path2d.h

一个用于智能手机的多媒体库适合S60 WinCE的跨平台开发库

/*
 *			GPAC - Multimedia Framework C SDK
 *
 *			Copyright (c) Jean Le Feuvre 2000-2005
 *					All rights reserved
 *
 *  This file is part of GPAC / common tools sub-project
 *
 *  GPAC 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, or (at your option)
 *  any later version.
 *   
 *  GPAC 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; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
 *
 */


#ifndef _GF_PATH2D_H_
#define _GF_PATH2D_H_

/*!
 *	\file <gpac/path2d.h>
 *	\brief 2D Vectorial Path functions.
 */



#ifdef __cplusplus
extern "C" {
#endif

#include <gpac/math.h>
#include <gpac/constants.h>


/*!
 *\addtogroup path_grp path2d
 *\ingroup utils_grp
 *\brief Vectorial 2D Path manipulation functions
 *
 *This section documents the 2D path object used in the GPAC framework. 
 *	@{
 */

	
/*!\brief 2D Path Object
 *
 *The 2D path object is used to construct complex 2D shapes for later drawing
 * or outlining.
 */
typedef struct
{
	/*! number of contours in path*/
	u32 n_contours;
	/*! number of points in path and alloc size*/
	u32 n_points, n_alloc_points;
	/*! path points */
	GF_Point2D *points;
	/*! point tags (one per point)*/
	u8 *tags;
	/*! contour end points*/
	u32 *contours;
	/*! path bbox - NEVER USE WITHOUT FIRST CALLING \ref gf_path_get_bounds*/
	GF_Rect bbox;
	/*! path flags*/
	s32 flags;
	/*! fineness to use whenever flattening the path - default is \ref FIX_ONE*/
	Fixed fineness;
} GF_Path;


/*!
 *	\brief path constructor
 *
 *	Constructs an empty 2D path object
 *	\return new path object
 */
GF_Path *gf_path_new();
/*!
 *	\brief path destructor
 *
 *	Destructs a 2D path object
 *	\param gp the target path
 */
void gf_path_del(GF_Path *gp);
/*!
 *	\brief path reset
 *
 *	Resets the 2D path object
 *	\param gp the target path
 */
void gf_path_reset(GF_Path *gp);
/*!
 *	\brief path copy constuctor
 *
 *	Resets a copy of a 2D path object
 *	\param gp the target path
 *	\return new path copy
 */
GF_Path *gf_path_clone(GF_Path *gp);
/*!
 *	\brief path close
 *
 *	Closes current path contour
 *	\param gp the target path
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_close(GF_Path *gp);
/*!
 *	\brief path moveTo
 *
 *	Starts a new contour from the specified point
 *	\param gp the target path
 *	\param x x-coordinate of the new point
 *	\param y y-coordinate of the new point
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_move_to(GF_Path *gp, Fixed x, Fixed y);
/*!
 *	\brief starts new contour
 *
 *	Starts a new contour from the specified point
 *	\param gp the target path
 *	\param pt pointer to the new start point
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_move_to_vec(GF_Path *gp, GF_Point2D *pt);
/*!
 *	\brief adds line to path
 *
 *	Adds a line from the current point in path to the specified point
 *	\param gp the target path
 *	\param x x-coordinate of the line end
 *	\param y y-coordinate of the line end
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_line_to(GF_Path *gp, Fixed x, Fixed y);
/*!
 *	\brief adds line to path
 *
 *	Adds a line from the current point in path to the specified point
 *	\param gp the target path
 *	\param pt line end
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_line_to_vec(GF_Path *gp, GF_Point2D *pt);
/*!
 *	\brief adds cubic to path
 *
 *	Adds a cubic bezier curve to the current contour, starting from the current path point
 *	\param gp the target path
 *	\param c1_x x-coordinate of the first control point of the cubic curve
 *	\param c1_y y-coordinate of the first control point of the cubic curve
 *	\param c2_x x-coordinate of the second control point of the cubic curve
 *	\param c2_y y-coordinate of the second control point of the cubic curve
 *	\param x x-coordinate of the end point of the cubic curve
 *	\param y y-coordinate of the end point of the cubic curve
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_cubic_to(GF_Path *gp, Fixed c1_x, Fixed c1_y, Fixed c2_x, Fixed c2_y, Fixed x, Fixed y);
/*!
 *	\brief adds cubic to path
 *
 *	Adds a cubic bezier curve to the current contour, starting from the current path point
 *	\param gp the target path
 *	\param c1 first control point of the cubic curve
 *	\param c2 second control point of the cubic curve
 *	\param pt end point of the cubic curve
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_cubic_to_vec(GF_Path *gp, GF_Point2D *c1, GF_Point2D *c2, GF_Point2D *pt);
/*!
 *	\brief adds quadratic to path
 *
 *	Adds a quadratic bezier curve to the current contour, starting from the current path point
 *	\param gp the target path
 *	\param c_x x-coordinate of the control point of the quadratic curve
 *	\param c_y y-coordinate of the control point of the quadratic curve
 *	\param x x-coordinate of the end point of the cubic quadratic
 *	\param y y-coordinate of the end point of the cubic quadratic
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_quadratic_to(GF_Path *gp, Fixed c_x, Fixed c_y, Fixed x, Fixed y);
/*!
 *	\brief adds quadratic to path
 *
 *	Adds a quadratic bezier curve to the current contour, starting from the current path point
 *	\param gp the target path
 *	\param c control point of the quadratic curve
 *	\param pt end point of the cubic quadratic
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_quadratic_to_vec(GF_Path *gp, GF_Point2D *c, GF_Point2D *pt);
/*!
 *	\brief adds rectangle to path
 *
 *	Adds a rectangle contour to the path
 *	\param gp the target path
 *	\param cx x-coordinate of the rectangle center
 *	\param cy y-coordinate of the rectangle center
 *	\param w width of the rectangle
 *	\param h height of the rectangle
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_rect_center(GF_Path *gp, Fixed cx, Fixed cy, Fixed w, Fixed h);
/*!
 *	\brief adds rectangle to path
 *
 *	Adds a rectangle contour to the path
 *	\param gp the target path
 *	\param ox left-most coordinate of the rectangle 
 *	\param oy top-most coordinate of the rectangle
 *	\param w width of the rectangle
 *	\param h height of the rectangle
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_rect(GF_Path *gp, Fixed ox, Fixed oy, Fixed w, Fixed h);
/*!
 *	\brief adds ellipse to path
 *
 *	Adds an ellipse contour to the path
 *	\param gp the target path
 *	\param cx x-coordinate of the ellipse center
 *	\param cy y-coordinate of the ellipse center
 *	\param a_axis length of the horizontal ellipse axis
 *	\param b_axis length of the vertical ellipse axis
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_ellipse(GF_Path *gp, Fixed cx, Fixed cy, Fixed a_axis, Fixed b_axis);
/*!
 *	\brief adds N-bezier curve to path
 *
 *	Adds an N-degree bezier curve to the path, starting from the current point
 *	\param gp the target path
 *	\param pts points used to define the curve
 *	\param nb_pts number of points used to define the curve. The degree of the curve is therefore (nb_pts-1).
 *	\return error code if any error, \ref GF_OK otherwise
 *	\note the fineness of the path must be set before calling this function.
 */
GF_Err gf_path_add_bezier(GF_Path *gp, GF_Point2D *pts, u32 nb_pts);
/*!
 *	\brief adds arc to path
 *
 *	Adds an arc contour to the path from focal and end points.
 *	\param gp the target path
 *	\param end_x x-coordinate of the arc end point
 *	\param end_y y-coordinate of the arc end point
 *	\param fa_x x-coordinate of the arc first focal point
 *	\param fa_y y-coordinate of the arc first focal point
 *	\param fb_x x-coordinate of the arc second focal point
 *	\param fb_y y-coordinate of the arc second focal point
 *	\param cw if 1, the arc will be clockwise, otherwise counter-clockwise.
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_arc_to(GF_Path *gp, Fixed end_x, Fixed end_y, Fixed fa_x, Fixed fa_y, Fixed fb_x, Fixed fb_y, Bool cw);
/*!
 *	\brief adds arc to path
 *
 *	Adds an arc contour to the path.
 *	\param gp the target path
 *	\param radius radius of the arc 
 *	\param start_angle start angle of the arc in radians
 *	\param end_angle end angle of the arc in radians
 *	\param close_type closing type: 0 for open arc, 1 for close arc, 2 for pie
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_add_arc(GF_Path *gp, Fixed radius, Fixed start_angle, Fixed end_angle, u32 close_type);
/*!
 *	\brief gets path control bounds
 *
 *	Gets the path control bounds, i.e. the rectangle covering all lineTo and bezier control points.
 *	\param gp the target path
 *	\param rc pointer to rectangle receiving the control rectangle
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_get_control_bounds(GF_Path *gp, GF_Rect *rc);
/*!
 *	\brief gets path bounds
 *
 *	Gets the path bounds, i.e. the rectangle covering all points in path except bezier control points.
 *	\param gp the target path
 *	\param rc pointer to rectangle receiving the control rectangle
 *	\return error code if any error, \ref GF_OK otherwise
 */
GF_Err gf_path_get_bounds(GF_Path *gp, GF_Rect *rc);