--- /dev/null
+/***************************************************************************/
+/* */
+/* fttrigon.h */
+/* */
+/* FreeType trigonometric functions (specification). */
+/* */
+/* Copyright 2001 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
+
+
+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 float 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: */
+ /* Contrainted value of `value2-value1'. */
+ /* */
+ 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 `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 );
+
+
+ /*************************************************************************/
+ /* */
+ /* @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 );
+
+
+ /*************************************************************************/
+ /* */
+ /* @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_Normalize */
+ /* */
+ /* @description: */
+ /* Normalize a given vector (i.e. compute the equivalent unit */
+ /* vector). */
+ /* */
+ /* @inout: */
+ /* vec :: The address of target vector. */
+ /* */
+ FT_EXPORT( void )
+ FT_Vector_Normalize( 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 */
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