/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

//=============================================================================
//
// Geometry data structures and helper functions
//
//=============================================================================

#ifndef AGS_SHARED_UTIL_GEOMETRY_H
#define AGS_SHARED_UTIL_GEOMETRY_H

#include "ags/shared/util/math.h"

namespace AGS3 {

namespace AGSMath = AGS::Shared::Math;
//namespace AGS
//{
//namespace Shared
//{

// Type of alignment of a geometric item of rectangular boundaries.
enum FrameAlignment {
	kAlignNone = 0,

	// Alignment options are representing 8 sides of a frame (rectangle);
	// they are implemented as flags that may be combined together if it
	// is wanted to define alignment to multiple sides at once.
	kAlignTopLeft = 0x0001,
	kAlignTopCenter = 0x0002,
	kAlignTopRight = 0x0004,
	kAlignMiddleLeft = 0x0008,
	kAlignMiddleCenter = 0x0010,
	kAlignMiddleRight = 0x0020,
	kAlignBottomLeft = 0x0040,
	kAlignBottomCenter = 0x0080,
	kAlignBottomRight = 0x0100,

	// Masks are helping to determine whether alignment parameter contains
	// particular horizontal or vertical component (for example: left side
	// or bottom side)
	kMAlignLeft = kAlignTopLeft | kAlignMiddleLeft | kAlignBottomLeft,
	kMAlignRight = kAlignTopRight | kAlignMiddleRight | kAlignBottomRight,
	kMAlignTop = kAlignTopLeft | kAlignTopCenter | kAlignTopRight,
	kMAlignBottom = kAlignBottomLeft | kAlignBottomCenter | kAlignBottomRight,
	kMAlignHCenter = kAlignTopCenter | kAlignMiddleCenter | kAlignBottomCenter,
	kMAlignVCenter = kAlignMiddleLeft | kAlignMiddleCenter | kAlignMiddleRight
};

// Horizontal alignment; based on FrameAlignment, used to restrict alignment
// setting to left/right/center option, while keeping compatibility with any
// alignment in case it will be supported in the future.
enum HorAlignment {
	kHAlignNone = kAlignNone,
	kHAlignLeft = kAlignTopLeft,
	kHAlignRight = kAlignTopRight,
	kHAlignCenter = kAlignTopCenter
};

enum RectPlacement {
	kPlaceOffset,
	kPlaceCenter,
	kPlaceStretch,
	kPlaceStretchProportional,
	kNumRectPlacement
};

struct Point {
	int X;
	int Y;

	Point() {
		X = 0;
		Y = 0;
	}

	Point(int x, int y) {
		X = x;
		Y = y;
	}

	inline bool operator ==(const Point &p) const {
		return X == p.X && Y == p.Y;
	}

	inline bool operator !=(const Point &p) const {
		return X != p.X || Y != p.Y;
	}

	inline Point operator +(const Point &p) const {
		return Point(X + p.X, Y + p.Y);
	}

	inline bool Equals(const int x, const int y) const {
		return X == x && Y == y;
	}
};

struct Line {
	int X1;
	int Y1;
	int X2;
	int Y2;

	Line() {
		X1 = 0;
		Y1 = 0;
		X2 = 0;
		Y2 = 0;
	}

	Line(int x1, int y1, int x2, int y2) {
		X1 = x1;
		Y1 = y1;
		X2 = x2;
		Y2 = y2;
	}
};

// Helper factory functions
inline Line HLine(int x1, int x2, int y) {
	return Line(x1, y, x2, y);
}

inline Line VLine(int x, int y1, int y2) {
	return Line(x, y1, x, y2);
}

struct Size {
	int Width;
	int Height;

	Size() {
		Width = 0;
		Height = 0;
	}

	Size(int width, int height) {
		Width = width;
		Height = height;
	}

	inline bool IsNull() const {
		return Width <= 0 || Height <= 0;
	}

	inline static Size Clamp(const Size &sz, const Size &floor, const Size &ceil) {
		return Size(AGSMath::Clamp(sz.Width, floor.Width, ceil.Width),
					AGSMath::Clamp(sz.Height, floor.Height, ceil.Height));
	}

	// Indicates if current size exceeds other size by any metric
	inline bool ExceedsByAny(const Size &size) const {
		return Width > size.Width || Height > size.Height;
	}

	inline bool operator==(const Size &size) const {
		return Width == size.Width && Height == size.Height;
	}

	inline bool operator!=(const Size &size) const {
		return Width != size.Width || Height != size.Height;
	}

	inline bool operator<(const Size &other) const { // TODO: this implementation is silly and not universally useful; make a realistic one and replace with another function where necessary
		return Width < other.Width || (Width == other.Width && Height < other.Height);
	}

	inline Size operator+(const Size &size) const {
		return Size(Width + size.Width, Height + size.Height);
	}

	inline Size operator-(const Size &size) const {
		return Size(Width - size.Width, Height - size.Height);
	}

	inline Size operator *(int x) const {
		return Size(Width * x, Height * x);
	}

	inline Size operator /(int x) const {
		return Size(Width / x, Height / x);
	}

	inline Size &operator *=(int x) {
		Width *= x;
		Height *= x;
		return *this;
	}

	inline Size &operator /=(int x) {
		Width /= x;
		Height /= x;
		return *this;
	}
};

// TODO: consider making Rect have right-bottom coordinate with +1 offset
// to comply with many other libraries (i.e. Right - Left == Width)
struct Rect {
	int Left;
	int Top;
	int Right;
	int Bottom;

	Rect() {
		Left = 0;
		Top = 0;
		Right = -1;
		Bottom = -1;
	}

	Rect(int l, int t, int r, int b) {
		Left = l;
		Top = t;
		Right = r;
		Bottom = b;
	}

	inline Point GetLT() const {
		return Point(Left, Top);
	}

	inline Point GetCenter() const {
		return Point(Left + GetWidth() / 2, Top + GetHeight() / 2);
	}

	inline int GetWidth() const {
		return Right - Left + 1;
	}

	inline int GetHeight() const {
		return Bottom - Top + 1;
	}

	inline Size GetSize() const {
		return Size(GetWidth(), GetHeight());
	}

	inline bool IsEmpty() const {
		return Right < Left || Bottom < Top;
	}

	inline bool IsInside(int x, int y) const {
		return x >= Left && y >= Top && (x <= Right) && (y <= Bottom);
	}

	inline bool IsInside(const Point &pt) const {
		return IsInside(pt.X, pt.Y);
	}

	inline void MoveToX(int x) {
		Right += x - Left;
		Left = x;
	}

	inline void MoveToY(int y) {
		Bottom += y - Top;
		Top = y;
	}

	inline void MoveTo(const Point &pt) {
		MoveToX(pt.X);
		MoveToY(pt.Y);
	}

	inline void SetWidth(int width) {
		Right = Left + width - 1;
	}

	inline void SetHeight(int height) {
		Bottom = Top + height - 1;
	}

	inline static Rect MoveBy(const Rect &r, int x, int y) {
		return Rect(r.Left + x, r.Top + y, r.Right + x, r.Bottom + y);
	}

	inline bool operator ==(const Rect &r) const {
		return Left == r.Left && Top == r.Top &&
			Right == r.Right && Bottom == r.Bottom;
	}
};

// Helper factory function
inline Rect RectWH(int x, int y, int width, int height) {
	return Rect(x, y, x + width - 1, y + height - 1);
}

inline Rect RectWH(const Size &sz) {
	return Rect(0, 0, sz.Width - 1, sz.Height - 1);
}


struct Triangle {
	int X1;
	int Y1;
	int X2;
	int Y2;
	int X3;
	int Y3;

	Triangle() {
		X1 = 0;
		Y1 = 0;
		X2 = 0;
		Y2 = 0;
		X3 = 0;
		Y3 = 0;
	}

	Triangle(int x1, int y1, int x2, int y2, int x3, int y3) {
		X1 = x1;
		Y1 = y1;
		X2 = x2;
		Y2 = y2;
		X3 = x3;
		Y3 = y3;
	}
};

struct Circle {
	int X;
	int Y;
	int Radius;

	Circle() {
		X = 0;
		Y = 0;
		Radius = 0;
	}

	Circle(int x, int y, int radius) {
		X = x;
		Y = y;
		Radius = radius;
	}

};


// Tells if two rectangles intersect (overlap) at least partially
bool AreRectsIntersecting(const Rect &r1, const Rect &r2);
// Tells if the item is completely inside place
bool IsRectInsideRect(const Rect &place, const Rect &item);
// Calculates a distance between two axis-aligned rectangles, returns 0 if they intersect
float DistanceBetween(const Rect &r1, const Rect &r2);

int AlignInHRange(int x1, int x2, int off_x, int width, FrameAlignment align);
int AlignInVRange(int y1, int y2, int off_y, int height, FrameAlignment align);
Rect AlignInRect(const Rect &frame, const Rect &item, FrameAlignment align);

Size ProportionalStretch(int dest_w, int dest_h, int item_w, int item_h);
Size ProportionalStretch(const Size &dest, const Size &item);

Rect OffsetRect(const Rect &r, const Point off);
Rect CenterInRect(const Rect &place, const Rect &item);
Rect ClampToRect(const Rect &place, const Rect &item);
Rect PlaceInRect(const Rect &place, const Rect &item, const RectPlacement &placement);
// Sum two rectangles, the result is the rectangle bounding them both
Rect SumRects(const Rect &r1, const Rect &r2);
// Intersect two rectangles, the resolt is the rectangle bounding their intersection
Rect IntersectRects(const Rect &r1, const Rect &r2);

//} // namespace Shared
//} // namespace AGS
} // namespace AGS3

#endif