kc3-lang/freetype/src/sdf/ftsdfcommon.h

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• Hash : 515bdfef
  Author :
  Date : 2023-01-04T19:15:38
  

  [sdf] Use 32-bit integers internally. * src/sdf/ftsdfcommon.h (FT_16D16, FT_26D6): Use 32-bit integers instead of `FT_Fixed` for internal data types. `FT_Fixed` i.e. `signed long` is 64-bit on some architectures.

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• src/sdf/ftsdfcommon.h

• /****************************************************************************
   *
   * ftsdfcommon.h
   *
   *   Auxiliary data for Signed Distance Field support (specification).
   *
   * Copyright (C) 2020-2023 by
   * David Turner, Robert Wilhelm, and Werner Lemberg.
   *
   * Written by Anuj Verma.
   *
   * 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.
   *
   */
  
  
    /****************************************************
     *
     * This file contains common functions and properties
     * for both the 'sdf' and 'bsdf' renderers.
     *
     */
  
  #ifndef FTSDFCOMMON_H_
  #define FTSDFCOMMON_H_
  
  #include <ft2build.h>
  #include FT_CONFIG_CONFIG_H
  #include <freetype/internal/ftobjs.h>
  
  
  FT_BEGIN_HEADER
  
  
    /**************************************************************************
     *
     * default values (cannot be set individually for each renderer)
     *
     */
  
    /* default spread value */
  #define DEFAULT_SPREAD  8
    /* minimum spread supported by the renderer */
  #define MIN_SPREAD      2
    /* maximum spread supported by the renderer */
  #define MAX_SPREAD      32
    /* pixel size in 26.6 */
  #define ONE_PIXEL       ( 1 << 6 )
  
  
    /**************************************************************************
     *
     * common definitions (cannot be set individually for each renderer)
     *
     */
  
    /* If this macro is set to 1 the rasterizer uses squared distances for */
    /* computation.  It can greatly improve the performance but there is a */
    /* chance of overflow and artifacts.  You can safely use it up to a    */
    /* pixel size of 128.                                                  */
  #ifndef USE_SQUARED_DISTANCES
  #define USE_SQUARED_DISTANCES  0
  #endif
  
  
    /**************************************************************************
     *
     * common macros
     *
     */
  
    /* convert int to 26.6 fixed-point   */
  #define FT_INT_26D6( x )   ( x * 64 )
    /* convert int to 16.16 fixed-point  */
  #define FT_INT_16D16( x )  ( x * 65536 )
    /* convert 26.6 to 16.16 fixed-point */
  #define FT_26D6_16D16( x ) ( x * 1024 )
  
  
    /* Convenience macro to call a function; it  */
    /* jumps to label `Exit` if an error occurs. */
  #define FT_CALL( x ) do                          \
                       {                           \
                         error = ( x );            \
                         if ( error != FT_Err_Ok ) \
                           goto Exit;              \
                       } while ( 0 )
  
  
    /*
     * The macro `VECTOR_LENGTH_16D16` computes either squared distances or
     * actual distances, depending on the value of `USE_SQUARED_DISTANCES`.
     *
     * By using squared distances the performance can be greatly improved but
     * there is a risk of overflow.
     */
  #if USE_SQUARED_DISTANCES
  #define VECTOR_LENGTH_16D16( v )  ( FT_MulFix( v.x, v.x ) + \
                                      FT_MulFix( v.y, v.y ) )
  #else
  #define VECTOR_LENGTH_16D16( v )  FT_Vector_Length( &v )
  #endif
  
  
    /**************************************************************************
     *
     * common typedefs
     *
     */
  
    typedef FT_Vector FT_26D6_Vec;   /* with 26.6 fixed-point components  */
    typedef FT_Vector FT_16D16_Vec;  /* with 16.16 fixed-point components */
  
    typedef FT_Int32  FT_16D16;      /* 16.16 fixed-point representation  */
    typedef FT_Int32  FT_26D6;       /* 26.6 fixed-point representation   */
    typedef FT_Byte   FT_SDFFormat;  /* format to represent SDF data      */
  
    typedef FT_BBox   FT_CBox;       /* control box of a curve            */
  
  
    FT_LOCAL( FT_16D16 )
    square_root( FT_16D16  val );
  
    FT_LOCAL( FT_SDFFormat )
    map_fixed_to_sdf( FT_16D16  dist,
                      FT_16D16  max_value );
  
    FT_LOCAL( FT_SDFFormat )
    invert_sign( FT_SDFFormat  dist );
  
  
  FT_END_HEADER
  
  #endif /* FTSDFCOMMON_H_ */
  
  
  /* END */
  

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