintptr_t weight2y = 65536 - weight1y;

		if ((y_src >> 16) == src_height - 1) {
			line2 = line1;
		}

		x_src = 0;
		for (x_dst = 0; x_dst < dst_width; x_dst++) {
			uintptr_t weight1x = 65536 - (x_src & 0xffff);
			uintptr_t weight2x = 65536 - weight1x;

			unsigned long x = (x_src >> 16) * 4;

			*dst++ = ((((line1[x] * weight1y) >> 16) 
				   * weight1x) >> 16)
				+ ((((line2[x] * weight2y) >> 16) 
					* weight1x) >> 16)
				+ ((((line1[4 + x] * weight1y) >> 16) 
				   * weight2x) >> 16)
				+ ((((line2[4 + x] * weight2y) >> 16) 
					* weight2x) >> 16);

			*dst++ = ((((line1[x + 1] * weight1y) >> 16) 
				   * weight1x) >> 16)
				+ ((((line2[x + 1] * weight2y) >> 16) 
					* weight1x) >> 16)
				+ ((((line1[4 + x + 1] * weight1y) >> 16) 
				   * weight2x) >> 16)
				+ ((((line2[4 + x + 1] * weight2y) >> 16) 
					* weight2x) >> 16);

			*dst++ = ((((line1[x + 2] * weight1y) >> 16) 
				   * weight1x) >> 16)
				+ ((((line2[x + 2] * weight2y) >> 16) 
					* weight1x) >> 16)
				+ ((((line1[4 + x + 2] * weight1y) >> 16) 
				   * weight2x) >> 16)
				+ ((((line2[4 + x + 2] * weight2y) >> 16) 
					* weight2x) >> 16);

			*dst++ = ((((line1[x + 3] * weight1y) >> 16) 
				   * weight1x) >> 16)
				+ ((((line2[x + 3] * weight2y) >> 16) 
					* weight1x) >> 16)
				+ ((((line1[4 + x + 3] * weight1y) >> 16) 
				   * weight2x) >> 16)
				+ ((((line2[4 + x + 3] * weight2y) >> 16) 
					* weight2x) >> 16);

			x_src += dx_src;
		}
		y_src += dy_src;
	}
}

struct scale_outpix_byte {
	uintptr_t r;
	uintptr_t g;
	uintptr_t b;
	uintptr_t a;

	uintptr_t weight;
};

static void shrink_picture_byte(
	unsigned char* src, unsigned char* dst, int src_width, 
	int src_height, int dst_width, int dst_height)
{
	double ratiox = (double) (dst_width) / (double) (src_width);
	double ratioy = (double) (dst_height) / (double) (src_height);
	uintptr_t x_src, dx_dst, x_dst;
	uintptr_t y_src, dy_dst, y_dst;
	intptr_t y_counter;
	unsigned char * dst_begin = dst;

	struct scale_outpix_byte * dst_line1 = NULL;
	struct scale_outpix_byte * dst_line2 = NULL;

	dst_line1 = (struct scale_outpix_byte*) MEM_callocN(
		(dst_width + 1) * sizeof(struct scale_outpix_byte), 
		"shrink_picture_byte 1");
	dst_line2 = (struct scale_outpix_byte*) MEM_callocN(
		(dst_width + 1) * sizeof(struct scale_outpix_byte),
		"shrink_picture_byte 2");

	dx_dst = 65536.0 * ratiox;
	dy_dst = 65536.0 * ratioy;

	y_dst = 0;
	y_counter = 65536;
	for (y_src = 0; y_src < src_height; y_src++) {
		unsigned char* line = src + y_src * 4 * src_width;
		uintptr_t weight1y = 65535 - (y_dst & 0xffff);
		uintptr_t weight2y = 65535 - weight1y;
		x_dst = 0;
		for (x_src = 0; x_src < src_width; x_src++) {
			uintptr_t weight1x = 65535 - (x_dst & 0xffff);
			uintptr_t weight2x = 65535 - weight1x;

			uintptr_t x = x_dst >> 16;

			uintptr_t w;

			w = (weight1y * weight1x) >> 16;

			/* ensure correct rounding, without this you get ugly banding, or too low color values (ton) */
			dst_line1[x].r += (line[0] * w + 32767) >> 16;
			dst_line1[x].g += (line[1] * w + 32767) >> 16;
			dst_line1[x].b += (line[2] * w + 32767) >> 16;
			dst_line1[x].a += (line[3] * w + 32767) >> 16;
			dst_line1[x].weight += w;

			w = (weight2y * weight1x) >> 16;

			dst_line2[x].r += (line[0] * w + 32767) >> 16;
			dst_line2[x].g += (line[1] * w + 32767) >> 16;
			dst_line2[x].b += (line[2] * w + 32767) >> 16;
			dst_line2[x].a += (line[3] * w + 32767) >> 16;
			dst_line2[x].weight += w;

			w = (weight1y * weight2x) >> 16;

			dst_line1[x+1].r += (line[0] * w + 32767) >> 16;
			dst_line1[x+1].g += (line[1] * w + 32767) >> 16;
			dst_line1[x+1].b += (line[2] * w + 32767) >> 16;
			dst_line1[x+1].a += (line[3] * w + 32767) >> 16;
			dst_line1[x+1].weight += w;

			w = (weight2y * weight2x) >> 16;

			dst_line2[x+1].r += (line[0] * w + 32767) >> 16;
			dst_line2[x+1].g += (line[1] * w + 32767) >> 16;
			dst_line2[x+1].b += (line[2] * w + 32767) >> 16;
			dst_line2[x+1].a += (line[3] * w + 32767) >> 16;
			dst_line2[x+1].weight += w;

			x_dst += dx_dst;
			line += 4;
		}

		y_dst += dy_dst;
		y_counter -= dy_dst;
		if (y_counter < 0) {
			int val;
			uintptr_t x;
			struct scale_outpix_byte * temp;

			y_counter += 65536;
			
			for (x=0; x < dst_width; x++) {
				uintptr_t f =  0x80000000UL / dst_line1[x].weight;
				*dst++ = (val= (dst_line1[x].r * f) >> 15) > 255 ? 255: val;
				*dst++ = (val= (dst_line1[x].g * f) >> 15) > 255 ? 255: val;
				*dst++ = (val= (dst_line1[x].b * f) >> 15) > 255 ? 255: val;
				*dst++ = (val= (dst_line1[x].a * f) >> 15) > 255 ? 255: val;
			}
			memset(dst_line1, 0, dst_width *
				   sizeof(struct scale_outpix_byte));
			temp = dst_line1;
			dst_line1 = dst_line2;
			dst_line2 = temp;
		}
	}
	if (dst - dst_begin < dst_width * dst_height * 4) {
		int val;
		uintptr_t x;
		for (x = 0; x < dst_width; x++) {
			uintptr_t f = 0x80000000UL / dst_line1[x].weight;
			*dst++ = (val= (dst_line1[x].r * f) >> 15) > 255 ? 255: val;
			*dst++ = (val= (dst_line1[x].g * f) >> 15) > 255 ? 255: val;
			*dst++ = (val= (dst_line1[x].b * f) >> 15) > 255 ? 255: val;
			*dst++ = (val= (dst_line1[x].a * f) >> 15) > 255 ? 255: val;
		}
	}
	MEM_freeN(dst_line1);
	MEM_freeN(dst_line2);
}


static void q_scale_byte(unsigned char* in, unsigned char* out, int in_width, 
			 int in_height, int dst_width, int dst_height)
{
	if (dst_width > in_width && dst_height > in_height) {
		enlarge_picture_byte(in, out, in_width, in_height,
					 dst_width, dst_height);
	} else if (dst_width < in_width && dst_height < in_height) {
		shrink_picture_byte(in, out, in_width, in_height,
					dst_width, dst_height);
	}
}

static void enlarge_picture_float(
	float* src, float* dst, int src_width, 
	int src_height, int dst_width, int dst_height)
{
	double ratiox = (double) (dst_width - 1.0) 
		/ (double) (src_width - 1.001);
	double ratioy = (double) (dst_height - 1.0) 
		/ (double) (src_height - 1.001);
	uintptr_t x_dst;
	uintptr_t y_dst;
	double x_src, dx_src;
	double y_src, dy_src;

	dx_src = 1.0 / ratiox;
	dy_src = 1.0 / ratioy;

	y_src = 0;
	for (y_dst = 0; y_dst < dst_height; y_dst++) {
		float* line1 = src + ((int) y_src) * 4 * src_width;
		float* line2 = line1 + 4 * src_width;
		float weight1y = 1.0 - (y_src - (int) y_src);
		float weight2y = 1.0 - weight1y;

		if ((int) y_src == src_height - 1) {
			line2 = line1;
		}
		       
		x_src = 0;
		for (x_dst = 0; x_dst < dst_width; x_dst++) {
			float weight1x = 1.0 - (x_src - (int) x_src);
			float weight2x = 1.0 - weight1x;

			float w11 = weight1y * weight1x;
			float w21 = weight2y * weight1x;
			float w12 = weight1y * weight2x;
			float w22 = weight2y * weight2x;

			uintptr_t x = ((int) x_src) * 4;

			*dst++ =  line1[x]     * w11	
				+ line2[x]     * w21
				+ line1[4 + x] * w12 
				+ line2[4 + x] * w22;

			*dst++ =  line1[x + 1] * w11 
				+ line2[x + 1] * w21
				+ line1[4 + x + 1] * w12
				+ line2[4 + x + 1] * w22;

			*dst++ =  line1[x + 2] * w11 
				+ line2[x + 2] * w21
				+ line1[4 + x + 2] * w12  
				+ line2[4 + x + 2] * w22;

			*dst++ =  line1[x + 3] * w11 
				+ line2[x + 3] * w21
				+ line1[4 + x + 3] * w12  
				+ line2[4 + x + 3] * w22;

			x_src += dx_src;
		}
		y_src += dy_src;
	}
}

struct scale_outpix_float {
	float r;
	float g;
	float b;
	float a;

	float weight;
};

static void shrink_picture_float(
	float* src, float* dst, int src_width, 
	int src_height, int dst_width, int dst_height)
{
	double ratiox = (double) (dst_width) / (double) (src_width);
	double ratioy = (double) (dst_height) / (double) (src_height);
	uintptr_t x_src;
	uintptr_t y_src;
		float dx_dst, x_dst;
	float dy_dst, y_dst;
	float y_counter;
	float * dst_begin = dst;

	struct scale_outpix_float * dst_line1;
	struct scale_outpix_float * dst_line2;

	dst_line1 = (struct scale_outpix_float*) MEM_callocN(
		(dst_width + 1) * sizeof(struct scale_outpix_float), 
		"shrink_picture_float 1");
	dst_line2 = (struct scale_outpix_float*) MEM_callocN(
		(dst_width + 1) * sizeof(struct scale_outpix_float),
		"shrink_picture_float 2");

	dx_dst = ratiox;
	dy_dst = ratioy;

	y_dst = 0;
	y_counter = 1.0;
	for (y_src = 0; y_src < src_height; y_src++) {
		float* line = src + y_src * 4 * src_width;
		uintptr_t weight1y = 1.0 - (y_dst - (int) y_dst);
		uintptr_t weight2y = 1.0 - weight1y;
		x_dst = 0;
		for (x_src = 0; x_src < src_width; x_src++) {
			uintptr_t weight1x = 1.0 - (x_dst - (int) x_dst);
			uintptr_t weight2x = 1.0 - weight1x;

			uintptr_t x = (int) x_dst;

			float w;

			w = weight1y * weight1x;

			dst_line1[x].r += line[0] * w;
			dst_line1[x].g += line[1] * w;
			dst_line1[x].b += line[2] * w;
			dst_line1[x].a += line[3] * w;
			dst_line1[x].weight += w;

			w = weight2y * weight1x;

			dst_line2[x].r += line[0] * w;
			dst_line2[x].g += line[1] * w;
			dst_line2[x].b += line[2] * w;
			dst_line2[x].a += line[3] * w;
			dst_line2[x].weight += w;

			w = weight1y * weight2x;

			dst_line1[x+1].r += line[0] * w;
			dst_line1[x+1].g += line[1] * w;
			dst_line1[x+1].b += line[2] * w;
			dst_line1[x+1].a += line[3] * w;
			dst_line1[x+1].weight += w;

			w = weight2y * weight2x;

			dst_line2[x+1].r += line[0] * w;
			dst_line2[x+1].g += line[1] * w;
			dst_line2[x+1].b += line[2] * w;
			dst_line2[x+1].a += line[3] * w;
			dst_line2[x+1].weight += w;

			x_dst += dx_dst;
			line += 4;
		}

		y_dst += dy_dst;
		y_counter -= dy_dst;
		if (y_counter < 0) {
			uintptr_t x;
			struct scale_outpix_float * temp;

			y_counter += 1.0;
			
			for (x=0; x < dst_width; x++) {
				float f = 1.0 / dst_line1[x].weight;
				*dst++ = dst_line1[x].r * f;
				*dst++ = dst_line1[x].g * f;
				*dst++ = dst_line1[x].b * f;
				*dst++ = dst_line1[x].a * f;
			}
			memset(dst_line1, 0, dst_width *
				   sizeof(struct scale_outpix_float));
			temp = dst_line1;
			dst_line1 = dst_line2;
			dst_line2 = temp;
		}
	}
	if (dst - dst_begin < dst_width * dst_height * 4) {
		uintptr_t x;
		for (x = 0; x < dst_width; x++) {
			float f = 1.0 / dst_line1[x].weight;
			*dst++ = dst_line1[x].r * f;
			*dst++ = dst_line1[x].g * f;
			*dst++ = dst_line1[x].b * f;
			*dst++ = dst_line1[x].a * f;
		}
	}
	MEM_freeN(dst_line1);
	MEM_freeN(dst_line2);
}


static void q_scale_float(float* in, float* out, int in_width, 
			 int in_height, int dst_width, int dst_height)
{
	if (dst_width > in_width && dst_height > in_height) {
		enlarge_picture_float(in, out, in_width, in_height,
					  dst_width, dst_height);
	} else if (dst_width < in_width && dst_height < in_height) {
		shrink_picture_float(in, out, in_width, in_height,
					 dst_width, dst_height);
	}
}

/* q_scale_linear_interpolation (derived from ppmqscale, http://libdv.sf.net)

   q stands for quick _and_ quality :)

   only handles common cases when we either

   scale  both, x and y or
   shrink both, x and y

   but that is pretty fast:
   * does only blit once instead of two passes like the old code
	 (fewer cache misses)
   * uses fixed point integer arithmetic for byte buffers
   * doesn't branch in tight loops

   Should be comparable in speed to the ImBuf ..._fast functions at least 
   for byte-buffers.

   NOTE: disabled, due to inacceptable inaccuracy and quality loss, see bug #18609 (ton)

*/
static int q_scale_linear_interpolation(
	struct ImBuf *ibuf, int newx, int newy)
{
	if ((newx >= ibuf->x && newy <= ibuf->y) ||
		(newx <= ibuf->x && newy >= ibuf->y)) {
		return FALSE;
	}

	if (ibuf->rect) {
		unsigned char * newrect = 
			MEM_mallocN(newx * newy * sizeof(int), "q_scale rect");
		q_scale_byte((unsigned char *)ibuf->rect, newrect, ibuf->x, ibuf->y,
				 newx, newy);

		imb_freerectImBuf(ibuf);
		ibuf->mall |= IB_rect;
		ibuf->rect = (unsigned int *) newrect;
	}
	if (ibuf->rect_float) {
		float * newrect = 
			MEM_mallocN(newx * newy * 4 *sizeof(float), 
					"q_scale rectfloat");
		q_scale_float(ibuf->rect_float, newrect, ibuf->x, ibuf->y,
				  newx, newy);
		imb_freerectfloatImBuf(ibuf);
		ibuf->mall |= IB_rectfloat;
		ibuf->rect_float = newrect;
	}
	ibuf->x = newx;
	ibuf->y = newy;

	return TRUE;
}

static struct ImBuf *scaledownx(struct ImBuf *ibuf, int newx)
{
	uchar *rect, *_newrect, *newrect;
	float *rectf, *_newrectf, *newrectf;
	float sample, add, val[4], nval[4], valf[4], nvalf[4];
	int x, y, do_rect = 0, do_float = 0;

	rectf= _newrectf= newrectf= NULL; 
	rect=_newrect= newrect= NULL; 
	nval[0]=  nval[1]= nval[2]= nval[3]= 0.0f;
	nvalf[0]=nvalf[1]=nvalf[2]=nvalf[3]= 0.0f;
	
	if (ibuf==NULL) return(0);
	if (ibuf->rect==NULL && ibuf->rect_float==NULL) return (ibuf);

	if (ibuf->rect) {
		do_rect = 1;
		_newrect = MEM_mallocN(newx * ibuf->y * sizeof(int), "scaledownx");
		if (_newrect==NULL) return(ibuf);
	}
	if (ibuf->rect_float) {
		do_float = 1;
		_newrectf = MEM_mallocN(newx * ibuf->y * sizeof(float) * 4, "scaledownxf");
		if (_newrectf==NULL) {
			if (_newrect) MEM_freeN(_newrect);
			return(ibuf);
		}
	}

	add = (ibuf->x - 0.001) / newx;

	if (do_rect) {
		rect = (uchar *) ibuf->rect;
		newrect = _newrect;
	}
	if (do_float) {
		rectf = ibuf->rect_float;
		newrectf = _newrectf;
	}
		
	for (y = ibuf->y; y>0 ; y--) {
		sample = 0.0f;
		val[0]=  val[1]= val[2]= val[3]= 0.0f;
		valf[0]=valf[1]=valf[2]=valf[3]= 0.0f;

		for (x = newx ; x>0 ; x--) {
			if (do_rect) {
				nval[0] = - val[0] * sample;
				nval[1] = - val[1] * sample;
				nval[2] = - val[2] * sample;
				nval[3] = - val[3] * sample;
			}
			if (do_float) {
				nvalf[0] = - valf[0] * sample;
				nvalf[1] = - valf[1] * sample;
				nvalf[2] = - valf[2] * sample;
				nvalf[3] = - valf[3] * sample;
			}
			
			sample += add;

			while (sample >= 1.0f){
				sample -= 1.0f;
				
				if (do_rect) {
					nval[0] += rect[0];
					nval[1] += rect[1];
					nval[2] += rect[2];
					nval[3] += rect[3];
					rect += 4;
				}
				if (do_float) {
					nvalf[0] += rectf[0];
					nvalf[1] += rectf[1];
					nvalf[2] += rectf[2];
					nvalf[3] += rectf[3];
					rectf += 4;
				}
			}
			
			if (do_rect) {
				val[0]= rect[0];val[1]= rect[1];val[2]= rect[2];val[3]= rect[3];
				rect += 4;
				
				newrect[0] = ((nval[0] + sample * val[0])/add + 0.5f);
				newrect[1] = ((nval[1] + sample * val[1])/add + 0.5f);
				newrect[2] = ((nval[2] + sample * val[2])/add + 0.5f);
				newrect[3] = ((nval[3] + sample * val[3])/add + 0.5f);
				
				newrect += 4;
			}
			if (do_float) {
				
				valf[0]= rectf[0];valf[1]= rectf[1];valf[2]= rectf[2];valf[3]= rectf[3];
				rectf += 4;
				
				newrectf[0] = ((nvalf[0] + sample * valf[0])/add);
				newrectf[1] = ((nvalf[1] + sample * valf[1])/add);
				newrectf[2] = ((nvalf[2] + sample * valf[2])/add);
				newrectf[3] = ((nvalf[3] + sample * valf[3])/add);
				
				newrectf += 4;
			}
			
			sample -= 1.0f;
		}
	}

	if (do_rect) {
		imb_freerectImBuf(ibuf);
		ibuf->mall |= IB_rect;
		ibuf->rect = (unsigned int *) _newrect;
	}
	if (do_float) {
		imb_freerectfloatImBuf(ibuf);
		ibuf->mall |= IB_rectfloat;
		ibuf->rect_float = _newrectf;
	}
	
	ibuf->x = newx;
	return(ibuf);
}


static struct ImBuf *scaledowny(struct ImBuf *ibuf, int newy)
{
	uchar *rect, *_newrect, *newrect;
	float *rectf, *_newrectf, *newrectf;
	float sample, add, val[4], nval[4], valf[4], nvalf[4];
	int x, y, skipx, do_rect = 0, do_float = 0;

	rectf= _newrectf= newrectf= NULL; 
	rect= _newrect= newrect= NULL; 
	nval[0]=  nval[1]= nval[2]= nval[3]= 0.0f;
	nvalf[0]=nvalf[1]=nvalf[2]=nvalf[3]= 0.0f;

	if (ibuf==NULL) return(0);
	if (ibuf->rect==NULL && ibuf->rect_float==NULL) return (ibuf);

	if (ibuf->rect) {
		do_rect = 1;
		_newrect = MEM_mallocN(newy * ibuf->x * sizeof(int), "scaledowny");
		if (_newrect==NULL) return(ibuf);
	}
	if (ibuf->rect_float) {
		do_float = 1;
		_newrectf = MEM_mallocN(newy * ibuf->x * sizeof(float) * 4, "scaledownyf");
		if (_newrectf==NULL) {
			if (_newrect) MEM_freeN(_newrect);
			return(ibuf);
		}
	}

	add = (ibuf->y - 0.001) / newy;
	skipx = 4 * ibuf->x;

	for (x = skipx - 4; x>=0 ; x-= 4) {
		if (do_rect) {
			rect = ((uchar *) ibuf->rect) + x;
			newrect = _newrect + x;
		}
		if (do_float) {
			rectf = ibuf->rect_float + x;
			newrectf = _newrectf + x;
		}
		
		sample = 0.0f;
		val[0]=  val[1]= val[2]= val[3]= 0.0f;
		valf[0]=valf[1]=valf[2]=valf[3]= 0.0f;

		for (y = newy ; y>0 ; y--) {
			if (do_rect) {
				nval[0] = - val[0] * sample;
				nval[1] = - val[1] * sample;
				nval[2] = - val[2] * sample;
				nval[3] = - val[3] * sample;
			}
			if (do_float) {
				nvalf[0] = - valf[0] * sample;
				nvalf[1] = - valf[1] * sample;
				nvalf[2] = - valf[2] * sample;
				nvalf[3] = - valf[3] * sample;
			}
			
			sample += add;

			while (sample >= 1.0) {
				sample -= 1.0;
				
				if (do_rect) {
					nval[0] += rect[0];
					nval[1] += rect[1];
					nval[2] += rect[2];
					nval[3] += rect[3];
					rect += skipx;
				}
				if (do_float) {
					nvalf[0] += rectf[0];
					nvalf[1] += rectf[1];
					nvalf[2] += rectf[2];
					nvalf[3] += rectf[3];
					rectf += skipx;
				}
			}

			if (do_rect) {
				val[0]= rect[0];val[1]= rect[1];val[2]= rect[2];val[3]= rect[3];
				rect += skipx;
				
				newrect[0] = ((nval[0] + sample * val[0])/add + 0.5f);
				newrect[1] = ((nval[1] + sample * val[1])/add + 0.5f);
				newrect[2] = ((nval[2] + sample * val[2])/add + 0.5f);
				newrect[3] = ((nval[3] + sample * val[3])/add + 0.5f);
				
				newrect += skipx;
			}
			if (do_float) {
				
				valf[0]= rectf[0];valf[1]= rectf[1];valf[2]= rectf[2];valf[3]= rectf[3];
				rectf += skipx;
				
				newrectf[0] = ((nvalf[0] + sample * valf[0])/add);
				newrectf[1] = ((nvalf[1] + sample * valf[1])/add);
				newrectf[2] = ((nvalf[2] + sample * valf[2])/add);
				newrectf[3] = ((nvalf[3] + sample * valf[3])/add);
				
				newrectf += skipx;
			}
			
			sample -= 1.0;
		}
	}	

	if (do_rect) {
		imb_freerectImBuf(ibuf);
		ibuf->mall |= IB_rect;
		ibuf->rect = (unsigned int *) _newrect;
	}
	if (do_float) {
		imb_freerectfloatImBuf(ibuf);
		ibuf->mall |= IB_rectfloat;
		ibuf->rect_float = (float *) _newrectf;
	}
	
	ibuf->y = newy;
	return(ibuf);
}


static struct ImBuf *scaleupx(struct ImBuf *ibuf, int newx)
{
	uchar *rect,*_newrect=NULL,*newrect;
	float *rectf,*_newrectf=NULL,*newrectf;
	float sample,add;
	float val_a,nval_a,diff_a;
	float val_b,nval_b,diff_b;
	float val_g,nval_g,diff_g;
	float val_r,nval_r,diff_r;
	float val_af,nval_af,diff_af;
	float val_bf,nval_bf,diff_bf;
	float val_gf,nval_gf,diff_gf;
	float val_rf,nval_rf,diff_rf;
	int x,y, do_rect = 0, do_float = 0;

	val_a = nval_a = diff_a = val_b = nval_b = diff_b = 0;
	val_g = nval_g = diff_g = val_r = nval_r = diff_r = 0;
	val_af = nval_af = diff_af = val_bf = nval_bf = diff_bf = 0;
	val_gf = nval_gf = diff_gf = val_rf = nval_rf = diff_rf = 0;
	if (ibuf==NULL) return(0);
	if (ibuf->rect==NULL && ibuf->rect_float==NULL) return (ibuf);

	if (ibuf->rect) {
		do_rect = 1;
		_newrect = MEM_mallocN(newx * ibuf->y * sizeof(int), "scaleupx");
		if (_newrect==NULL) return(ibuf);
	}
	if (ibuf->rect_float) {
		do_float = 1;
		_newrectf = MEM_mallocN(newx * ibuf->y * sizeof(float) * 4, "scaleupxf");
		if (_newrectf==NULL) {
			if (_newrect) MEM_freeN(_newrect);
			return(ibuf);
		}
	}

	add = (ibuf->x - 1.001) / (newx - 1.0);

	rect = (uchar *) ibuf->rect;
	rectf = (float *) ibuf->rect_float;
	newrect = _newrect;
	newrectf = _newrectf;

	for (y = ibuf->y; y>0 ; y--){

		sample = 0;
		
		if (do_rect) {
			val_a = rect[0] ;
			nval_a = rect[4];
			diff_a = nval_a - val_a ;
			val_a += 0.5;

			val_b = rect[1] ;
			nval_b = rect[5];
			diff_b = nval_b - val_b ;
			val_b += 0.5;

			val_g = rect[2] ;
			nval_g = rect[6];
			diff_g = nval_g - val_g ;
			val_g += 0.5;

			val_r = rect[3] ;
			nval_r = rect[7];
			diff_r = nval_r - val_r ;
			val_r += 0.5;

			rect += 8;
		}
		if (do_float) {
			val_af = rectf[0] ;
			nval_af = rectf[4];
			diff_af = nval_af - val_af;
	
			val_bf = rectf[1] ;
			nval_bf = rectf[5];
			diff_bf = nval_bf - val_bf;

			val_gf = rectf[2] ;
			nval_gf = rectf[6];
			diff_gf = nval_gf - val_gf;

			val_rf = rectf[3] ;
			nval_rf = rectf[7];
			diff_rf = nval_rf - val_rf;

			rectf += 8;
		}
		for (x = newx ; x>0 ; x--){
			if (sample >= 1.0){
				sample -= 1.0;

				if (do_rect) {
					val_a = nval_a ;
					nval_a = rect[0] ;
					diff_a = nval_a - val_a ;
					val_a += 0.5;

					val_b = nval_b ;
					nval_b = rect[1] ;
					diff_b = nval_b - val_b ;
					val_b += 0.5;

					val_g = nval_g ;
					nval_g = rect[2] ;
					diff_g = nval_g - val_g ;
					val_g += 0.5;

					val_r = nval_r ;
					nval_r = rect[3] ;
					diff_r = nval_r - val_r ;
					val_r += 0.5;
					rect += 4;
				}
				if (do_float) {
					val_af = nval_af ;
					nval_af = rectf[0] ;
					diff_af = nval_af - val_af ;
	
					val_bf = nval_bf ;
					nval_bf = rectf[1] ;
					diff_bf = nval_bf - val_bf ;

					val_gf = nval_gf ;
					nval_gf = rectf[2] ;
					diff_gf = nval_gf - val_gf ;

					val_rf = nval_rf ;
					nval_rf = rectf[3] ;
					diff_rf = nval_rf - val_rf;
					rectf += 4;
				}
			}
			if (do_rect) {
				newrect[0] = val_a + sample * diff_a;
				newrect[1] = val_b + sample * diff_b;
				newrect[2] = val_g + sample * diff_g;
				newrect[3] = val_r + sample * diff_r;
				newrect += 4;
			}
			if (do_float) {
				newrectf[0] = val_af + sample * diff_af;
				newrectf[1] = val_bf + sample * diff_bf;
				newrectf[2] = val_gf + sample * diff_gf;
				newrectf[3] = val_rf + sample * diff_rf;
				newrectf += 4;
			}
			sample += add;
		}
	}

	if (do_rect) {
		imb_freerectImBuf(ibuf);
		ibuf->mall |= IB_rect;
		ibuf->rect = (unsigned int *) _newrect;
	}
	if (do_float) {
		imb_freerectfloatImBuf(ibuf);
		ibuf->mall |= IB_rectfloat;
		ibuf->rect_float = (float *) _newrectf;
	}
	
	ibuf->x = newx;
	return(ibuf);
}

static struct ImBuf *scaleupy(struct ImBuf *ibuf, int newy)
{
	uchar *rect,*_newrect=NULL,*newrect;
	float *rectf,*_newrectf=NULL,*newrectf;
	float sample,add;
	float val_a,nval_a,diff_a;
	float val_b,nval_b,diff_b;
	float val_g,nval_g,diff_g;
	float val_r,nval_r,diff_r;
	float val_af,nval_af,diff_af;
	float val_bf,nval_bf,diff_bf;
	float val_gf,nval_gf,diff_gf;
	float val_rf,nval_rf,diff_rf;
	int x,y, do_rect = 0, do_float = 0, skipx;

	val_a = nval_a = diff_a = val_b = nval_b = diff_b = 0;
	val_g = nval_g = diff_g = val_r = nval_r = diff_r = 0;
	val_af = nval_af = diff_af = val_bf = nval_bf = diff_bf = 0;
	val_gf = nval_gf = diff_gf = val_rf = nval_rf = diff_rf = 0;
	if (ibuf==NULL) return(0);
	if (ibuf->rect==NULL && ibuf->rect_float==NULL) return (ibuf);

	if (ibuf->rect) {
		do_rect = 1;
		_newrect = MEM_mallocN(ibuf->x * newy * sizeof(int), "scaleupy");
		if (_newrect==NULL) return(ibuf);
	}
	if (ibuf->rect_float) {
		do_float = 1;
		_newrectf = MEM_mallocN(ibuf->x * newy * sizeof(float) * 4, "scaleupyf");
		if (_newrectf==NULL) {
			if (_newrect) MEM_freeN(_newrect);
			return(ibuf);
		}
	}

	add = (ibuf->y - 1.001) / (newy - 1.0);
	skipx = 4 * ibuf->x;

	rect = (uchar *) ibuf->rect;
	rectf = (float *) ibuf->rect_float;
	newrect = _newrect;
	newrectf = _newrectf;

	for (x = ibuf->x; x>0 ; x--){

		sample = 0;
		if (do_rect) {
			rect = ((uchar *)ibuf->rect) + 4*(x-1);
			newrect = _newrect + 4*(x-1);

			val_a = rect[0] ;
			nval_a = rect[skipx];
			diff_a = nval_a - val_a ;
			val_a += 0.5;

			val_b = rect[1] ;
			nval_b = rect[skipx+1];
			diff_b = nval_b - val_b ;
			val_b += 0.5;

			val_g = rect[2] ;
			nval_g = rect[skipx+2];
			diff_g = nval_g - val_g ;
			val_g += 0.5;

			val_r = rect[3] ;
			nval_r = rect[skipx+4];
			diff_r = nval_r - val_r ;
			val_r += 0.5;

			rect += 2*skipx;
		}
		if (do_float) {
			rectf = ((float *)ibuf->rect_float) + 4*(x-1);
			newrectf = _newrectf + 4*(x-1);

			val_af = rectf[0] ;
			nval_af = rectf[skipx];
			diff_af = nval_af - val_af;
	
			val_bf = rectf[1] ;
			nval_bf = rectf[skipx+1];
			diff_bf = nval_bf - val_bf;

			val_gf = rectf[2] ;
			nval_gf = rectf[skipx+2];
			diff_gf = nval_gf - val_gf;

			val_rf = rectf[3] ;
			nval_rf = rectf[skipx+3];
			diff_rf = nval_rf - val_rf;

			rectf += 2*skipx;
		}
		
		for (y = newy ; y>0 ; y--){
			if (sample >= 1.0){
				sample -= 1.0;

				if (do_rect) {
					val_a = nval_a ;
					nval_a = rect[0] ;
					diff_a = nval_a - val_a ;
					val_a += 0.5;

					val_b = nval_b ;
					nval_b = rect[1] ;
					diff_b = nval_b - val_b ;
					val_b += 0.5;

					val_g = nval_g ;
					nval_g = rect[2] ;
					diff_g = nval_g - val_g ;
					val_g += 0.5;

					val_r = nval_r ;
					nval_r = rect[3] ;
					diff_r = nval_r - val_r ;
					val_r += 0.5;
					rect += skipx;
				}
				if (do_float) {
					val_af = nval_af ;
					nval_af = rectf[0] ;
					diff_af = nval_af - val_af ;
	
					val_bf = nval_bf ;
					nval_bf = rectf[1] ;
					diff_bf = nval_bf - val_bf ;

					val_gf = nval_gf ;
					nval_gf = rectf[2] ;
					diff_gf = nval_gf - val_gf ;

					val_rf = nval_rf ;
					nval_rf = rectf[3] ;
					diff_rf = nval_rf - val_rf;
					rectf += skipx;
				}
			}
			if (do_rect) {
				newrect[0] = val_a + sample * diff_a;
				newrect[1] = val_b + sample * diff_b;
				newrect[2] = val_g + sample * diff_g;
				newrect[3] = val_r + sample * diff_r;
				newrect += skipx;
			}
			if (do_float) {
				newrectf[0] = val_af + sample * diff_af;
				newrectf[1] = val_bf + sample * diff_bf;
				newrectf[2] = val_gf + sample * diff_gf;
				newrectf[3] = val_rf + sample * diff_rf;
				newrectf += skipx;
			}
			sample += add;
		}
	}

	if (do_rect) {
		imb_freerectImBuf(ibuf);
		ibuf->mall |= IB_rect;
		ibuf->rect = (unsigned int *) _newrect;
	}
	if (do_float) {
		imb_freerectfloatImBuf(ibuf);
		ibuf->mall |= IB_rectfloat;
		ibuf->rect_float = (float *) _newrectf;
	}
	
	ibuf->y = newy;
	return(ibuf);
}


/* no float buf needed here! */
static void scalefast_Z_ImBuf(ImBuf *ibuf, short newx, short newy)
{
	unsigned int *rect, *_newrect, *newrect;
	int x, y;
	int ofsx, ofsy, stepx, stepy;

	if (ibuf->zbuf) {
		_newrect = MEM_mallocN(newx * newy * sizeof(int), "z rect");
		if (_newrect==NULL) return;
		
		stepx = (65536.0 * (ibuf->x - 1.0) / (newx - 1.0)) + 0.5;
		stepy = (65536.0 * (ibuf->y - 1.0) / (newy - 1.0)) + 0.5;
		ofsy = 32768;

		newrect = _newrect;
	
		for (y = newy; y > 0 ; y--){
			rect = (unsigned int*) ibuf->zbuf;
			rect += (ofsy >> 16) * ibuf->x;
			ofsy += stepy;
			ofsx = 32768;
			for (x = newx ; x > 0 ; x--){
				*newrect++ = rect[ofsx >> 16];
				ofsx += stepx;
			}
		}
	
		IMB_freezbufImBuf(ibuf);
		ibuf->mall |= IB_zbuf;
		ibuf->zbuf = (int*) _newrect;
	}
}

struct ImBuf *IMB_scaleImBuf(struct ImBuf * ibuf, unsigned int newx, unsigned int newy)
{
	if (ibuf==NULL) return (0);
	if (ibuf->rect==NULL && ibuf->rect_float==NULL) return (ibuf);
	
	if (newx == ibuf->x && newy == ibuf->y) { return ibuf; }

	/* scaleup / scaledown functions below change ibuf->x and ibuf->y
	   so we first scale the Z-buffer (if any) */
	scalefast_Z_ImBuf(ibuf, newx, newy);

	/* try to scale common cases in a fast way */
	/* disabled, quality loss is inacceptable, see report #18609  (ton) */
	if (0 && q_scale_linear_interpolation(ibuf, newx, newy)) {
		return ibuf;
	}

	if (newx < ibuf->x) if (newx) scaledownx(ibuf,newx);
	if (newy < ibuf->y) if (newy) scaledowny(ibuf,newy);
	if (newx > ibuf->x) if (newx) scaleupx(ibuf,newx);
	if (newy > ibuf->y) if (newy) scaleupy(ibuf,newy);
	
	return(ibuf);
}

struct imbufRGBA {
	float r, g, b, a;
};

struct ImBuf *IMB_scalefastImBuf(struct ImBuf *ibuf, unsigned int newx, unsigned int newy)
{
	unsigned int *rect,*_newrect,*newrect;
	struct imbufRGBA *rectf, *_newrectf, *newrectf;
	int x,y, do_float=0, do_rect=0;
	int ofsx,ofsy,stepx,stepy;

	rect = NULL; _newrect = NULL; newrect = NULL;
	rectf = NULL; _newrectf = NULL; newrectf = NULL;

	if (ibuf==NULL) return(0);
	if (ibuf->rect) do_rect = 1;
	if (ibuf->rect_float) do_float = 1;
	if (do_rect==0 && do_float==0) return(ibuf);
	
	if (newx == ibuf->x && newy == ibuf->y) return(ibuf);
	
	if(do_rect) {
		_newrect = MEM_mallocN(newx * newy * sizeof(int), "scalefastimbuf");
		if (_newrect==NULL) return(ibuf);
		newrect = _newrect;
	}
	
	if (do_float) {
		_newrectf = MEM_mallocN(newx * newy * sizeof(float) * 4, "scalefastimbuf f");
		if (_newrectf==NULL) {
			if (_newrect) MEM_freeN(_newrect);
			return(ibuf);
		}
		newrectf = _newrectf;
	}

	stepx = (65536.0 * (ibuf->x - 1.0) / (newx - 1.0)) + 0.5;
	stepy = (65536.0 * (ibuf->y - 1.0) / (newy - 1.0)) + 0.5;
	ofsy = 32768;

	for (y = newy; y > 0 ; y--){
		if(do_rect) {
			rect = ibuf->rect;
			rect += (ofsy >> 16) * ibuf->x;
		}
		if (do_float) {
			rectf = (struct imbufRGBA *)ibuf->rect_float;
			rectf += (ofsy >> 16) * ibuf->x;
		}
		ofsy += stepy;
		ofsx = 32768;
		
		if (do_rect) {
			for (x = newx ; x>0 ; x--){
				*newrect++ = rect[ofsx >> 16];
				ofsx += stepx;
			}
		}

		if (do_float) {
			ofsx = 32768;
			for (x = newx ; x>0 ; x--){
				*newrectf++ = rectf[ofsx >> 16];
				ofsx += stepx;
			}
		}
	}

	if (do_rect) {
		imb_freerectImBuf(ibuf);
		ibuf->mall |= IB_rect;
		ibuf->rect = _newrect;
	}
	
	if (do_float) {
		imb_freerectfloatImBuf(ibuf);
		ibuf->mall |= IB_rectfloat;
		ibuf->rect_float = (float *)_newrectf;
	}
	
	scalefast_Z_ImBuf(ibuf, newx, newy);
	
	ibuf->x = newx;
	ibuf->y = newy;
	return(ibuf);
}