/*
 * ***** 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.
 *
 * Contributor(s): Matt Ebb, Campbell Barton, Shuvro Sarker
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/blenkernel/intern/image_gen.c
 *  \ingroup bke
 */

#include <math.h>
#include <stdlib.h>

#include "BLI_math_base.h"
#include "BLI_math_color.h"
#include "BLI_math_vector.h"

#include "BKE_image.h"

#include "BLF_api.h"

void BKE_image_buf_fill_color(unsigned char *rect, float *rect_float, int width, int height, const float color[4])
{
	int x, y;

	/* blank image */
	if (rect_float) {
		for (y = 0; y < height; y++) {
			for (x = 0; x < width; x++) {
				copy_v4_v4(rect_float, color);
				rect_float += 4;
			}
		}
	}
	
	if (rect) {
		unsigned char ccol[4];

		rgba_float_to_uchar(ccol, color);

		for (y = 0; y < height; y++) {
			for (x = 0; x < width; x++) {
				
				rect[0] = ccol[0];
				rect[1] = ccol[1];
				rect[2] = ccol[2];
				rect[3] = ccol[3];
				rect += 4;
			}
		}
	}
}


void BKE_image_buf_fill_checker(unsigned char *rect, float *rect_float, int width, int height)
{
	/* these two passes could be combined into one, but it's more readable and 
	 * easy to tweak like this, speed isn't really that much of an issue in this situation... */
 
	int checkerwidth = 32, dark = 1;
	int x, y;

	unsigned char *rect_orig = rect;
	float *rect_float_orig = rect_float;

	
	float h = 0.0, hoffs = 0.0;
	float hsv[3] = {0.0f, 0.9f, 0.9f};
	float rgb[3];

	/* checkers */
	for (y = 0; y < height; y++) {
		dark = powf(-1.0f, floorf(y / checkerwidth));
		
		for (x = 0; x < width; x++) {
			if (x % checkerwidth == 0) dark = -dark;
			
			if (rect_float) {
				if (dark > 0) {
					rect_float[0] = rect_float[1] = rect_float[2] = 0.25f;
					rect_float[3] = 1.0f;
				}
				else {
					rect_float[0] = rect_float[1] = rect_float[2] = 0.58f;
					rect_float[3] = 1.0f;
				}
				rect_float += 4;
			}
			else {
				if (dark > 0) {
					rect[0] = rect[1] = rect[2] = 64;
					rect[3] = 255;
				}
				else {
					rect[0] = rect[1] = rect[2] = 150;
					rect[3] = 255;
				}
				rect += 4;
			}
		}
	}

	rect = rect_orig;
	rect_float = rect_float_orig;

	/* 2nd pass, colored + */
	for (y = 0; y < height; y++) {
		hoffs = 0.125f * floorf(y / checkerwidth);
		
		for (x = 0; x < width; x++) {
			h = 0.125f * floorf(x / checkerwidth);
			
			if ((abs((x % checkerwidth) - (checkerwidth / 2)) < 4) &&
			    (abs((y % checkerwidth) - (checkerwidth / 2)) < 4))
			{
				if ((abs((x % checkerwidth) - (checkerwidth / 2)) < 1) ||
				    (abs((y % checkerwidth) - (checkerwidth / 2)) < 1))
				{
					hsv[0] = fmodf(fabsf(h - hoffs), 1.0f);
					hsv_to_rgb_v(hsv, rgb);
					
					if (rect) {
						rect[0] = (char)(rgb[0] * 255.0f);
						rect[1] = (char)(rgb[1] * 255.0f);
						rect[2] = (char)(rgb[2] * 255.0f);
						rect[3] = 255;
					}
					
					if (rect_float) {
						rect_float[0] = rgb[0];
						rect_float[1] = rgb[1];
						rect_float[2] = rgb[2];
						rect_float[3] = 1.0f;
					}
				}
			}

			if (rect_float) rect_float += 4;
			if (rect) rect += 4;
		}
	}
}


/* Utility functions for BKE_image_buf_fill_checker_color */

#define BLEND_FLOAT(real, add)  (real + add <= 1.0f) ? (real + add) : 1.0f
#define BLEND_CHAR(real, add) ((real + (char)(add * 255.0f)) <= 255) ? (real + (char)(add * 255.0f)) : 255

static void checker_board_color_fill(unsigned char *rect, float *rect_float, int width, int height)
{
	int hue_step, y, x;
	float hsv[3], rgb[3];

	hsv[1] = 1.0;

	hue_step = power_of_2_max_i(width / 8);
	if (hue_step < 8) hue_step = 8;

	for (y = 0; y < height; y++) {

		hsv[2] = 0.1 + (y * (0.4 / height)); /* use a number lower then 1.0 else its too bright */
		for (x = 0; x < width; x++) {
			hsv[0] = (float)((double)(x / hue_step) * 1.0 / width * hue_step);
			hsv_to_rgb_v(hsv, rgb);

			if (rect) {
				rect[0] = (char)(rgb[0] * 255.0f);
				rect[1] = (char)(rgb[1] * 255.0f);
				rect[2] = (char)(rgb[2] * 255.0f);
				rect[3] = 255;
				
				rect += 4;
			}

			if (rect_float) {
				rect_float[0] = rgb[0];
				rect_float[1] = rgb[1];
				rect_float[2] = rgb[2];
				rect_float[3] = 1.0f;
				
				rect_float += 4;
			}
		}
	}
}

static void checker_board_color_tint(unsigned char *rect, float *rect_float, int width, int height, int size, float blend)
{
	int x, y;
	float blend_half = blend * 0.5f;

	for (y = 0; y < height; y++) {
		for (x = 0; x < width; x++) {
			if (((y / size) % 2 == 1 && (x / size) % 2 == 1) || ( (y / size) % 2 == 0 && (x / size) % 2 == 0)) {
				if (rect) {
					rect[0] = (char)BLEND_CHAR(rect[0], blend);
					rect[1] = (char)BLEND_CHAR(rect[1], blend);
					rect[2] = (char)BLEND_CHAR(rect[2], blend);
					rect[3] = 255;
				
					rect += 4;
				}
				if (rect_float) {
					rect_float[0] = BLEND_FLOAT(rect_float[0], blend);
					rect_float[1] = BLEND_FLOAT(rect_float[1], blend);
					rect_float[2] = BLEND_FLOAT(rect_float[2], blend);
					rect_float[3] = 1.0f;
				
					rect_float += 4;
				}
			}
			else {
				if (rect) {
					rect[0] = (char)BLEND_CHAR(rect[0], blend_half);
					rect[1] = (char)BLEND_CHAR(rect[1], blend_half);
					rect[2] = (char)BLEND_CHAR(rect[2], blend_half);
					rect[3] = 255;
				
					rect += 4;
				}
				if (rect_float) {
					rect_float[0] = BLEND_FLOAT(rect_float[0], blend_half);
					rect_float[1] = BLEND_FLOAT(rect_float[1], blend_half);
					rect_float[2] = BLEND_FLOAT(rect_float[2], blend_half);
					rect_float[3] = 1.0f;
				
					rect_float += 4;
				}
			}
			
		}
	}
}

static void checker_board_grid_fill(unsigned char *rect, float *rect_float, int width, int height, float blend)
{
	int x, y;
	for (y = 0; y < height; y++) {
		for (x = 0; x < width; x++) {
			if (((y % 32) == 0) || ((x % 32) == 0) || x == 0) {
				if (rect) {
					rect[0] = BLEND_CHAR(rect[0], blend);
					rect[1] = BLEND_CHAR(rect[1], blend);
					rect[2] = BLEND_CHAR(rect[2], blend);
					rect[3] = 255;

					rect += 4;
				}
				if (rect_float) {
					rect_float[0] = BLEND_FLOAT(rect_float[0], blend);
					rect_float[1] = BLEND_FLOAT(rect_float[1], blend);
					rect_float[2] = BLEND_FLOAT(rect_float[2], blend);
					rect_float[3] = 1.0f;
				
					rect_float += 4;
				}
			}
			else {
				if (rect_float) rect_float += 4;
				if (rect) rect += 4;
			}
		}
	}
}

/* defined in image.c */

static void checker_board_text(unsigned char *rect, float *rect_float, int width, int height, int step, int outline)
{
	int x, y;
	int pen_x, pen_y;
	char text[3] = {'A', '1', '\0'};
	const int mono = blf_mono_font_render;

	BLF_size(mono, 54, 72); /* hard coded size! */

	/* OCIO_TODO: using NULL as display will assume using sRGB display
	 *            this is correct since currently generated images are assumed to be in sRGB space,
	 *            but this would probably needed to be fixed in some way
	 */
	BLF_buffer(mono, rect_float, rect, width, height, 4, NULL);

	for (y = 0; y < height; y += step) {
		text[1] = '1';

		for (x = 0; x < width; x += step) {
			/* hard coded offset */
			pen_x = x + 33;
			pen_y = y + 44;

			/* terribly crappy outline font! */
			BLF_buffer_col(mono, 1.0, 1.0, 1.0, 1.0);

			BLF_position(mono, pen_x - outline, pen_y, 0.0);
			BLF_draw_buffer(mono, text);
			BLF_position(mono, pen_x + outline, pen_y, 0.0);
			BLF_draw_buffer(mono, text);
			BLF_position(mono, pen_x, pen_y - outline, 0.0);
			BLF_draw_buffer(mono, text);
			BLF_position(mono, pen_x, pen_y + outline, 0.0);
			BLF_draw_buffer(mono, text);

			BLF_position(mono, pen_x - outline, pen_y - outline, 0.0);
			BLF_draw_buffer(mono, text);
			BLF_position(mono, pen_x + outline, pen_y + outline, 0.0);
			BLF_draw_buffer(mono, text);
			BLF_position(mono, pen_x - outline, pen_y + outline, 0.0);
			BLF_draw_buffer(mono, text);
			BLF_position(mono, pen_x + outline, pen_y - outline, 0.0);
			BLF_draw_buffer(mono, text);

			BLF_buffer_col(mono, 0.0, 0.0, 0.0, 1.0);
			BLF_position(mono, pen_x, pen_y, 0.0);
			BLF_draw_buffer(mono, text);

			text[1]++;
		}
		text[0]++;
	}

	/* cleanup the buffer. */
	BLF_buffer(mono, NULL, NULL, 0, 0, 0, NULL);
}

void BKE_image_buf_fill_checker_color(unsigned char *rect, float *rect_float, int width, int height)
{
	checker_board_color_fill(rect, rect_float, width, height);
	checker_board_color_tint(rect, rect_float, width, height, 1, 0.03f);
	checker_board_color_tint(rect, rect_float, width, height, 4, 0.05f);
	checker_board_color_tint(rect, rect_float, width, height, 32, 0.07f);
	checker_board_color_tint(rect, rect_float, width, height, 128, 0.15f);
	checker_board_grid_fill(rect, rect_float, width, height, 1.0f / 4.0f);

	checker_board_text(rect, rect_float, width, height, 128, 2);
}