
#ifndef _SIF_H
#define _SIF_H

#include "../common/misc.h"	// stprintf

// a sprite has certain settings global to the whole sprite.
// each sprite also contains a certain number of frames.
// each frame contains one or more directions, for example for when that
// frame is facing left or right, and sometimes up or down.
// the number of directions is settable per-sprite, but each frame in
// a given sprite always has the same number of directions.

// this layout is somewhat wasteful of memory what with all static allocations and few pointers
// or dynamically-sized substructures. the reason I did it this way is for speed; hoping the
// tradeoff in memory will mean less indirections to access the sprite data, which is generally
// read several times per frame per sprite.

#define SIF_MAX_DIRS			4
#define SIF_MAX_BLOCK_POINTS	4

struct SIFPoint
{
	int16_t x, y;
	
	void set(int x, int y)
	{
		this->x = x;
		this->y = y;
	}
	
	void offset(int dx, int dy)
	{
		x += dx;
		y += dy;
	}
	
	bool equ(int x, int y)
	{
		return (this->x == x && this->y == y);
	}
	
	const char *ToString()
	{
		return stprintf("[%d, %d]", this->x, this->y);
	}
	
	bool operator== (const SIFPoint &other) const
	{
		return (this->x == other.x && this->y == other.y);
	}
	
	bool operator!= (const SIFPoint &other) const
	{
		return (this->x != other.x || this->y != other.y);
	}
};

typedef SIFPoint Point;

struct SIFRect
{
	int16_t x1, y1, x2, y2;
	
	void set(int x1, int y1, int x2, int y2)
	{
		this->x1 = x1;
		this->y1 = y1;
		this->x2 = x2;
		this->y2 = y2;
	}
	
	void offset(int dx, int dy)
	{
		x1 += dx; y1 += dy;
		x2 += dx; y2 += dy;
	}
	
	bool equ(int x1, int y1, int x2, int y2)
	{
		return (this->x1 == x1 && this->y1 == y1 && \
				this->x2 == x2 && this->y2 == y2);
	}
	
	const char *ToString()
	{
		return stprintf("[%d, %d] - [%d, %d]", this->x1, this->y1, this->x2, this->y2);
	}
	
	bool operator== (const SIFRect &other) const
	{
		return (x1 == other.x1 && y1 == other.y1 && \
				x2 == other.x2 && y2 == other.y2);
	}
	
	bool operator!= (const SIFRect &other) const
	{
		return (x1 != other.x1 || y1 != other.y1 || \
				x2 != other.x2 || y2 != other.y2);
	}
};

struct SIFPointList
{
	SIFPoint point[SIF_MAX_BLOCK_POINTS];
	int count;
	
	SIFPoint& operator[] (const int nIndex)
	{
		return point[nIndex];
	}
	
	bool operator== (const SIFPointList &other) const
	{
		if (other.count != count)
			return false;
		
		for(int i=0;i<count;i++)
			if (point[i] != other.point[i]) return false;
		
		return true;
	}
	
	bool operator!= (const SIFPointList &other) const
	{
		return !(*this == other);
	}
	
	void offset(int dx, int dy)
	{
		for(int i=0;i<count;i++)
		{
			point[i].x += dx;
			point[i].y += dy;
		}
	}
};


struct SIFDir
{
	// the offset on the sprite sheet where this frame is located.
	SIFPoint sheet_offset;
	
	// when a sprite is drawn, it's sprite will be offset such that this pixel is
	// placed at the (x,y) coordinates that were given for the sprite to be drawn at.
	// i.e., it's a "hot point".
	// this also offsets the bounding boxes and blockl/r/u/d points but not the
	// action points or spawn point.
	// it is not super-well tested and isn't intended to be frequently used on objects which
	// interact with the world or are solid, etc. mostly it is for use with objects
	// such as the caret effects etc, so that their o->x & o->y can represent their center
	// point instead of their upper-left corner.
	SIFPoint drawpoint;
	
	//	a pixel of "noteworthiness" on the sprite.
	//  * for Player: position he holds his gun at
	//  * for Guns: position to spawn the shots at
	//	* for everything else: whatever they want it for
	SIFPoint actionpoint;
	
	// optional secondary action point
	SIFPoint actionpoint2;
	
	// optional additional/extra per-frame/dir bbox
	// (has no effect to engine, it's just metadata. but object AI can copy the
	//  per-frame bbox over the real bbox when changing the frame).
	SIFRect pf_bbox;
};

struct SIFFrame
{
	SIFDir dir[SIF_MAX_DIRS];
};

// a design goal here is that this structure MUST STAY POD so
// no virtuals, constructors, classes for members or anything else
// dodgy that might endanger that. we should able to zero out a SIFSprite
// with memset and worry about nothing. yes it has a few member functions
// but those are just a syntactical detail and should be harmless.
struct SIFSprite
{
	void Init();
	void Zero();
	void FreeData();
	
	void AddFrame(SIFFrame *newframe);
	void InsertFrame(SIFFrame *newframe, int insertbefore);
	void DeleteFrame(int index);
	void SetNumFrames(int newcount);
	SIFDir *dir(int frame, int dir);
	
	void CopyFrom(SIFSprite *other);
	SIFSprite *Duplicate();
	
	// ---------------------------------------
	
	int w, h;
	uint8_t spritesheet;	// # of spritesheet sprite is located on
	
	int nframes;
	int ndirs;
	SIFFrame *frame;
	
	SIFRect bbox;			// bounding box for hit detection with other sprites
	SIFRect solidbox;		// bounding box for solidity w/ other objects
	SIFRect slopebox;		// bounding box for moving up and down slopes (generated at runtime)
	
	// when an object is spawned or changed from one type to another, this point is subtracted
	// from it's x,y coordinates, so that this point ends up being centered on the given x,y coords.
	SIFPoint spawn_point;
	
	// points to check for setting the corresponding block vars on the object
	// (which determine whether it's blocked on that side by a solid wall or object).
	SIFPointList block_l;
	SIFPointList block_r;
	SIFPointList block_u;
	SIFPointList block_d;
};


#endif
