/***************************************************************************/
/* */
/*fttrigon.h */
/* */
/*FreeType trigonometric functions (specification).*/
/* */
/*Copyright 2001-2015 by */
/*David Turner, Robert Wilhelm, and Werner Lemberg.*/
/* */
/*This file is part of the FreeType project, and may only be used, */
/*modified, and distributed under the terms of the FreeType project*/
/*license, LICENSE.TXT.By continuing to use, modify, or distribute */
/*this file you indicate that you have read the license and*/
/*understand and accept it fully.*/
/* */
/***************************************************************************/
#ifndef __FTTRIGON_H__
#define __FTTRIGON_H__
#include FT_FREETYPE_H
#ifdef FREETYPE_H
#error freetype.h of FreeType 1 has been loaded!
#error Please fix the directory search order for header files
#error so that freetype.h of FreeType 2 is found first.
#endif
FT_BEGIN_HEADER
/*************************************************************************/
/* */
/*
/* computations*/
/* */
/*************************************************************************/
/*************************************************************************
*
* @type:
* FT_Angle
*
* @description:
* This type is used to model angle values in FreeType.Note that the
* angle is a 16.16 fixed-point value expressed in degrees.
*
*/
typedef FT_FixedFT_Angle;
/*************************************************************************
*
* @macro:
* FT_ANGLE_PI
*
* @description:
* The angle pi expressed in @FT_Angle units.
*
*/
#define FT_ANGLE_PI( 180L << 16 )/************************************************************************* * * @macro: * FT_ANGLE_2PI * * @description: * The angle 2*pi expressed in @FT_Angle units. * */#define FT_ANGLE_2PI( FT_ANGLE_PI * 2 )/************************************************************************* * * @macro: * FT_ANGLE_PI2 * * @description: * The angle pi/2 expressed in @FT_Angle units. * */#define FT_ANGLE_PI2( FT_ANGLE_PI / 2 )/************************************************************************* * * @macro: * FT_ANGLE_PI4 * * @description: * The angle pi/4 expressed in @FT_Angle units. * */#define FT_ANGLE_PI4( FT_ANGLE_PI / 4 )/************************************************************************* * * @function: * FT_Sin * * @description: * Return the sinus of a given angle in fixed-point format. * * @input: * angle :: * The input angle. * * @return: * The sinus value. * * @note: * If you need both the sinus and cosinus for a given angle, use the * function @FT_Vector_Unit. * */FT_EXPORT( FT_Fixed )FT_Sin( FT_Angleangle );/************************************************************************* * * @function: * FT_Cos * * @description: * Return the cosinus of a given angle in fixed-point format. * * @input: * angle :: * The input angle. * * @return: * The cosinus value. * * @note: * If you need both the sinus and cosinus for a given angle, use the * function @FT_Vector_Unit. * */FT_EXPORT( FT_Fixed )FT_Cos( FT_Angleangle );/************************************************************************* * * @function: * FT_Tan * * @description: * Return the tangent of a given angle in fixed-point format. * * @input: * angle :: * The input angle. * * @return: * The tangent value. * */FT_EXPORT( FT_Fixed )FT_Tan( FT_Angleangle );/************************************************************************* * * @function: * FT_Atan2 * * @description: * Return the arc-tangent corresponding to a given vector (x,y) in * the 2d plane. * * @input: * x :: * The horizontal vector coordinate. * * y :: * The vertical vector coordinate. * * @return: * The arc-tangent value (i.e. angle). * */FT_EXPORT( FT_Angle )FT_Atan2( FT_Fixedx,FT_Fixedy );/************************************************************************* * * @function: * FT_Angle_Diff * * @description: * Return the difference between two angles.The result is always * constrained to the ]-PI..PI] interval. * * @input: * angle1 :: * First angle. * * angle2 :: * Second angle. * * @return: * Constrained value of `value2-value1′. * */FT_EXPORT( FT_Angle )FT_Angle_Diff( FT_Angleangle1, FT_Angleangle2 );/************************************************************************* * * @function: * FT_Vector_Unit * * @description: * Return the unit vector corresponding to a given angle.After the * call, the value of `vec.x’ will be `cos(angle)’, and the value of * `vec.y’ will be `sin(angle)’. * * This function is useful to retrieve both the sinus and cosinus of a * given angle quickly. * * @output: * vec :: * The address of target vector. * * @input: * angle :: * The input angle. * */FT_EXPORT( void )FT_Vector_Unit( FT_Vector*vec,FT_Angleangle );/************************************************************************* * * @function: * FT_Vector_Rotate * * @description: * Rotate a vector by a given angle. * * @inout: * vec :: * The address of target vector. * * @input: * angle :: * The input angle. * */FT_EXPORT( void )FT_Vector_Rotate( FT_Vector*vec,FT_Angleangle );/************************************************************************* * * @function: * FT_Vector_Length * * @description: * Return the length of a given vector. * * @input: * vec :: * The address of target vector. * * @return: * The vector length, expressed in the same units that the original * vector coordinates. * */FT_EXPORT( FT_Fixed )FT_Vector_Length( FT_Vector*vec );/************************************************************************* * * @function: * FT_Vector_Polarize * * @description: * Compute both the length and angle of a given vector. * * @input: * vec :: * The address of source vector. * * @output: * length :: * The vector length. * * angle :: * The vector angle. * */FT_EXPORT( void )FT_Vector_Polarize( FT_Vector*vec,FT_Fixed *length,FT_Angle *angle );/************************************************************************* * * @function: * FT_Vector_From_Polar * * @description: * Compute vector coordinates from a length and angle. * * @output: * vec :: * The address of source vector. * * @input: * length :: * The vector length. * * angle :: * The vector angle. * */FT_EXPORT( void )FT_Vector_From_Polar( FT_Vector*vec,FT_Fixedlength,FT_Angleangle );/* */FT_END_HEADER#endif /* __FTTRIGON_H__ *//* END */
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