/*  image_gen.c	
 * 
 * $Id$
 *
 * ***** 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 "BKE_image.h"
#include "BLI_math_color.h"
#include "BLF_api.h"

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

	/* blank image */
	if(rect_float) {
		for(y= 0; y<height; y++) {
			for(x= 0; x<width; x++) {
				rect_float[0]= color[0];
				rect_float[1]= color[1];
				rect_float[2]= color[2];
				rect_float[3]= color[3];
				rect_float+= 4;
			}
		}
	}
	
	if(rect) {
		char ccol[4];

		ccol[0]= (char)(color[0]*255.0f);
		ccol[1]= (char)(color[1]*255.0f);
		ccol[2]= (char)(color[2]*255.0f);
		ccol[3]= (char)(color[3]*255.0f);
		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, hue=0.0, s=0.9, v=0.9, r, g, b;

	/* 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 ((fabs((x % checkerwidth) - (checkerwidth / 2)) < 4) &&
				(fabs((y % checkerwidth) - (checkerwidth / 2)) < 4)) {
				
				if ((fabs((x % checkerwidth) - (checkerwidth / 2)) < 1) ||
					(fabs((y % checkerwidth) - (checkerwidth / 2)) < 1)) {
					
					hue= fmodf(fabs(h-hoffs), 1.0f);
					hsv_to_rgb(hue, s, v, &r, &g, &b);
					
					if (rect) {
						rect[0]= (char)(r * 255.0f);
						rect[1]= (char)(g * 255.0f);
						rect[2]= (char)(b * 255.0f);
						rect[3]= 255;
					}
					
					if (rect_float) {
						rect_float[0]= r;
						rect_float[1]= g;
						rect_float[2]= b;
						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 int is_pow2(int n)
{
	return ((n)&(n-1))==0;
}
static int larger_pow2(int n)
{
	if (is_pow2(n))
		return n;

	while(!is_pow2(n))
		n= n&(n-1);

	return n*2;
}

static void checker_board_color_fill(unsigned char *rect, float *rect_float, int width, int height)
{
	int hue_step, y, x;
	float hue, val, sat, r, g, b;

	sat= 1.0;

	hue_step= larger_pow2(width / 8);
	if(hue_step < 8) hue_step= 8;

	for(y= 0; y < height; y++)
	{
        
		val= 0.1 + (y * (0.4 / height)); /* use a number lower then 1.0 else its too bright */
		for(x= 0; x < width; x++)
		{
			hue= (float)((double)(x/hue_step) * 1.0 / width * hue_step);
			hsv_to_rgb(hue, sat, val, &r, &g, &b);

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

			if (rect_float) {
				rect_float[0]= r;
				rect_float[1]= g;
				rect_float[2]= b;
				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;

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

	BLF_buffer(mono, rect_float, rect, width, height, 4);
    
	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);
}

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);
}