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Diffstat (limited to 'src/autofit/afangles.c')
| -rw-r--r-- | src/autofit/afangles.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/src/autofit/afangles.c b/src/autofit/afangles.c new file mode 100644 index 0000000..e2360d1 --- /dev/null +++ b/src/autofit/afangles.c @@ -0,0 +1,292 @@ +/***************************************************************************/ +/* */ +/* afangles.c */ +/* */ +/* Routines used to compute vector angles with limited accuracy */ +/* and very high speed. It also contains sorting routines (body). */ +/* */ +/* Copyright 2003, 2004, 2005, 2006 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. */ +/* */ +/***************************************************************************/ + + +#include "aftypes.h" + + +#if 0 + + FT_LOCAL_DEF( FT_Int ) + af_corner_is_flat( FT_Pos x_in, + FT_Pos y_in, + FT_Pos x_out, + FT_Pos y_out ) + { + FT_Pos ax = x_in; + FT_Pos ay = y_in; + + FT_Pos d_in, d_out, d_corner; + + + if ( ax < 0 ) + ax = -ax; + if ( ay < 0 ) + ay = -ay; + d_in = ax + ay; + + ax = x_out; + if ( ax < 0 ) + ax = -ax; + ay = y_out; + if ( ay < 0 ) + ay = -ay; + d_out = ax + ay; + + ax = x_out + x_in; + if ( ax < 0 ) + ax = -ax; + ay = y_out + y_in; + if ( ay < 0 ) + ay = -ay; + d_corner = ax + ay; + + return ( d_in + d_out - d_corner ) < ( d_corner >> 4 ); + } + + + FT_LOCAL_DEF( FT_Int ) + af_corner_orientation( FT_Pos x_in, + FT_Pos y_in, + FT_Pos x_out, + FT_Pos y_out ) + { + FT_Pos delta; + + + delta = x_in * y_out - y_in * x_out; + + if ( delta == 0 ) + return 0; + else + return 1 - 2 * ( delta < 0 ); + } + +#endif + + + /* + * We are not using `af_angle_atan' anymore, but we keep the source + * code below just in case... + */ + + +#if 0 + + + /* + * The trick here is to realize that we don't need a very accurate angle + * approximation. We are going to use the result of `af_angle_atan' to + * only compare the sign of angle differences, or check whether its + * magnitude is very small. + * + * The approximation + * + * dy * PI / (|dx|+|dy|) + * + * should be enough, and much faster to compute. + */ + FT_LOCAL_DEF( AF_Angle ) + af_angle_atan( FT_Fixed dx, + FT_Fixed dy ) + { + AF_Angle angle; + FT_Fixed ax = dx; + FT_Fixed ay = dy; + + + if ( ax < 0 ) + ax = -ax; + if ( ay < 0 ) + ay = -ay; + + ax += ay; + + if ( ax == 0 ) + angle = 0; + else + { + angle = ( AF_ANGLE_PI2 * dy ) / ( ax + ay ); + if ( dx < 0 ) + { + if ( angle >= 0 ) + angle = AF_ANGLE_PI - angle; + else + angle = -AF_ANGLE_PI - angle; + } + } + + return angle; + } + + +#elif 0 + + + /* the following table has been automatically generated with */ + /* the `mather.py' Python script */ + +#define AF_ATAN_BITS 8 + + static const FT_Byte af_arctan[1L << AF_ATAN_BITS] = + { + 0, 0, 1, 1, 1, 2, 2, 2, + 3, 3, 3, 3, 4, 4, 4, 5, + 5, 5, 6, 6, 6, 7, 7, 7, + 8, 8, 8, 9, 9, 9, 10, 10, + 10, 10, 11, 11, 11, 12, 12, 12, + 13, 13, 13, 14, 14, 14, 14, 15, + 15, 15, 16, 16, 16, 17, 17, 17, + 18, 18, 18, 18, 19, 19, 19, 20, + 20, 20, 21, 21, 21, 21, 22, 22, + 22, 23, 23, 23, 24, 24, 24, 24, + 25, 25, 25, 26, 26, 26, 26, 27, + 27, 27, 28, 28, 28, 28, 29, 29, + 29, 30, 30, 30, 30, 31, 31, 31, + 31, 32, 32, 32, 33, 33, 33, 33, + 34, 34, 34, 34, 35, 35, 35, 35, + 36, 36, 36, 36, 37, 37, 37, 38, + 38, 38, 38, 39, 39, 39, 39, 40, + 40, 40, 40, 41, 41, 41, 41, 42, + 42, 42, 42, 42, 43, 43, 43, 43, + 44, 44, 44, 44, 45, 45, 45, 45, + 46, 46, 46, 46, 46, 47, 47, 47, + 47, 48, 48, 48, 48, 48, 49, 49, + 49, 49, 50, 50, 50, 50, 50, 51, + 51, 51, 51, 51, 52, 52, 52, 52, + 52, 53, 53, 53, 53, 53, 54, 54, + 54, 54, 54, 55, 55, 55, 55, 55, + 56, 56, 56, 56, 56, 57, 57, 57, + 57, 57, 57, 58, 58, 58, 58, 58, + 59, 59, 59, 59, 59, 59, 60, 60, + 60, 60, 60, 61, 61, 61, 61, 61, + 61, 62, 62, 62, 62, 62, 62, 63, + 63, 63, 63, 63, 63, 64, 64, 64 + }; + + + FT_LOCAL_DEF( AF_Angle ) + af_angle_atan( FT_Fixed dx, + FT_Fixed dy ) + { + AF_Angle angle; + + + /* check trivial cases */ + if ( dy == 0 ) + { + angle = 0; + if ( dx < 0 ) + angle = AF_ANGLE_PI; + return angle; + } + else if ( dx == 0 ) + { + angle = AF_ANGLE_PI2; + if ( dy < 0 ) + angle = -AF_ANGLE_PI2; + return angle; + } + + angle = 0; + if ( dx < 0 ) + { + dx = -dx; + dy = -dy; + angle = AF_ANGLE_PI; + } + + if ( dy < 0 ) + { + FT_Pos tmp; + + + tmp = dx; + dx = -dy; + dy = tmp; + angle -= AF_ANGLE_PI2; + } + + if ( dx == 0 && dy == 0 ) + return 0; + + if ( dx == dy ) + angle += AF_ANGLE_PI4; + else if ( dx > dy ) + angle += af_arctan[FT_DivFix( dy, dx ) >> ( 16 - AF_ATAN_BITS )]; + else + angle += AF_ANGLE_PI2 - + af_arctan[FT_DivFix( dx, dy ) >> ( 16 - AF_ATAN_BITS )]; + + if ( angle > AF_ANGLE_PI ) + angle -= AF_ANGLE_2PI; + + return angle; + } + + +#endif /* 0 */ + + + FT_LOCAL_DEF( void ) + af_sort_pos( FT_UInt count, + FT_Pos* table ) + { + FT_UInt i, j; + FT_Pos swap; + + + for ( i = 1; i < count; i++ ) + { + for ( j = i; j > 0; j-- ) + { + if ( table[j] > table[j - 1] ) + break; + + swap = table[j]; + table[j] = table[j - 1]; + table[j - 1] = swap; + } + } + } + + + FT_LOCAL_DEF( void ) + af_sort_widths( FT_UInt count, + AF_Width table ) + { + FT_UInt i, j; + AF_WidthRec swap; + + + for ( i = 1; i < count; i++ ) + { + for ( j = i; j > 0; j-- ) + { + if ( table[j].org > table[j - 1].org ) + break; + + swap = table[j]; + table[j] = table[j - 1]; + table[j - 1] = swap; + } + } + } + + +/* END */ |