From abef6da56913f1c55528103e60a50451a39628b1 Mon Sep 17 00:00:00 2001 From: WlodekM Date: Sun, 16 Jun 2024 10:35:45 +0300 Subject: initial commit --- src/freetype/afangles.c | 285 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 285 insertions(+) create mode 100644 src/freetype/afangles.c (limited to 'src/freetype/afangles.c') diff --git a/src/freetype/afangles.c b/src/freetype/afangles.c new file mode 100644 index 0000000..c65a3ae --- /dev/null +++ b/src/freetype/afangles.c @@ -0,0 +1,285 @@ +/***************************************************************************/ +/* */ +/* afangles.c */ +/* */ +/* Routines used to compute vector angles with limited accuracy */ +/* and very high speed. It also contains sorting routines (body). */ +/* */ +/* Copyright 2003-2018 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" + + + /* + * 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_and_quantize_widths( FT_UInt* count, + AF_Width table, + FT_Pos threshold ) + { + FT_UInt i, j; + FT_UInt cur_idx; + FT_Pos cur_val; + FT_Pos sum; + AF_WidthRec swap; + + + if ( *count == 1 ) + return; + + /* sort */ + 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; + } + } + + cur_idx = 0; + cur_val = table[cur_idx].org; + + /* compute and use mean values for clusters not larger than */ + /* `threshold'; this is very primitive and might not yield */ + /* the best result, but normally, using reference character */ + /* `o', `*count' is 2, so the code below is fully sufficient */ + for ( i = 1; i < *count; i++ ) + { + if ( table[i].org - cur_val > threshold || + i == *count - 1 ) + { + sum = 0; + + /* fix loop for end of array */ + if ( table[i].org - cur_val <= threshold && + i == *count - 1 ) + i++; + + for ( j = cur_idx; j < i; j++ ) + { + sum += table[j].org; + table[j].org = 0; + } + table[cur_idx].org = sum / (FT_Pos)j; + + if ( i < *count - 1 ) + { + cur_idx = i + 1; + cur_val = table[cur_idx].org; + } + } + } + + cur_idx = 1; + + /* compress array to remove zero values */ + for ( i = 1; i < *count; i++ ) + { + if ( table[i].org ) + table[cur_idx++] = table[i]; + } + + *count = cur_idx; + } + + +/* END */ -- cgit 1.4.1-2-gfad0