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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