/* EINA - EFL data type library
 * Copyright (C) 2007-2008 Jorge Luis Zapata Muga
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library;
 * if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef EINA_INLINE_RECTANGLE_H__
#define EINA_INLINE_RECTANGLE_H__

/**
 * @addtogroup Eina_Rectangle_Group Rectangle
 *
 * @brief These functions provide rectangle management.
 *
 * @{
 */

/**
 * @brief Check if the given spans intersect.
 *
 * @param c1 The column of the first span.
 * @param l1 The length of the first span.
 * @param c2 The column of the second span.
 * @param l2 The length of the second span.
 * @return #EINA_TRUE on success, #EINA_FALSE otherwise.
 *
 * This function returns #EINA_TRUE if the  given spans intersect, #EINA_FALSE
 * otherwise.
 */
static inline int
eina_spans_intersect(int c1, int l1, int c2, int l2)
{
	return (!(((c2 + l2) <= c1) || (c2 >= (c1 + l1))));
}

/**
 * @brief Check if the given rectangle is empty.
 *
 * @param r The rectangle to check.
 * @return #EINA_TRUE if the rectangle is empty, #EINA_FALSE otherwise.
 *
 * This function returns #EINA_TRUE if @p r is empty, #EINA_FALSE
 * otherwise. No check is done on @p r, so it must be a valid
 * rectangle.
 */
static inline Eina_Bool
eina_rectangle_is_empty(const Eina_Rectangle *r)
{
	return ((r->w < 1) || (r->h < 1)) ? EINA_TRUE : EINA_FALSE;
}

/**
 * @brief Set the coordinates and size of the given rectangle.
 *
 * @param r The rectangle.
 * @param x The top-left x coordinate of the rectangle.
 * @param y The top-left y coordinate of the rectangle.
 * @param w The width of the rectangle.
 * @param h The height of the rectangle.
 *
 * This function sets its top-left x coordinate to @p x, its top-left
 * y coordinate to @p y, its width to @p w and its height to @p h. No
 * check is done on @p r, so it must be a valid rectangle.
 */
static inline void
eina_rectangle_coords_from(Eina_Rectangle *r, int x, int y, int w, int h)
{
	r->x = x;
	r->y = y;
	r->w = w;
	r->h = h;
}

/**
 * @brief Check if the given rectangles intersect.
 *
 * @param r1 The first rectangle.
 * @param r2 The second rectangle.
 * @return #EINA_TRUE if the rectangles intersect, #EINA_FALSE otherwise.
 *
 * This function returns #EINA_TRUE if @p r1 and @p r2 intersect, #EINA_FALSE
 * otherwise. No check is done on @p r1 and @p r2, so they must be valid
 * rectangles.
 */
static inline Eina_Bool
eina_rectangles_intersect(const Eina_Rectangle *r1, const Eina_Rectangle *r2)
{
	return (eina_spans_intersect(r1->x, r1->w, r2->x, r2->w) && eina_spans_intersect(r1->y, r1->h, r2->y, r2->h)) ? EINA_TRUE : EINA_FALSE;
}

/**
 * @brief Check if the given x-coordinate is in the rectangle .
 *
 * @param r The rectangle.
 * @param x The x coordinate.
 * @return #EINA_TRUE on success, #EINA_FALSE otherwise.
 *
 * This function returns #EINA_TRUE if @p x is in @p r with respect to
 * the horizontal direction, #EINA_FALSE otherwise. No check is done
 * on @p r, so it must be a valid rectangle.
 */
static inline Eina_Bool
eina_rectangle_xcoord_inside(const Eina_Rectangle *r, int x)
{
	return ((x >= r->x) && (x < (r->x + r->w))) ? EINA_TRUE : EINA_FALSE;
}

/**
 * @brief Check if the given y-coordinate is in the rectangle .
 *
 * @param r The rectangle.
 * @param y The y coordinate.
 * @return #EINA_TRUE on success, #EINA_FALSE otherwise.
 *
 * This function returns #EINA_TRUE if @p y is in @p r with respect to
 * the vertical direction, #EINA_FALSE otherwise. No check is done
 * on @p r, so it must be a valid rectangle.
 */
static inline Eina_Bool
eina_rectangle_ycoord_inside(const Eina_Rectangle *r, int y)
{
	return ((y >= r->y) && (y < (r->y + r->h))) ? EINA_TRUE : EINA_FALSE;
}

/**
 * @brief Check if the given point is in the rectangle .
 *
 * @param r The rectangle.
 * @param x The x coordinate of the point.
 * @param y The y coordinate of the point.
 * @return #EINA_TRUE on success, #EINA_FALSE otherwise.
 *
 * This function returns #EINA_TRUE if the point of coordinate (@p x,
 * @p y) is in @p r, #EINA_FALSE otherwise. No check is done on @p r,
 * so it must be a valid rectangle.
 */
static inline Eina_Bool
eina_rectangle_coords_inside(const Eina_Rectangle *r, int x, int y)
{
	return (eina_rectangle_xcoord_inside(r, x) && eina_rectangle_ycoord_inside(r, y)) ? EINA_TRUE : EINA_FALSE;
}

/**
 * @brief Get the union of two rectangles.
 *
 * @param dst The first rectangle.
 * @param src The second rectangle.
 *
 * This function get the union of the rectangles @p dst and @p src. The
 * result is stored in @p dst. No check is done on @p dst or @p src,
 * so they must be valid rectangles.
 */
static inline void
eina_rectangle_union(Eina_Rectangle *dst, const Eina_Rectangle *src)
{
	/* left */
	if (dst->x > src->x)
	{
		dst->w += dst->x - src->x;
		dst->x = src->x;
	}
	/* right */
	if ((dst->x + dst->w) < (src->x + src->w))
		dst->w = src->x + src->w;
	/* top */
	if (dst->y > src->y)
	{
		dst->h += dst->y - src->y;
		dst->y = src->y;
	}
	/* bottom */
	if ((dst->y + dst->h) < (src->y + src->h))
		dst->h = src->y + src->h;
}

/**
 * @brief Get the intersection of two rectangles.
 *
 * @param dst The first rectangle.
 * @param src The second rectangle.
 * @return #EINA_TRUE if the rectangles intersect, #EINA_FALSE
 * otherwise.
 *
 * This function get the intersection of the rectangles @p dst and
 * @p src. The result is stored in @p dst. No check is done on @p dst
 * or @p src, so they must be valid rectangles.
 */
static inline Eina_Bool
eina_rectangle_intersection(Eina_Rectangle *dst, const Eina_Rectangle *src)
{
	if (!(eina_rectangles_intersect(dst, src)))
		return EINA_FALSE;

	/* left */
	if (dst->x < src->x)
	{
		dst->w += dst->x - src->x;
		dst->x = src->x;
		if (dst->w < 0)
			dst->w = 0;
	}
	/* right */
	if ((dst->x + dst->w) > (src->x + src->w))
		dst->w = src->x + src->w - dst->x;
	/* top */
	if (dst->y < src->y)
	{
		dst->h += dst->y - src->y;
		dst->y = src->y;
		if (dst->h < 0)
			dst->h = 0;
	}
	/* bottom */
	if ((dst->y + dst->h) > (src->y + src->h))
		dst->h = src->y + src->h - dst->y;

	return EINA_TRUE;
}

static inline void
eina_rectangle_rescale_in(const Eina_Rectangle *out, const Eina_Rectangle *in, Eina_Rectangle *res)
{
	res->x = in->x - out->x;
	res->y = in->y - out->y;
	res->w = in->w;
	res->h = in->h;
}

static inline void
eina_rectangle_rescale_out(const Eina_Rectangle *out, const Eina_Rectangle *in, Eina_Rectangle *res)
{
	res->x = out->x + in->x;
	res->y = out->y + in->y;
	res->w = out->w;
	res->h = out->h;
}

static inline Eina_Bool
eina_rectangle_is_valid(const Eina_Rectangle *r)
{
	if (r->w <= 0 || r->h <= 0)
		return EINA_FALSE;
	return EINA_TRUE;
}

static inline int
eina_rectangle_max_x(Eina_Rectangle *thiz)
{
	return thiz->x + thiz->w;
}

static inline int
eina_rectangle_max_y(Eina_Rectangle *thiz)
{
	return thiz->y + thiz->h;
}

static inline Eina_Bool
eina_rectangle_x_cut(Eina_Rectangle *thiz, Eina_Rectangle *slice, Eina_Rectangle *leftover, int amount)
{
	Eina_Rectangle tmp1, tmp2;
	if (amount > thiz->w)
		return EINA_FALSE;
	eina_rectangle_coords_from(&tmp1, thiz->x, thiz->y, amount, thiz->h);
	eina_rectangle_coords_from(&tmp2, thiz->x + amount, thiz->y, thiz->w - amount, thiz->h);
	if (slice) *slice = tmp1;
	if (leftover) *leftover = tmp2;
	return EINA_TRUE;
}

static inline Eina_Bool
eina_rectangle_y_cut(Eina_Rectangle *thiz, Eina_Rectangle *slice, Eina_Rectangle *leftover, int amount)
{
	Eina_Rectangle tmp1, tmp2;
	if (amount > thiz->h)
		return EINA_FALSE;
	eina_rectangle_coords_from(&tmp1, thiz->x, thiz->y, thiz->w, amount);
	eina_rectangle_coords_from(&tmp2, thiz->x, thiz->y + amount, thiz->w, thiz->h - amount);
	if (slice) *slice = tmp1;
	if (leftover) *leftover = tmp2;
	return EINA_TRUE;
}

static inline Eina_Bool
eina_rectangle_width_cut(Eina_Rectangle *thiz, Eina_Rectangle *slice, Eina_Rectangle *leftover, int amount)
{
	Eina_Rectangle tmp1, tmp2;
	if (thiz->w - amount < 0)
		return EINA_FALSE;
	eina_rectangle_coords_from(&tmp1, thiz->x + (thiz->w - amount), thiz->y, amount, thiz->h);
	eina_rectangle_coords_from(&tmp2, thiz->x, thiz->y, thiz->w - amount, thiz->h);
	if (slice) *slice = tmp1;
	if (leftover) *leftover = tmp2;
	return EINA_TRUE;
}

static inline Eina_Bool
eina_rectangle_height_cut(Eina_Rectangle *thiz, Eina_Rectangle *slice, Eina_Rectangle *leftover, int amount)
{
	Eina_Rectangle tmp1, tmp2;
	if (thiz->h - amount < 0)
		return EINA_FALSE;
	eina_rectangle_coords_from(&tmp1, thiz->x, thiz->y + (thiz->h - amount), thiz->w, amount);
	eina_rectangle_coords_from(&tmp2, thiz->x, thiz->y, thiz->w, thiz->h - amount);
	if (slice) *slice = tmp1;
	if (leftover) *leftover = tmp2;
	return EINA_TRUE;
}

/**
 * @brief Subtract two rectangles.
 *
 * @param thiz The minuend rectangle
 * @param src The subtrahend rectangle
 *
 * This function subtract two rectangles. The difference is stored on @p out
 * There will be at most four differences, use eina_rectangle_is_valid to
 * confirm the number of differences.
 */
static inline Eina_Bool
eina_rectangle_subtract(Eina_Rectangle *thiz, Eina_Rectangle *other, Eina_Rectangle out[4])
{
	Eina_Rectangle intersection;
	Eina_Rectangle leftover = EINA_RECTANGLE_INIT;
	Eina_Rectangle tmp;
	int cut = 0;

	if (!eina_rectangle_is_valid(thiz))
		return EINA_FALSE;

	eina_rectangle_coords_from(&out[0], 0, 0, 0, 0);
	eina_rectangle_coords_from(&out[1], 0, 0, 0, 0);
	eina_rectangle_coords_from(&out[2], 0, 0, 0, 0);
	eina_rectangle_coords_from(&out[3], 0, 0, 0, 0);
	intersection = *thiz;
	if (!eina_rectangle_intersection(&intersection, other))
	{
		out[0] = *thiz;
		return EINA_TRUE;
	}

	/* cut in height */
	{
		cut = thiz->h - (intersection.y - thiz->y);
		if (cut > thiz->h) { cut = thiz->h; }
		eina_rectangle_height_cut(thiz, &leftover, &out[0], cut);
	}
	/* cut in y */
	tmp = leftover;
	if (eina_rectangle_intersection(&tmp, &intersection))
	{
		cut = leftover.h - (eina_rectangle_max_y(&leftover) - eina_rectangle_max_y(&tmp));
		if (cut > leftover.h) { cut = leftover.h; }
		eina_rectangle_y_cut(&leftover, &leftover, &out[1], cut);
	}
	/* cut in width */
	tmp = leftover;
	if (eina_rectangle_intersection(&tmp, &intersection))
	{
		cut = leftover.w - (tmp.x - leftover.x);
		if (cut > leftover.w) { cut = leftover.w; }
		eina_rectangle_width_cut(&leftover, &leftover, &out[2], cut);
	}
	/* cut in x */
	tmp = leftover;
	if (eina_rectangle_intersection(&tmp, &intersection))
	{
		cut = leftover.w - (eina_rectangle_max_x(&leftover) - eina_rectangle_max_x(&tmp));
		if (cut > leftover.w) { cut = leftover.w; }
		eina_rectangle_x_cut(&leftover, &leftover, &out[3], cut);
	}

	return EINA_TRUE;
}

/**
 * @}
 */

#endif