#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "common.h"
#include <string.h>
#include <X11/Xlib.h>
#include <X11/extensions/XShm.h>
#include <X11/Xutil.h>
#include <math.h>
#include "image.h"
#include "script.h"
#include "dynamic_filters.h"

#define GET_INT(x, ptr) (((ptr)->type == VAR_PTR) ?	\
			(x) = (*(int *)(ptr)->data) :	\
			((ptr)->type == VAR_CHAR) ?	\
			(x) = strtol((ptr)->data, 0, 0)	\
			: 0)

#define GET_DOUBLE(x, ptr) (((ptr)->type == VAR_PTR) ?	\
			(x) = (*(double *)(ptr)->data) :	\
			((ptr)->type == VAR_CHAR) ?	\
			(x) = strtod((ptr)->data, 0)	\
			: 0)

static void
mod_brightness(double t[256], double v)
{
	int i;
	for (i = 256; --i >= 0; )
		t[i] += v;
}

static void
mod_contrast(double t[256], double v)
{
	int i;
	for (i = 256; --i >= 0; )
		t[i] = ((t[i] - 0.5) * v) + 0.5;
}

static void
mod_gamma(double t[256], double v)
{
	int i;
	for (i = 256; --i >= 0; )
		t[i] = pow(t[i], 1 / v);
}

static void
mod_tint(double t[256], double v)
{
	int i;
	for (i = 256; --i >= 0; )
		t[i] *= v;
}

static Imlib_Image
colormod(Imlib_Image im, pIFunctionParam par)
{
	double a_d[256], r_d[256], g_d[256], b_d[256];
	DATA8 a_b[256], r_b[256], g_b[256], b_b[256];
        pIFunctionParam ptr;
	int x = 0, y = 0, h, w, i;
	double v=0.0;

	imlib_context_set_image(im);
	w = imlib_image_get_width();
	h = imlib_image_get_height();

	for (i = 256; --i >= 0; )
		a_d[i] = r_d[i] = g_d[i] = b_d[i] = (double)i / 255;

	for (ptr = par; ptr; ptr = ptr->next) {
		if (!strcmp("x", ptr->key)) {
			GET_INT(x, ptr);
		} else if (!strcmp("y", ptr->key)) {
			GET_INT(y, ptr);
		} else if (!strcmp("w", ptr->key)) {
			GET_INT(w, ptr);
		} else if (!strcmp("h", ptr->key)) {
			GET_INT(h, ptr);
		} else if (!memcmp("brightness", ptr->key, 10)) {
			GET_DOUBLE(v, ptr);
			if (!ptr->key[10]) {
				mod_brightness(r_d, v);
				mod_brightness(g_d, v);
				mod_brightness(b_d, v);
				mod_brightness(a_d, v);
			} else if (!strcmp("_r", ptr->key + 10)) {
				mod_brightness(r_d, v);
			} else if (!strcmp("_g", ptr->key + 10)) {
				mod_brightness(g_d, v);
			} else if (!strcmp("_b", ptr->key + 10)) {
				mod_brightness(b_d, v);
			} else if (!strcmp("_a", ptr->key + 10)) {
				mod_brightness(a_d, v);
			}
		} else if (!memcmp("contrast", ptr->key, 8)) {
			GET_DOUBLE(v, ptr);
			if (!ptr->key[8]) {
				mod_contrast(r_d, v);
				mod_contrast(g_d, v);
				mod_contrast(b_d, v);
				mod_contrast(a_d, v);
			} else if (!strcmp("_r", ptr->key + 8)) {
				mod_contrast(r_d, v);
			} else if (!strcmp("_g", ptr->key + 8)) {
				mod_contrast(g_d, v);
			} else if (!strcmp("_b", ptr->key + 8)) {
				mod_contrast(b_d, v);
			} else if (!strcmp("_a", ptr->key + 8)) {
				mod_contrast(a_d, v);
			}
		} else if (!memcmp("gamma", ptr->key, 5)) {
			GET_DOUBLE(v, ptr);
			if (!ptr->key[5]) {
				mod_gamma(r_d, v);
				mod_gamma(g_d, v);
				mod_gamma(b_d, v);
				mod_gamma(a_d, v);
			} else if (!strcmp("_r", ptr->key + 5)) {
				mod_gamma(r_d, v);
			} else if (!strcmp("_g", ptr->key + 5)) {
				mod_gamma(g_d, v);
			} else if (!strcmp("_b", ptr->key + 5)) {
				mod_gamma(b_d, v);
			} else if (!strcmp("_a", ptr->key + 5)) {
				mod_gamma(a_d, v);
			}
		} else if (!memcmp("tint", ptr->key, 4)) {
			GET_DOUBLE(v, ptr);
			if (!ptr->key[4]) {
				mod_tint(r_d, v);
				mod_tint(g_d, v);
				mod_tint(b_d, v);
				mod_tint(a_d, v);
			} else if (!strcmp("_r", ptr->key + 4)) {
				mod_tint(r_d, v);
			} else if (!strcmp("_g", ptr->key + 4)) {
				mod_tint(g_d, v);
			} else if (!strcmp("_b", ptr->key + 4)) {
				mod_tint(b_d, v);
			} else if (!strcmp("_a", ptr->key + 4)) {
				mod_tint(a_d, v);
			}
		}
	}
	for (i = 256; --i >= 0; ) {
		if (a_d[i] < 0) a_d[i] = 0;
		if (a_d[i] > 1) a_d[i] = 1;
		a_b[i] = a_d[i] * 255;
		if (r_d[i] < 0) r_d[i] = 0;
		if (r_d[i] > 1) r_d[i] = 1;
		r_b[i] = r_d[i] * 255;
		if (g_d[i] < 0) g_d[i] = 0;
		if (g_d[i] > 1) g_d[i] = 1;
		g_b[i] = g_d[i] * 255;
		if (b_d[i] < 0) b_d[i] = 0;
		if (b_d[i] > 1) b_d[i] = 1;
		b_b[i] = b_d[i] * 255;
	}
	imlib_context_set_color_modifier(imlib_create_color_modifier());
	imlib_set_color_modifier_tables(r_b, g_b, b_b, a_b);
	imlib_apply_color_modifier_to_rectangle(x, y, w, h);
	imlib_free_color_modifier();
	return im;
}

static void
init(struct imlib_filter_info *info)
{
   char *filters[] = { "colormod" };
   int i = (sizeof(filters) / sizeof(*filters));
   
   info->name = strdup( "Tinting" );
   info->author = strdup( "Willem Monsuwe (willem@stack.nl)" );
   info->description = strdup( "Provides most common color modification filters." );
   info->num_filters = i;
   info->filters = malloc(sizeof(char *) * i);
   while (--i >= 0)
     info->filters[i] = strdup(filters[i]);
   
}

static void
deinit()
{
	return;
}

static void *
exec(char *filter, void *im, pIFunctionParam par)
{
	if (!strcmp(filter, "colormod"))
		return colormod((Imlib_Image)im, par);
	return im;
}