0,0 → 1,350 |
/***************************************************************************/ |
/* */ |
/* fttrigon.h */ |
/* */ |
/* FreeType trigonometric functions (specification). */ |
/* */ |
/* Copyright 2001, 2003, 2005, 2007, 2013 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. */ |
/* */ |
/***************************************************************************/ |
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#ifndef __FTTRIGON_H__ |
#define __FTTRIGON_H__ |
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#include FT_FREETYPE_H |
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#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 |
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FT_BEGIN_HEADER |
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/*************************************************************************/ |
/* */ |
/* <Section> */ |
/* computations */ |
/* */ |
/*************************************************************************/ |
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/************************************************************************* |
* |
* @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_Fixed FT_Angle; |
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/************************************************************************* |
* |
* @macro: |
* FT_ANGLE_PI |
* |
* @description: |
* The angle pi expressed in @FT_Angle units. |
* |
*/ |
#define FT_ANGLE_PI ( 180L << 16 ) |
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/************************************************************************* |
* |
* @macro: |
* FT_ANGLE_2PI |
* |
* @description: |
* The angle 2*pi expressed in @FT_Angle units. |
* |
*/ |
#define FT_ANGLE_2PI ( FT_ANGLE_PI * 2 ) |
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/************************************************************************* |
* |
* @macro: |
* FT_ANGLE_PI2 |
* |
* @description: |
* The angle pi/2 expressed in @FT_Angle units. |
* |
*/ |
#define FT_ANGLE_PI2 ( FT_ANGLE_PI / 2 ) |
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/************************************************************************* |
* |
* @macro: |
* FT_ANGLE_PI4 |
* |
* @description: |
* The angle pi/4 expressed in @FT_Angle units. |
* |
*/ |
#define FT_ANGLE_PI4 ( FT_ANGLE_PI / 4 ) |
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/************************************************************************* |
* |
* @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_Angle angle ); |
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/************************************************************************* |
* |
* @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_Angle angle ); |
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/************************************************************************* |
* |
* @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_Angle angle ); |
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/************************************************************************* |
* |
* @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_Fixed x, |
FT_Fixed y ); |
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/************************************************************************* |
* |
* @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_Angle angle1, |
FT_Angle angle2 ); |
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/************************************************************************* |
* |
* @function: |
* FT_Vector_Unit |
* |
* @description: |
* Return the unit vector corresponding to a given angle. After the |
* call, the value of `vec.x' will be `sin(angle)', and the value of |
* `vec.y' will be `cos(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 address of angle. |
* |
*/ |
FT_EXPORT( void ) |
FT_Vector_Unit( FT_Vector* vec, |
FT_Angle angle ); |
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/************************************************************************* |
* |
* @function: |
* FT_Vector_Rotate |
* |
* @description: |
* Rotate a vector by a given angle. |
* |
* @inout: |
* vec :: |
* The address of target vector. |
* |
* @input: |
* angle :: |
* The address of angle. |
* |
*/ |
FT_EXPORT( void ) |
FT_Vector_Rotate( FT_Vector* vec, |
FT_Angle angle ); |
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/************************************************************************* |
* |
* @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 ); |
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/************************************************************************* |
* |
* @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 ); |
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/************************************************************************* |
* |
* @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_Fixed length, |
FT_Angle angle ); |
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/* */ |
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FT_END_HEADER |
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#endif /* __FTTRIGON_H__ */ |
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/* END */ |