/*
 * ***** 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 *****
 */

/** \file blender/imbuf/intern/imageprocess.c
 *  \ingroup imbuf
 *
 * This file was moved here from the src/ directory. It is meant to
 * deal with endianness. It resided in a general blending lib. The
 * other functions were only used during rendering. This single
 * function remained. It should probably move to imbuf/intern/util.c,
 * but we'll keep it here for the time being. (nzc)
 *
 */

#include <stdlib.h>

#include "MEM_guardedalloc.h"

#include "BLI_utildefines.h"
#include "BLI_threads.h"
#include "BLI_listbase.h"

#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"
#include <math.h>

/* Only this one is used liberally here, and in imbuf */
void IMB_convert_rgba_to_abgr(struct ImBuf *ibuf)
{
	int size;
	unsigned char rt, *cp = (unsigned char *)ibuf->rect;
	float rtf, *cpf = ibuf->rect_float;

	if (ibuf->rect) {
		size = ibuf->x * ibuf->y;

		while (size-- > 0) {
			rt = cp[0];
			cp[0] = cp[3];
			cp[3] = rt;
			rt = cp[1];
			cp[1] = cp[2];
			cp[2] = rt;
			cp += 4;
		}
	}

	if (ibuf->rect_float) {
		size = ibuf->x * ibuf->y;

		while (size-- > 0) {
			rtf = cpf[0];
			cpf[0] = cpf[3];
			cpf[3] = rtf;
			rtf = cpf[1];
			cpf[1] = cpf[2];
			cpf[2] = rtf;
			cpf += 4;
		}
	}
}
static void pixel_from_buffer(struct ImBuf *ibuf, unsigned char **outI, float **outF, int x, int y)

{
	int offset = ibuf->x * y * 4 + 4 * x;
	
	if (ibuf->rect)
		*outI = (unsigned char *)ibuf->rect + offset;
	
	if (ibuf->rect_float)
		*outF = ibuf->rect_float + offset;
}

/**************************************************************************
 *                            INTERPOLATIONS
 *
 * Reference and docs:
 * http://wiki.blender.org/index.php/User:Damiles#Interpolations_Algorithms
 ***************************************************************************/

/* BICUBIC Interpolation functions
 *  More info: http://wiki.blender.org/index.php/User:Damiles#Bicubic_pixel_interpolation
 * function assumes out to be zero'ed, only does RGBA */

static float P(float k)
{
	float p1, p2, p3, p4;
	p1 = MAX2(k + 2.0f, 0);
	p2 = MAX2(k + 1.0f, 0);
	p3 = MAX2(k, 0);
	p4 = MAX2(k - 1.0f, 0);
	return (float)(1.0f / 6.0f) * (p1 * p1 * p1 - 4.0f * p2 * p2 * p2 + 6.0f * p3 * p3 * p3 - 4.0f * p4 * p4 * p4);
}


#if 0
/* older, slower function, works the same as above */
static float P(float k)
{
	return (float)(1.0f / 6.0f) * (pow(MAX2(k + 2.0f, 0), 3.0f) - 4.0f * pow(MAX2(k + 1.0f, 0), 3.0f) + 6.0f * pow(MAX2(k, 0), 3.0f) - 4.0f * pow(MAX2(k - 1.0f, 0), 3.0f));
}
#endif

void bicubic_interpolation_color(struct ImBuf *in, unsigned char outI[4], float outF[4], float u, float v)
{
	int i, j, n, m, x1, y1;
	unsigned char *dataI;
	float a, b, w, wx, wy[4], outR, outG, outB, outA, *dataF;

	/* sample area entirely outside image? */
	if (ceil(u) < 0 || floor(u) > in->x - 1 || ceil(v) < 0 || floor(v) > in->y - 1) {
		return;
	}

	/* ImBuf in must have a valid rect or rect_float, assume this is already checked */

	i = (int)floor(u);
	j = (int)floor(v);
	a = u - i;
	b = v - j;

	outR = outG = outB = outA = 0.0f;
	
/* Optimized and not so easy to read */
	
	/* avoid calling multiple times */
	wy[0] = P(b - (-1));
	wy[1] = P(b -  0);
	wy[2] = P(b -  1);
	wy[3] = P(b -  2);

	for (n = -1; n <= 2; n++) {
		x1 = i + n;
		CLAMP(x1, 0, in->x - 1);
		wx = P(n - a);
		for (m = -1; m <= 2; m++) {
			y1 = j + m;
			CLAMP(y1, 0, in->y - 1);
			/* normally we could do this */
			/* w = P(n-a) * P(b-m); */
			/* except that would call P() 16 times per pixel therefor pow() 64 times, better precalc these */
			w = wx * wy[m + 1];

			if (outF) {
				dataF = in->rect_float + in->x * y1 * 4 + 4 * x1;
				outR += dataF[0] * w;
				outG += dataF[1] * w;
				outB += dataF[2] * w;
				outA += dataF[3] * w;
			}
			if (outI) {
				dataI = (unsigned char *)in->rect + in->x * y1 * 4 + 4 * x1;
				outR += dataI[0] * w;
				outG += dataI[1] * w;
				outB += dataI[2] * w;
				outA += dataI[3] * w;
			}
		}
	}

/* Done with optimized part */
	
#if 0 
	/* older, slower function, works the same as above */
	for (n = -1; n <= 2; n++) {
		for (m = -1; m <= 2; m++) {
			x1 = i + n;
			y1 = j + m;
			if (x1 > 0 && x1 < in->x && y1 > 0 && y1 < in->y) {
				if (do_float) {
					dataF = in->rect_float + in->x * y1 * 4 + 4 * x1;
					outR += dataF[0] * P(n - a) * P(b - m);
					outG += dataF[1] * P(n - a) * P(b - m);
					outB += dataF[2] * P(n - a) * P(b - m);
					outA += dataF[3] * P(n - a) * P(b - m);
				}
				if (do_rect) {
					dataI = (unsigned char *)in->rect + in->x * y1 * 4 + 4 * x1;
					outR += dataI[0] * P(n - a) * P(b - m);
					outG += dataI[1] * P(n - a) * P(b - m);
					outB += dataI[2] * P(n - a) * P(b - m);
					outA += dataI[3] * P(n - a) * P(b - m);
				}
			}
		}
	}
#endif
	
	if (outI) {
		outI[0] = (int)outR;
		outI[1] = (int)outG;
		outI[2] = (int)outB;
		outI[3] = (int)outA;
	}
	if (outF) {
		outF[0] = outR;
		outF[1] = outG;
		outF[2] = outB;
		outF[3] = outA;
	}
}


void bicubic_interpolation(ImBuf *in, ImBuf *out, float u, float v, int xout, int yout)
{
	unsigned char *outI = NULL;
	float *outF = NULL;
	
	if (in == NULL || (in->rect == NULL && in->rect_float == NULL)) {
		return;
	}
	
	pixel_from_buffer(out, &outI, &outF, xout, yout); /* gcc warns these could be uninitialized, but its ok */
	
	bicubic_interpolation_color(in, outI, outF, u, v);
}

/* function assumes out to be zero'ed, only does RGBA */
/* BILINEAR INTERPOLATION */
void bilinear_interpolation_color(struct ImBuf *in, unsigned char outI[4], float outF[4], float u, float v)
{
	float *row1, *row2, *row3, *row4, a, b;
	unsigned char *row1I, *row2I, *row3I, *row4I;
	float a_b, ma_b, a_mb, ma_mb;
	float empty[4] = {0.0f, 0.0f, 0.0f, 0.0f};
	unsigned char emptyI[4] = {0, 0, 0, 0};
	int y1, y2, x1, x2;
	
	
	/* ImBuf in must have a valid rect or rect_float, assume this is already checked */

	x1 = (int)floor(u);
	x2 = (int)ceil(u);
	y1 = (int)floor(v);
	y2 = (int)ceil(v);

	/* sample area entirely outside image? */
	if (x2 < 0 || x1 > in->x - 1 || y2 < 0 || y1 > in->y - 1) {
		return;
	}

	if (outF) {
		/* sample including outside of edges of image */
		if (x1 < 0 || y1 < 0) row1 = empty;
		else row1 = in->rect_float + in->x * y1 * 4 + 4 * x1;
		
		if (x1 < 0 || y2 > in->y - 1) row2 = empty;
		else row2 = in->rect_float + in->x * y2 * 4 + 4 * x1;
		
		if (x2 > in->x - 1 || y1 < 0) row3 = empty;
		else row3 = in->rect_float + in->x * y1 * 4 + 4 * x2;
		
		if (x2 > in->x - 1 || y2 > in->y - 1) row4 = empty;
		else row4 = in->rect_float + in->x * y2 * 4 + 4 * x2;

		a = u - floorf(u);
		b = v - floorf(v);
		a_b = a * b; ma_b = (1.0f - a) * b; a_mb = a * (1.0f - b); ma_mb = (1.0f - a) * (1.0f - b);

		outF[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0];
		outF[1] = ma_mb * row1[1] + a_mb * row3[1] + ma_b * row2[1] + a_b * row4[1];
		outF[2] = ma_mb * row1[2] + a_mb * row3[2] + ma_b * row2[2] + a_b * row4[2];
		outF[3] = ma_mb * row1[3] + a_mb * row3[3] + ma_b * row2[3] + a_b * row4[3];
	}
	if (outI) {
		/* sample including outside of edges of image */
		if (x1 < 0 || y1 < 0) row1I = emptyI;
		else row1I = (unsigned char *)in->rect + in->x * y1 * 4 + 4 * x1;
		
		if (x1 < 0 || y2 > in->y - 1) row2I = emptyI;
		else row2I = (unsigned char *)in->rect + in->x * y2 * 4 + 4 * x1;
		
		if (x2 > in->x - 1 || y1 < 0) row3I = emptyI;
		else row3I = (unsigned char *)in->rect + in->x * y1 * 4 + 4 * x2;
		
		if (x2 > in->x - 1 || y2 > in->y - 1) row4I = emptyI;
		else row4I = (unsigned char *)in->rect + in->x * y2 * 4 + 4 * x2;
		
		a = u - floorf(u);
		b = v - floorf(v);
		a_b = a * b; ma_b = (1.0f - a) * b; a_mb = a * (1.0f - b); ma_mb = (1.0f - a) * (1.0f - b);
		
		/* need to add 0.5 to avoid rounding down (causes darken with the smear brush)
		 * tested with white images and this should not wrap back to zero */
		outI[0] = (ma_mb * row1I[0] + a_mb * row3I[0] + ma_b * row2I[0] + a_b * row4I[0]) + 0.5f;
		outI[1] = (ma_mb * row1I[1] + a_mb * row3I[1] + ma_b * row2I[1] + a_b * row4I[1]) + 0.5f;
		outI[2] = (ma_mb * row1I[2] + a_mb * row3I[2] + ma_b * row2I[2] + a_b * row4I[2]) + 0.5f;
		outI[3] = (ma_mb * row1I[3] + a_mb * row3I[3] + ma_b * row2I[3] + a_b * row4I[3]) + 0.5f;
	}
}

/* function assumes out to be zero'ed, only does RGBA */
/* BILINEAR INTERPOLATION */

/* Note about wrapping, the u/v still needs to be within the image bounds,
 * just the interpolation is wrapped.
 * This the same as bilinear_interpolation_color except it wraps rather than using empty and emptyI */
void bilinear_interpolation_color_wrap(struct ImBuf *in, unsigned char outI[4], float outF[4], float u, float v)
{
	float *row1, *row2, *row3, *row4, a, b;
	unsigned char *row1I, *row2I, *row3I, *row4I;
	float a_b, ma_b, a_mb, ma_mb;
	int y1, y2, x1, x2;
	
	
	/* ImBuf in must have a valid rect or rect_float, assume this is already checked */

	x1 = (int)floor(u);
	x2 = (int)ceil(u);
	y1 = (int)floor(v);
	y2 = (int)ceil(v);

	/* sample area entirely outside image? */
	if (x2 < 0 || x1 > in->x - 1 || y2 < 0 || y1 > in->y - 1) {
		return;
	}

	/* wrap interpolation pixels - main difference from bilinear_interpolation_color  */
	if (x1 < 0) x1 = in->x + x1;
	if (y1 < 0) y1 = in->y + y1;

	if (x2 >= in->x) x2 = x2 - in->x;
	if (y2 >= in->y) y2 = y2 - in->y;

	if (outF) {
		/* sample including outside of edges of image */
		row1 = in->rect_float + in->x * y1 * 4 + 4 * x1;
		row2 = in->rect_float + in->x * y2 * 4 + 4 * x1;
		row3 = in->rect_float + in->x * y1 * 4 + 4 * x2;
		row4 = in->rect_float + in->x * y2 * 4 + 4 * x2;

		a = u - floorf(u);
		b = v - floorf(v);
		a_b = a * b; ma_b = (1.0f - a) * b; a_mb = a * (1.0f - b); ma_mb = (1.0f - a) * (1.0f - b);

		outF[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0];
		outF[1] = ma_mb * row1[1] + a_mb * row3[1] + ma_b * row2[1] + a_b * row4[1];
		outF[2] = ma_mb * row1[2] + a_mb * row3[2] + ma_b * row2[2] + a_b * row4[2];
		outF[3] = ma_mb * row1[3] + a_mb * row3[3] + ma_b * row2[3] + a_b * row4[3];
	}
	if (outI) {
		/* sample including outside of edges of image */
		row1I = (unsigned char *)in->rect + in->x * y1 * 4 + 4 * x1;
		row2I = (unsigned char *)in->rect + in->x * y2 * 4 + 4 * x1;
		row3I = (unsigned char *)in->rect + in->x * y1 * 4 + 4 * x2;
		row4I = (unsigned char *)in->rect + in->x * y2 * 4 + 4 * x2;

		a = u - floorf(u);
		b = v - floorf(v);
		a_b = a * b; ma_b = (1.0f - a) * b; a_mb = a * (1.0f - b); ma_mb = (1.0f - a) * (1.0f - b);
		
		/* need to add 0.5 to avoid rounding down (causes darken with the smear brush)
		 * tested with white images and this should not wrap back to zero */
		outI[0] = (ma_mb * row1I[0] + a_mb * row3I[0] + ma_b * row2I[0] + a_b * row4I[0]) + 0.5f;
		outI[1] = (ma_mb * row1I[1] + a_mb * row3I[1] + ma_b * row2I[1] + a_b * row4I[1]) + 0.5f;
		outI[2] = (ma_mb * row1I[2] + a_mb * row3I[2] + ma_b * row2I[2] + a_b * row4I[2]) + 0.5f;
		outI[3] = (ma_mb * row1I[3] + a_mb * row3I[3] + ma_b * row2I[3] + a_b * row4I[3]) + 0.5f;
	}
}

void bilinear_interpolation(ImBuf *in, ImBuf *out, float u, float v, int xout, int yout)
{
	unsigned char *outI = NULL;
	float *outF = NULL;
	
	if (in == NULL || (in->rect == NULL && in->rect_float == NULL)) {
		return;
	}
	
	pixel_from_buffer(out, &outI, &outF, xout, yout); /* gcc warns these could be uninitialized, but its ok */
	
	bilinear_interpolation_color(in, outI, outF, u, v);
}

/* function assumes out to be zero'ed, only does RGBA */
/* NEAREST INTERPOLATION */
void neareast_interpolation_color(struct ImBuf *in, unsigned char outI[4], float outF[4], float u, float v)
{
	float *dataF;
	unsigned char *dataI;
	int y1, x1;

	/* ImBuf in must have a valid rect or rect_float, assume this is already checked */
	
	x1 = (int)(u);
	y1 = (int)(v);

	/* sample area entirely outside image? */
	if (x1 < 0 || x1 > in->x - 1 || y1 < 0 || y1 > in->y - 1) {
		return;
	}

	/* sample including outside of edges of image */
	if (x1 < 0 || y1 < 0) {
		if (outI) {
			outI[0] = 0;
			outI[1] = 0;
			outI[2] = 0;
			outI[3] = 0;
		}
		if (outF) {
			outF[0] = 0.0f;
			outF[1] = 0.0f;
			outF[2] = 0.0f;
			outF[3] = 0.0f;
		}
	}
	else {
		dataI = (unsigned char *)in->rect + in->x * y1 * 4 + 4 * x1;
		if (outI) {
			outI[0] = dataI[0];
			outI[1] = dataI[1];
			outI[2] = dataI[2];
			outI[3] = dataI[3];
		}
		dataF = in->rect_float + in->x * y1 * 4 + 4 * x1;
		if (outF) {
			outF[0] = dataF[0];
			outF[1] = dataF[1];
			outF[2] = dataF[2];
			outF[3] = dataF[3];
		}
	}
}

void neareast_interpolation(ImBuf *in, ImBuf *out, float x, float y, int xout, int yout)
{
	unsigned char *outI = NULL;
	float *outF = NULL;

	if (in == NULL || (in->rect == NULL && in->rect_float == NULL)) {
		return;
	}
	
	pixel_from_buffer(out, &outI, &outF, xout, yout); /* gcc warns these could be uninitialized, but its ok */
	
	neareast_interpolation_color(in, outI, outF, x, y);
}

/*********************** Threaded image processing *************************/

void IMB_processor_apply_threaded(int buffer_lines, int handle_size, void *init_customdata,
                                  void (init_handle) (void *handle, int start_line, int tot_line,
                                                      void *customdata),
                                  void *(do_thread) (void *))
{
	void *handles;
	ListBase threads;

	int i, tot_thread = BLI_system_thread_count();
	int start_line, tot_line;

	handles = MEM_callocN(handle_size * tot_thread, "processor apply threaded handles");

	if (tot_thread > 1)
		BLI_init_threads(&threads, do_thread, tot_thread);

	start_line = 0;
	tot_line = ((float)(buffer_lines / tot_thread)) + 0.5f;

	for (i = 0; i < tot_thread; i++) {
		int cur_tot_line;
		void *handle = ((char *) handles) + handle_size * i;

		if (i < tot_thread - 1)
			cur_tot_line = tot_line;
		else
			cur_tot_line = buffer_lines - start_line;

		init_handle(handle, start_line, cur_tot_line, init_customdata);

		if (tot_thread > 1)
			BLI_insert_thread(&threads, handle);

		start_line += tot_line;
	}

	if (tot_thread > 1)
		BLI_end_threads(&threads);
	else
		do_thread(handles);

	MEM_freeN(handles);
}