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Diffstat (limited to 'modules/freetype2/include/freetype/fttrigon.h')
| -rw-r--r-- | modules/freetype2/include/freetype/fttrigon.h | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/modules/freetype2/include/freetype/fttrigon.h b/modules/freetype2/include/freetype/fttrigon.h new file mode 100644 index 0000000000..294981a6f3 --- /dev/null +++ b/modules/freetype2/include/freetype/fttrigon.h @@ -0,0 +1,350 @@ +/**************************************************************************** + * + * fttrigon.h + * + * FreeType trigonometric functions (specification). + * + * Copyright (C) 2001-2023 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 <freetype/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 + + + /************************************************************************** + * + * @section: + * 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_Fixed FT_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_Angle angle ); + + + /************************************************************************** + * + * @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 ); + + + /************************************************************************** + * + * @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 ); + + + /************************************************************************** + * + * @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 ); + + + /************************************************************************** + * + * @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 `angle2-angle1`. + * + */ + FT_EXPORT( FT_Angle ) + FT_Angle_Diff( FT_Angle angle1, + FT_Angle angle2 ); + + + /************************************************************************** + * + * @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_Angle angle ); + + + /************************************************************************** + * + * @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_Angle angle ); + + + /************************************************************************** + * + * @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_Fixed length, + FT_Angle angle ); + + /* */ + + +FT_END_HEADER + +#endif /* FTTRIGON_H_ */ + + +/* END */ |