[692] | 1 | /***************************************************************************/
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| 2 | /* */
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| 3 | /* ftcalc.h */
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| 4 | /* */
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| 5 | /* Arithmetic computations (specification). */
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| 6 | /* */
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| 7 | /* Copyright 1996-2001, 2002, 2003, 2004 by */
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| 8 | /* David Turner, Robert Wilhelm, and Werner Lemberg. */
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| 9 | /* */
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| 10 | /* This file is part of the FreeType project, and may only be used, */
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| 11 | /* modified, and distributed under the terms of the FreeType project */
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| 12 | /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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| 13 | /* this file you indicate that you have read the license and */
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| 14 | /* understand and accept it fully. */
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| 15 | /* */
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| 16 | /***************************************************************************/
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| 17 |
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| 18 |
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| 19 | #ifndef __FTCALC_H__
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| 20 | #define __FTCALC_H__
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| 21 |
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| 22 |
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| 23 | #include <ft2build.h>
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| 24 | #include FT_FREETYPE_H
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| 25 |
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| 26 |
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| 27 | FT_BEGIN_HEADER
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| 28 |
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| 29 |
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| 30 | /*************************************************************************/
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| 31 | /* */
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| 32 | /* <Function> */
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| 33 | /* FT_FixedSqrt */
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| 34 | /* */
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| 35 | /* <Description> */
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| 36 | /* Computes the square root of a 16.16 fixed point value. */
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| 37 | /* */
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| 38 | /* <Input> */
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| 39 | /* x :: The value to compute the root for. */
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| 40 | /* */
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| 41 | /* <Return> */
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| 42 | /* The result of `sqrt(x)'. */
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| 43 | /* */
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| 44 | /* <Note> */
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| 45 | /* This function is not very fast. */
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| 46 | /* */
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| 47 | FT_EXPORT( FT_Int32 )
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| 48 | FT_SqrtFixed( FT_Int32 x );
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| 49 |
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| 50 |
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| 51 | #define SQRT_32( x ) FT_Sqrt32( x )
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| 52 |
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| 53 |
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| 54 | /*************************************************************************/
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| 55 | /* */
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| 56 | /* <Function> */
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| 57 | /* FT_Sqrt32 */
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| 58 | /* */
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| 59 | /* <Description> */
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| 60 | /* Computes the square root of an Int32 integer (which will be */
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| 61 | /* handled as an unsigned long value). */
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| 62 | /* */
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| 63 | /* <Input> */
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| 64 | /* x :: The value to compute the root for. */
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| 65 | /* */
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| 66 | /* <Return> */
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| 67 | /* The result of `sqrt(x)'. */
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| 68 | /* */
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| 69 | FT_EXPORT( FT_Int32 )
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| 70 | FT_Sqrt32( FT_Int32 x );
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| 71 |
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| 72 |
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| 73 | /*************************************************************************/
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| 74 | /* */
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| 75 | /* FT_MulDiv() and FT_MulFix() are declared in freetype.h. */
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| 76 | /* */
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| 77 | /*************************************************************************/
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| 78 |
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| 79 |
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| 80 | #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
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| 81 |
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| 82 | /*************************************************************************/
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| 83 | /* */
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| 84 | /* <Function> */
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| 85 | /* FT_MulDiv_No_Round */
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| 86 | /* */
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| 87 | /* <Description> */
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| 88 | /* A very simple function used to perform the computation `(a*b)/c' */
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| 89 | /* (without rounding) with maximal accuracy (it uses a 64-bit */
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| 90 | /* intermediate integer whenever necessary). */
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| 91 | /* */
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| 92 | /* This function isn't necessarily as fast as some processor specific */
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| 93 | /* operations, but is at least completely portable. */
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| 94 | /* */
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| 95 | /* <Input> */
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| 96 | /* a :: The first multiplier. */
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| 97 | /* b :: The second multiplier. */
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| 98 | /* c :: The divisor. */
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| 99 | /* */
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| 100 | /* <Return> */
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| 101 | /* The result of `(a*b)/c'. This function never traps when trying to */
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| 102 | /* divide by zero; it simply returns `MaxInt' or `MinInt' depending */
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| 103 | /* on the signs of `a' and `b'. */
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| 104 | /* */
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| 105 | FT_BASE( FT_Long )
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| 106 | FT_MulDiv_No_Round( FT_Long a,
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| 107 | FT_Long b,
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| 108 | FT_Long c );
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| 109 |
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| 110 | #endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
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| 111 |
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| 112 |
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| 113 | #define INT_TO_F26DOT6( x ) ( (FT_Long)(x) << 6 )
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| 114 | #define INT_TO_F2DOT14( x ) ( (FT_Long)(x) << 14 )
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| 115 | #define INT_TO_FIXED( x ) ( (FT_Long)(x) << 16 )
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| 116 | #define F2DOT14_TO_FIXED( x ) ( (FT_Long)(x) << 2 )
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| 117 | #define FLOAT_TO_FIXED( x ) ( (FT_Long)( x * 65536.0 ) )
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| 118 |
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| 119 | #define ROUND_F26DOT6( x ) ( x >= 0 ? ( ( (x) + 32 ) & -64 ) \
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| 120 | : ( -( ( 32 - (x) ) & -64 ) ) )
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| 121 |
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| 122 |
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| 123 | FT_END_HEADER
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| 124 |
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| 125 | #endif /* __FTCALC_H__ */
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| 126 |
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| 127 |
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| 128 | /* END */
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